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HomeMy WebLinkAboutPZ - Storm Drainage Calcs Prepared For: Apex Northwest Subdivision No. 4 Brighton Development, Inc., ACHD, City of Meridian Meridian, Idaho Storm Drainage Report Digitally signed by �o` ��cENsFo Lachlin C Kinsella, P.E. Date:2022.11.18 860 08:26:12-07'00' 11/18/22 �C, qTF F \�P /N C Prepared By: Lachlin Kinsella, P.E. Project Manager KM Engineering, LLP 5725 North Discovery Way Boise, I D 83713 208.639.6939 Ikinsella@kmengllp.com Ian November 2022 Project No: 22-054 E N G I N E E R I N G TABLE OF CONTENTS Introduction ................................................................................................................................. 1 ProjectDescription ...................................................................................................................... 1 SiteDescription............................................................................................................................... 1 Scopeand Methods ...................................................................................................................... 1 Existing Drainage Conditions .......................................................................................................... 1 Proposed Drainage Conditions and Analysis .................................................................................. 1 SeepageBeds.................................................................................................................................. 2 Summary......................................................................................................................................... 2 APPENDICES Appendix A - Figures Figure 1 - Vicinity Map Figure 2 - Post-Development Drainage Map Figure 3 - Storm Water Improvement Plans Appendix B - Tables Table 1 - Peak Flow Rates and Runoff Volumes Appendix C - Calculations Post-Development 25-year Calculations Post-Development 100-year Calculations Seepage Bed Calculations Appendix D - Geotechnical Engineering Report & Groundwater Data Apex West Subdivision (Atlas, 2/8/2022) 2022 final groundwater report— Pinnacle West Project (NRS, 10/18/2022) INTRODUCTION The purpose of this report is to show that the storm drainage facilities for the proposed Apex Northwest Subdivision No. 4 (Project) are designed to meet Ada County Highway District (ACHD), City of Meridian, and the water quality requirements of the Idaho Department of Environmental Quality (DEQ). This report has been prepared at the request of the developer, Brighton Development, Inc. PROJECT DESCRIPTION The project consists of the fourth phase of a residential subdivision that includes 55 single-family residential lots and 9 common lots. The proposed improvements to the site include roadways, sidewalks, lot grading, and site utilities. SITE DESCRIPTION The project site is located along the west of S. Locust Grove Rd. and north of E. Lake Hazel Rd. in Meridian, Idaho. See Appendix A, Figure 1 for a vicinity map of the project. The proposed project area is 12.64 acres. SCOPE AND METHODS The stormwater system for the Project has been designed per the 2017 ACHD Stormwater Policy. The Rational Method is the standard method for small catchments and was used to calculate post-development peak runoff rates and runoff volumes. The Rational Method provided in the ACHD calculation sheets was used to calculate the storm water volumes and flow rates for this project (see Appendix C - Calculations). Flow rates and storm volumes were established for each basin for the 25-year and 100-year storms. Refer to Appendix B, Table 1 - Peak Flow Rates and Runoff Volumes, for a summary of flow rates and runoff volumes. Calculations for the seepage beds were completed to verify capacity. EXISTING DRAINAGE CONDITIONS The pre-project watershed consists primarily of agricultural land and is currently irrigated through open channels. The flow path for the existing drainage basin involves overland sheet flow from north to south with irrigation wastewater being collected through open channels and routed to the Watkins Drain. There are no existing storm drainage facilities in place to reduce the peak runoff volumes prior to discharging into the Watkins Drain. PROPOSED DRAINAGE CONDITIONS AND ANALYSIS The proposed drainage system improvements consist of roadway inlets and gutters, sand and grease traps, manholes, and seepage beds. The post-development site was broken into 15 basins as shown in Appendix A, Figure 2 - Post-Development Drainage Map. For land use type and runoff coefficients (0.1 — open space, .95—impervious, 0.40—lots)for each basin, refer to ACHD calculations in Appendix C. Each basin was delineated according to the tributary area draining to each drainage 1 structure or facility such as gutter, catch basin inlet, etc. For individual sub-basin peak flow calculations, in addition to combined sub-basin peak flows used for downstream facility sizing and analysis, see Table 1 (Peak Flow Rates and Runoff Volumes). The proposed drainage basins include the front half of the lots and all the proposed roadway, curb and gutter, and sidewalks. Storm water runoff consists of overland sheet flow over short grass and is then conveyed with curb and gutter to catch basin inlets before entering a pipe network. The storm water runoff is then conveyed to the proposed seepage beds. SEEPAGE BEDS The Project includes six (6) seepage beds (SB #1-6) that should be built per the details shown on the civil construction plans. Based on our calculations, the seepage beds are adequately sized to ensure that no ponding occurs on the surface and that the volumes required to retain the 100-year storm event are met. Once the sizes of the seepage beds were calculated, the times necessary for 90% of the 100-year storm events to be infiltrated into the ground was calculated at less than 48 hours for each of the seepage beds. The design infiltration rate at 8 in/hr was used in the calculations and is based on the testing results from the geotechnical report prepared by Atlas. The calculations included with this report show the volumes that are required to be retained for the 100-year storm and the drain time through the bottom of the seepage beds, refer to Appendix B—Tables and Appendix C—Seepage Bed Calculations. SUMMARY This report determines that the Project storm water design sizing and analysis conforms to ACHD, City of Meridian, and the water quality requirements of the Idaho Department of Environmental Quality(DEQ). The post-development storm water runoff for half of the proposed residential lots and the entire roadway, curb and gutters, and sidewalks should be completely retained onsite through the proposed seepage beds. 2 APPENDIX A - FIGURES PROJECT F7�� N E.LAKE HAZEL RD. MERIDIAN, IDAHO ®�® o LOCATION MAP 0 O U O J N a 2 xX W O u V a 0 a O 1 l7 N N O N W Vf Z Y Z 2 0 0 2000 4000 6000 a Plan Scale: 1" = 2000' Z m E N G I N E E R I N G 0 5725 NORTH DISCOVERY WAY N BOISE,IDAHO 83713 G PHONE(208)639-6939 APEX NORTHWEST SUBDIVISION No. 4 m kmengllp.com x MERIDIAN, IDAHO DATE: NOVEMBER 2022 PROJECT: 22-053 N SHEET: VICINITY MAP O a 1 OF 1 I \ \ \ \ \ DRAINAGE LEGEND DESIGN POINTS Q \ x _ A BASIN DESIGNATION 1. INLET #1 I \ \ 2.5 AREA IN ACRES 3. INLET #3 4. INLET #4 DESIGN POINT 5. INLET INLET #5 oI \ \ EXISTING GRADE CONTOUR 7. INLET #78, INLET #8 xl \ \ 2470- 9. INLET #9 10. INLET 0 11. INLET #11 1 I d \ \ �� \ \ FINISHED GRADE CONTOUR 12, INLET #12 --2470 13. I N LET #13 -27 0 14. INLET #14\ \ 4 15. SGT #1 \ \ \ \ 16. SGT #2 \ 17. SGT #3 18. SGT #4 \ \ D-2 D-1 6� \ \ 195 \ 0.46 0.2 . SGT # 9 \ r - \�, \ \ \ \ - \ 21. SEEPAGE BED #1 0 lX 22. SEEPAGE BED #2 `S \ 23. SEEPAGE BED #3 24. SEEPAGE BED #4 A I \ 25. SEEPAGE BED #5 \ W W W I W 26. SEEPAGE BED #6 0 50 100 150 I N \\ \ 24 \ \ \ I I A Plan Scale: 1" = 50' 0 \�, I > 18 I \ V \ 2) I I I w 0 2)36' 3j 0r4 I I \ 12 11 \ - - - - 2) E-1 \ 3s 1.19 I I I \ - - - - - - - - - - - - - - - - - - - - - - - - - - i FF - - - - - - - - - - - - - - - - - - - - - - - - E. CRESCENDO ST. 21-bl 2��a - - - - - - - - - - - - - - - - 14 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Tj - - - - - - - - - - - - - - - - \ - - - - II �II I 25 E-2 1.14 0-1 fl I I \ I I \ I � I z��$ - - ' III C-2 C-1 o \ III z o I I III I 0.41 0.5�2 �� \ \ z w � I \ O a 23 I iol II I III > = I I ~I 17 I II ; \ 2 2�� I �. Q a } I '�s \ II I I oo 0 Q I I� WI � of I \ z z I 10 I 9 w H a - - - - - - - - - - - - - - - - - - - - - - - -11- - - - - - - - - - - - - - Ln IW Lu of N 1 E. MAINACHTST. 2�3� 2'1�6 , w O I w w I > o � ll ~I W - - - - - - - - - - - - o w __ _ - - - - zLu o aI bW I I N \ A-2 X V) C-qI F cW, I F- 11 I \ I \I I I I I >1 I I I \ I I I I a aI I I III } I I I I I I I I A-1 co I I 2>33 1.7 2j3Q 2'3A I I 0 I I APEX NORTHWEST No. 3 a X � II N I I o I vi I I N� SUBDIVISION \ Z � N I I I I w _ _ - - - ,I1I ALLEY (PRIVATE) I II I - - - - - - U Ln 1.16 t-j- ` - z 0- B-2 26B-1 QH I Z I 0.33 0.33 I O O Q z 3 I I 2 j32 I �� �� \ I z f \ 0 � I \ = I I I x _ I a I I N � 2732 0 5 1 1 6 16 22 1 CIA2 \ A-3 I I \ ENGINEERING ILL \ 5725 NORTH DISCOVERY WAY BOISE,IDAHO 83713 18"SD I I J L - PHONE(208)639-6939 0 w I I o 3 kmengllp.com z o - - - - - - - - - - - - - - - - - - - - - B-4 s e i DESIGN BY: LCK IL 8 _ _ U.I 2-732 2132 - -2�33 21�� I DRAWN BY: LCK CHECKED BY: LCK a z ^ - (� I N , B-3 A-4 E. PHENOMENAL ST. DATE: SEPTEMBER 2022 z II 7 0.16 _ $�� _ 0.27 PROJECT: 22 053 _ - - - - - - - - - - - % \ I \ - SHEET NO. Top - L - - - - - - - w15 �oE _J 10 F 1 a \ 6), L � SHEET NOTES o s INLET #12 \ \ I ACHD SD-601, TYPE I A. SEE SHEET C1.1 FOR GENERAL, ACHD, AND UTILITY �SS\ONAL x fNGi \ �\ \ I RIM:2733.04 °\ 0 50 100 150 NOTES. �o� ���ENSFO ti \ > SUMP:2728.79 B. SEE SHEET C4.1 FOR STORM WATER DETAILS. 686� 0 \ O� S \ Q TOP INV IN:2729.79 12" (E) i0P TOP TOP TOP TOP TOP TOP TOP TOP TOP TOP TOP TOP TOP TOP rIOP- - Plan Scale: 1" = 50'° jff TOP FOP TOP TOP TOP roP roP TO TOP TOP TOP TOP TOP TOP TOP TOP TOP TOP TOP TOP TOP C. GROUNDWATER ELEVATIONS ARE EXPECTED TO REMAIN 21/27/22 � \ \ INV OUT:2729.79 12" (W) \ \ \ x Q25=0.45cfs Q100=0.63cfs I I AT OR BELOW 20 FEET FROM EXISTING GROUND `!'� �� Q I I SURFACE. THE DESIGN INFILTRATION RATE IS 8 IN/HR 9T P v �"\� BASED ON THE INFILTRATION TEST RESULTS WITHIN THE �,5, F OF \' \ s I PI�6 PI 6 PI 6 PI 6 PII UPI 6-pi 6 PI 6 PI 6 PI 6 PI 6 PI 6 PI u 6 PIcli 6'PI 6"P PI POORLY GRADED GRAVEL THAT WERE 12 IN/HR OR ��/�/ C. K\N \o� �,� \ ACHD STORM DRAIN INLET 1 1 \ \ EASEMENT I N ACHD SD-601, TYPE I I I GREATER. FOR ADDITIONAL INFORMATION REFER TO THE 37.0' 18" ADS N-12 HP - I RIM:2733.04 GEOTECHNICAL INVESTIGATION "APEX WEST SUBDIVISION" I } I PREPARED BY ATLAS, DATED FEBRUARY 8, 2022. o ® 0.00% 7 SUMP:2728.93 Q q ' r \ \ r INV OUT:2729.93 12" (W) I N I D. PROVIDE WATER-TIGHT SEALS AT PIPING o� o\ \A SGT #4 (1500 GAL) \ IQ25=0.31cfs ENTRANCES/EXITS FOR CATCH BASINS, DIVERSION BOXES, RIM:2733.62 (S)\,s 4 I I Q100=0.43cfs BLOCK 11 \ RIM:2733.65 (N) s \ I I I I I AND MANHOLES. J N \ oq INV IN:2729.77 12" (E) \\I I I11 10 Og Oj O O O O O 1 I I E. ALL STORM PIPE WITHIN ROW SHALL BE C900 WHERE m \ INV OUT:2728.92 18" (N)\ 7 INLET #13 I v; N COVER OVER PIPE IS LESS THAN 2 FEET. OUTSIDE OF ACHD SD-601, TYPE I I I "' °J I WHERE ADS NEAT THAN THE \ INLET BAFFLE:2729.09 \ ,s ACHD 33-6 w .49 OUTLET BAFFLE:2729.67 I SUMP:2729.36 - - - - - - - _ - - - - - - - Q25=0.71 cfs BLOCK 13 1 m - - - - APPROVED EQUAL. FLOWABLE FILL SHALL BE USED WHEN Q100=0.99cfs '33.5' 12" ADS N-12 HP INV OUT:2730.36 12" (S) LESS THAN 543" 0 0.42% Q25=0.79cfs o� STRUCTURES. 5-FEET OF SEPARATION BETWEEN x / 12" ADS N '12 HP_ - Q100=1. cfs- - - - - L - OD - - - - - - - - - - - - - - - - - @ 0.46% - - - - - - - - - - - - - - - � - - - - - - - - - F. ALL DRAINAGE STRUCTURES SHALL BE PER ISPWC : - -30.5' 12" ADS N-12 HP- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - STANDARDS AND THE ACHD SUPPLEMENTS TO THE ISPWC. + Q 0.43% _ STORM DRAIN STRUCTURES SHALL HAVE HS-25 TRAFFIC V) m N N < RATED LIDS UNLESS OTHERWISE SPECIFIED. �23.7' 12" ADS N-12 HP INLET #14 a"w a";x's a"w a"w s"w © s"w s" a"w:::1a"w ' a"w s"w s"w00 °w s^w 8"w p 0.42% ACHD SD-601, TYPE I III II I I RIM:2733.49 . CRESCENDO ST. :TL - G. THE CONTRACTOR SHALL COMPLY WITH ALL THE REQUIREMENTS FOR STORM WATER DISCHARGE SGT #5 (1500 GAL) 8 3 a" SUMP:2729.23 8"s a"s s"s s"s a"s 8 s" a"s 8"s s"s S a"s $"s ^s s's ASSOCIATED WITH CONSTRUCTION ACTIVITY. THIS INCLUDES cn - RIM:2734.27 (N) INV IN:2730.23 12" (N) 3 3 3 � IMPLEMENTING THE BMP'S RECOMMENDED IN THE SWPP RIM:2734.35 (S) INV OUT:2730.23 12" (S) 21 PLAN PREPARED FOR THIS SITE, REGULAR SITE z INV IN:2730.10 12" (E) - - _Q25=0.76cfs - - - - - - - - - - - - _ _ INV OUT:2729.25 18" (S) - - - Q100=1.06cfs -_T - - - - SWPPPT�ND MODIFICATIONS AS FORTH TONTHE cn INLET BAFFLE:2729.42 ( I �I I - - - - - � OUTLET BAFFLE:2730.00 I I 5.3' 12" ADS N-12 HP i i THE NPDES GENERAL PERMIT. L F o- o " Q25=1.55cfs I� O1 I �I 0.57% I H. ALL CHANGES REQUIRE APPROVAL BY THE DESIGN w or ' w Q100=2.16cfs II°° I SDMH #3 I I ENGINEER AND ACHD. N 5 I v RIM: SDMH FLAT TOP I I I. THE CONTRACTOR SHALL PROVIDE AND INSTALL STORM I I RIM:2734.00 I I I I SUMP:2728.20 DRAIN MONUMENTS TO IDENTIFY ALL STORM DRAIN L o x I I 7 I I 55 INV IN:2730.20 12" (N) 58 59 60 61 62 63 64 65 I MANHOLES, SEDIMENT BOXES, DROP INLETS, AND OTHER L ~ w I ACHD STORM DRAIN INV OUT:2730.20 12" (W) PIPE JUNCTIONS OR TERMINUSES IN ACCORDANCE WITH v I SECTION 8018 OF THE ACHD DEVELOPMENT POLICY EASEMENT I 76.2' 18"I ADS N-12 HP I I MANUAL AND ISPWC SD-623. 0.00% I I J. FOR UTILITY CROSSINGS AT SEEPAGE BED LOCATIONS, w I a I 56 57 I - - THE CONTRACTOR SHALL CONFORM TO THE STANDARDS o w I I N SET BY THE CITY OF MERIDIAN AND SECTION 8200 OF Z THE ACHD STORMWATER GUIDELINES. I I I I 4"PI 4"PI 4"PI 4"PI 4"PI 4"PI 4"PI 4"PI "PI 4"PI "PI 4"PI PI 4"PI 3S 4" 1 4" I 4"PI 4"PI 4"PI 4"I I � � I K. THE STORM WATER DESIGN IS BASED ON SECTIONS 8000 ACHD STORM DRAIN I I J PI PI 7 AND 8200 OF THE 2017 ACHD POLICY MANUAL. CD EASEMENT o I 7 I I I cn L. THE BUILDING FINISH FLOOR ELEVATIONS SHALL BE LOCATED ABOVE THE MAXIMUM GROUNDWATER SURFACE 45.0' 18" ADS N-12 0% I i 3 I ELEVATION PER THE INTERNATIONAL BUILDING CODE, ® O:Oi% 57.5' 12" ADS N-12 HP BLOCK 7 I - - INTERNATIONAL RESIDENTIAL CODE, AND CITY OF MERIDIAN REQUIREMENTS. SGT #3 (1500 GAL) I i ® 11 0.40% 45 44 42 41 40 39 38 37 36 RIM:2732.05 (S) I I I I 46 O 43 O O O O O O O I I RIM:2732.09 (N) II I N KEYNOTES INV IN:2728.13 12" (E) I I I INLET #9 INV OUT:2727.28 18" (N) I ACHD SD-601, TYPE I INLET BAFFLE:2727.45 I RIM:2731.49 I I O UTILITY MAIN/MAIN CROSSING OUTLET BAFFLE:2728.03 L SUMP:2727.38 \ I I MAINTAIN VERTICAL AND HORIZONTAL Q25=1.05cfs I INV OUT:2728.38 12" (W) s - - - - I I POTABLE/NON-POTABLE MAIN LINE SEPARATION Q100=1.47cfs N I Q25=0.50cfs s I I I Q 100=0.69cfs 47 s - - - - - - - - - - - - - - - - - _ _ _ PER CITY OF MERIDIAN REQUIREMENTS. SEE WATER (,/') � - - - - - - - - - - - - - NOTE 2 SHEET C1.1 FOR ADDITIONAL 4.3' 12" ADS N-12 HP O z / N fA fn Vl Vl N VI N® 0.46% C N N INFORMATION. INLET #10i I_ I '... 1 V7 < a"w e"w w a w 8 a" a"w "w "w 8"w "w 1. SB #1 (PUBLIC) SEE SEEPAGE BED DETAIL #1/SECTION z ACHD SD-601, TYPE I N I s a" a"s a"s s"s s"s s a"s s"s a"s 5 s"s "s P a"s a"s s"s A-A ON SHEET C4.1 (141'L x 15'W x 8.5'D) z RIM:2731.49 I / ' �, 3 3E. MAINACHT ST. 3 3L _ SUMP:2727.15 s co e 0 3 3 2. SB #2 (PUBLIC) SEE SEEPAGE BED DETAIL #1/SECTION INV IN:2728.15 12" E N I O 0 �, �, �, �, �, >� N ( ) 49 \ B-B ON SHEET C4.1 (61'L x 9'W x 8.5'D) z INV OUT:2728.15 12" (W) I �/ - - - - - - - - (n O W Q25=0.55cfs °° `�' - - - - - - - - - - - - - - - - - - - v; I s / 3. SB #3 (PUBLIC) SEE SEEPAGE BED DETAIL #1/SECTION CC Q 100=0.77cfs N G t a. o I I w I 1 A-A ON SHEET C4.1 (40'L x 15'W x 8.5'D) O Q W w 4. SB #4 (PUBLIC) SEE SEEPAGE BED DETAIL #1/SECTION > 0 I A-A ON SHEET C4.1 (32'L x 15'W x 8.5'D) m 0 1 N PI J PI I SGT #6 (1500 GAL) i BLOCK 9 I I 5. SB #5 (PUBLIC) SEE SEEPAGE BED DETAIL #1/SECTION z RIM:2732.62 (W) (OPEN GRATE) I I B-B ON SHEET C4.1 (68'L x 15'W x 8.5'D) � °' 15 16 17 18 19 20 21 22 23 24 APEX NORTHWEST No. 3 (~ Q 00 o w x I I RIM:2732.65 (E) (CLOSED LID) O O O O O O O O I w I SUBDIVISION 6. SB 6 PRIVATE SEE SEEPAGE BED DETAIL 1 SECTION INV OUT:2728.66 18" (E) I W _ W INLET BAFFLE:2728.83 co Q I C-C ON SHEET C4.1 (59'L x 1O'W x 8.5'D) OUTLET BAFFLE:2729.41 I I z I � Q25=0.87cfs I O d I Q100=1.22cfs I 7. INSTALL GROUND WATER OBSERVATION WELL PER ACHD W W I I yyvi I Z I SD-627, SHEET C4.1. INSTALL WITHIN THE INFILTRATION . ; I 6 6 0.00% ADS N-12 HP BED 5' FROM THE END AND OUTSIDE OF BED A I• I \ MINIMUM OF 50' FROM THE PERIMETER OF THE BED. I > u O N I 52 16.6' 12" ADS N-12 HP Cli N I v SGT #2 (1500��GAL) ® 0.42% I oo ALLEY (PRIVATE) 14 I vi I z RIM:2732.27 (W) v 15.7' 12" ADS N-12 HP co I 6"PI 6"PI 6"PI 6"PI 6"PI 6"PI 6"PI 6"PI 6 PI s"PI 6"PI fi"PI "P1 6 _ I N oQ RIM:2732.30 (E) ® 0.45% `� I I I xw LL / BLOCK 12 INV IN:2727.88 12" (W) INLET #1 I I 12 11 I I O 1 INV IN:2727.88 12" (S) 53 ACHD SD-601, TYPE I I I INLET #2 oe INV OUT: 2727.03 18" (E) O RIM:2731.87 I ACHD SD-601, TYPE I INLET BAFFLE:2727.20 SUMP:2727.76 Ln co RIM:2731.87 I I V) 0 57.5' 12" ADS N-12 HP I OUTLET BAFFLE:2727.78 INV OUT:2728.76 12" (E) I 13 SUMP:2727.76 Q' @ 0.40% I Q25=1.20cfs Q25=1.12cfs INV OUT:2728.76 12" (W) m / INLET #5I Q100�1.68cfi Q100=1.55cfs I - Q25=0.70cfs 10 O9 O8 O7 O6 O O I I I m Q ACHD SD-601, TYPE II 54 Q100=0.97cfs I I I / RIM:2731.35 I O ' I ACHD SD-601, TYPE I z ° INLET #3 SUMP:2727.24 I 2 66.0' 18" ADS N-12 HP INV OUT:2728.24 12" (E)I _ @ 0.00% I RIM:2731.70 I I I z E / Q25=0.44cfs I "PI 6"PI 7 6"PI SUMP:2727.59 I I I O Q100=0.6�cfsl 18'SD ACHD STORM 7 INV OUT:2728.59 12" (S) I J Q25=0.51 cfs S INLET #6 : - - - - - - - - -DRAIN Q100=0.72cfs a ACHD SD-601, TYPE I EASEMENT - - - - - W RIM:2731.35 /per/ ems, 21.8' 12" ADS N-12 HP ! N - - - - -� - - - - - - �? SUMP:2727.01 22.3' 12" ADS N-12 HP ' - @ 0.82% - 8"w 0 0.98% a"w � "w s"w r � z � INV IN:2728.01 12" (W) 8.6' 15" ADS N-12 HP $" 8 a 8"W "w w "w $' "w INV OUT:2728.01 12" (E) 18 8"s 18's- SDMH 1 : # 18"S 18"S 18"S Q 0.46% 18"S�18°S 18"S 18"S 18"S - - "S 5 18"S 18"S 1a°S 1a"S o Q25=0.31cfs 48'0 SDMH FLAT TOP 4.3 15" ADS N-12 HP Q100=0.43cfs RIM:2732.23 ® 0.46% E. PHENOMENAL ST. z N K I 1 11 1 1 11 1 SUMP-2726.44 Z N 31.8' 12" ADS N-12 HP N INV IN:2728.69 12" (W) ---1$"�Q --- 1�"�D-------- 000 O r 1 1 1 1 1 : 0.41% - -- - INV IN:2728.69 12" (E) - - - - - INV OUT:2728.44 15" (SE)-TOP roe P TOP 7 INLET #8 T ( ) TOP TO - - - - - - -- - - - - I- - - -I L - - - - - - - J - - - ACHD SD-601, TYPE I oQ of TOE TOE TOE of rnF RIM:2731.51 69.1' 15" ADS N-12 HP 36"cl 1 146.0' 18" ADS N-12 HP ACHD STORM DRAIN I I 0 Z SUMP:2727.10 �0E P ® 0.41%TOP P _oE-@ 0.00% EASEMENT L - - - J 0 Z INV IN:2728.10 12" (S) I -SGT #1 (1800TGAL) r11 1LL opF ��r E N G I N E E R I N G 3 INV OUT:2728.10 12" (N) I oe 45 oQ SDMH #2 LRIM:2732.27 (W) \ °F °A 5725 NORTH DISCOVERY WAY Q25=0.21 cfs 48"0 SDMH FLAT TOP �O RIM:2732.30 (E) p TOF\ BOISE, IDAHO 83713 O o Q100=0.29cfs / RIM:2731.93 Tpp \ PHONE(208)639-6939 "• SUMP:2726.16 INV IN:2728.10 15" (N) z 0 30.5 12" ADS N-12 HP oE�oP INV IN:2728.16 15" (NW) INV OUT:2727.35 18" (E)\ roq meng p.com m ® 0'99% INV IN:2728.41 12" (N) INLET BAFFLE:2727.42 TpTOo DESIGN BY: LCK 161NLET I#7 INV OUT:2728.16 15" (S) OUTLET BAFFLE:2728.00 F \ T\ ACHD SD-601, TYPE I Q100=3.60c \ Toa -,0 F �Q100=3.60cfs p Co. DRAWN BY: LCK g I RIM:2731.51 INLET #4 ToF ° \ CHECKED BY: LCK Z SUMP:2727.40 ACHD SD-601, TYPE I Q X INV OUT:2728.40 12" (N) RIM:2731.70 \ T°\ DATE: NOVEMBER 2022 z Q25=0.24cfs SUMP:2727.12 \ z Q100=0.34cfs INV IN:2728.12 15" (N) rpF °� °o PROJECT: 22 053 g INV OUT:2728.12 15" (S) SHEET NO. _ a Q25=0.37cfs \ Q100=0.51 cfs o J o � C4.0w N i 2 S�p fN LEGEND NAL�CF'S PENS c�ti U WELL COVER, 8" DIA. WATERTIGHT GALVANIZED STEEL BOLT DOWN COVER AND CANISTER �� N,� FO 2 OR 3 BOLT LID WITH 9/16" HEAD AND SAE THREADS, GASKETED Q �° FINISH GRADE O CONCRETE (COLLAR), CLASS 3000 (ISPWC SECTION 703) 8 0 OO 3/8" DIA HOLES OR SLOTS CUT INTO PIPE AT 3" ON CENTER - --- - - --- - - - -- - ----- - - O TRACER WIRE SHALL BE PLACED ON OUTSIDE OF PVC PIPE, MINIMUM 18 GAUGE, INSULATED, SINGLE- I s 21/27/22 p CONDUCTOR COPPER WIRE, INSULATION COLOR SHALL BE GREEN WITH THREE 6" DIAMETER COILS 1= -=I I MITI .4.°, e. . 00 PIPE SHALL BE PERFORATED PVC, ASTM D-3035, SDR 35. WELLS BACKFILLED IN A PIT REQUIRE 6" I C OF !v PIPE. DRILLED WELLS MAY USE 4" PIPE y�//V C. Y0 I II'- IIIII� ` ° ° °• Q °.Q ' NONWOVEN FILTER FABRIC AROUND OPENINGS AND BOTTOM, FABRIC OVER CHIPS/DRAIN ROCK _____ __� �� �� r=---------- POLYPR OPYLENE A A III POLYPROPYLENE FIBER REINFORCEMENT AT 1 1/2 LBS/CY - III-JI 3 ''° AP ° 4 O BACKFILL MATERIAL TO MATCH STORAGE MEDIA FOR OBSERVATION WELLS LOCATED WITHIN A BMP FACILITY. I >,. USE PIPE BEDDING CHIPS FOR OBSERVATION WELLS LOCATED OUTSIDE BMP FACILITIES b ---------- NOTES: 2 I PLAN CONCRETE COLLAR 1. GROUNDWATER OBSERVATION WELLS ARE FOR MEASUREMENT OF GROUNDWATER LEVELS WITHIN OR NEAR r STORM DRAINAGE FACILITIES N.T.S. 2. THIS DETAIL IS FOR WELLS INSTALLED BY DRILLING OR BY EXCAVATED PITS L - - - - - - - - - - 0 3. LOCATION OF GROUNDWATER OBSERVATION WELLS SHALL BE APPROVED BY ACHD 4. OBSERVATION WELLS NOT ALLOWED IN CURB OR VALLEY GUTTER SECTION PLAN VIEW 6 w o w 6 ' N.T.S. o III=1I I=1 I=1I=1 18" '11=1 11=1 11=1 11=1 I o ~- -III-III=III=III III=III-III=III=i m II I-1 -II1=111=11I III-111=III=1"-' �o= Il, llli II 5 - �IIIII�III; 0 LLJ z X $ U�ll 3 4 Liit Li 6 SECTION CONCRETE COLLAR FLo Lq d BAFFLE WALL N > N.T.S. - ELEV B FLOW O ELEV A N w a a ELEV D w w INLET BAFFLE WALL a ELEV C 2p"ISTD 9 r7 SECTION A-A N.T.S. NOTES 1. SAND AND GREASE TRAP USED FOR SUBSURFACE FACILITIES ONLY c LEGEND: o 8„ z 0 MANHOLE FRAME AND COVER PER SD-617 (TYPICAL) SECTION 2 LOCATION AND FL ELEV. PER DESIGN PLANS (TYPICAL) N.T.S. H 11-F USE H =GRADE< 2-FT USE 2 " DIA RCP RISER 2-FT < H <= 10-FT USE MANHOLE CONE & 48" DIA RISERS O EL. A > EL. B BY 0.10' MIN EL. D < EL. B BY 0.10' MIN EL. C < EL. B BY 0.50' MIN. UNLESS OTHERWISE APPROVED BY ACHD s WATERTIGHT SEAL s PRECAST BOX MANUFACTURER SHALL MARK FLOW DIRECTION AND LABEL INLET OR OUTLET ON SIDE OF BOX 2017 ACHD REVISION 2017 ACHD REVISION IDAFORHPUBL PUBLIC WORKS GROUNDWATER STANDARD DRAWING FORIDAHPUBL PUBLIC WORKS GROUNDWATER STANDARD DRAWING ACHD STORMWATER DESIGN 2015 SAND AND GREASE TRAP STANDARD DRAWING CONSTRUCTION OBSERVATION WELL S D- 6 2 7 CONSTRUCTION OBSERVATION WELL S D- 6 2 7 GUIDELINES Bo P 01 (ACHD SUPPLEMENT) 1 OF 2 (ACHD SUPPLEMENT) 2 OF 2 CONCRETE ALLEY SECTION. FULL MINIMUM 1.0-FT COVER FROM TOP Ln ROADWAY SECTION IS REQUIRED NO TREES ARE ALLOWED WITHIN OF BED TO PAVEMENT SUBGRADE z NO TREES ARE ALLOWED WITHIN OVER SEEPAGE BEDS. SEEPAGE 10' OF THE OUTSIDE PERIMETER SIDEWALK PER ACHD SUPPLEMENTAL FINISHED GROUND BEDS SHALL NOT EXTEND ABOVE OF THE SEEPAGE BED IS REQUIRED. BACKFILL OVER BED O Q A,B,C STANDARD DRAWING SD-709. 10' OF THE OUTSIDE PERIMETER 1,000 GALLON �� OF THE SEEPAGE BED CURB AND GUTTER SUBGRADE TO SUBGRADE WITH 6"-8" MINUS z J SAND AND GREASE TRAP PER ACHD REQUIREMENTS. REFER PER ROADWAY PLANS. NO TREES ARE ALLOWED WITHIN PIT RUN. TO ACHD DETAIL BMP 01. ELEV. - "A" MIN. i , 10' OF THE OUTSIDE PERIMETER FINISHED GROUND ELEV. - "A" (MIN.) z (MIN.) "A" OF THE SEEPAGE BED * i�i�/�i�/�/�i�/�� �� �i�� ELEV. - >,A„ (MIN.) O 5 LF OF 18'0 vi V�V�V�V�V�V�V�V�V�V�V�V�V�V�V� ww / / / / / / / / / / / �j�j� ADS N-12 HP -m �, �j /���j s i/��j�i���i�i/��j� „ i/ i ��j� , ELEV. - „B„ - W riLq SD -------- --------- aELEV. - B ���������� ��� ����������� ELEV. - B' ' � 6 ' ��� ------- --------- zwv, 3 �� 3 _ 3 Z -�� ELEV. "C" V) ELEV. - "C" ELEV. - "C" vi 0 Q W V c/ 5 5 w w Q > 5 5 �J 5 5 �J 0° - O *18"0 PERFORATED ADS N-12 HP. >Q Q J TRANSITION 5' IN BED NON-PERFORATED TO Ly A g C w z Q PERFORATED PIPE =w =w w LENGTH VARIES, SEE TABLE THIS SHEET 0 w a w w if w N w N < LLJ 1,000 GALLON PLAN VIEW - 2 cnM � o SAND AND GREASE TRAP PER 2 2 ELEV. - "D" w ACHD REQUIREMENTS. REFER TO ELEV. - "D" ELEV. - "D" ACHD DETAIL BMP 01. WATERTIGHT CONNECTION z 1Q uj LOCATIONS, ELEVATIONS, AND z_ 1Q z_ 1Q = w ADDITIONAL INFORMATION PER 18"0 SOLID WALL ADS N-12 HP r WIDTH VARIES, SEE , 5 SHEET C4.0 (EXTEND 5' INTO SEEPAGE BED) WIDTH VARIES SEE WIDTH VARIES, SEE MAX. HSGW M ` Q ro TABLE THIS SHEET 18"0 PERFORATED ADS * FINISH GROUND MAX. HSGW TABLE THIS SHEET z7 MAX. HSGW TABLE THIS SHEET = OR ROCK N-12 HP = OR ROCK = OR ROCK ELEVATION 18" ADS CAP ELEVATION ELEVATION O 4 4 4 z 0% SLOPE x Yo w O ;- KEY 1. ISPWC 801 OR ASTM C33 FILTER SAND. 1. ISPWC 801 OR ASTM C33 FILTER SAND. KEY 2. 3/4" - 2" ANGULAR ROCK. Q MINIMUM OF 20' 2. 3/4" - 2" ANGULAR ROCK. 1. ISPWC 801 OR ASTM C33 FILTER SAND. 3. 18"0 PERFORATED PIPE. INSTALL PERFORATIONS PER ACHD STORMWATER BAFFLE SPACING T " 3. 18"0 PERFORATED PIPE. INSTALL PERFORATIONS PER ACHD STORMWATER 2. 3/4" - 2" ANGULAR ROCK. DESIGN GUIDELINES DETAIL BMP 20 AND DETAIL ON THIS SHEET. DESIGN GUIDELINES DETAIL BMP 20 AND DETAIL ON THIS SHEET. 3. 18"0 PERFORATED PIPE. INSTALL PERFORATIONS PER ACHD STORMWATER 4. SUITABILITY OF SUBGRADE TO BE VERIFIED BY GEOTECHNICAL ENGINEER. m 4" OF CHIPS PIPE BEDDING 4. SUITABILITY OF SUBGRADE TO BE VERIFIED BY GEOTECHNICAL ENGINEER. DESIGN GUIDELINES DETAIL BMP 20 AND DETAIL ON THIS SHEET. 5. NON-WOVEN FABRIC SHALL BE PROPEX GEOTEX 401 OR APPROVED N 5. NON-WOVEN FABRIC SHALL BE PROPEX GEOTEX 401 OR APPROVED 4. SUITABILITY OF SUBGRADE TO BE VERIFIED BY GEOTECHNICAL ENGINEER. EQUAL MEETING ACHD STORMWATER DESIGN GUIDELINES SECTION m EQUAL MEETING ACHD STORMWATER DESIGN GUIDELINES SECTION 5. NON-WOVEN FABRIC SHALL BE PROPEX GEOTEX 401 OR APPROVED 8202.23. OVERLAP MINIMUM OF 1-FT TOP AND SIDES ONLY. 8202.23. OVERLAP MINIMUM OF 1-FT TOP AND SIDES ONLY. EQUAL MEETING ACHD STORMWATER DESIGN GUIDELINES SECTION 8202.23. 6. FOR SEEPAGE BEDS IN THE PUBLIC RIGHT-OF-WAY A MINIMUM OF o GROUND WATER OBSERVATION WELL PER 6. FOR SEEPAGE BEDS IN THE PUBLIC RIGHT-OF-WAY A MINIMUM OF OVERLAP MINIMUM OF 1-FT TOP AND SIDES ONLY. 1.0-FT COVER FROM TOP OF BED TO PAVEMENT SUBGRADE. INSTALL a DETAIL. EXTEND MINIMUM OF 1' BELOW 1.0-FT COVER FROM TOP OF BED TO PAVEMENT SUBGRADE. INSTALL 6. FOR SEEPAGE BEDS OUTSIDE OF PUBLIC RIGHT-OF-WAY A MINIMUM OF WOVEN GEOTEXTILE FABRIC OVER TOP OF BED. WOVEN FABRIC SHALL BE z WOVEN GEOTEXTILE FABRIC OVER TOP OF BED. WOVEN FABRIC SHALL BE 1.5-FT COVER FROM TOP OF BED TO FINISH GRADE WITHIN LANDSCAPE PROPEX GEOTEX 401 F OR APPROVED EQUAL MEETING ACHD O w THE BOTTOM OF SAND LAYER PROPEX GEOTEX 401 F OR APPROVED EQUAL MEETING ACHD AREAS. STORMWATER DESIGN GUIDELINES SECTION 8202.23. PROFILE VIEW STORMWATER DESIGN GUIDELINES SECTION 8202.23. U PLAN AND PROFILE SECTION VIEW A-A: SEEPAGE BEDS WITHIN PUBLIC ROW SECTION VIEW B-B: SEEPAGE BEDS SECTION VIEW C-C: SEEPAGE BED a OUTSIDE OF PUBLIC ROW (COMMON LOT OUTSIDE OF PUBLIC ROW (PRIVATE ALLEY 0 0 a z N O N 1 GENERAL NOTES U SEEPAGE BED TABLE A. GROUNDWATER ELEVATIONS ARE EXPECTED TO REMAIN AT OR BELOW 20 FEET FROM EXISTING GROUND SURFACE. THE DESIGN INFILTRATION RATE IS �5p0 �S�p• w 8 IN/HR BASED ON THE INFILTRATION TEST RESULTS WITHIN THE POORLY GRADED GRAVEL THAT WERE 12 IN/HR OR GREATER. FOR ADDITIONALIf 1 Z SEEPAGE BED SECTION BED LENGTH BED WIDTH BED DEPTH (FT) ELEVATION "A" ELEVATION "B" ELEVATION "C" ELEVATION "D" GROUND WATER EL. DESIGN VOLUME (CF) DESIGN INFILTRATION RATE INFORMATION REFER TO THE GEOTECHNICAL INVESTIGATION "APEX WEST SUBDIVISION" PREPARED BY ATLAS, DATED FEBRUARY 8, 2022. 0 Z (FT) (FT) (IN/HR) B. ALL DRAINAGE STRUCTURES SHALL BE HS25 OR GREATER LOAD RATED. Q� LL C. ALL GEOTEXTILE SEAMS SHALL OVERLAP 1 FOOT MINIMUM. p E N G I N E E R I N G g SB #1 (PUBLIC) A-A 141 15 8.5 2732.26 2729.85 2727.35 2721.35 2710.9f 8,589 8.0 D. BED WIDTH SHALL REMAIN CONSTANT. & 0O•, 5725 NORTH DISCOVERY WAY E. IF ROCK IS ENCOUNTERED, CONTRACTOR MUST HAVE A PERCOLATION TEST PERFORMED BY A SOILS ENGINEER AFTER SEEPAGE BED IS FULLY h SB #2 (PUBLIC) B-B 61 9 8.5 2732.28 2729.53 2727.03 2721.03 2711.3f 2,248 8.0 EXCAVATED. (NOTE: AN ACHD INSPECTOR MUST BE PRESENT FOR THE TEST). IF THE PERCOLATION IS LESS THAN SPECIFIED BY THE SOILS BOISE,IDAHO 83713 O o REPORT AND ENGINEER, CONTRACTOR MAY NEED TO BLAST OR BORE TO CREATE CONDUIT FOR DRAINAGE TO OCCUR OR RE-DESIGN THE SYSTEM PHONE(208)639-6939 SB #3 (PUBLIC) A-A 40 15 8.5 2732.08 2729.78 2727.28 2721.28 2712.1 f 2,454 8.0 TO ACHIEVE THE REQUIRED INFILTRATION. kmengllp.com z F. STORAGE VOLUME DOESN'T INCLUDE SAND WINDOW. SB #4 (PUBLIC) A-A 32 15 8.5 2733.64 2731.42 2728.92 2722.92 2713.0f 1,958 8.0 G. WATER SERVICES, SEWER SERVICES, AND PRESSURE IRRIGATION MAINS CROSSING SEEPAGE BEDS SHALL BE INSTALLED PER ACHD REQUIREMENTS. DESIGN BY: LCK H. FOR UNDERGROUND INFILTRATION SYSTEMS, INSTALL ELECTRONIC MARKERS ON EACH CORNER OF THE FACILITY. THE CONTRACTOR SHALL SB #5 (PUBLIC) B-B 68 15 8.5 2733.34 2731.26 2729.25 2722.76 2712.7f 4,128 8.0 COORDINATE WITH THE ACHD INSPECTION DEPARTMENT FOR PLACEMENT OF THE MARKERS DURING CONSTRUCTION AND PRIOR TO BACKFILLING. DRAWN BY: LCK z I. CONTRACTOR SHALL VERIFY INFILTRATION RATE AFTER THE FACILITY IS FULLY EXCAVATED WITH THE ACHD INSPECTOR PRESENT. 3 J. CONTRACTOR SHALL NOTIFY THE ENGINEER IMMEDIATELY IF GROUNDWATER IS ENCOUNTERED WITHIN 3-FEET OF THE BOTTOM DESIGN ELEVATION FOR 18" PIPE CHECKED BY: LCK z SB #6 (PRIVATE) C-C 59 10 8.5 2732.70 2730.67 2728.66 2722.17 2712.2t 2,416 8.0 ANY INFILTRATION FACILITY AND/OR IF IT IS HIGHER THAN ANTICIPATED. o DATE: NOVEMBER 2022 z u 18 PERF PIPE N WQ PROJECT: 22-053 PERFORATION SCHEDULE SHEET NO. _ SEEPAGE BED DETAIL #1 3/8" PERFORATIONS IN VALLEY J C4. 1 w m NTS OF CORRUGATED PIPE. 5 EA ON 18". 9 O IIiT N APPENDIX B - TABLES Table 1 - Peak Flow Rates and Runoff Volumes Post-Development Peak Flow Rates (cfs) Tc (min.) 25-yr 100-yr Basin A-1 24.4 1.12 1.55 Basin A-2 24.0 0.70 0.97 Basins A-1-A-2 24.4 1.81 2.53 Basin A-3 21.1 0.51 0.72 Basins A-1-A-3 24.4 2.33 3.24 Basin A-4 10.0 0.37 0.51 Basins A-1-A-4 24.4 2.58 3.60 Basin B-1 10.0 0.44 0.62 Basin B-2 10.0 0.31 0.43 Basins B-1 - B-2 10.0 0.75 1.04 Basin B-3 10.0 0.24 0.34 Basin B-4 10.0 0.21 0.29 Basins B-3 - B-4 10.0 0.46 0.64 Basins B-1 - B-4 10.0 1.20 1.68 Basin C-1 10.0 0.50 0.69 Basin C-2 10.0 0.55 0.77 Basins C-1 -C-2 10.0 1.05 1.47 Basin D-1 10.0 0.31 0.43 Basin D-2 19.2 0.45 0.63 Basins D-1- D-2 19.2 0.71 0.99 Basin E-1 23.2 0.79 1.10 Basin E-2 22.6 0.76 1.06 Basins E-1 - E-2 23.2 1.55 2.16 Basin F-11 18.9 0.87 1.22 Post-Development Runoff Volumes 100-yr Runoff Design Volume Volume Basins A-1-A-4, SB#1 6,871 8,589 Basins B-1 - B-4, SB#2 2,248 2,248 Basins C-1 -C-2, SB#3 1,963 2,454 Basins D-1- D-2, SB#4 1,567 1,958 Basins E-1 - E-2, SB#5 4,128 4,128 Basins F-1, SB#6 1,932 2,416 APPENDIX C - CALCULATIONS POST-DEVELOPMENT 25-YEAR CALCULATIONS ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin A-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 300-Year Flood Route) 25 4 Enter number of storage facilities(25 max) 7 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 17,995 49,041 6,966 Acres 1.70 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.51 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min I User calculate to Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope[ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b 0.008 0.619 670 1.8 6.1 Parks,Cemeteries 0.10-0.2-1 Playgrounds 0.20-0.35 segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 74 0.240 4.0 18.2 Computed Tc= 24.4 User-Entered Tc= 24.4 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.30 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 1.12 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 2,133 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,855 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 213 ft' Streets Asphalt 0.95 Primary Treatment/StorageBasin V 1,920 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 2,133 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0 Average:2-6% 0.09 0.12 0.15 0 Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Caks\22-053 Storm Drain Calc Basin A 11/17/2022,3:58 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin A-2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 14,636 21,776 7,461 Acres 1.01 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.53 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min I User calculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential ID Pipe Size(in) Slope(f/ft) Coeff. Length Manning n Perm (fps) (min) Single Family 0.35-0.50 Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Segment 2:Gutter Shallow Concentrated Flow Light areas 0.80 Heavy areas 0.90 b 0.008 0.619 621 1.8 5.7 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 74 0.240 4.0 18.3 Computed Tc= 24.0 User-Entered Tc= 24.0 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.30 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 0.70 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V ft V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,158 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 133 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,199 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,332 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,3:59 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Peak Discha Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins A-1-A-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 32,631 70,817 14,427 Acres 2.71 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.52 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 24.4 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.30 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 1.81 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 3,465 ft V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 3,013 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 347 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 3,119 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 3,465 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,3:59 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar culated for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin A-3 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 8,657 21,779 2,925 Acres 0.77 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.52 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0 Segment 2:Gutter Shallow Concentrated Flow .0 Heavy areas .90 b 0.010 0.619 351 2.0 2.9 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 74 0.240 4.0 18.2 Computed Tc= 21.1 User-Entered Tc= 21.1 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.30 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qpexk 0.51 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 982 ft V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 854 ft 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 98 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 884 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 982 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,3:59 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Develo cha Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins A-1-A-3 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 41,288 92,596 17,352 Acres 3.47 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.52 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 24.4 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.30 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 2.33 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 4,448 ft V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 3,868 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 445 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 4,003 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 4,448 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,3:59 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Develo d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin A-4 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 8,742 3,066 Acres 0.27 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.73 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate fto Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.37 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 s Residential 10 Calculate total runoff vol(V)(for sizing primary storage) ft Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Apartment Dwelling Areas 0.70Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) 'U-427 ft' eight areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 49 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 442 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 491 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,4:00 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Develo d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins A-1-A-4 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 50,030 92,596 20,418 Acres 3.74 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.53 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUsercalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 24.4 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.30 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 2.58 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 4,939 ft V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 4,295 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) CfS 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 494 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 4,445 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 4,939 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,4:00 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. -Steps for Peak Di Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin B-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 4 Enter number of storage facilities(25 max) 7 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 10,532 3,892 Acres 0.33 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.72 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user Calculate [io Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(C!Peak) Qpeak 0.44 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 593 ft Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 515 W Light areas 0.30 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 59 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 533 W Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 593 W Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin B 11/17/2022,4:12 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Develo d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin B-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 6,788 7,730 Acres 0.33 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.50 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate fto Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.31 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 s Residential 10 Calculate total runoff vol(V)(for sizing primary storage) 412 ft Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Enter Percentile Storm Apartment Dwelling Areas 0.70(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 358 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 41 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 371 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 412 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin B 11/17/2022,4:12 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins B-1-B-2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(300-Year or 25-Year With 300-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 17,320 0 11,622 Acres 0.66 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.61 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Q', 0.75 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 3 Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,005 ft single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in lndustrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 874 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary I Railroad yard areas 0.20-0.40 Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 100 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 904 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,005 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin B 11/17/2022,4:13 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Develo d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin B-3 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 5,950 1,141 Acres 0.16 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.81 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.24 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primary storage) 329 V ft Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 286 W Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 arks,Cem Peteries 0.1010-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 33 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 296 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 329 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin B 11/17/2022,4:13 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin B-4 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 4,836 3,629 Acres 0.19 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.59 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.21 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primary storage) 283 V ft Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 246 W Llght areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90,Cem Parkseteries 0.1010-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 28 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 254 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 283 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin B 11/17/2022,4:22 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Develo cha Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins B-3-B-4 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 300-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 10,786 0 4,770 Acres 0.36 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.69 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate fto Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Q', 0.46 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 s Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 612 ft Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 532 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 61 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 550 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 612 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin B 11/17/2022,4:23 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Develo d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins B-1-B-4 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 28,106 0 16,392 Acres 1.02 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.64 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 1.20 CIS Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primarystorage) �,616W Residential g ) Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,405 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 162 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,454 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,616 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin B 11/17/2022,4:24 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin C-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 4 Enter number of storage facilities(25 max) 3 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 11,106 11,485 Acres 0.52 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.52 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user Calculate [io Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Q,A 0.50 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 667 ft single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 580 W Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 67 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 600 W Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 667 W Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 0 Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin C 11/17/2022,4:14 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin C-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 13,265 4,458 Acres 0.41 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.74 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate fto Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(CiPeak) Qpeak 0.55 CIS Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 s Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 744 ft Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Enter Percentile Storm Apartment Dwelling Areas 0.70(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 647 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) CIS Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 74 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 670 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 744 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin C 11/17/2022,4:14 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins C-1-C-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 300-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 24,371 0 15,943 Acres 0.93 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.61 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Q', 1.05 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 3 Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,411 ft single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,227 W Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary I Railroad yard areas 0.20-0.40 Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 141 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,270 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,411 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin C 11/17/2022,4:15 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. �r Peak Di Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin D-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 4 Enter number of storage facilities(25 max) 3 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 7,039 5,466 Acres 0.29 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.58 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user Calculate [io Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(C!Peak) Q,A 0.31 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 412 ft single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 359 W Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 41 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 371 W Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 412 W Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin D 11/17/2022,4:15 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Pe for Iculate Post-Development Flows(for pre-development flows, increase increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin D-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 9,787 7,358 2,723 Acres 0.46 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.63 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUsercalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Single Family 0.35-0.50 Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Segment 2:Gutter Shallow Concentrated Flow Light areas 0.80 Heavy areas 0.90 b 0.010 0.619 160 2.0 1.3 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 72 0.240 4.0 17.9 Computed Tc= 19.2 User-Entered Tc= 19.2 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.56 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 0.45 Cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 714 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 620 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 71 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 642 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 714 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin D 11/17/2022,4:15 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Discha Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins D-1-D-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 16,826 7,358 8,189 Acres 0.74 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.61 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 19.2 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.56 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 0.71 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,126 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 979 ft 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 113 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,013 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,126 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin D 11/17/2022,4:15 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin E-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 300-Year Flood Route) 25 4 Enter number of storage facilities(25 max) 3 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 12,844 34,565 4,421 Acres 1.19 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.51 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min I User calculate to Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope[ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b 0.010 0.619 520 2.0 4.3 Parks,Cemeteries 0.10-0.2-1 Playgrounds 0.20-0.35 segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 77 0.240 4.1 18.9 Computed Tc= 23.2 User-Entered Tc= 23.2 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.30 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qpezk 0.79 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,509 ft; V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,313 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 151 ft' Streets Asphalt 0.95 Primary Treatment/StorageBasin V 1,358 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,509 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0 Average:2-6% 0.09 0.12 0.15 0 Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Caks\22-053 Storm Drain Calc Basin E 11/17/2022,4:16 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. ischar Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin E-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 12,848 32,229 4,593 Acres 1.14 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.51 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUsercalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Single Family 0.35-0.50 Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Segment 2:Gutter Shallow Concentrated Flow Light areas 0.80 Heavy areas 0.90 b 0.010 0.619 520 2.0 4.3 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 74 0.240 4.0 18.3 Computed Tc= 22.6 User-Entered Tc= 22.6 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.30 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 0.76 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,457 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,267 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) CIS 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 146 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,312 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,457 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin E 11/17/2022,4:16 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. -Steps for Pe culated for Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins E-1-E-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 25,692 66,794 9,014 Acres 2.33 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.51 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 23.2 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.30 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 1.55 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 2,967 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 2,580 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 297 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 2,670 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 2,967 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin E 11/17/2022,4:16 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin F-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 300-Year Flood Route) 25 4 Enter number of storage facilities(25 max) 1 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 7,450 43,200 Acres 1.16 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.48 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min I User calculate to Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope[ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b 0.007 0.619 352 1.7 3.5 Parks,Cemeteries 0.10-0.2-1 Playgrounds 0.20-0.35 segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 60 0.240 3.9 15.5 Computed Tc ttl User-Entered Tc 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.56 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qpezk 0.87 Cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,389 ft; V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,208 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 139 ft' Streets Asphalt 0.95 Primary Treatment/StorageBasin V 1,250 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,389 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0 Average:2-6% 0.09 0.12 0.15 0 Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin F 11/17/2022,4:19 PM Version 10.5,November 2018 POST-DEVELOPMENT 100-YEAR CALCULATIONS ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin A-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 300-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 7 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 17,995 49,041 6,966 Acres 1.70 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.51 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min I User calculate to Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope[ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b 0.008 0.619 670 1.8 6.1 Parks,Cemeteries 0.10-0.2-1 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 74 0.240 4.0 18.2 Computed Tc= 24.4 User-Entered Tc= 24.4 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 1.55 CfS 10 Calculate total runoff vol(V)(for sizing primary storage) V 2,968 ft; V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,855 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 297 ft' Streets Asphalt 0.95 Primary Treatment/StorageBasin V 2,671 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 2,968 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0 Average:2-6% 0.09 0.12 0.15 0 Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,2:29 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin A-2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 14,636 21,776 7,461 Acres 1.01 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.53 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min I User calculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Single Family 0.35-0.50 Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Segment 2:Gutter Shallow Concentrated Flow Light areas 0.80 Heavy areas 0.90 b 0.008 0.619 621 1.8 5.7 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 74 0.240 4.0 18.3 Computed Tc= 24.0 User-Entered Tc= 24.0 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 0.97 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,853 ft V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,158 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 185 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,668 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,853 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,2:30 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar culated for Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins A-1-A-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 32,631 70,817 14,427 Acres 2.71 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.52 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 24.4 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 2.53 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 4,821 ft3 V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 3,013 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 482 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 4,339 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 4,821 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin A 11/17/2022,2:31 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. -steps for Peak Dischar d for Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin A-3 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 8,657 21,779 2,925 Acres 0.77 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.52 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b 0.010 0.619 351 2.0 2.9 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 74 0.240 4.0 18.2 Computed Tc= 21.1 User-Entered Tc= 21.1 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in/hr 9 Calculate the Post-Development peak discharge(OPeak) Qp,.k 0.72 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,367 ft V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 854 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 137 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,230 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,367 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin A 11/17/2022,2:31 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Pe Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins A-1-A-3 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 41,288 92,596 17,352 Acres 3.47 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.52 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" suss Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Segment 2:Gutter Shallow Concentrated Flow dent areas 0. 0 g Heavy areas .90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 24.4 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 3.24 CfS 10 Calculate total runoff vol(V)(for sizing primary storage) V 6,188 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 3,868 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 619 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 5,569 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 6,188 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,2:31 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin A-4 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 8,742 3,066 Acres 0.27 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.73 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate fto Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.51 CIS Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primary storage) 683 ft3 Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 427 W Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) CIS Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 68 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 615 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 683 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin A 11/17/2022,2:31 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins A-1-A-4 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(300-Year or 25-Year With 300-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 50,030 92,596 20,418 Acres 3.74 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.53 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min I user calculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" suss Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 24.4 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 3.60 Cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 6,871 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 4,295 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 687 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 6,184 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 6,871 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,2:32 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Di alculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin B-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 7 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 10,532 3,892 Acres 0.33 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.72 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user Calculate [io Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.62 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 825 ft Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 515 W Light areas 0.30 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 82 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 742 W Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 825 W Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin B 11/17/2022,2:32 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Pe culated for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin B-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 6,788 7,730 Acres 0.33 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.50 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate fto Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Q', 0.43 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primary storage) V 573 ft3 Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 358 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 57 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 516 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 573 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin B 11/17/2022,2:33 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar culated for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins B-1-B-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 17,320 0 11,622 Acres 0.66 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.61 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Q', 1.04 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primarY storag e] V 1,398 ft3 Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in lndustrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 874 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary I Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 140 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,258 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,398 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin B 11/17/2022,2:33 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Pe for Iculate Post-Development Flows(for pre-development flows, increase increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin B-3 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 5,950 1,141 Acres 0.16 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.81 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.34 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primary storage) 458 ft Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm (95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 286 ft' eight areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 46 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 412 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 458 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin B 11/17/2022,2:33 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar culated for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin B-4 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 4,836 3,629 Acres 0.19 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.59 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.29 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primary storage) 393 V ft Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 246 W Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 39 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 354 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 393 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin B 11/17/2022,2:33 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins B-3-B-4 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 10,786 0 4,770 Acres 0.36 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.69 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate fto Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Q', 0.64 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primary storage) 851 ft3 Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 532 W Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 85 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 766 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 851 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin B 11/17/2022,2:33 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins B-1-B-4 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 28,106 0 16,392 Acres 1.02 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.64 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 1.68 CfS Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primarY storag a) 248 2, ft3 Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm (95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,405 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) CfS Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 225 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 2,024 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 2,248 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin B 11/17/2022,2:34 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. -steps for Pe d for Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin C-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 3 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 11,106 11,485 Acres 0.52 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.52 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user Calculate [io Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Q,A 0.69 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 928 ft single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 580 W Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 93 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 835 W Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 928 W Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 0 Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin C 11/17/2022,2:34 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar culated for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin C-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 13,265 4,458 Acres 0.41 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.74 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate fto Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.77 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 10 Calculate total runoff vol(V)(for sizing primary storage) ft3 Residential Single Family 0.35-0.50 V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Apartment Dwelling Areas 0.70 offIndustrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 647 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 104 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 932 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,035 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin C 11/17/2022,2:35 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins C-1-C-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 300-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 24,371 0 15,943 Acres 0.93 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.61 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user calculate [to Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 1.47 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 3 Residential 10 Calculate total runoff vol(V)(for sizing primary storage) ft single Family 0.35-0.50 MOM V=Ci(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in lndustrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,227 ft' Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary I Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 196 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,767 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,963 ft' Roofs 0.95 Gravel 0.75 Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-0S3 Storm Drain Cale Basin C 11/17/2022,2:3S PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. d for Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin D-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 3 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 7,039 5,466 Acres 0.29 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.58 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min user Calculate [io Min. Estimated Runoff Coefficients for Various Surfac 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Type of Surface Runoff Coefficients" Business 9 Calculate the Post-Development peak discharge(C!Peak) Q,A 0.43 cfs Downtown areas 0.70-0.95 Urban neighborhoods 0.50-0.70 Residential 10 Calculate total runoff vol(V)(for sizing primary storage) V 574 ft single Family 0.35-0.50 V=Cf(Tc=60)Ax3600 Multi-family 0.60-0.75 11 Calculate Volume of Runoff Reduction Vrr Residential(rural) 0.25-0.40 Apartment Dwelling Areas 0.70 Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Industrial and Commercial Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 359 W Light areas 0.80 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Heavy areas 0.90Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 13 Volume Summary Railroad yard areas 0.20-0.40 Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 57 ft' streets Asphalt 0.95 Primary Treatment/Storage Basin V 517 W Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 574 W Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 0 Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin D 11/17/2022,2:52 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar culated for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin D-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 9,787 7,358 2,723 Acres 0.46 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.63 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUsercalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential ID Pipe Size(in) Slope(f/ft) Coeff. Length Manning n Perm (fps) (min) Single Family 0.35-0.50 Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Segment 2:Gutter Shallow Concentrated Flow Light areas 0.80 Heavy areas 0.90 b 0.010 0.619 160 2.0 1.3 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 72 0.240 4.0 17.9 Computed Tc= 19.2 User-Entered Tc= 19.2 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.18 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 0.63 Cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 993 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 620 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 99 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 894 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 993 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin D 11/17/2022,2:53 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins D-1-D-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 16,826 7,358 8,189 Acres 0.74 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.61 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0 Segment 2:Gutter Shallow Concentrated Flow .0 Heavy areas .90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 19.2 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.18 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 0.99 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,567 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 979 ft 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) CIS 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 157 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,410 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,567 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin D 11/17/2022,2:55 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin E-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 3 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 12,844 34,565 4,421 Acres 1.19 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgI 0.51 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min I User calculate to Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope[ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b 0.010 0.619 520 2.0 4.3 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 77 0.240 4.1 18.9 Computed Tc- 23.2 User-Entered Tc= 23.2 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qpezk 1.10 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 2,100 ft; V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,313 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 210 ft' Streets Asphalt 0.95 Primary Treatment/StorageBasin V 1,890 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 2,100 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0 Average:2-6% 0.09 0.12 0.15 0 Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin E 11/17/2022,3:09 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Pe d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin E-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 12,848 32,229 4,593 Acres 1.14 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.51 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUsercalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential ID Pipe Size(in) Slope(f/ft) Coeff. Length Manning n Perm (fps) (min) Single Family 0.35-0.50 Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Segment 2:Gutter Shallow Concentrated Flow Light areas 0.80 Heavy areas 0.90 b 0.010 0.619 520 2.0 4.3 Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 74 0.240 4.0 18.3 Computed Tc= 22.6 User-Entered Tc= 22.6 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 1.06 Cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 2,028 W V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,267 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 203 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 1,825 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 2,028 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin E 11/17/2022,3:09 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. for Peak Dischar d for Iculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins E-1-E-2 2 Is area drainage basin map provided? YES (map must be included with stormwoter calculations) 3 Enter Design Storm(300-Year or 25-Year With 300-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 25,692 66,794 9,014 Acres 2.33 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.51 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min lUserCalculate 10 Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0 Segment 2:Gutter Shallow Concentrated Flow .0 Heavy areas .90 b Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c Computed Tc= 0.0 User-Entered Tc= 23.2 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qp,.k 2.16 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 4,128 ft3 V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 2,580 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) CIS 13 Volume Summary Surface Storage:Basin unimproved areas 0.10-0.30 Basin Forebay V 413 ft' Streets Asphalt 0.95 Primary Treatment/Storage Basin V 3,715 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 4,128 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 O.li 0 Average:2-6% 0.09 0.12 0.15 O Steep:>6% 0.13 0.18 0.23 O Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Cale Basin E 11/17/2022,3:09 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin F-1 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 1 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 Subbasin 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 7,450 43,200 Acres 1.16 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.40 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgI 0.48 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 min I User calculate to Min. _ Estimated Runoff Coefficients for Various Surfac Type of Surface Runoff Coefficients" Business Hydraulic Downtown areas 0.70-0.95 Radius Flow Urban neighborhoods 0.50-0.70 Intercept A/Wet Velocity Flow Time Residential Single Family 0.35-0.50 ID Pipe Size(in) Slope[ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75 Segment 1:Pipe Flow Residential(rural) 0.25-0.40 a Apartment Dwelling Areas 0.70 Industrial and Commercial Light areas 0.80 Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90 b 0.007 0.619 352 1.7 3.5 Parks,Cemeteries 0.10-0.2-1 Playgrounds 0.20-0.35 segment 3:Overland Sheet Flow By TR-55,<300-ft Railroad yard areas 0.20-0.40 c 0.020 60 0.240 3.9 15.5 Computed Tc ttl User-Entered Tc 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.18 in/hr 9 Calculate the Post-Development peak discharge(QPeak) Qpezk 1.22 cfs 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,932 ft; V=Ci(Tc=60)Ax3600 11 Calculate Volume of Runoff Reduction Vrr Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,208 W 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs 13 Volume Summary Surface Storage:Basin Unimproved areas 0.10-0.30 Basin Forebay V 193 ft' Streets Asphalt 0.95 Primary Treatment/StorageBasin V 1,739 ft' Concrete 0.95 Subsurface Storage Brick 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,932 ft' Roofs 0.95 Gravel 0.75 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0 Average:2-6% 0.09 0.12 0.15 0 Steep:>6% 0.13 0.18 0.23 0 Adapted from ASCE P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin F 11/17/2022,4:19 PM Version 10.5,November 2018 SEEPAGE BED CALCULATIONS ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins A-1-A-4,SB#1 2 Enter number of Seepage Beds(25 max) 1 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.53 Link to: QVa 5 Area A(Acres) 3.74 acres QV6 6 Approved discharge rate(if applicable) 0.00 cfs [0,V7� QV TR55 _ 7 Is Seepage Bed in Common Lot? No V 8,589 ft3 25%Sediment 8 Infiltartion Volume in the First Hour V 1421 9 Set Total Design Width of All Drain Rock W 15.0 ft 10 Set Total Design Depth of All Drain Rock D 8.5 ft Rock Only,Do Not Include Filter Sand Depth or Cover 11 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 12 Design Infiltration Rate(8 in/hr max) Perc 8.00 in/hr 13 Size of WQ Perf Pipe(Perf 1800) Dia pipe 18 in 14 Size of Overflow Perf Pipe(Perfs 3600),REQD if Q100>3.3 cfs in 15 Calculate Design Length L 141 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 141 ft 17 Variable Infiltration Window W SWW 15.0 ft 18 Time to Drain 5.5 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 141 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ftz 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin A 11/17/2022,3:11 PM Version 10.0,May 2018 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins B-1-B-4,SIB#2 2 Enter number of Seepage Beds(25 max) 1 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.64 Link to: QVa 5 Area A(Acres) 1.02 acres QV6 6 Approved discharge rate(if applicable) 0.00 cfs [0,V7� QV TR55 _ 7 Is Seepage Bed in Common Lot? Yes V 2,248 ft3 0%Sediment 8 Infiltartion Volume in the First Hour V 372 9 Set Total Design Width of All Drain Rock W 9.0 ft 10 Set Total Design Depth of All Drain Rock D 8.5 ft Rock Only,Do Not Include Filter Sand Depth or Cover 11 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 12 Design Infiltration Rate(8 in/hr max) Perc 8.00 in/hr 13 Size of WQ Perf Pipe(Perf 1800) Dia pipe 18 in 14 Size of Overflow Perf Pipe(Perfs 3600),REQD if Q100>3.3 cfs in 15 Calculate Design Length L 61 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 61 ft 17 Variable Infiltration Window W SWW 9.0 ft 18 Time to Drain 5.5 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 61 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ftz 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin B 11/17/2022,3:39 PM Version 10.0,May 2018 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins C-1-C-2,SIB q3 2 Enter number of Seepage Beds(25 max) 1 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.61 Link to: QV 5 Area A(Acres) 0.93 acres [0,V3� 6 Approved discharge rate(if applicable) 0.00 cfs QVTR55 7 Is Seepage Bed in Common Lot? No V 2,454 ft3 25%Sediment 8 Infiltartion Volume in the First Hour V 406 9 Set Total Design Width of All Drain Rock W 15.0 ft 10 Set Total Design Depth of All Drain Rock D 8.5 ft Rock Only,Do Not Include Filter Sand Depth or Cover 11 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 12 Design Infiltration Rate(8 in/hr max) Perc 8.00 in/hr 13 Size of WQ Perf Pipe(Perf 1800) Dia pipe 18 in 14 Size of Overflow Perf Pipe(Perfs 3600),REQD if Q100>3.3 cfs in 15 Calculate Design Length L 40 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 40 ft 17 Variable Infiltration Window W SWW 15.0 ft 18 Time to Drain 5.5 hours 90%volume in 48-hours minimum EEFK 19 Length of WQ&Overflow Perf Pipes 40 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ftz 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin C 11/17/2022,3:42 PM Version 10.0,May 2018 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins D-1-D-2,SIB#4 2 Enter number of Seepage Beds(25 max) 1 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.61 Unkto: QV 5 Area A(Acres) 0.74 acres [0,V3� 6 Approved discharge rate(if applicable) 0.00 cfs QVTR55 7 Is Seepage Bed in Common Lot? No V 1,958 ft3 25%Sediment 8 Infiltartion Volume in the First Hour V 324 9 Set Total Design Width of All Drain Rock W 15.0 ft 10 Set Total Design Depth of All Drain Rock D 8.5 ft Rock Only,Do Not Include Filter Sand Depth or Cover 11 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 12 Design Infiltration Rate(8 in/hr max) Perc 8.00 in/hr 13 Size of WQ Perf Pipe(Perf 1800) Dia pipe 18 in 14 Size of Overflow Perf Pipe(Perfs 3600),REQD if Q100>3.3 cfs in 15 Calculate Design Length L 32 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 32 ft 17 Variable Infiltration Window W SWW 15.0 ft 18 Time to Drain 77 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 32 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ftz 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin D 11/17/2022,3:43 PM Version 10.0,May 2018 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basins E-1-E-2,SIB#5 2 Enter number of Seepage Beds(25 max) 1 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.51 Unkto: QV 5 Area A(Acres) 2.33 acres [0,V3� 6 Approved discharge rate(if applicable) 0.00 cfs QVTR55 7 Is Seepage Bed in Common Lot? Yes V 4,128 ft3 0%Sediment 8 Infiltartion Volume in the First Hour V 683 9 Set Total Design Width of All Drain Rock W 15.0 ft 10 Set Total Design Depth of All Drain Rock D 8.5 ft Rock Only,Do Not Include Filter Sand Depth or Cover 11 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 12 Design Infiltration Rate(8 in/hr max) Perc 8.00 in/hr 13 Size of WQ Perf Pipe(Perf 1800) Dia pipe 18 in 14 Size of Overflow Perf Pipe(Perfs 3600),REQD if Q100>3.3 cfs in 15 Calculate Design Length L 68 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 68 ft 17 Variable Infiltration Window W SWW 15.0 ft 18 Time to Drain 5.5 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 68 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ftz 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin E 11/17/2022,4:49 PM Version 10.0,May 2018 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Apex Northwest No.4-Basin F-1,SIB#6(Private) 2 Enter number of Seepage Beds(25 max) 1 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.48 Unkto: QV QV TR55 5 Area A(Acres) 1.16 acres 6 Approved discharge rate(if applicable) 0.00 cfs 7 Is Seepage Bed in Common Lot? No V 2,416 ft3 25%Sediment 8 Infiltartion Volume in the First Hour V 400 9 Set Total Design Width of All Drain Rock W 10.0 ft 10 Set Total Design Depth of All Drain Rock D 8.5 ft Rock Only,Do Not Include Filter Sand Depth or Cover 11 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 12 Design Infiltration Rate(8 in/hr max) Perc 8.00 in/hr 13 Size of WQ Perf Pipe(Perf 1800) Dia pipe 18 in 14 Size of Overflow Perf Pipe(Perfs 3600),REQD if Q100>3.3 cfs in 15 Calculate Design Length L 59 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 59 ft 17 Variable Infiltration Window W SWW 10.0 ft 18 Time to Drain 77 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 59 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ftz 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum P:\22-053\Documents\Reports\Storm Drainage\Calcs\22-053 Storm Drain Calc Basin F 11/17/2022,4:49 PM Version 10.0,May 2018 APPENDIX D - GEOTECHNICAL ENGINEERING REPORT & GROUNDWATER DATA GEOTECHNICAL INVESTIGATION APEX WEST SUBDIVISION (ATLAS, 6/22/2022) =4G i A. . tt I. Ste' T i s � Y T r Rk - 4 GEOTECHNICAL INVESTIGATION APEX WEST SUBDIVISION East Lake Hazel Road Meridian, ID Ani PREPARED FOR: Mr. Zach Meyers Brighton Development, Inc. 2929 Navigator Drive, Suite 400 Meridian, ID 83642 PREPARED BY: Atlas Technical Consultants, LLC February 8, 2022 2791 South Victory View Way B220036g Boise, ID 83709 2791 South Victory View Way Boise, ID 83709 (208)376-4748 1 oneatlas.com February 8, 2022 Atlas No. B220036g Mr. Zach Meyers Brighton Development, Inc. 2929 Navigator Drive, Suite 400 Meridian, ID 83642 Subject: Geotechnical Investigation Apex West Subdivision East Lake Hazel Road Meridian, ID Dear Mr. Meyers: In compliance with your instructions, Atlas has conducted a soils exploration and foundation evaluation for the above referenced development. Fieldwork for this investigation was conducted on January 17, 2022. Data have been analyzed to evaluate pertinent geotechnical conditions. Results of this investigation, together with our recommendations, are to be found in the following report. We have provided a PDF copy for your review and distribution. Often, questions arise concerning soil conditions because of design and construction details that occur on a project. Atlas would be pleased to continue our role as geotechnical engineers during project implementation. If you have any questions, please call us at (208) 376-4748. Respectfully submitted, SS�pNAL FN ENSF0 C/yF 1 -� /3 2/8/20224898 Clinton Wyllie, PG Elizabeth Brown, P Staff Geologist Geotechnical Ser ' T roar Py> �ZgSETH 8R� cc: Daniel Frisby, Brighton Corporation (PDF copy) Page 1 1 � N+■ G7T��. CONTENTS 1. INTRODUCTION................................................................................................................. 1 1.1 Project Description ..................................................................................................... 1 1.2 Authorization .............................................................................................................. 1 1.3 Scope of Investigation................................................................................................ 1 2. SITE DESCRIPTION........................................................................................................... 2 2.1 Site Access ................................................................................................................ 2 2.2 Regional Geology....................................................................................................... 2 2.3 General Site Characteristics....................................................................................... 2 2.4 Regional Site Climatology and Geochemistry............................................................. 3 3. SEISMIC SITE EVALUATION ........................................................................................... 3.1 Geoseismic Setting .................................................................................................... 3 3.2 Seismic Design Parameter Values ............................................................................. 3 4. SOILS EXPLORATION....................................................................................................... 4 4.1 Exploration and Sampling Procedures........................................................................ 4 4.2 Laboratory Testing Program....................................................................................... 4 4.3 Soil and Sediment Profile........................................................................................... 5 4.4 Volatile Organic Scan................................................................................................. 5 5. SITE HYDROLOGY............................................................................................................ 3 5.1 Groundwater .............................................................................................................. 6 5.2 Soil Infiltration Rates .................................................................................................. 6 5.3 Infiltration Testing....................................................................................................... 7 6. FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS............................ 7 6.1 Foundation Design Recommendations....................................................................... 8 6.2 Crawl Space Recommendations ................................................................................ 9 6.3 Floor, Patio, and Garage Slab-on-Grade.................................................................... 9 7. PAVEMENT DISCUSSION AND RECOMMENDATIONS..................................................10 7.1 Flexible Pavement Sections ......................................................................................10 7.2 Rigid Pavement Section ............................................................................................11 7.3 Pavement Subgrade Preparation ..............................................................................12 7.4 Common Pavement Section Construction Issues......................................................12 8. CONSTRUCTION CONSIDERATIONS .............................................................................13 8.1 Earthwork..................................................................................................................13 8.2 Dry Weather..............................................................................................................13 8.3 Wet Weather.............................................................................................................14 8.4 Soft Subgrade Soils...................................................................................................14 8.5 Frozen Subgrade Soils..............................................................................................14 8.6 Structural Fill .............................................................................................................15 Atlas No. B220036g Page I i Copyright©2022 Atlas Technical Consultants 07 �TrT—G7T1. 8.7 Backfill of Walls.........................................................................................................16 8.8 Excavations...............................................................................................................16 8.9 Groundwater Control.................................................................................................17 9. GENERAL COMMENTS....................................................................................................17 10. REFERENCES.................................................................................................................18 TABLES Table 1 — Seismic Design Values................................................................................................4 Table 2 — Groundwater Data.......................................................................................................6 Table 3— Infiltration Test Results................................................................................................7 Table4— Soil Bearing Capacity..................................................................................................8 Table 5— Gravel Equivalent Method Flexible Pavement Specifications ....................................11 Table 6—AASHTO Rigid Pavement Specifications...................................................................11 APPENDICES Appendix I Warranty and Limiting Conditions Appendix II Vicinity Map Appendix III Site Map Appendix IV Geotechnical Investigation Test Pit Log Appendix V Geotechnical General Notes Appendix VI Gravel Equivalent Method Pavement Design Appendix VI AASHTO Rigid Pavement Design Appendix Vill R-value Laboratory Test Data Appendix IX Important Information About This Geotechnical Engineering Report Atlas No. B220036g Page I ii Copyright©2022 Atlas Technical Consultants Ile 1. INTRODUCTION This report presents results of a geotechnical investigation and analysis in support of data utilized in design of structures as defined in the 2018 International Building Code (IBC). Information in support of groundwater and stormwater issues pertinent to the practice of Civil Engineering is included. Observations and recommendations relevant to the earthwork phase of the project are also presented. Revisions in plans or drawings for the proposed development from those enumerated in this report should be brought to the attention of the soils engineer to determine whether changes in the provided recommendations are required. Deviations from noted subsurface conditions, if encountered during construction, should also be brought to the attention of the soils engineer. 1.1 Project Description The proposed development is in the southern portion of the City of Meridian, Ada County, ID, and occupies portions of the E'/2SW'/4 and the W'/2SE'/4 of Section 31, Township 3 North, Range 1 East, Boise Meridian. This project will consist of construction of a residential subdivision with associated streets. The site to be developed is approximately 70 acres in size. Total settlements are limited to 1 inch. Loads of up to 4,000 pounds per lineal foot for wall footings, and column loads of up to 50,000 pounds were assumed for settlement calculations. Retaining walls are not anticipated as part of the project. Atlas has not been informed of the proposed grading plan. 1.2 Authorization Authorization to perform this exploration and analysis was given in the form of a written authorization to proceed from Mr. Zach Meyers of Brighton Development, Inc. to Clinton Wyllie of Atlas Technical Consultants (Atlas), on January 4, 2022. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between Brighton Development, Inc. and Atlas. Our scope of services for the proposed development has been provided in our proposal dated January 4, 2022 and repeated below. 1.3 Scope of Investigation The scope of this investigation included review of geologic literature and existing available geotechnical studies of the area, visual site reconnaissance of the immediate site, subsurface exploration of the site,field and laboratory testing of materials collected, and engineering analysis and evaluation of foundation materials. The scope of work did not include design recommendations specific to individual residences. Atlas No. 13220036g Page 1 1 Copyright©2022 Atlas Technical Consultants Ile 2. SITE DESCRIPTION 2.1 Site Access Access to the site may be gained via Interstate 84 to the Meridian Road exit. Proceed south on Meridian Road approximately 3.25 miles to its intersection with Lake Hazel Road. From this intersection, proceed east on Lake Hazel Road roughly 0.7 mile. The site is located on the north side of Lake Hazel Road. The location is depicted on site maps included in the Appendix. 2.2 Regional Geology The project site is located within the western Snake River Plain of southwestern Idaho and eastern Oregon. The plain is a northwest trending rift basin, about 45 miles wide and 200 miles long, that developed about 14 million years ago (Ma) and has since been occupied sporadically by large inland lakes. Geologic materials found within and along the plain's margins reflect volcanic and fluvial/lacustrine sedimentary processes that have led to an accumulation of approximately 1 to 2 km of interbedded volcanic and sedimentary deposits within the plain. Along the margins of the plain, streams that drained the highlands to the north and south provided coarse to fine-grained sediments eroded from granitic and volcanic rocks, respectively. About 2 million years ago the last of the lakes was drained and since that time fluvial erosion and deposition has dominated the evolution of the landscape. The project site is underlain by "Gravel of Amity Terrace" as mapped by Othberg and Stanford (1993). The Amity terrace is the fifth terrace above the modern Boise River and represents the first level of Quaternary incision by the Boise River. The terrace, which has been correlated with Deer Flat terrace deposits to the west, is modified extensively by erosion and faulting. Where little erosion has taken place the terrace is mantled with loess 1.6-7 feet thick. 2.3 General Site Characteristics The site to be developed is approximately 70 acres in size. Currently, the site consists primarily of agricultural fields and undeveloped land. Livestock enclosures and a barn structure are present in the northeastern portion of the site, which were being demolished at the time of the field investigation. The central portion of the site is bisected by the McBirney Lateral. A small drainage ditch runs along the western property boundary. The surrounding properties consist of residential properties and agricultural land. The site is relatively flat. Vegetation on the site consists of native weeds and grasses. Minor agricultural crop remnants were noted in the farmed portions of the site. Regional drainage is north and west toward the Boise River. Stormwater drainage for the site is achieved by percolation through surficial soils. The site is situated so that it is unlikely that it will receive any drainage from off-site sources. Stormwater drainage collection and retention systems are not in place on the project site but are planned as part of the development. Atlas No. 13220036g Page 12 Copyright©2022 Atlas Technical Consultants Ile 2.4 Regional Site Climatology and Geochemistry According to the Western Regional Climate Center, the average precipitation for the Treasure Valley is on the order of 10 to 12 inches per year, with an annual snowfall of approximately 20 inches and a range from 3 to 49 inches. The monthly mean daily temperatures range from 21°F to 950F, with daily extremes ranging from roughly -250F to 111 OF. Winds are generally from the northwest or southeast with an annual average wind speed of approximately 9 miles per hour (mph) and a maximum of 62 mph. Soils and sediments in the area are primarily derived from siliceous materials and exhibit low electro-chemical potential for corrosion of metals or concretes. Local aggregates are generally appropriate for Portland cement and lime cement mixtures. Surface water, groundwater, and soils in the region typically have pH levels ranging from 7.2 to 8.2. 3. SEISMIC SITE EVALUATION 3.1 Geoseismic Setting Soils on site are classed as Site Class D in accordance with Chapter 20 of the American Society of Civil Engineers (ASCE) publication ASCE/SEI 7-16. Structures constructed on this site should be designed per IBC requirements for such a seismic classification. Our investigation did not reveal hazards resulting from potential earthquake motions including: slope instability, liquefaction, and surface rupture caused by faulting or lateral spreading. Incidence and anticipated acceleration of seismic activity in the area is low. 3.2 Seismic Design Parameter Values The United States Geological Survey National Seismic Hazard Maps (2008), includes a peak ground acceleration map. The map for 2% probability of exceedance in 50 years in the Western United States in standard gravity (g) indicates that a peak ground acceleration of 0.194 is appropriate for the project site based on a Site Class D. The following section provides an assessment of the earthquake-induced earthquake loads for the site based on the Risk-Targeted Maximum Considered Earthquake (MCER). The MCER spectral response acceleration for short periods, SMs, and at 1-second period, SM1, are adjusted for site class effects as required by the 2018 IBC. Design spectral response acceleration parameters as presented in the 2018 IBC are defined as a 5% damped design spectral response acceleration at short periods, SDs, and at 1-second period, SD1• The USGS National Seismic Hazards Mapping Project includes a program that provides values for ground motion at a selected site based on the same data that were used to prepare the USGS ground motion maps. The maps were developed using attenuation relationships for soft rock sites; the source model, assumptions, and empirical relationships used in preparation of the maps are described in Petersen and others (1996). Atlas No. B220036g Page 13 Copyright©2022 Atlas Technical Consultants � N+■ e G7T�� Table 1 — Seismic Design Values Site Class D "Stiff Soil' Ss 0.284 (g) S1 0.104 (g) Fa 1.573 F 2.393 SMs 0.446 SM1 0.248 Sos 0.297 Sol 0.165 4. SOILS EXPLORATION I Exploration and Sampling Procedures Field exploration conducted to determine engineering characteristics of subsurface materials included a reconnaissance of the project site and investigation by test pit. Test pit sites were selected by Mr. Zach Meyers of Brighton Development and staked in the field. Actual test pit sites were located in the field by means of a Global Positioning System (GPS)device and are reportedly accurate to within ten feet. Upon completion of investigation, each test pit was backfilled with loose excavated materials. Re-excavation and compaction of these test pit areas are required prior to construction of overlying structures. In addition, samples were obtained from representative soil strata encountered. Samples obtained have been visually classified in the field by professional staff, identified according to test pit number and depth, placed in sealed containers, and transported to our laboratory for additional testing. Subsurface materials have been described in detail on logs provided in the Appendix. Results of field and laboratory tests are also presented in the Appendix. Atlas recommends that these logs not be used to estimate fill material quantities. $.2 Laboratory Testing Program Along with our field investigation, a supplemental laboratory testing program was conducted to determine additional pertinent engineering characteristics of subsurface materials necessary in an analysis of anticipated behavior of the proposed structures. Laboratory tests were conducted in accordance with current applicable American Society for Testing and Materials (ASTM) specifications, and results of these tests are to be found in the Appendix. The laboratory testing program for this report included: Atterberg Limits Testing — ASTM D4318, Grain Size Analysis — ASTM C117/C136, and Resistance Value (R-value) and Expansion Pressure of Compacted Soils — Idaho T-8. Atlas No. B220036g Page 14 Copyright©2022 Atlas Technical Consultants Ile 4.3 Soil and Sediment Profile The profile below represents a generalized interpretation for the project site. Note that on site soils strata, encountered between test pit locations, may vary from the individual soil profiles presented in the logs, which can be found in the Appendix. The materials encountered during exploration were quite typical for the geologic area mapped as Gravel of the Amity Terrace. Lean clay with sand and gravel fills were encountered at ground surface in test pit 2, and sandy silt fills were observed at ground surface in test pit 6. Fill materials were dark brown to light brown, slightly moist, and medium stiff to stiff, with fine to medium-grained sand and 6-inch minus cobbles. Wood and trash debris were noted within these materials in test pit 6. Native lean clay with sand soils were found beneath fill materials in test pit 2 and at ground surface in the remaining test pits. These soils were dark brown to brown, slightly moist, and soft to very stiff, with fine-grained sand. Plow zones and organics were noted to depths of up to 1.4 feet bgs. Sandy silt soils were encountered beneath fill materials in test pit 6 and underlying lean clay with sand soils. Sandy silts were light brown to gray-brown, dry to slightly moist, and very stiff to hard,with fine to medium-grained sand. Varying degrees of cementation were encountered within this horizon. Silty sand with gravel sediments were found beneath sandy silts in test pits 1 and 2. These sediments were light brown to brown, slightly moist, and medium dense, with fine to coarse-grained sand and fine to coarse gravel. Poorly graded gravel with sand sediments were encountered at depth in the test pits. These sediments were brown to light brown or orange- brown, slightly moist, and dense to very dense, with fine to coarse-grained sand, fine to coarse gravel, and 12-inch minus cobbles. Competency of test pit sidewalls varied little across the site. In general, fine grained soils remained stable while more granular sediments readily sloughed. However, moisture contents will also affect wall competency with saturated soils having a tendency to readily slough when under load and unsupported. 4.4 Volatile Organic Scan No environmental concerns were identified prior to commencement of the investigation. Therefore, soils obtained during on-site activities were not assessed for volatile organic compounds by portable photoionization detector. Samples obtained during our exploration activities exhibited no odors or discoloration typically associated with this type of contamination. No groundwater was encountered. 5. SITE HYDROLOGY Existing surface drainage conditions are defined in the General Site Characteristics section. Information provided in this section is limited to observations made at the time of the investigation. Either regional or local ordinances may require information beyond the scope of this report. Atlas No. B220036g Page 15 Copyright©2022 Atlas Technical Consultants Ile 5.1 Groundwater During this field investigation, groundwater was not encountered in test pits advanced to a maximum depth of 16.2 feet bgs. Soil moistures in the test pits were generally dry to slightly moist throughout. Atlas has previously performed 5 geotechnical investigations within 0.50 mile of the project site. Information from these investigations has been provided in the table below. Table 2 — Groundwater Data DepthApproximate Distance Groundwater Date from Site(mile) Direction from Site (feet bgs) March 2021 0.15 East Not Encountered to 17.1 January 2021 0.17 South Not Encountered to 16.5 February 2020 0.20 Northwest Not Encountered to 14.2 January 2021 0.25 Southeast Not Encountered to 14.6 October 2015 0.42 Northwest Not Encountered to 16.6 Furthermore, according to Idaho Department of Water Resources (IDWR) well Logs within approximately %-mile of the site, groundwater was measured at depths ranging from 50 to 130 feet bgs. For construction purposes, groundwater depth can be assumed to remain greater than 20 feet bgs throughout the year. Since this is an estimated depth and seasonal groundwater levels fluctuate, actual levels should be confirmed by periodic groundwater data collected from piezometers installed in the test pits. If desired, Atlas is available to perform this monitoring. 5.2 Soil Infiltration Rates Soil permeability, which is a measure of the ability of a soil to transmit a fluid, was tested in the field. For this report, an estimation of infiltration is also presented using generally recognized values for each soil type and gradation. Of soils comprising the generalized soil profile for this study, lean clay with sand soils generally offer little permeability, with typical hydraulic infiltration rates of less than 2 inches per hour. Sandy silt soils will commonly exhibit infiltration rates from 2 to 4 inches per hour; though calcium carbonate cementation may reduce this value to near zero. Silty sand with gravel sediments usually display rates of 4 to 8 inches per hour. Poorly graded gravel with sand sediments typically exhibit infiltration values in excess of 12 inches per hour. Atlas No. B220036g Page 16 Copyright©2022 Atlas Technical Consultants 07 �TrT—G7T � i.3 Infiltration Testing Infiltration testing was conducted in general accordance with the Ada County Highway District (ACHD) Policy Manual. Test pit areas will need to be re-excavated and compacted prior to construction of structures that will be sensitive to settlement. Test locations were presoaked prior to testing. Pre-soaking increases soil moistures, which allows the tested soils to reach a saturated condition more readily during testing. Saturation of the tested soils is desirable in order to isolate the vertical component of infiltration by inhibiting horizontal seepage during testing. Details and results of testing are as follows: Table 3— Infiltration Test Results 2 • . Rate TP-1 12.0 Poorly Graded Gravel with Sand >12.0 8.0* TP-2 9.0 Poorly Graded Gravel with Sand >12.0 8.0* TP-3 10.0 Poorly Graded Gravel with Sand >12.0 8.0* TP-4 9.0 Poorly Graded Gravel with Sand >12.0 8.0* TP-5 7.5 Poorly Graded Gravel with Sand >12.0 8.0* TP-6 7.0 Poorly Graded Gravel with Sand >12.0 8.0* TP-7 10.0 Poorly Graded Gravel with Sand >12.0 8.0* TP-8 9.0 Poorly Graded Gravel with Sand >12.0 8.0* *Per the ACHD Policy Manual,the maximum design infiltration rate is 8 inches per hour. Per the ACHD Policy Manual requirements, the maximum design soil infiltration rate shall not exceed 8 inches per hour. Therefore, a design infiltration rate of 8 inches per hour should be used for the poorly graded gravel with sand sediments encountered at depth across the site. It should be confirmed that infiltration facilities are constructed on relatively silt free poorly graded gravel with sand sediments. Atlas recommends that all infiltration facilities be constructed in accordance with the local municipality requirements. FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS Various foundation types have been considered for support of the proposed structures. Two requirements must be met in the design of foundations. First, the applied bearing stress must be less than the ultimate bearing capacity of foundation soils to maintain stability. Second, total and differential settlement must not exceed an amount that will produce an adverse behavior of the superstructure. Allowable settlement is usually exceeded before bearing capacity considerations become important; thus, allowable bearing pressure is normally controlled by settlement considerations. Atlas No. B220036g Page 17 Copyright©2022 Atlas Technical Consultants Considering subsurface conditions and the proposed construction, it is recommended that the structures be founded upon conventional spread footings and continuous wall footings. Total settlements should not exceed 1 inch if the following design and construction recommendations are observed. The following recommendations are not specific to the individual structures, but rather should be viewed as guidelines for the subdivision-wide development. 6.1 Foundation Design Recommendations Based on data obtained from the site and test results from various laboratory tests performed, Atlas recommends the following guidelines for the net allowable soil bearing capacity: Table 4— Soil Bearing Capacity Footing Depth ASTM D1557 Net Allowable Soil Subgrade Compaction Bearing Capacity Footings must bear on competent, undisturbed, native sandy silt soils or compacted structural fill. Not Required for Native Existing fill materials and lean clay with sand soils Soil must be completely removed from below foundation 2,000 Ibs/ft2 elements.' Excavation depths ranging from roughly 95%for Structural Fill 0.8 to 2.6 feet bgs should be anticipated to expose proper bearing soils.2 'It will be required for Atlas personnel to verify the bearing soil suitability for each structure at the time of construction. 2Depending on the time of year construction takes place,the subgrade soils may be unstable because of high moisture contents. If unstable conditions are encountered,over-excavation and replacement with granular structural fill and/or use of geotextiles may be required. The following sliding frictional coefficient values should be used: 1) 0.35 for footings bearing on native sandy silt soils and 2) 0.45 for footings bearing on granular structural fill. A passive lateral earth pressure of 337 pounds per square foot per foot (psf/ft) should be used for sandy silt soils. For compacted sandy gravel fill, a passive lateral earth pressure of 496 psf/ft should be used. Footings should be proportioned to meet either the stated soil bearing capacity or the 2018 IBC minimum requirements. Total settlement should be limited to approximately 1 inch, and differential settlement should be limited to approximately '/2 inch. Objectionable soil types encountered at the bottom of footing excavations should be removed and replaced with structural fill. Excessively loose or soft areas that are encountered in the footings subgrade will require over-excavation and backfilling with structural fill. To minimize the effects of slight differential movement that may occur because of variations in the character of supporting soils and seasonal moisture content, Atlas recommends continuous footings be suitably reinforced to make them as rigid as possible. For frost protection, the bottom of external footings should be 24 inches below finished grade. Atlas No. 13220036g Page 18 Copyright©2022 Atlas Technical Consultants Ile 6.2 Crawl Space Recommendations All residences constructed with crawl spaces should be designed in a manner that will inhibit water in the crawl spaces. Atlas recommends that roof drains carry stormwater at least 10 feet away from each residence. Grades should be at least 5 percent for a distance of 10 feet away from all residences. In addition, rain gutters should be placed around all sides of residences, and backfill around stem walls should be placed and compacted in a controlled manner. 6.3 Floor, Patio, and Garage Slab-on-Grade Uncontrolled fill, which contained debris, was encountered in portions of the site. Atlas recommends that these fill materials be completely removed. Once final grades have been determined, Atlas is available to provide additional recommendations. Plow zones with organic materials were encountered in portions of the site. Atlas recommends that the organic materials be removed. If plow zones remain after organic materials have been removed, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D1557. Atlas personnel must be present during excavation to identify these materials. Native clay soils are moderately plastic and will be susceptible to shrink/swell movements associated with moisture changes. The clay soils (if exposed) should be scarified to a depth of 6 inches and compacted between 92 to 98 percent of the maximum dry density as determined by ASTM D698. The moisture content should be within 2 percent of optimum. Structural fill should be placed as soon as possible after compaction of clay soils in order to limit moisture loss within the upper clays. Ground surfaces should be sloped away from structures at a minimum of 5 percent for a distance of 10 feet to provide positive drainage of surface water away from buildings. Grading must be provided and maintained following construction. Organic, loose, or obviously compressive materials must be removed prior to placement of concrete floors or floor-supporting fill. In addition, the remaining subgrade should be treated in accordance with guidelines presented in the Earthwork section. Areas of excessive yielding should be excavated and backfilled with structural fill. Fill used to increase the elevation of the floor slab should meet requirements detailed in the Structural Fill section. Fill materials must be compacted to a minimum 95 percent of the maximum dry density as determined by ASTM D1557. A free-draining granular mat should be provided below slabs-on-grade to provide drainage and a uniform and stable bearing surface. This should be a minimum of 4 inches in thickness and properly compacted. The mat should consist of a sand and gravel mixture, complying with Idaho Standards for Public Works Construction (ISPWC) specifications for %-inch (Type 1) crushed aggregate. The granular mat should be compacted to no less than 95 percent of the maximum dry density as determined by ASTM D1557. Atlas No. B220036g Page 19 Copyright©2022 Atlas Technical Consultants Ile A moisture-retarder should be placed beneath floor slabs to minimize potential ground moisture effects on moisture-sensitive floor coverings. The moisture-retarder should be at least 15-mil in thickness and have a permeance of less than 0.01 US perms as determined by ASTM E96. Placement of the moisture-retarder will require special consideration with regard to effects on the slab-on-grade and should adhere to recommendations outlined in the ACI 302.1 R and ASTM E1745 publications. Upon request, Atlas can provide further consultation regarding installation. 7. PAVEMENT DISCUSSION AND RECOMMENDATIONS As required by Ada County Highway District (ACHD), Atlas has used traffic indexes of 6 and 8 to determine the necessary pavement cross-sections for the site. Atlas has made assumptions for traffic loading variables based on the character of the proposed construction. The Client should review these assumptions to make sure they reflect intended use and loading of pavements both now and in the future. Atlas collected a sample of near-surface soils for Resistance Value (R- value) testing representative of soils to depths of 0.5 to 1.4 feet below existing ground surface. This sample, consisting of lean clay with sand collected from test pit 7, yielded a R-value of less than 5. A R-value of 4 was used for design calculations. The following are minimum thickness requirements for assured pavement function. Depending on site conditions, additional work, e.g. soil preparation, may be required to support construction equipment. These have been listed within the Soft Subgrade Soils section. Results of the test are graphically depicted in the Appendix. 7.1 Flexible Pavement Sections The Gravel Equivalent Method, as defined in Section 500 of the State of Idaho Department of Transportation (ITD) Materials Manual, was used to develop the pavement sections. ACHD parameters for traffic index and substitution ratios, which were obtained from the ACHD Policy Manual, were also used in the design. Calculation sheets provided in the Appendix indicate the soils constant, traffic loading, traffic projections, and material constants used to calculate the pavement sections. Atlas recommends that materials used in the construction of asphaltic concrete pavements meet the requirements of the ISPWC Standard Specification for Highway Construction. Construction of the pavement section should be in accordance with these specifications and should adhere to guidelines recommended in the section on Construction Considerations. Atlas No. B220036g Page 1 10 Copyright©2022 Atlas Technical Consultants �TrT—G7T�� Table 5— Gravel Equivalent Method Flexible Pavement Specifications RoadsPavement Section Roadway Section —7—oadway Section Roadway Section Component LocalRoads Collector Roads Collector O. (Option Asphaltic Concrete 2.5 Inches 3.0 Inches 3.0 Inches Crushed Aggregate Base 4.0 Inches 6.0 Inches 6.0 Inches Structural Subbase 14.0 Inches 18.0 Inches 18.0 Inches See Pavement See Pavement See Pavement Compacted Subgrade Subgrade Preparation Subgrade Preparation Subgrade Preparation Section Section Section 'It will be required for Atlas personnel to verify subgrade competency at the time of construction. • Asphaltic Concrete: Asphalt mix design shall meet the requirements of ISPWC, Section 810 Class III plant mix. Materials shall be placed in accordance with ISPWC Standard Specifications for Highway Construction. • Aggregate Base: Material complying with ISPWC Standards for Crushed Aggregate Materials. • Structural Subbase: Granular structural fill material complying with the requirements detailed in the Structural Fill section of this report except that the maximum material diameter is no more than 2/3 the component thickness. Gradation and suitability requirements shall be per ISPWC Section 801, Table 1. 7.2 Rigid Pavement Section It is our understanding that concrete alleyways will be included as part of the project. The AASHTO pavement design method was used to develop the following rigid concrete pavement section. Concrete pavement shall be batched and constructed in accordance with the most current American Concrete Institute Standards and in accordance with Idaho Transportation Department Standard Drawings 411-1 and 409-1. Native subgrade soils on the site are frost susceptible, and therefore, do require joint sealers or under-drains. Table 6—AASHTO Rigid Pavement Specifications Pavement Section Component Portland Cement Concrete 5.0 Inches Crushed Aggregate Base 6.0 Inches Structural Subbase Not Required Compacted Subgrade See Pavement Subgrade Preparation Section 'It will be required for Atlas personnel to verify subgrade competency at the time of construction. • Portland Cement Concrete: 4,000 psi concrete with a modulus of rupture greater than 650 psi generally complying with ITD requirement for Urban Concrete. • Aggregate Base: Material complying with ITD Standard Specifications for Highway Construction Sections 303 and 703 for aggregates. Atlas No. 13220036g Page l 11 Copyright©2022 Atlas Technical Consultants • Ile Structural Subbase: Granular structural fill material complying with the requirements detailed in the Structural Fill section of this report except that the maximum material diameter is no more than 2/3 the component thickness. Gradation and suitability requirements shall be per ISPWC Section 801, Table 1. 7.3 Pavement Subgrade Preparation Uncontrolled fill, which contained debris, was encountered in portions of the site. Atlas recommends that these fill materials be completely removed. Once final grades have been determined, Atlas is available to provide additional recommendations. Plow zones with organic materials were encountered in portions of the site. Atlas recommends that the organic materials be removed. If plow zones remain after organic materials have been removed, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D698 for flexible pavements and ASTM D1557 for rigid pavements. Atlas personnel must be present during excavation to identify these materials. Native clay soils are moderately plastic and will be susceptible to shrink/swell movements associated with moisture changes. The clay soils (if exposed) should be scarified to a depth of 6 inches and compacted between 92 to 98 percent of the maximum dry density as determined by ASTM D698. The moisture content should be within 2 percent of optimum. Structural fill should be placed as soon as possible after compaction of clay soils in order to limit moisture loss within the upper clays. 7.4 Common Pavement Section Construction Issues The subgrade upon which above pavement sections are to be constructed must be properly stripped, compacted (if indicated), inspected, and proof-rolled. Proof rolling of subgrade soils should be accomplished using a heavy rubber-tired, fully loaded, tandem-axle dump truck or equivalent. Verification of subgrade competence by Atlas personnel at the time of construction is required. Fill materials on the site must demonstrate the indicated compaction prior to placing material in support of the pavement section. Atlas anticipated that pavement areas will be subjected to moderate traffic. Subgrade clayey and silty soils near and above optimum moisture contents may pump during compaction. Pumping or soft areas must be removed and replaced with structural fill. Fill material and aggregates, as well as compacted native subgrade soils, in support of the pavement section must be compacted to no less than 95 percent of the maximum dry density as determined by ASTM D698 for flexible pavements and by ASTM D1557 for rigid pavements. If a material placed as a pavement section component cannot be tested by usual compaction testing methods, then compaction of that material must be approved by observed proof rolling. Minor deflections from proof rolling for flexible pavements are allowable. Deflections from proof rolling of rigid pavement support courses should not be visually detectable. Atlas No. B220036g Page 1 12 Copyright©2022 Atlas Technical Consultants Ile 8. CONSTRUCTION CONSIDERATIONS Recommendations in this report are based upon structural elements of the project being founded on competent, sandy silt soils or compacted structural fill. Structural areas should be stripped to an elevation that exposes these soil types. 8.1 Earthwork Excessively organic soils, deleterious materials, or disturbed soils generally undergo high volume changes when subjected to loads, which is detrimental to subgrade behavior in the area of pavements, floor slabs, structural fills, and foundations. It is recommended that organic or disturbed soils, if encountered, be removed to depths of 1 foot (minimum), and wasted or stockpiled for later use. However, in areas where trees are/were present, deeper excavation depths should be anticipated. Stripping depths should be adjusted in the field to assure that the entire root zone or disturbed zone (plow depths) or topsoil are removed prior to placement and compaction of structural fill materials. Exact removal depths should be determined during grading operations by Atlas personnel, and should be based upon subgrade soil type, composition, and firmness or soil stability. If underground storage tanks, underground utilities, wells, or septic systems are discovered during construction activities, they must be decommissioned then removed or abandoned in accordance with governing Federal, State, and local agencies. Excavations developed as the result of such removal must be backfilled with structural fill materials as defined in the Structural Fill section. Atlas should oversee subgrade conditions (i.e., moisture content) as well as placement and compaction of new fill (if required) after native soils are excavated to design grade. Recommendations for structural fill presented in this report can be used to minimize volume changes and differential settlements that are detrimental to the behavior of footings, pavements, and floor slabs. Sufficient density tests should be performed to properly monitor compaction. For structural fill beneath building structures, one in-place density test per lift for every 5,000 square feet is recommended. In parking and driveway areas, this can be decreased to one test per lift for every 10,000 square feet. 8.2 Dry Weather If construction is to be conducted during dry seasonal conditions, many problems associated with soft soils may be avoided. However, some rutting of subgrade soils may be induced by shallow groundwater conditions related to springtime runoff or irrigation activities during late summer through early fall. Solutions to problems associated with soft subgrade soils are outlined in the Soft Subgrade Soils section. Problems may also arise because of lack of moisture in native and fill soils at time of placement. This will require the addition of water to achieve near-optimum moisture levels. Low-cohesion soils exposed in excavations may become friable, increasing chances of sloughing or caving. Measures to control excessive dust should be considered as part of the overall health and safety management plan. Atlas No. B220036g Page 1 13 Copyright©2022 Atlas Technical Consultants Ile 8.3 Wet Weather If construction is to be conducted during wet seasonal conditions (commonly from mid-November through May), problems associated with soft soils must be considered as part of the construction plan. During this time of year, fine-grained soils such as silts and clays will become unstable with increased moisture content, and eventually deform or rut. Additionally, constant low temperatures reduce the possibility of drying soils to near optimum conditions. 8.4 Soft Subgrade Soils Shallow fine-grained subgrade soils that are high in moisture content should be expected to pump and rut under construction traffic. During periods of wet weather, construction may become very difficult if not impossible. The following recommendations and options have been included for dealing with soft subgrade conditions: • Track-mounted vehicles should be used to strip the subgrade of root matter and other deleterious debris. Heavy rubber-tired equipment should be prohibited from operating directly on the native subgrade and areas in which structural fill materials have been placed. Construction traffic should be restricted to designated roadways that do not cross, or cross on a limited basis, proposed roadway or parking areas. • Soft areas can be over-excavated and replaced with granular structural fill. • Construction roadways on soft subgrade soils should consist of a minimum 2-foot thickness of large cobbles of 4 to 6 inches in diameter with sufficient sand and fines to fill voids. Construction entrances should consist of a 6-inch thickness of clean, 2-inch minimum, angular drain-rock and must be a minimum of 10 feet wide and 30 to 50 feet long. During the construction process, top dressing of the entrance may be required for maintenance. • Scarification and aeration of subgrade soils can be employed to reduce the moisture content of wet subgrade soils. After stripping is complete, the exposed subgrade should be ripped or disked to a depth of 1'/2 feet and allowed to air dry for 2 to 4 weeks. Further disking should be performed on a weekly basis to aid the aeration process. • Alternative soil stabilization methods include use of geotextiles, lime, and cement stabilization. Atlas is available to provide recommendations and guidelines at your request. 8.5 Frozen Subgrade Soils Prior to placement of structural fill materials or foundation elements, frozen subgrade soils must either be allowed to thaw or be stripped to depths that expose non-frozen soils and wasted or stockpiled for later use. Stockpiled materials must be allowed to thaw and return to near-optimal conditions prior to use as structural fill. Atlas No. B220036g Page 1 14 Copyright©2022 Atlas Technical Consultants Ile The onsite, shallow clayey and silty soils are susceptible to frost heave during freezing temperatures. For exterior flatwork and other structural elements, adequate drainage away from subgrades is critical. Compaction and use of structural fill will also help to mitigate the potential for frost heave. Complete removal of frost susceptible soils for the full frost depth, followed by replacement with a non-frost susceptible structural fill, can also be used to mitigate the potential for frost heave. Atlas is available to provide further guidance/assistance upon request. 8.6 Structural Fill Soils recommended for use as structural fill are those classified as GW, GP, SW, and SP in accordance with the Unified Soil Classification System (USCS) (ASTM D2487). Use of silty soils (USCS designation of GM, SM, and ML) as structural fill may be acceptable. However, use of silty soils (GM. SM, and ML) as structural fill below footings is prohibited. These materials require very high moisture contents for compaction and require a long time to dry out if natural moisture contents are too high and may also be susceptible to frost heave under certain conditions. Therefore, these materials can be quite difficult to work with as moisture content, lift thickness, and compactive effort becomes difficult to control. If silty soil is used for structural fill, lift thicknesses should not exceed 6 inches (loose), and fill material moisture must be closely monitored at both the working elevation and the elevations of materials already placed. Following placement, silty soils must be protected from degradation resulting from construction traffic or subsequent construction. Recommended granular structural fill materials, those classified as GW, GP, SW, and SP, should consist of a 6-inch minus select, clean, granular soil with no more than 50 percent oversize (greater than %-inch) material and no more than 12 percent fines (passing No. 200 sieve). These fill materials should be placed in layers not to exceed 12 inches in loose thickness. Prior to placement of structural fill materials, surfaces must be prepared as outlined in the Construction Considerations section. Structural fill material should be moisture-conditioned to achieve optimum moisture content prior to compaction. For structural fill below footings, areas of compacted backfill must extend outside the perimeter of the footings for a distance equal to the thickness of fill between the bottom of foundation and underlying soils, or 5 feet, whichever is less. All fill materials must be monitored during placement and tested to confirm compaction requirements, outlined below, have been achieved. Each layer of structural fill must be compacted, as outlined below: • Below Structures and Rigid Pavements: A minimum of 95 percent of the maximum dry density as determined by ASTM D1557. • Below Flexible Pavements: A minimum of 92 percent of the maximum dry density as determined by ASTM D1557 or 95 percent of the maximum dry density as determined by ASTM D698. Atlas No. 13220036g Page 1 15 Copyright©2022 Atlas Technical Consultants Ile The ASTM D1557 test method must be used for samples containing up to 40 percent oversize (greater than 3/4-inch) particles. If material contains more than 40 percent but less than 50 percent oversize particles, compaction of fill must be confirmed by proof rolling each lift with a 10-ton vibratory roller(or equivalent) until the maximum density has been achieved. Density testing must be performed after each proof rolling pass until the in-place density test results indicate a drop (or no increase) in the dry density, defined as maximum density or "break over" point. The number of required passes should be used as the requirements on the remainder of fill placement. Material should contain sufficient fines to fill void spaces, and must not contain more than 50 percent oversize particles. 8.7 Backfill of Walls Backfill materials must conform to the requirements of structural fill, as defined in this report. For wall heights greater than 2.5 feet, the maximum material size should not exceed 4 inches in diameter. Placing oversized material against rigid surfaces interferes with proper compaction, and can induce excessive point loads on walls. Backfill shall not commence until the wall has gained sufficient strength to resist placement and compaction forces. Further, retaining walls above 2.5 feet in height shall be backfilled in a manner that will limit the potential for damage from compaction methods and/or equipment. It is recommended that only small hand-operated compaction equipment be used for compaction of backfill within a horizontal distance equal to the height of the wall, measured from the back face of the wall. Backfill should be compacted in accordance with the specifications for structural fill, except in those areas where it is determined that future settlement is not a concern, such as planter areas. In nonstructural areas, backfill must be compacted to a firm and unyielding condition. 8.8 Excavations Shallow excavations that do not exceed 4 feet in depth may be constructed with side slopes approaching vertical. Below this depth, it is recommended that slopes be constructed in accordance with Occupational Safety and Health Administration (OSHA) regulations, Section 1926, Subpart P. Based on these regulations, on-site soils are classified as type "C" soil, and as such, excavations within these soils should be constructed at a maximum slope of 1'/2 feet horizontal to 1 foot vertical (11/2:1) for excavations up to 20 feet in height. Excavations in excess of 20 feet will require additional analysis. Note that these slope angles are considered stable for short-term conditions only, and will not be stable for long-term conditions. During the subsurface exploration, test pit sidewalls generally exhibited little indication of collapse; however, sloughing of native granular sediments from test pit sidewalls was observed. For deep excavations, native granular sediments cannot be expected to remain in position. These materials are prone to failure and may collapse, thereby undermining upper soil layers. This is especially true when excavations approach depths near the water table. Care must be taken to ensure that excavations are properly backfilled in accordance with procedures outlined in this report. Atlas No. 13220036g Page 1 16 Copyright©2022 Atlas Technical Consultants Ile 8.9 Groundwater Control Groundwater was not encountered during the investigation and is anticipated to be below the depth of most construction. Special precautions may be required for control of surface runoff and subsurface seepage. It is recommended that runoff be directed away from open excavations. Silty and clayey soils may become soft and pump if subjected to excessive traffic during time of surface runoff. Ponded water in construction areas should be drained through methods such as trenching, sloping, crowning grades, nightly smooth drum rolling, or installing a French drain system. Additionally, temporary or permanent driveway sections should be constructed if extended wet weather is forecasted. GENERAL COMMENTS Based on the subsurface conditions encountered during this investigation and available information regarding the proposed development, the site is adequate for the planned construction. When plans and specifications are complete, and if significant changes are made in the character or location of the proposed development, consultation with Atlas must be arranged as supplementary recommendations may be required. Suitability of subgrade soils and compaction of structural fill materials must be verified by Atlas personnel prior to placement of structural elements. Additionally, monitoring and testing should be performed to verify that suitable materials are used for structural fill and that proper placement and compaction techniques are utilized. Atlas No. 13220036g Page 1 17 Copyright©2022 Atlas Technical Consultants 10. REFERENCES Ada County Highway District (ACHD) (2017). Ada County Highway District Policy Manual (August 2017). [Online] Available: <http://www.achdidaho.org/AboutACHD/PolicyManual.aspx> (2021). American Concrete Institute (ACI) (2015). Guide for Concrete Floor and Slab Construction: ACI 302.1R. Farmington Hills, MI: ACI. American Society of Civil Engineers (2021). ASCE 7 Hazards Tool: Web Interface [Online] Available: <https:Hasce7hazardtool.online/> (2021). American Society of Civil Engineers (ASCE) (2013). Minimum Design Loads for Buildings and Other Structures: ASCE/SEI 7-16. Reston, VA: ASCE. American Society for Testing and Materials (ASTM) (2017). Standard Test Method for Materials Finer than 75-pm (No. 200) Sieve in Mineral Aggregates by Washing: ASTM C117.West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2014). Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates: ASTM C136. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2012). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort: ASTM D698. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2012). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort: ASTM D1557. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2013). Standard Test Methods for Resistance Value (R-Value) and Expansion Pressure of Compacted Soils: ASTM D2844. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2017). Standard Practice for Classification of Soils for Engineering Purposes(Unified Soil Classification System):ASTM D2487.West Conshohocken, PA:ASTM. American Society for Testing and Materials (ASTM) (2017). Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils: ASTM D4318. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2011). Standard Specification for Plastic Water Vapor Retarders Used in Contact with Soil or Granular Fill Under Concrete Slabs: ASTM E1745. West Conshohocken, PA: ASTM. Desert Research Institute.Western Regional Climate Center. [Online]Available: <http://www.wrcc.dri.edu/> (2021). Idaho Department of Water Resources. [Online] Well Construction & Drilling, Find a Well Mapping Tool. <http://www.idwr.idaho.gov/wells/find-a-well.html> (2021). Idaho Transportation Department (ITD) (2019). Idaho Transportation Department Materials Manual, 2019. Boise, ID: Author. Idaho Transportation Department (ITD) (2018). Idaho Transportation Department Standard Specifications for Highway Construction, 2018. Boise, ID: Author. Atlas No. B220036g Page 1 18 Copyright©2022 Atlas Technical Consultants International Building Code Council (2018). International Building Code, 2018. Country Club Hills, IL: Author. Local Highway Technical Assistance Council (LHTAC) (2017). Idaho Standards for Public Works Construction, 2017. Boise, ID: Author. Othberg, K. L. and Stanford, L. A., Idaho Geologic Society (1993). Geologic Map of the Boise Valley and Adjoining Area, Western Snake River Plain, Idaho. (scale 1:100,000). Boise, ID: Joslyn and Morris. U.S. Department of Labor, Occupational Safety and Health Administration. CFR 29, Part 1926, Subpart P: Safety and Health Regulations for Construction. Excavations (1986). [Online] Available: <www.osha.gov> (2021). Atlas No. B220036g Page 1 19 Copyright©2022 Atlas Technical Consultants Ile Appendix I WARRANTY AND LIMITING CONDITIONS Atlas warrants that findings and conclusions contained herein have been formulated in accordance with generally accepted professional engineering practice in the fields of foundation engineering, soil mechanics, and engineering geology only for the site and project described in this report. These engineering methods have been developed to provide the client with information regarding apparent or potential engineering conditions relating to the site within the scope cited above and are necessarily limited to conditions observed at the time of the site visit and research. Field observations and research reported herein are considered sufficient in detail and scope to form a reasonable basis for the purposes cited above. Exclusive Use This report was prepared for exclusive use of the property owner(s), at the time of the report, and their retained design consultants ("Client"). Conclusions and recommendations presented in this report are based on the agreed-upon scope of work outlined in this report together with the Contract for Professional Services between the Client and Atlas Technical Consultants ("Consultant'). Use or misuse of this report, or reliance upon findings hereof, by parties other than the Client is at their own risk. Neither Client nor Consultant make representation of warranty to such other parties as to accuracy or completeness of this report or suitability of its use by such other parties for purposes whatsoever, known or unknown, to Client or Consultant. Neither Client nor Consultant shall have liability to indemnify or hold harmless third parties for losses incurred by actual or purported use or misuse of this report. No other warranties are implied or expressed. Report Recommendations are Limited and Subject to Misinterpretation There is a distinct possibility that conditions may exist that could not be identified within the scope of the investigation or that were not apparent during our site investigation. Findings of this report are limited to data collected from noted explorations advanced and do not account for unidentified fill zones, unsuitable soil types or conditions, and variability in soil moisture and groundwater conditions. To avoid possible misinterpretations of findings, conclusions, and implications of this report, Atlas should be retained to explain the report contents to other design professionals as well as construction professionals. Since actual subsurface conditions on the site can only be verified by earthwork, note that construction recommendations are based on general assumptions from selective observations and selective field exploratory sampling. Upon commencement of construction, such conditions may be identified that require corrective actions, and these required corrective actions may impact the project budget. Therefore, construction recommendations in this report should be considered preliminary, and Atlas should be retained to observe actual subsurface conditions during earthwork construction activities to provide additional construction recommendations as needed. Since geotechnical reports are subject to misinterpretation, do not separate the soil logs from the report. Rather, provide a copy of, or authorize for their use, the complete report to other design Atlas No. B220036g Page 120 Copyright©2022 Atlas Technical Consultants Ile professionals or contractors. Locations of exploratory sites referenced within this report should be considered approximate locations only. For more accurate locations, services of a professional land surveyor are recommended. This report is also limited to information available at the time it was prepared. In the event additional information is provided to Atlas following publication of our report, it will be forwarded to the client for evaluation in the form received. Environmental Concerns Comments in this report concerning either onsite conditions or observations, including soil appearances and odors, are provided as general information. These comments are not intended to describe, quantify, or evaluate environmental concerns or situations. Since personnel, skills, procedures, standards, and equipment differ, a geotechnical investigation report is not intended to substitute for a geoenvironmental investigation or a Phase II/III Environmental Site Assessment. If environmental services are needed, Atlas can provide, via a separate contract, those personnel who are trained to investigate and delineate soil and water contamination. 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I Az I I I Y � �TrT—G7T�� Appendix IV GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-1 Latitude: 43.548087 Date Advanced: January 17, 2022 Longitude: -116.382583 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 15.0 feet bgs Field Description Find USCS S i Sample Sample Depth a e . . . Sediment • • bgs) T ej Lean Clay with Sand (CL): Brown, slightly 0.0-1.4 moist, soft, with fine-grained sand. 0.5 --Organics noted to 1.0 foot bgs. Sandy Silt (ML): Light brown, dry to slightly 1.4-5.0 moist, hard, with fine to medium-grained sand. --Weak to moderate cementation encountered throughout. Silty Sand with Gravel (SM): Brown to light 5.0-8.8 brown, slightly moist, medium dense, with fine to coarse-grained sand and fine to coarse gravel. Poorly Graded Gravel with Sand (GP): Brown 8.8-15.0 to light brown, slightly moist, dense to very dense, with fine to coarse-grained sand, fine to coarse gravel, and 8-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.0 feet bgs. Infiltration testing conducted at a depth of 12.0 feet bgs. Atlas No. 13220036g Page 124 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-2 Latitude: 43.549238 Date Advanced: January 17, 2022 Longitude: -116.383986 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 15.0 feet bgs Depth Field Description and USCS Soil and Sample Sample Depth Qp Lab . • • bgs) Test ID Lean Clay with Sand(CL): Dark brown, slightly 0.0-1.7 moist, very stiff, with fine-grained sand. 3.0-3.5 --Plow zone and organics noted to 1.0 foot bgs. Sandy Silt (ML): Light brown, dry to slightly 1.7-4.0 moist, hard,with fine to medium-grained sand. --Strong cementation encountered throughout. Silty Sand with Gravel (SM): Brown, slightly 4.0-6.5 moist, medium dense, with fine to coarse- GS 5.5-6.5 A grained sand and fine to coarse gravel. --Intermittent clay content noted throughout. Poorly Graded Gravel with Sand (GP): Brown 6.5-15.0 to light brown, slightly moist, dense to very dense, with fine to coarse-grained sand, fine to coarse gravel, and 8-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.0 feet bgs. Infiltration testing conducted at a depth of 9.0 feet bgs. Lab Test ID Moisture LL P11 Sieve Analysis (% Passing) I #40 #100 #200 !7A 17.6 N P N P 79 73 58 49 38.1 Atlas No. B220036g Page 125 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-3 Latitude: 43.551971 Date Advanced: January 17, 2022 Longitude: -116.385322 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 14.5 feet bgs Depth Field Description and USCS Soil and Sample Sample Depth Qp Lab . • • bgs) Test ID Lean Clay with Sand and Gravel Fill(CL-FILL): Dark brown, slightly moist, stiff, with fine to 0.0-0.5 medium-grained sand and 6-inch minus 1.5 cobbles. --Organics noted throughout. Lean Clay with Sand(CL): Dark brown, slightly 0.5-1.2 moist, stiff to very stiff, with fine-grained sand. --Plow zone and organics noted throughout. Sandy Silt (ML): Gray-brown to light brown, 1.2-5.9 dry to slightly moist, very stiff to hard, with fine to medium-grained sand. --Weak cementation encountered throughout. Poorly Graded Gravel with Sand (GP): Brown to light brown, slightly moist, dense to very 5.9-14.5 dense, with fine to coarse-grained sand, fine to coarse gravel, and 8-inch minus cobbles. --Some silt content noted from 5.9 to 8.0 feet bgs. Notes:See Site Map for test pit location. Piezometer installed to a depth of 14.5 feet bgs. Infiltration testing conducted at a depth of 10.0 feet bgs. Atlas No. B220036g Page 126 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-4 Latitude: 43.553737 Date Advanced: January 17, 2022 Longitude: -116.384352 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 15.3 feet bgs Depth Field Description and USCS Soil and Sample Sample Depth Qp Lab . • . bgs) Test ID Lean Clay with Sand (CL): Brown, slightly moist, stiff to very stiff, with fine-grained sand. 0.0-2.6 --Plow zone and organics noted to 1.0 foot 2.0-2.5 bgs. Sandy Silt (ML): Light brown, dry to slightly 2.6-4.5 moist, hard,with fine to medium-grained sand. --Strong cementation encountered throughout. Poorly Graded Gravel with Sand (GP): Brown 4.5-15.3 to light brown, slightly moist, dense to very dense, with fine to coarse-grained sand, fine to coarse gravel, and 8-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.3 feet bgs. Infiltration testing conducted at a depth of 9.0 feet bgs. Atlas No. B220036g Page 127 Copyright©2022 Atlas Technical Consultants /�—" ■ �TrT M0 7T��. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-5 Latitude: 43.551676 Date Advanced: January 17, 2022 Longitude: -116.382984 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 14.8 feet bgs jL ■epth ield Description and USCS Soiland Sample�Sample Depth ••s) Sediment Classification . bgs) NEEL— Lean Clay with Sand (CL): Dark brown, slightly 0.0-0.8 moist, stiff to very stiff, with fine-grained sand. 1.5-2.5 --Plow zone and organics noted throughout. Sandy Silt (ML): Light brown, dry to slightly 0.8-5.8 moist, hard, with fine to medium-grained sand. --Strong cementation encountered throughout. Poorly Graded Gravel with Sand (GP): Brown 5.8-14.8 to light brown, slightly moist, dense to very dense, with fine to coarse-grained sand, fine to coarse gravel, and 12-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 14.8 feet bgs. Infiltration testing conducted at a depth of 7.5 feet bgs. Atlas No. B220036g Page 128 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-6 Latitude: 43.551196 Date Advanced: January 17, 2022 Longitude: -116.379352 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 16.2 feet bgs Depth Field Description and USCS Soil and Sample Sample Depth e . Lab . • • bgs) Test ID Sandy Silt Fill (ML-FILL): Light brown, slightly 0.0-1.0 moist, medium stiff to stiff, with fine-grained 1.0-1.5 sand. --Wood and trash debris noted throughout. 1.0-2.9 Sandy Silt (ML): Light brown, slightly moist, very stiff, with fine-grained sand. Poorly Graded Gravel with Sand (GP): Light brown to orange-brown, slightly moist, dense 2.9-16.2 to very dense, with fine to coarse-grained sand,fine to coarse gravel, and 12-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 16.2 feet bgs. Infiltration testing conducted at a depth of 7.0 feet bgs. Atlas No. B220036g Page 129 Copyright©2022 Atlas Technical Consultants �Tr M0 7T � GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-7 Latitude: 43.549144 Date Advanced: January 17, 2022 Longitude: -116.379957 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 14.3 feet bgs �06epth ield Description and USCS Soiland Sample Sample Depth ••s) Sediment Classification . •• JLjL_ — ir Lean Clay with Sand (CL): Brown, slightly B 0.0-1.4 moist, stiff, with fine-grained sand. Bulk 0.5-1.4 1.5 R-value --Plow zone and organics noted throughout. Sandy Silt (ML): Light brown, dry to slightly 1.4-6.2 moist, hard, with fine-grained sand. --Moderate cementation encountered from 1.4 to 4.4 feet bgs. Poorly Graded Gravel with Sand (GP): Light 6.2-14.3 brown, slightly moist, dense to very dense, with fine to coarse-grained sand,fine to coarse gravel, and 12-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 14.3 feet bgs. Infiltration testing conducted at a depth of 10.0 feet bgs. A 26.9 44 21 98 97 94 90 82.4 Atlas No. B220036g Page 130 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-8 Latitude: 43.550007 Date Advanced: January 17, 2022 Longitude: -116.381574 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 13.2 feet bgs Depth Field Description and USCS Soil and Sample Sample Depth e . Lab . • • bgs) Test ID Lean Clay with Sand(CL): Dark brown, slightly 0.0-1.3 moist, medium stiff to stiff, with fine-grained 1.0-1.5 sand. --Plow zone and organics noted throughout. Sandy Silt (ML): Light brown, dry to slightly 1.3-6.0 moist, hard, with fine-grained sand. --Weak to moderate cementation encountered throughout. Poorly Graded Gravel with Sand (GP): Light 6.0-13.2 brown, slightly moist, dense to very dense, with fine to coarse-grained sand,fine to coarse gravel, and 12-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 13.2 feet bgs. Infiltration testing conducted at a depth of 9.0 feet bgs. Atlas No. 13220036g Page 131 Copyright©2022 Atlas Technical Consultants �TrT—G7T�� Appendix V GEOTECHNICAL GENERAL NOTES Unified Soil Classification System Major Divisions Symbol Soil Descriptions Gravel & GW Well-graded ravels; ravel/sand mixtures with little or no fines Coarse- Gravelly Soils GP Poorly-graded ravels; ravel/sand mixtures with little or no fines Grained < 50% GM Silty gravels; poorly-graded ravel/sand/silt mixtures Soils < coarse GC Clayey gravels; poorly-graded gravel/sand/clay mixtures 50% Sand & Sandy SW Well-graded sands; gravelly sands with little or no fines passes Soils > 50% SP Poorly-graded sands; gravelly sands with little or no fines No.200 coarse SM Silty sands; poorly-graded sand/gravel/silt mixtures sieve fraction SC Clayey sands; poorly-graded sand/gravel/clay mixtures Fine- ML Inorganic silts; sandy, gravellyor clayey silts Grained Silts &Clays CL Lean clays; inorganic, gravelly, sandy, or silty, low to medium- Soils > LL < 50 plasticity clays 50% OL Organic, low-plasticity clays and silts passes MH Inorganic, elastic silts; sand gravellyor clayey elastic silts No.200 Silts & Clays CH Fat clays; high-plasticity, inorganic clays sieve LL > 50 OH Organic, medium to high-plasticity clays and silts Highly Organic Soils PT Peat, humus, h dric soils with high organic content L Relative Density and Consistency isture Content • Cementation • '�— Classification Coarse-Grained Soils SPT Blow Counts (N) Description Field Test Very Loose: < 4 Dry Absence of moisture, dry to touch Loose: 4-10 Slightly Moist Damp, but no visible moisture Medium Dense: 10-30 Moist Visible moisture Dense: 30-50 Wet Visible free water Very Dense: > 50 Saturated Soil is usually below water table Fine-Grained Soils SPT Blow Counts N Description Field Test Very Soft: <2 Weak Crumbles or breaks with handling or Soft: 2-4 slight finger pressure Medium Stiff: 4-8 Moderate Crumbles or breaks with Stiff: 8-15 considerable finger pressure Very Stiff: 15-30 Strong Will not crumble or break with finger Hard: > 30 pressure Boulders: > 12 in. 7Liquid ab sample Cobbles: 12 to 3 in. Limit Gravel: 3 in. to 5 mm oisture content Coarse-Grained Sand: 5 to 0.6 mm NP non-plastic Medium-Grained Sand: 0.6 to 0.2 mm PI Plasticity Index Fine-Grained Sand: 0.2 to 0.075 mm QP penetrometer value, unconfined compressive Silts: 0.075 to 0.005 mm strength, tsf Clays: < 0.005 mm V vane value, ultimate shearing strength, tsf Atlas No. B220036g Page 132 Copyright©2022 Atlas Technical Consultants Ile Appendix VI GRAVEL EQUIVALENT METHOD PAVEMENT DESIGN Pavement Section Design Location: Apex West Subdivision, Local Roads Average Daily Traffic Count: All Lanes &Both Directions Design Life: 20 Years Traffic Index: 6.00 Climate Factor: 1 R-Value of Subgrade: 4.00 Subgrade CBRValue: 2.25 Subgrade Mr: 3,375 R-Value of Aggregate Base: 80 R-Value of Granular Borrow: 60 Subgrade R-Value: 4 Expansion Pressure of Subgrade: 1.40 Unit Weight of Base Materials: 130 Total Design Life 18 kip ESAL's: 33,131 ASPHALTIC CONCRETE: Gravel Equivalent,Calculated: 0.384 Thickness: 0.1969231 Use = 2.5 Inches Gravel Equivalent,ACTUAL: 0.41 CRUSHED AGGREGATE BASE: Gravel Equivalent(Ballast): 0.768 Thickness: 0.329 Use = 4 Inches Gravel Equivalent,ACTUAL: 0.773 SUBBASE: Gravel Equivalent(Ballast): 1.843 Thickness: 1.070 Use = 14 Inches Gravel Equivalent,ACTUAL: 1.940 TOTAL Thickness: 1.708 Thickness Required by Exp. Pressure: 1.551 Design ACHD Depth Substitution Inches Ratios Asphaltic Concrete (at least 2.5): 2.50 1.95 Asphalt Treated Base (at least 4.2): 0.00 Cement Treated Base (at least 4.2): 0.00 Crushed Aggregate Base (at least 4.2): 4.00 1.10 Subbase (at least 4.2): 14.00 1.00 Atlas No. B220036g Page 133 Copyright©2022 Atlas Technical Consultants Ile GRAVEL EQUIVALENT METHOD PAVEMENT DESIGN Pavement Section Design Location: Apex West Subdivision,Collector Roads(Option 1) Average Daily Traffic Count: All Lanes&Both Directions Design Life: 20 Years Traffic Index: 8.00 Climate Factor: 1 R-Value of Subgrade: 4.00 Subgrade CBR Value: 2.25 Subgrade Mr: 3,375 R-Value of Aggregate Base: 80 R-Value of Granular Borrow: 60 Subgrade R-Value: 4 Expansion Pressure of Subgrade: 1.40 Unit Weight of Base Materials: 130 Total Design Life 18 kip ESAL's: 371,659 ASPHALTIC CONCRETE: Gravel Equivalent,Calculated: 0.512 Thickness: 0.2625641 Use= 3 Inches Gravel Equivalent,ACTUAL: 0.49 CRUSHED AGGREGATE BASE: Gravel Equivalent(Ballast): 1.024 Thickness: 0.488 Use= 4 Inches Gravel Equivalent,ACTUAL: 0.854 SUBBASE: Gravel Equivalent(Ballast): 2.458 Thickness: 1.603 Use= 20 Inches Gravel Equivalent,ACTUAL: 2.521 TOTAL Thickness: 2.250 Thickness Required by Exp.Pressure: 1.551 Design ACHD Depth Substitution Inches Ratios Asphaltic Concrete(at least 2.5): 3.00 1.95 Asphalt Treated Base(at least 4.2): 0.00 Cement Treated Base(at least 4.2): 0.00 Crushed Aggregate Base(at least 4.2): 4.00 1.10 Subbase(at least 4.2): 20.00 1.00 Atlas No. 13220036g Page 134 Copyright©2022 Atlas Technical Consultants Ile GRAVEL EQUIVALENT METHOD PAVEMENT DESIGN Pavement Section Design Location: Apex West Subdivision, Collector Roads(Option 2) Average Daily Traffic Count: All Lanes&Both Directions Design Life: 20 Years Traffic Index: 8.00 Climate Factor: 1 R-Value of Subgrade: 4.00 Subgrade CBR Value: 2.25 Subgrade Mr: 3,375 R-Value of Aggregate Base: 80 R-Value of Granular Borrow: 60 Subgrade R-Value: 4 Expansion Pressure of Subgrade: 1.40 Unit Weight of Base Materials: 130 Total Design Life 18 kip ESAL's: 371,659 ASPHALTIC CONCRETE: Gravel Equivalent,Calculated: 0.512 Thickness: 0.2625641 Use= 3 Inches Gravel Equivalent,ACTUAL: 0.49 CRUSHED AGGREGATE BASE: Gravel Equivalent(Ballast): 1.024 Thickness: 0.488 Use= 6 Inches Gravel Equivalent,ACTUAL: 1.038 SUBBASE: Gravel Equivalent(Ballast): 2.458 Thickness: 1.420 Use= 18 Inches Gravel Equivalent,ACTUAL: 2.538 TOTAL Thickness: 2.250 Thickness Required by Exp. Pressure: 1.551 Design ACHD Depth Substitution Inches Ratios Asphaltic Concrete(at least 2.5): 3.00 1.95 Asphalt Treated Base(at least 4.2): 0.00 Cement Treated Base(at least 4.2): 0.00 Crushed Aggregate Base(at least 4.2): 6.00 1.10 Subbase(at least 4.2): 18.00 1.00 Atlas No. 13220036g Page 135 Copyright©2022 Atlas Technical Consultants Appendix VII AASHTO RIGID PAVEMENT DESIGN Pavement Section Design Location: Apex West Subdivision, Concrete Alleyways Average Daily Traffic Count: 100 All Lanes &Both Directions Design Life: 20 Years %of Traffic in Design Lane: 50% Terminal Seviceability Index, Pt: 2 Level of Reliability, R: 95 R-Value: 4 Subgrade CBRValue: 2.25 Subgrade Mr: 3,375 Native Modulus of Subgrade Reaction, K: 100 fective Modulus of Subgrade Reaction, K: 180 Concrete Elastic Modulus, Ec: 4200000 Modulus of Rupture, S'c: 650 Load Transfer Coefficient, J: 4.2 Drainage Coefficient, Cd: 1 Standard Deviation, So: 0.34 Design Serviceability Loss, Delta PSI: 2.5 Calculation of Design 18 kip ESALs Daily Growth Load Design Traffic Rate Factors ESAL's Passenger Cars: 32 2.0% 0.0008 227 Buses: 0 2.0% 0.6806 0 Panel& Pickup Trucks: 15 2.0% 0.0122 1,623 2 Axle, 6 Tire Trucks: 2 2.0% 0.1890 3,352 Concrete Trucks: 1 2.0% 4.4800 39,731 Dump Trucks: 0 2.0% 3.6300 0 Tractor Semi Trailer Trucks: 0 2.0% 2.3719 0 Double Trailer Trucks 0 2.0% 2.3187 0 Heavy Tractor Trailer Combo Trucks: 0 2.0% 2.9760 0 Average Daily Traffic in Design Lane: 50 Total Design Life 18 kip ESAL's: 44,933 Traffic Index equivalent= 6.2 Actual Log (ESAL's): 4.653 rial Pavement Design Thickness, inches: 5.00 Trial Log (ESAL's): 4.844 Pavement Design Thickness, Inches: 5.0 Road Mix Section Thickness, Inches:1 6.0 Atlas No. B220036g Page 136 Copyright©2022 Atlas Technical Consultants Ile Appendix VIII R-VALUE LABORATORY TEST DATA Source and Description: TP-7: 0.5'-1.4', Lean Clay with Sand Date Obtained: January 17, 2021 Sample ID: 22-0042 Sampling and Preparation: ASTM D75: AASHTO T2: X ASTM AASHTO X D421: T87: Test Standard: ASTM AASHTO Idaho T8: X D2844: T190: Sample A B C Dry Density Ib/ft3 NA NA NA Moisture Content % NA NA NA Expansion Pressure (psi) NA NA NA Exudation Pressure (psi) NA NA NA R-Value NA NA NA R-Value @ 200 psi Exudation Pressure = Less than 5** ** ASTM D2844 Note 2: Occasionally, material from very plastic clay-test specimens will extrude from under the mold and around the follower ram during the loading operation. If this occurs when the 800-psi point is reached and fewer than five lights are lighted, the soil should be reported as less than 5 R-value. Atlas No. 13220036g Page 137 Copyright©2022 Atlas Technical Consultants Impoplant Infopmation ahoul Geolechnical-Engineeping SubWhile . . . following . . . . . _ . .cost overruns, claims, and help. The Geoprofessional Business Association (GBA) will not likely meet the needs of a civil-works constructor or even a has prepared this advisory to help you—assumedly different civil engineer.Because each geotechnical-engineering study a client representative—interpret and apply this is unique,each geotechnical-engineering report is unique,prepared geotechnical-engineering report as effectively as solely for the client. possible. In that way, you can benefit from a lowered Likewise,geotechnical-engineering services are performed for a specific exposure to problems associated with subsurface project and purpose.For example,it is unlikely that a geotechnical- conditions at project sites and development of engineering study for a refrigerated warehouse will be the same as them that,for decades, have been a principal cause one prepared for a parking garage;and a few borings drilled during of construction delays, cost overruns, claims, a preliminary study to evaluate site feasibility will not be adequate to and disputes. If you have questions or want more develop geotechnical design recommendations for the project. information about any of the issues discussed herein, contact your GBA-member geotechnical engineer. Do not rely on this report if your geotechnical engineer prepared it: Active engagement in GBA exposes geotechnical • for a different client; engineers to a wide array of risk-confrontation • for a different project or purpose; techniques that can be Of genuine benefit for • for a different site(that may or may not include all or a portion of everyone involved with a construction project. the original site);or before important events occurred at the site or adjacent to it; e.g.,man-made events like construction or environmental Understand the Geotechnical-Engineering Services remediation,or natural events like floods,droughts,earthquakes, Provided for this Report or groundwater fluctuations. Geotechnical-engineering services typically include the planning, collection,interpretation,and analysis of exploratory data from Note,too,the reliability of a geotechnical-engineering report can widely spaced borings and/or test pits.Field data are combined be affected by the passage of time,because of factors like changed with results from laboratory tests of soil and rock samples obtained subsurface conditions;new or modified codes,standards,or from field exploration(if applicable),observations made during site regulations;or new techniques or tools.If you are the least bit uncertain reconnaissance,and historical information to form one or more models about the continued reliability of this report,contact your geotechnical of the expected subsurface conditions beneath the site.Local geology engineer before applying the recommendations in it.A minor amount and alterations of the site surface and subsurface by previous and of additional testing or analysis after the passage of time-if any is proposed construction are also important considerations.Geotechnical required at all-could prevent major problems. engineers apply their engineering training,experience,and judgment to adapt the requirements of the prospective project to the subsurface Read this Report in Full model(s). Estimates are made of the subsurface conditions that Costly problems have occurred because those relying on a geotechnical- will likely be exposed during construction as well as the expected engineering report did not read the report in its entirety.Do not rely on performance of foundations and other structures being planned and/or an executive summary.Do not read selective elements only.Read and affected by construction activities. refer to the report in full. The culmination of these geotechnical-engineering services is typically a You Need to Inform Your Geotechnical Engineer geotechnical-engineering report providing the data obtained,a discussion About Change of the subsurface model(s),the engineering and geologic engineering Your geotechnical engineer considered unique,project-specific factors assessments and analyses made,and the recommendations developed when developing the scope of study behind this report and developing to satisfy the given requirements of the project.These reports maybe the confirmation-dependent recommendations the report conveys. titled investigations,explorations,studies,assessments,or evaluations. Typical changes that could erode the reliability of this report include Regardless of the title used,the geotechnical-engineering report is an those that affect: engineering interpretation of the subsurface conditions within the context . the site's size or shape; of the project and does not represent a close examination,systematic . the elevation,configuration,location,orientation, inquiry,or thorough investigation of all site and subsurface conditions. function or weight of the proposed structure and Geotechnical-Engineering Services are Performed the desired performance criteria; for Specific Purposes, Persons, and Projects, • the composition of the design team;or and At Specific Times project ownership. Geotechnical engineers structure their services to meet the specific As a general rule,always inform your geotechnical engineer of project needs,goals,and risk management preferences of their clients.A or site changes-even minor ones-and request an assessment of their geotechnical-engineering study conducted for a given civil engineer impact.The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical conspicuously that you've included the material for information purposes engineer was not informed about developments the engineer otherwise only.To avoid misunderstanding,you may also want to note that would have considered. "informational purposes"means constructors have no right to rely on the interpretations,opinions,conclusions,or recommendations in the Most of the "Findings" Related in This Report report.Be certain that constructors know they may learn about specific Are Professional Opinions project requirements,including options selected from the report,only Before construction begins,geotechnical engineers explore a site's from the design drawings and specifications.Remind constructors subsurface using various sampling and testing procedures.Geotechnical that they may perform their own studies if they want to,and be sure to engineers can observe actual subsurface conditions only at those specific allow enough time to permit them to do so.Only then might you be in locations where sampling and testing is performed.The data derived from a position to give constructors the information available to you,while that sampling and testing were reviewed by your geotechnical engineer, requiring them to at least share some of the financial responsibilities who then applied professional judgement to form opinions about stemming from unanticipated conditions.Conducting prebid and subsurface conditions throughout the site.Actual sitewide-subsurface preconstruction conferences can also be valuable in this respect. conditions may differ-maybe significantly-from those indicated in this report.Confront that risk by retaining your geotechnical engineer Read Responsibility Provisions Closely to serve on the design team through project completion to obtain Some client representatives,design professionals,and constructors do informed guidance quickly,whenever needed. not realize that geotechnical engineering is far less exact than other engineering disciplines.This happens in part because soil and rock on This Report's Recommendations Are project sites are typically heterogeneous and not manufactured materials Confirmation-Dependent with well-defined engineering properties like steel and concrete.That The recommendations included in this report-including any options or lack of understanding has nurtured unrealistic expectations that have alternatives-are confirmation-dependent.In other words,they are not resulted in disappointments,delays,cost overruns,claims,and disputes. final,because the geotechnical engineer who developed them relied heavily To confront that risk,geotechnical engineers commonly include on judgement and opinion to do so.Your geotechnical engineer can finalize explanatory provisions in their reports.Sometimes labeled"limitations; the recommendations only after observing actual subsurface conditions many of these provisions indicate where geotechnical engineers' exposed during construction.If through observation your geotechnical responsibilities begin and end,to help others recognize their own engineer confirms that the conditions assumed to exist actually do exist, responsibilities and risks.Read these provisions closely.Ask questions. the recommendations can be relied upon,assuming no other changes have Your geotechnical engineer should respond fully and frankly. occurred.The geotechnical engineer who prepared this report cannot assume responsibility or liabilityfor confirmation-dependent recommendations ifyou Geoenvironmental Concerns Are Not Covered fail to retain that engineer to perform construction observation. The personnel,equipment,and techniques used to perform an environmental study-e.g.,a"phase-one"or"phase-two"environmental This Report Could Be Misinterpreted site assessment-differ significantly from those used to perform a Other design professionals'misinterpretation of geotechnical- geotechnical-engineering study.For that reason,a geotechnical-engineering engineering reports has resulted in costly problems.Confront that risk report does not usually provide environmental findings,conclusions,or by having your geotechnical engineer serve as a continuing member of recommendations;e.g.,about the likelihood of encountering underground the design team,to: storage tanks or regulated contaminants.Unanticipated subsurface • confer with other design-team members; environmental problems have led to project failures.If you have not • help develop specifications; obtained your own environmental information about the project site, • review pertinent elements of other design professionals'plans and ask your geotechnical consultant for a recommendation on how to find specifications;and environmental risk-management guidance. • be available whenever geotechnical-engineering guidance is needed. Obtain Professional Assistance to Deal with You should also confront the risk of constructors misinterpreting this Moisture Infiltration and Mold report.Do so by retaining your geotechnical engineer to participate in While your geotechnical engineer may have addressed groundwater, prebid and preconstruction conferences and to perform construction- water infiltration,or similar issues in this report,the engineer's phase observations. services were not designed,conducted,or intended to prevent migration of moisture-including water vapor-from the soil Give Constructors a Complete Report and Guidance through building slabs and walls and into the building interior,where Some owners and design professionals mistakenly believe they can shift it can cause mold growth and material-performance deficiencies. unanticipated-subsurface-conditions liability to constructors by limiting Accordingly,proper implementation of the geotechnical engineer's the information they provide for bid preparation.To help prevent recommendations will not of itself be sufficient to prevent the costly,contentious problems this practice has caused,include the moisture infiltration.Confront the risk of moisture infiltration by complete geotechnical-engineering report,along with any attachments including building-envelope or mold specialists on the design team. or appendices,with your contract documents,but be certain to note Geotechnical engineers are not building-envelope or mold specialists. GEOPROFESSIONAL BUSINESS &Hit ASSOCIATION Telephone:301/565-2733 e-mail:info@geoprofessional.org www.geoprofessional.org Copyright 2019 by Geoprofessional Business Association(GBA).Duplication,reproduction,or copying of this document,in whole or in part,by any means whatsoever,is strictly prohibited,except with GBAs specific written permission.Excerpting,quoting,or otherwise extracting wording from this document is permitted only with the express written permission of GBA,and only for purposes of scholarly research or book review.Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind. Any other firm,individual,or other entity that so uses this document without being a GBA member could be committing negligent or intentional(fraudulent)misrepresentation. 2022 FINAL GROUNDWATER REPORT - PINNACLE WEST PROJECT (NRS, 10/18/2022) Ck NATURAL RESOURCE LLC Consulting, Soil Evaluations & Data Collection HARLEYR.NOE Phone: 208.850.4926 October 18, 2022 Mr. Jon Wardle 2929 W. Navigator Drive Suite 400 Meridian, ID 83642 RE: 2022 final groundwater report— Pinnacle West Project I have completed biweekly data collection as requested at the 8 piezometers on the Pinnacle site west of Locust Grove and north of Lake Hazel. This report is to provide you with the resulting summer monitor data. I have attached a map on Google Earth 2020 imagery that displays all monitor points. Pre-irrigation values were collected on March 19th and bi-weekly readings of all the piezometers through October 6'. All pipes have remained dry to measured depths ranging from 13.7 to 15.25 feet below ground level for the entire season. This project is on a large alluvial fan terrace formed in Pleistocene glacial outwash some 25,000 plus years ago. I have collected monitor data on a number of points on this landform and have found them to also remain well drained well below 13 to 20 feet below ground level. The data shows you can design developments with groundwater below a depth of 15 feet without any problem. If you have questions, please feel free to contact me by e- mail, text or phone. transmitted via e-mail HARLEY R. NOE Professional Soil Scientist cc w/attachments by e-mail: Daniel Frisby, Brighton Corporation 5740 N. APPLEBRooK WAY BoisE,IDAHo 83713 Pinnacle West Final 2022 GW Monitoring All readings are depth below ground level in inches Hole Bottom 3/19 3/25 4/7 4/23 5/5 5/18 6/2 6/16 6/30 7/16 7/29 8/12 8125 9/10 9/18 10/6 Number Depth 22-1 180 180+ 180+ 180+ 180+ 180+ 180+ 180+ 180+ 180+ 180+ 180+ 180+ 180+ 180+ 180+ 180+ 22-2 1 170 172+ 172+ 172+ 172+ 172+ 172+ 172+ 1 172+ 172+ 1 172+ 172+ 1 172+ 172+ 172+ 1 172+ 172+ 22-3 176 176+ 176+ 176+ 176+ 176+ 176+ 176+ 176+ 176+ 176+ 176+ 176+ 176+ 176+ 176+ 176+ 22-4 179 179+ 179+ 179+ 179+ 179+ 179+ 179+ 179+ 179+ 179+ 179+ 179+ 179+ 179+ 179+ 179+ 22-5 163 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 22-6 183 1 183+ 183+ 183+ 183+ 183+ 183+ 183+ 183+ 183+ 183+ 183+ 183+ 183+ 183+ 183+ 183+ 22-7 166 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 164+ 22-8 157 155+ 155+ 155+ 155+ 155+ 155+ 155+ 155+ 155+ 155+ 155+ 155+ 155+ 155+ 155+ 155+ BOTTOM DEPTH value is from ground level to bottom of pipe NOTE: a "+"following the readings indicates pipe was dry to the bottom '4 a 22-5A 'CAP 0 622 �22-s '-22-7 AN `, he Gavgle Earth �1000 ft