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HomeMy WebLinkAboutCC - Storm Drainage Calcs Prepared For: TM Creek No. 7 Roadway and Utility Project Brighton Development, Inc. & City of Meridian Meridian, Idaho Storm Drainage Report SS�pN A L £, 0 �aFk LENS£ /2F Digitally signed by Lachlin C Kinsella,P.E. 16860 Date:2023.03.28 17:29:17-06'00' s� 3/28/23 o Q �C' qTF 0 F /N C. K\N� 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 IM, March 2023 Project No: 23-004 E N G I N E E R I N G TABLE OF CONTENTS Introduction ................................................................................................................................. 1 ProjectDescription ...................................................................................................................... 1 SiteDescription............................................................................................................................... 1 Scopeand Methods........................................................................................................................ 1 ExistingDrainage Conditions .......................................................................................................... 1 Proposed Drainage Conditions and Analysis .................................................................................. 1 Inletand Gutter Capacities............................................................................................................. 2 SeepageBeds.................................................................................................................................. 2 TemporaryPonds............................................................................................................................ 2 Summary......................................................................................................................................... 3 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 Temporary Pond Calculations Appendix D - Geotechnical Engineering Report Geotechnical Investigation —Ten Mile Creek Apartments (Atlas, 8/30/22) INTRODUCTION The purpose of this report is to show that the storm drainage facilities for the proposed TM Creek Subdivision No. 7 Roadway and Utility (Project) are designed to meet the 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 new roadways, sidewalks, and utilities for the future TM Creek Subdivision No. 7, which includes the TM Creek Apartments No. 4 project. The two proposed streets will be privately owned and maintained per the construction plans and connect to existing ACHD roadways. SITE DESCRIPTION The Project site is located near the southwest corner of Franklin Rd. and Benchmark Way in Meridian, Idaho. See Appendix A, Figure 1 for a vicinity map of the project. The proposed Project area is approximately 2.01 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) as required by the City of Meridian. 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 and temporary ponds were completed to verify capacity. EXISTING DRAINAGE CONDITIONS The pre-project watershed consists of primarily agricultural land that slopes from north to the south, where the Tenmile Drain is located. There are no existing storm drainage facilities in place to reduce the peak runoff volumes prior to discharging into the drain. PROPOSED DRAINAGE CONDITIONS AND ANALYSIS The proposed drainage system improvements consist of roadway inlets and gutters, sand and grease traps, seepage beds, and temporary ponds. The post-development site was broken into eleven (11) drainage basins as shown in Appendix A, Figure 2 - Post-Development Drainage Map. The proposed drainage basins consist of roadways, sidewalks, and planter strips. For land use type and runoff coefficients (0.1—open space, .95—impervious)for each basin, refer to ACHD calculations in Appendix C. Each basin was delineated according to the tributary area draining to each drainage structure or facility such as gutter, catch basin inlet, etc. For individual sub-basin 1 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 time of concentration was calculated using shallow concentrated flow for the road curb and gutters. The stormwater runoff from the roads is conveyed using the curb and gutter to catch basins and is then retained on site through seepage beds and temporary ponds. INLET AND GUTTER CAPACITIES The catch basin inlets should be built per the details shown on the civil construction plans. There is a total of six (6) inlets, one for each drainage basin where storm water is routed to a seepage bed. Based on our calculations, all inlets will require a single sump grate inlet to intercept the flows. The gutter capacity of the proposed roadways was verified to ensure that overtopping of the curb would not occur in the 25-year and 100-year storm event. SEEPAGE BEDS The Project includes four (4) private seepage beds (SB#1-#4) that should be built per the details shown on the civil construction plans and meet the City of Meridian requirements. Based on our calculations, the seepage beds are adequately sized to ensure that no ponding occurs on the surface and the volumes required to retain the 100-year storm event are met. The invert elevation of the seepage bed is set above the estimated high groundwater level based on the geotechnical investigation prepared by Atlas. Once the size of the seepage beds was calculated,the time necessary for 90% of the 100- year storm events to be infiltrated into the ground was calculated at less than 48 hours. An infiltration rate of 4 inch/hour was used in the design of the seepage beds. 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. TEMPORARY PONDS There are seven (7) private temporary ponds that should be built per the civil construction plans. Each temporary pond has been sized to store the 100-year volume and infiltrate 90% of the required volume within a 48-hour period. 2 SUMMARY This report determines that the Project storm water design sizing and analysis conforms to the City of Meridian and the water quality requirements of the Idaho Department of Environmental Quality (DEQ). The post-development storm water runoff for the entire roadway, sidewalks, and planter strips should be completely retained onsite through the proposed seepage beds and temporary ponds. 3 APPENDIX A - FIGURES PROJECT SITE N W.FRANKLIN RD. 0 MERIDIAN, IDAHO z IL LOCATION MAP v; INTERSTATE84 0 a a r, x x 0 0 VICINITY MAP a o NO SCALE 3 0 m N O N W N M 5 w z Z Y z 2 3 3 0 2000 4000 6000 4n 0Nor- Plan Scale: 1" = 2000' Z a E N G I N E E R I N G O 5725 NORTH DISCOVERY WAY 0 m BOISE,IDAHO 83713 PHONE(208)639-6939 TM CREEK SUBDIVISION No. 7 ROADWAY AND UTILITY PROJECT kmengllp.com MERIDIAN, IDAHO DATE: MARCH 2O23 o PROJECT: 23-004 0 SHEET: FIGURE 1 - VICINITY MAP a 1 OF 1 DRAINAGE LEGEND DESIGN POINTS 0 A BASIN DESIGNATION 1. INLET #1 0 50 100 150 2.5 AREA IN ACRES 2, INLET #2 3. INLET #3 Plan Scale: 1" = 50' 4. INLET #4 DESIGN POINT 5. INLET #5 6. INLET #6 EXISTING GRADE CONTOUR 7. SGT #1 -2470- 8. SGT #2 9. SGT #3 10. SGT #4 FINISHED GRADE CONTOUR 11. SEEPAGE BED #1 _ - - - - W. FRANKLIN RD. 1 12. SEEPAGE BED #2 13. SEEPAGE BED #3 d6 18"S s 3 18"g 14. SEEPAGE BED #4 4 15. TEMPORARY POND #1 m T 16. TEMPORARY POND #2 ro m m m 3 24"GI 4"GI 24"GI 24 24"GI 24"GI 24"GI 17. TEMPORARY POND #3 �I ® 24"GI 24"GI 24"GI 24"GI J -24"GI 24"GI -24"GI�-24"GI 24"GI 24"GI 24"GI 24"GI 24"GI j -2 0�41 24"GI 1 24' 18. TEMPORARY POND #4 - - - 19. TEMPORARY POND #5 20. TEMPORARY POND #6 w 6 jPl 6"PI 6"PI 6"PI "PI "II- 6"PI 6"P1 6"PI 6"PI 6"PI 6"PI 6"PI 6"PI 6"PI 6" -6"11 6"PI 6"PI 6"PI 6"PI "PI 6"PI 21. TEMPORARY POND #7 0 6 6 I m I o I a e + t w I I TM CREEK SUDIVISION No. 7 I I N l I I (FUTURE) t I 15 i 16 17 I I z o ® I I > W STOP - - � I I I I w � TOE - - E-1 F-1 - - - - - - - - - - - - - I "w G-18„W 8„W 8 It . . " w 18 I I 8 ` 0.07 s s 7 s 8"s 8"s 8„S „S „S s I \ \ - - - � a"sD \ I I II II � � 2sD 0.18 0.31 r 8QLPAt au ,� v I _ _ - -I- - - - - - - - - - - - 7 \ 1 J /L9 H-1 \ i / - - - - - - - - - 8 �Flp� 0.04 \ A // - - - w ' 8 I O - - - 11 12 2 9� \ \ I / / s` 8„ I I z 3 f ii 800 \ . d, 01 I lit 0.03Lu U 8"SD 8'S 8"SD 4"SD / J-1 a"w 4 / lb� 0.09 20 Q I I Q I -6"W u x. L - - - - - - ry \\ w 4 ® I I J - - - - \ sy\/ 1\ m I I Z A3 A3 - - A3 A3 - T - - - - - -A3 3 A3 A3 A3 A3 �y\/ \/ \/ / 0.37 / ! !- - - - - _ - - - - -! - - - - - - - - -\ - - /s � \ \ S \ \ l\\ II 1 LII II z0 EV EV E E -� N, W - - - - - - - - - - - - - - - - - - - - - -- ! J-� - 21 - - Z `n 8„ 6 a„W 8„W 8„W 8„W 8„Vg a„W 8„W 8„ 8„W 8„ - - - - - -____ - - - _=_- - - s "s ., s \\s \ s \\\ �° A3 A3 JA30A310 ! ! ! ! ! ! ! ! t m I o \ - - - - - - - - \� - 8"w Q! ! r ! ! - \ \ 0.04 8., 8"W- - - Ev ® - - 'SD 4 8„SD4 ° f 8t - Q 10 J"SD Z Z 4 ,. ...:..,:'i• a Se:}. ^:` \ \ \ \ fLu 0.1 6 2 TEN MILE CREEK ` 0 APARTMENTS No. 4 ! ! ! \ \ \ \ I t (FUTURE) ` \ \ \ \ ^ O s"sD 6 W z O J ®a I I \ I I z W o I Aa 14 1 I I ® O > ' I W ® m � � � ®� X t 1 1 m I 6' ae0 6 11 _ t 1 I I �- - - - e I I 1 I cn N I Q 6,.SD � I (/ I 6"S� 4•. cNiC 12 SD _ o -6"PI t t - 1 SD - N t I W _ „ , , _ G�EG ��� \ v N % - - I L�u x G�EG EG�EG-., 11 �X - - o ! (- - - I vi 6 L.L rci EG EG E �fi6P-EG " ., ® ° ! 00 I w U Z u �-E �G EG ++ - a TOP TOP EG-��G� EG EG „ „ ., ci to O _ I a o TOPS/ TOPS�&�EG = EG�EG� G GG TOP E70P�GTO EG "PI 6"PI 6"PI I vi U m -TOE TOE �j -TOP-TO-EG EG EG N TOE I g Tnt, T.0 TOE TOE TOE TOP TOP TOP E EG E I o ��TOE rnc' TOE TOE TOE TOP�G TO�EG EG I..I- m i TGE-- TOE-TOE O TOP�TOP EG EG EG J OP�TOP TOP TOE��- E�TOE � TOP- TOE �TOELn z OP TOP 70P-TOP -TOE TOE me-TOE _-�-- � I O T P- z Z rr�oE TOP TOP- TOE TOE�TOE_TO TOE " DOE-�Tor EG IN) P EG O u ---- TO _P TOE- TOP-TOP E-TOE I �TOE TOE f 1 I 5 TOE TOE 4E 3' U TOP TOP I �TOE TOE w LL o TOP TOP TOP TOP� TOE TOE E m O z TOP TOP TO I E t� TOP TOP AAAAA ""' of w ENGINEERING L.L o TOP TOP 1 w I Top 5725 NORTH DISCOVERY WAY P TOP_ BOISE,IDAHO 83713 O 0 w � I PHONE(208)639-6939 o -- -L-- kmengllp.com Z -L--- I a DESIGN BY: LCK M DRAWN BY: LCK N aCHECKED BY: LCK Q DATE: MARCH 2O23 Z o F PROJECT: 23 004 C w SHEET NO. C M 1 OF 1 w a � SHEET NOTES A. SEE SHEET C1.1 FOR GENERAL, ACHD, AND UTILITY ASS\ONAL f^r0/ NOTES. \C E N SF10 'yam 0 50 100 150 B. SEE SHEET C4.1 FOR STORM WATER DETAILS. Plan Scale: 1" = 50' 0 C. GROUNDWATER ELEVATIONS ARE EXPECTED TO REMAIN 3 686 686 AT OR BELOW 12 FEET FROM EXISTING GROUND SURFACE. `f'� � Q THE DESIGN INFILTRATION RATE IS 4 IN/HR BASED ON "9 qTF \OP THE INFILTRATION TEST RESULTS. FOR ADDITIONAL C' OF lv INFORMATION REFER TO THE GEOTECHNICAL y��/�/ C. K\�� INVESTIGATION "TEN MILE CREEK APARTMENTS 4" PREPARED BY ATLAS, DATED AUGUST 30, 2022. !4G W. FRANKLIN RD. D. PROVIDE WATER-TIGHT SEALS AT PIPING ENTRANCES/EXITS FOR CATCH BASINS, DIVERSION BOXES, is"s s ia"s AND MANHOLES. SGT #2 (1000 GAL) 3 E. ALL STORM PIPE WITHIN ROW SHALL BE C900 WHERE m m COVER OVER PIPE IS LESS THAN 2 FEET. OUTSIDE OF 24"GI 24"GI 2 24"GI 24"GI 24"GI® 24"GI 24"GI 24"GI 24'GI RIM:2583.33 E 7 ( ) 24"GIB-24"GI 24"cI 24"GI 24"cI 24"GI 24"cI 2 l°�Al 24"GI 24' ROW OR WHERE COVER IS GREATER THAN 2 FEET THE RIM:2583.31 (W) - - INV IN:2579.04 12" (E) - STORM PIPE SHALL BE ADS N-12 HP PIPE OR 6jPI 6"PI 6"PI 6"PI INV IN:2579.04 12" (E) APPROVED EQUAL. FLOWABLE FILL SHALL BE USED WHEN �, "Ii 6"PI 6"Pi 6"Pi 6"Pi 6"PI 6'PI s'PI LESS THAN 5-FEET OF SEPARATION BETWEEN a 6' I 6"PI 6"PI 6"PI 6"PI 6"PI 6"PIIt STRUCTURES. 0 INV OUT:2578.19 18' (W) s s ' INLET BAFFLE:2578.36 m OUTLET BAFFLE:2578.94 F. ALL DRAINAGE STRUCTURES SHALL BE PER ISPWC INLET I = I TM CREEK SUDIVISION No. 7 I I I STANDARDS AND THE ACHD SUPPLEMENTS TO THE ISPWC. I Q I (FUTURE) ACHD SD-601, TYPE I I I I STORM DRAIN STRUCTURES SHALL HAVE HS-25 TRAFFIC a I w I RIM:2583.15 N� I I RATED LIDS UNLESS OTHERWISE SPECIFIED. � I I SUMP:2579.08 I 17 b I > I 15 INV OUT:2 9.75 4" (" I I G. REQUIREMENTS OR SHALL FOR STORMOMPLY WATERWITH ALL DISCHARGE E O INV OUT:2579.08 12" (N) I 14 I a. I I ASSOCIATED WITH CONSTRUCTION ACTIVITY. THIS INCLUDES 5 I A I 6 69.2' 12" ADS N-12 HP ° I I IMPLEMENTING THE BMP'S RECOMMENDED IN THE SWPP N 7 p 0•49%; ^' I PLAN PREPARED FOR THIS SITE, REGULAR SITE 12 I INLET 3 _ _ L I INSPECTIONS, DOCUMENTATION OF MODIFICATIONS TO THE z 36.4' 18" ADS N-12 HP 58.5' 18" ADS N-12 HP ACHD SD-601, TYPE I T �- I SWPPP AND OTHER REQUIREMENTS AS SET FORTH IN O @ 0.00% I @ 0.00% 16 RIM:2583.17 I I I I I THE NPDES GENERAL PERMIT. roP - - SUMPLu -2578.38 I I o I I w - - - - - - - - - _ - _ INV IN:2580.05 4" (SE) I I H. ALL CHANGES REQUIRE APPROVAL BY THE DESIGN - - - - - - - - - __� - - J - - _ I I N o I ENGINEER AND CITY OF MERIDIAN. SGT #1 (1000 GAL) - - - - - - - - - - - - - - - - - - - INV OUT:2579.38 12" (NW) W s"w- RIM:2583.32 (W) s" s"w 1 s"w s"w a"w� °s"w : : s» 12„ e \ BLOCK 3 I I I. FOR UTILITY CROSSINGS AT SEEPAGE BED LOCATIONS, RIM:2583.34 (E) _ _ _ I I THE CONTRACTOR SHALL CONFORM TO THE STANDARDS 2 1v \ INV IN:2578.98 12" (S) s"s $"s $"s 6.7' 4" ADS N-12 HP - \ 8 I I 18 I I I SET BY THE CITY OF MERIDIAN AND SECTION 8200 OF - -INV OUT:2578.13 18" (E) 13 (� 0.96% 13 e'w \ \ I I N ® 2 SD- I I THE ACHD STORMWATER GUIDELINES. INLET BAFFLE:2578.30 - - _,- s - - - 3�- - - j I ci OUTLET BAFFLE:2578.88- - - - - - - - - - - - - - _ _ - _ - _ _ _ _ _ - _ \ I I I J. THE STORM WATER DESIGN IS BASED ON SECTIONS 8000 II3.3' 12" ADS N-12 HP 7 \ 12 `� \\\ I I _ _ _I_ _ _ - - - - - - - - - - - _ I I AND 8200 OF THE 2017 ACHD POLICY MANUAL. ® 0.61,% INLET #1 � \ \ I / / / L - - - - - - - - - 1 - 14 INV. 2580.60 \ \ � / - � KEYNOTES ACHD SD-601, TYPE 1 106.4' 4" ADS N-12 HP 72.5' 4" ADS N-12 HP \ \ \ I 9 / ' a I I z RIM:2583.16 @ 0.96% \ \ \ / / s' a" I O UTILITY MAIN/MAIN CROSSING SUMP:2579.00 @ 1.02% \ // - - - - - - - - - - - - - - - - - _ MAINTAIN VERTICAL AND HORIZONTAL 3.3' 12" ADS N-12 HP \ \� / INV IN:2579.67 4" (S) 8.2' 4" ADS N-12 HP © 1.22% �' / POTABLE/NON-POTABLE MAIN LINE SEPARATION INV OUT:2579.00 12" (N) @ 1.09% \ / / _ } I PER CITY OF MERIDIAN REQUIREMENTS. SEE WATER SDCO 2 - - - - - - - - - - - - - - - - - -� Q / NOTE 2 SHEET C1.1 FOR ADDITIONAL 9.8' 4' ADS N-12 HP 14 INV. 2580.93 4" CLEANOUT \ 1 \ 12 INFORMATION. 2 ® 0.87% RIM:2583.75 \ \ / / / Y SDCO #1 , SUMP:2579.84 \ �2y 4" CLDCO #1 INV:2579.84 4" PVC(W) / 0 I I 1. SB #1 (PRIVATE) SEE SEEPAGE BED DETAIL #1/SECTION u 9.7' 4" ADS N-12 HP / _` A-A ON SHEET C4.1 (31'L x 9'W x 4'D) W RIM:2583.76 s"sD s's a"sD- / \ ( u I I a"w - SUMP:2579.75 0 96% / w I I 2. SB #2 (PRIVATE) SEE SEEPAGE BED DETAIL #1/SECTION O INV:2579.75 4' E y 1 0 2y 10 CO I I I A-A ON SHEET C4.1 (53'L x 9'W x 4'D) ( ) 82.4' 4" ADS N-12 HPo � /A 12 � vi � _ ® 1.01% 14 INV. 2580.88 / - I 3. SB #3 (PRIVATE) SEE SEEPAGE BED DETAIL #1/SECTION A-A ON SHEET C4.1 (68'L x 9'W x 4.5'D) 1�+_l- - - - �P \ 19 12"sD ® 12"sD / I L INLET 4 / ?' \ / - ACHD SD-601, TYPE I / S� \ 90% \\ 0 4. SB #4 (PRIVATE) SEE SEEPAGE BED DETAIL #1/SECTION - - - n3 n3 - - n3 n3 - - - - - - n3 a - - n3 n3 RIM:2582.68 / \ \ 9O` \ \ 87.3' 18" ADS N-12 HP Q I I B-B ON SHEET C4.1 (27'L x 6'W x 5'D) J Ln SUMP:2578.68 � 3 ® 0.00% 5. INSTALL TEMPORARY POND #1 (PRIVATE) PER DETAIL, ~ z / \/ INV OUT:2579.68 12" (E) / \ -2y \ N D / � \ I I I SHEET C4.1. 12'Lx12'Wx2'D Q < e �� �• o TOP ELEV:2582.65 Q \ 92.0' 12" ADS N-12 HP \ ,\ �\ I I I I I I v ` s\ / 11 IV EV - - IV EV - - - - - _ IV Ev - - _ -/ ® 0.45% \ I SDMH 1 DESIGN TOE ENFILTRAT 0 RATE = 4 I / R - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - �.��� �\ \ � �\ �a 48"� SDMH FLAT TOP I I N N H INLET #5 \\\� `�\ I VOLUME REQUIRED = 297 CF Q s" a a"w a"w a"w a„w a" a"w ; a"w e" a"w 8" I \ \\ N� RIM:2585.79 =I - - -- - - - - - - - - -- _ - ACHD SD-601, TYPE I z I n3 n3 s "s �, rrs s-s----ohs 6 5 RIM:2583.81s e \ \ ` \ \\\ SUMP:2581.64 I / VOLUME PROVIDED = 439 CF O W I n3 n3 ® ® SUMP:2579.31- 2C \ _ INV IN:2581.64 12" (W) ` ` ` ` rn I °' I INV OUT:2579.31 12" (NE), \/IQ _ _ - - INV OUT:2581.64 12" (S) 6. INSTALL TEMPORARY POND #2 (PRIVATE) PER DETAIL, Q = 2 A - s F� ��\ s - - - I - - _ SHEET C4.1. 12'Lx12'Wx2'D W Z 3.3' 12" ADS N-12 HP \ \ s, 13 �a,.w : 12.4' 12" ADS N-12 HP TOP ELEV:2582.65 Q z < < ® 1.22% \ \ , 12\ \ \ \ _ 0.73% s w- TOE ELEV:2580.65 / 0Ev tLt a"sD SGT #3 \\\ \\\ \ s a"s s s -4.9' 4" ADS N-12 HP - - - - - DESIGN INFILTRATION RATE = 4 IN/HR Q - RIM:2583.97 (NW)� \ \\\ \ �\ \- - - p 3.91% VOLUME REQUIRED = 422 CF � U i s"sD i s"sD i s"sD ® "sD RIM:2584.03 (SE) \ - - 1 1 I O Lu -I I 12"sD \ _ - - _ _ _ VOLUME PROVIDED = 439 CF Z o INV IN:2579.27 12" (NW) \ \\\ \ INV. 2582.41 14 - - - - - - - _ _ INV IN:2579.27 12" (SW) \ \ \ e N 5 TEN MILE CREEK INV OUT:2578.42 18" (SE) \ \ s\ \ � ■� I 7. INSTALL TEMPORARY POND #3 (PRIVATE) PER DETAIL, I� L W N APARTMENTS No. 4 J - _ INLET BAFFLE: \ \ \ \\ SGT #4 I SHEET C4.1. 12'Lx12'Wx2'D - w T (FUTURE) OUTLET BAFFLE:2579.17 \ \ INLET #6 RIM:2585.44 (N) TOP ELEV:2582.90or _ b su \ \ ACHD SD-601, TYPE I RIM:2585.36 (S) I���IIII TOE ELEV:2580.90 O W T , un / SUMP:2580.74 INV IN:2581.55 12" (N) I I DESIGN INFILTRATION RATE = 4 IN/HR z W INV IN:2582.22 4" (E) I I VOLUME REQUIRED = 239 CF z Q y I INV OUT:2581.74 12" (E) I INV OUT:2580.70 18" (S) VOLUME PROVIDED = 439 CF O ` BLOCK 3 I r� I �fa� 4 INLET BAFFLE:2580.87 13.8 12" ADS N-12 HP OUTLET BAFFLE:2581.45 ® m I 8. INSTALL TEMPORARY POND #4 (PRIVATE) PER DETAIL, 6' ae0 6' � ® ® " 20 v I I i ® 0.72% 13 32.5' 18" ADS N-12 HP I SHEET C4.1. 12'Lx12'Wx2'D Ln ■ ® I y V I 6 i @ 0.00% I I TOP ELEV:2582.75 > I I I TOE ELEV:2580.75 DESIGN INFILTRATION RATE = 4 IN/HR 0 O VOLUME REQUIRED = 145 CF m � I I I VOLUME PROVIDED = 439 CFLn 6 SD V o I y 6"so I \\ _ I I 9. INSTALL TEMPORARY POND #5 (PRIVATE) PER DETAIL, s"s \ \ I NFL ® 2 sD I SHEET C4.1. 12'Lx12'Wx2'D M -6"PIS - �- I I - � sD �� N I I TOP ELEV:2583.00 W N EG �EG " - ® � _ �/ I n TOE ELEV:2581.00 W a EG --EG EG�EG- - - �x - - o , - - - I 6' DESIGN INFILTRATION RATE = 4 IN/HR o EG EG E - - - ® �� I VOLUME REQUIRED = 144 CF U z-fie -Ec� VOLUME PROVIDED = 439 CF O�TOPEG �E Q�G-EGA - r� TOP EG�4tG _EEGG to 8 TOP �P-�TQP�EG�EG�EG�EG STOP ESo�c� " - - „�_ N - 10. INSTALL TEMPORARY POND #6 (PRIVATE) PER DETAIL, o -OP��EG- 6 - 6"PI s"PI I SHEET C4.1. 12'Lx12'Wx2'D (, -TOE TOE Top-TOP EG EG-EG I TOP ELEV:2583.00 N TOE me TOE TOE TOP TOP TOP E ��EG EG I I I TOE ELEV:2581.00 TO z TOE TOE�TOE TOE TOE TOE�TOE_ r� EG EG AEG Top EG ` - - - l DESIGN INFILTRATION RATE = 4 IN/HR LJ�_ Y TOP VOLUME REQUIRED = 291 CF TOP TOP-rOP- TOE-�-� --TOE TOE TOE TOE -�TOP EG TOP EG ' EG EG\ VOLUME PROVIDED = 439 CF z TOP TOP TOE me TOE 7 SOP TOP TOP TOE TOE TOE --TOE f" EG I ^ EG- Z g E rOP_ TOE �oETnr 11. INSTALL TEMPORARY POND #7 (PRIVATE) PER DETAIL, O _ TO�op _TOE r°P TOE-TOE- TOE TOE_ I I 1 I 3 - SHEET C4.1. 12'Lx12'Wx2'D -- 70E TOP TOP TOP I TOE�TOE TOP ELEV:2584.50 U o Top TOP TOP TOE TOE TOE TOE ELEV:2582.50 Of roP�_T0P_ N I DESIGN INFILTRATION RATE = 4 IN/HR O TOP o TOP� TOP .. ��.N..... w VOLUME REQUIRED = 144 CF W o TOP TOP I - VOLUME PROVIDED = 439 CF I 5725 NORTH DISCOVERY WAY TOP- 12. INSTALL RIP RAP SWALE PER DETAIL, SHEET C4.1. BOISE,IDAHO83713 O > ' ' I PHONE(208)639-6939 13. INSTALL GROUND WATER OBSERVATION WELL PER ACHD kmengllp.com a -- SD-627, SHEET C4.1. INSTALL WITHIN THE INFILTRATION DESIGN BY: LCK BED 5' FROM THE END. DRAWN BY: LCK 14. CAP 4" STORM DRAIN AND INSTALL MARKER FOR CHECKED BY: LCK Z FUTURE CONNECTION TO INLET PER TEN MILE CREEK Q 0 APARTMENT PLANS. DATE: MARCH 2O23 z u PROJECT: 23-004 C 0 SHEET NO. C 0 s W O m d SS\ONAL fNC LEGEND ��, OENS WELL COVER, 8" DIA. WATERTIGHT GALVANIZED STEEL BOLT DOWN COVER AND CANISTER �p N\ FO 0 2 OR 3 BOLT LID WITH 9/16" HEAD AND SAE THREADS, GASKETED FINISH GRADE 9 CONCRETE (COLLAR), CLASS 3000 (ISPWC SECTION 703) 6860 2 3/8" DIA HOLES OR SLOTS CUT INTO PIPE AT 3" ON CENTER - - TRACER WIRE SHALL BE PLACED ON OUTSIDE OF PVC PIPE, MINIMUM 18 GAUGE, INSULATED, SINGLE- i J,� 3128123 p ,•� - - - CONDUCTOR COPPER WIRE, INSULATION COLOR SHALL BE GREEN WITH THREE 6" DIAMETER COILS i y 9p Px -III . 1 I I=1 P- 6 ' C� F 0 F \� v _-I I-III-III-II PIPE SHALL BE PERFORATED PVC, ASTM D-3035, SDR 35. WELLS BACKFILLED IN A PIT REQUIRE 6" i II I II II II - 11�111=11 - FABRIC OVER CHIP /DRAIN ROCK --a --- `/� C. K\� Q. PIPE DRILLED WELLS MAY USE 4" PIPE III=III NONWOVEN FILTER FABRIC AROUND OPENINGS AND BOTTOM, S A � ________________ A 1=III=11 =III= � E POLYPROPYLENE FIBER REINFORCEMENT AT 1 1/2 LBS/CY oQP pQP i 111�11 -III-1� 3 ° AP BACKFILL MATERIAL TO MATCH STORAGE MEDIA FOR OBSERVATION WELLS LOCATED WITHIN A BMP FACILITY. ' USE PIPE BEDDING CHIPS FOR OBSERVATION WELLS LOCATED OUTSIDE BMP FACILITIES 3 NOTES: 5 PLAN CONCRETE COLLAR 1. GROUNDWATER OBSERVATION WELLS ARE FOR MEASUREMENT OF GROUNDWATER LEVELS WITHIN OR NEAR z i STORM DRAINAGE FACILITIES i ~ N.T.S. 2. THIS DETAIL IS FOR WELLS INSTALLED BY DRILLING OR BY EXCAVATED PITS L - - - - - - - - -- < 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 s ' N.T.S. o O Q 111=I I I=11=111=11I=11 _1 I 1=1 I 1=1 - - 18" -III-I 1=1I1=1I- 3 I1=1I1El I1El I I II o �~ -111-111-111=1TI ITI=ITI-ITI=ITI=I >-IT-I 11=1 11 1 I o °� 5 - I_Illilllll; Z - w - _Z H 8 - 3 X W cn u 6 UTLE SECTION CONCRETE COLLAR FLOW o BAFFLE WALL N > N.T.S. ELEV B FLOV 0 ELEV A N a a ELEV D W uj w INLET BAFFLE WALL a ELEV C 20" STD 9 r� SECTION A-A N.T.S. NOTES 1. SAND AND GREASE TRAP USED FOR SUBSURFACE FACILITIES ONLY 0 � 8 LEGEND:(]) MANHOLE FRAME AND COVER PER SD-617 (TYPICAL) Z SECTION z LOCATION AND FL ELEV. PER DESIGN PLANS (TYPICAL) s H 1-FT USE GRADE RINGS (TYPICAL) 3 N.T.S. 1-FT < H <= 2-FT USE 24" DIA RCP RISER 1 2-FT < H <= 10-FT USE MANHOLE CONE & 48" DIA RISERS Oa EL. A > EL. B BY 0.10, MIN EL. D < EL. B BY 0.10 MIN Q EL. C < EL. B BY 0.50MIN. UNLESS OTHERWISE APPROVED BY ACHD Qa 6"-12" DIA. COBBLE U 8 a WATERTIGHT SEAL PRECAST BOX MANUFACTURER SHALL MARK FLOW DIRECTION AND LABEL INLET OR OUTLET 5' TYP. Lu ON SIDE OF BOX O 2017 ACHD REVISION 2017 ACHD REVISION RIP-RAP SWALE Of IDAHO C WORKS GROUNDWATER IDAHO STANDARDS C WORKS GROUNDWATER 2015 SAND AND GREASE TRAP STANDARD DRAWING SCALE: NTS STANDARD DRAWING STANDARD DRAWING ACHD STORMWATER DESIGN BMP �1 � CONSTRUCTION OBSERVATION WELL SD - 627 CONSTRUCTION OBSERVATION WELL SD- 627 1 OF 2 (ACHD SUPPLEMENT) 1 OF 2 (ACHD SUPPLEMENT) 2 OF 2 J Ln SIDEWALK PER ACHD CURB AND GUTTER SUPPLEMENTAL PER ROADWAY PLANS. 1,000 GALLON I A STANDARD DRAWING SD-709. ELEV. - "A" (MIN.) APPROXIMATE 100-YEAR Q SAND AND GREASE TRAP PER WATER SURFACE ACHD REQUIREMENTS. REFER TOP OF BANK TO ACHD DETAIL BMP o1. FINISHED GROUND ELEVATION PER PLAN z 5 LF OF 18"0* ELEV. - "A" (MIN.) Q ADS N-12 HP w w w ���i��i�ii i��i i��i��i��i��i��i��i� ��% �� �< 6" FREEBOARD MIN. 1.5' ---- m w ///�//�/j�/j��/j j��/ 6 /j��/jam/j��/j�/j��/jam ELEV. »B» \�A� 6 �j/�j/� W >Q� ELEV. - B' V��������� ��\ �� - �a SD SDI _________ � - = Ply wV) L J7 o vwi ELEV. - >C�> 3 ELEV. - ��C,� 3 V\�VA�VA VA �VA�VA� Q W 5 5 w w s z s w w \/��/��/�� �/ 3 LENGTH/WIDTH VARIES 3.� > \ \\ \\ \\ \\ \ PER PLAN \�\\/�\\/�\\/�\\/ �_ *12"0 PERFORATED ADS N-12 HP. Q°° Q 00 \�j\�j\�j Q O Ln TRANSITION 5' IN BED NON-PERFORATED TO Ly A O PERFORATED PIPE =w =w LENGTH VARIES, SEE TABLE THIS SHEET w F-w 0-0) LL N TOE ELEVATION PER PLAN \ \ \ \ ` Q ~ 0 0 �j%�j���\� C \�\ \ - - - SEASONAL HIGH GROUNDWATER w 1,000 GALLON PLAN V I E W - - - - - - - - SAND AND GREASE TRAP PER 2 _ 18" MIN. ASTM C-33 ELEVATION ACHD REQUIREMENTS. REFER TO ELEV. - "D" ELEV. - "D" FILTER SAND��\\�\\/ ACHD DETAIL BMP 01. WATERTIGHT CONNECTION W LOCATIONS, ELEVATIONS, AND z_ 1Q z_ 1Q z W ADDITIONAL INFORMATION PER 12"0 SOLID WALL ADS N-12 HP :2 3.0' MIN. BASIN SIDE SLOPES SHALL BE CONSTRUCTED C SHEET C4.0 WITH 4" MIN. TOPSOIL OR AMENDED NATIVE G (EXTEND 5' INTO SEEPAGE BED) ;� WIDTH VARIES, SEE ;,� WIDTH VARIES, SEE z 12"0 PERFORATED ADS * FINISH GROUND MAX. HSGW TABLE THIS SHEET MAX. HSGW TABLE THIS SHEET MATERIAL. SEED MIXTURE SHALL BE DROUGHT OR ROCK = OR ROCK TOLERANT PER LANDSCAPE PLANS. O N-12 HP 12" ADS CAP ELEVATION ELEVATION Ln 4 4 NOTES: 0%' SLOPE- 1. CONTRACTOR SHALL OVER EXCAVATE TEMPORARY POND TO POORLY GRADED SAND WITH ---- --- --- GRAVEL MATERIAL. EXTEND SAND A MINIMUM OF 12" INTO FREE DRAINING MATERIAL SEE 0 O KEY SOILS INVESTIGATION REPORT FOR FURTHER SOILS INFORMATION. m 1. ISPWC 801 OR ASTM C33 FILTER SAND. I Y 2. CONTRACTOR SHALL NOTIFY ENGINEER IMMEDIATELY IF GROUNDWATER OR EVIDENCE OF MINIMUM OF 20" 2. 3/4" - 2" ANGULAR ROCK. 1. ISPWC 801 OR ASTM C33 FILTER SAND. GROUNDWATER IS ENCOUNTERED DURING CONSTRUCTION. SEE SOILS INVESTIGATION REPORT BAFFLE SPACING 3. 12"0 PERFORATED PIPE. INSTALL PERFORATIONS PER ACHD STORMWATER 2. 3/4" - 2" ANGULAR ROCK. PREPARED BY ATLAS FOR FURTHER GROUNDWATER INFORMATION. a DESIGN GUIDELINES DETAIL BMP 20 AND DETAIL ON THIS SHEET. 3. 12"0 PERFORATED PIPE. INSTALL PERFORATIONS PER ACHD STORMWATER 3. CONTRACTOR TO CONTACT GEOTECHNICAL ENGINEER TO CONFIRM INFILTRATION RATES AT N 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. BOTTOM OF EACH SAND SECTION WITH A PERCOLATION TEST ONCE EXCAVATED. NOTIFY 5. NON-WOVEN FABRIC SHALL BE PROPEX GEOTEX 401 OR APPROVED 4. SUITABILITY OF SUBGRADE TO BE VERIFIED BY GEOTECHNICAL ENGINEER. ENGINEER IMMEDIATELY IF INFILTRATION RATES ARE LESS THAN 4 INCHES PER HOUR. 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. EQUAL MEETING ACHD STORMWATER DESIGN GUIDELINES SECTION 8202.23. m 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._ TEMPORARY POND _ LL DETAIL. EXTEND MINIMUM OF 1' BELOW WOVEN G�OTEX IL� FABRIC OOVER DTOP OF BED. WOVEN SUBGRADE. FABRICINSTALL SHALL BE 6 105R FT COVER BEDS FROM OP OUTSIDE OF BED TO PUBLIC FINRIGHT-OF-WAY SHH _GRADE WW THIN MINIMUM LANDSCAPE SCALE: NTS U z Z THE BOTTOM OF SAND LAYER PROPEX GEOTEX 401F OR APPROVED EQUAL MEETING ACHD AREAS. O PROFILE VIEW STORMWATER DESIGN GUIDELINES SECTION 8202.23. m � ` N O V a SECTION A - PLAN AND PROFILE SECTION VIEW A-A: SEEPAGE BEDS WITHIN ROADWAY SECTION VIEW B-B: SEEPAGE BEDS IN COMMON LOT Y Z = z J GENERAL NOTES U A. GROUNDWATER ELEVATIONS ARE EXPECTED TO REMAIN AT OR BELOW 12 FEET FROM EXISTING GROUND SURFACE. THE DESIGN INFILTRATION RATE IS 4 IN/HR BASED ON THE INFILTRATION TEST RESULTS. FOR ADDITIONAL INFORMATION REFER TO THE GEOTECHNICAL INVESTIGATION Of MILE CREEK O SEEPAGE BED TABLE APARTMENTS 4" PREPARED BY ATLAS, DATED AUGUST 30, 2022. N BED LENGTH BED WIDTH B. ALL DRAINAGE STRUCTURES SHALL BE HS25 OR GREATER LOAD RATED. LL o SEEPAGE BED BED DEPTH (FT) ELEVATION "A" ELEVATION "B" ELEVATION "C" ELEVATION "D" GROUND WATER EL. VOLUME PROVIDED DESIGN INFILTRATION RATE C. ALL GEOTEXTILE SEAMS SHALL OVERLAP 1 FOOT MINIMUM. (CF) (IN/HR) D. BED WIDTH SHALL REMAIN CONSTANT. 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 EXCAVATED. NOTE: AN ACHD INSPECTOR MUST BE PRESENT FOR THE TEST). IF THE PERCOLATION IS LESS THAN SPECIFIED BY THE SOILS BOISE,IDAHO 83713 SIB #1 (PRIVATE) 31 9 4.0 2583.21 2580.50 2578.13 2576.50 2573.4f 533 4.0 ( ) PHONE(208)639 6939 O a REPORT AND ENGINEER, CONTRACTOR MAY NEED TO BLAST OR BORE TO CREATE CONDUIT FOR DRAINAGE TO OCCUR OR RE-DESIGN THE SYSTEM a SB #2 (PRIVATE) 53 9 4.0 2583.20 2580.50 2578.19 2576.50 2573.4t 933 4.0 TO ACHIEVE THE REQUIRED INFILTRATION. kmengllp.com o F. STORAGE VOLUME DOESN'T INCLUDE SAND WINDOW. SB #3 (PRIVATE) 68 9 4.5 2583.97 2581.00 2578.42 2576.50 2573.4t 1,325 4.0 G. WATER SERVICES, SEWER SERVICES, AND PRESSURE IRRIGATION MAINS CROSSING SEEPAGE BEDS SHALL BE INSTALLED PER ACHD REQUIREMENTS. DESIGN BY: LCK H. CONTRACTOR SHALL VERIFY INFILTRATION RATE AFTER THE FACILITY IS FULLY EXCAVATED WITH THE PROJECT ENGINEER PRESENT. ~ SB #4 (PRIVATE) 27 6 5.0 2585.24 2583.00 2580.70 2578.00 2573.7t 383 4.0 I. CONTRACTOR SHALL NOTIFY THE ENGINEER IMMEDIATELY IF GROUNDWATER IS ENCOUNTERED WITHIN 3-FEET OF THE BOTTOM DESIGN ELEVATION FOR DRAWN BY: LCK aANY INFILTRATION FACILITY AND/OR IF IT IS HIGHER THAN ANTICIPATED. CHECKED BY: LCK a o DATE: MARCH 2O23 z u SEEPAGE BED DETAIL #1 PROJECT: 23004 C- NTS SHEET NO. C J W O m d 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 10.0 0.24 0.33 Basin B-1 10.0 0.40 0.56 Basin C-1 10.0 0.57 0.79 Basin D-1 10.0 0.16 0.23 Basin E-1 10.0 0.16 0.22 Basin F-1 10.0 0.23 0.32 Basin G-1 10.0 0.13 0.18 Basin H-1 10.0 0.08 0.11 Basin 1-1 10.0 0.06 0.08 Basin J-1 10.0 0.16 0.22 Basin K-1 10.0 0.07 0.09 Post-Development Runoff Volumes Required Storage Volume (CF) Basins A-1,SB#1 553 Basins B-1, SB#2 933 Basins C-1, SB#3 1,325 Basins D-1, SB#4 383 Basins E-1,Temporary Pond#1 297 Basins F-2,Temporary Pond#2 422 Basins G-3, Temporary Pond#3 239 Basins H-1,Temporary Pond#4 145 Basins 1-2, Temporary Pond#5 112 Basins J-3,Temporary Pond#6 291 Basins K-1,Temporary Pond#7 123 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-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 100-Year Flood Route) 25 4 Enter number of storage facilities(25 max) 11 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 5,620 2,397 Acres 0.18 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 Usercalculate min �10 Min. Estimated Runoff Coefficients for Various Surfau — Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc I 1.85 n hr Business Downtown areas 0,70-0.95 9 Calculate the Post-Development peak discharge(ClPeak) QP.k 0.24 cfs urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0-50 10 Calculate total runoff vol(V)(for sizing primary storage) V 318 ft3 Multi-family 0.6o-o.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 277 ft' Heavy areas 0.90 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,cemeteries a.10-o.25 Playgrounds 0.20.035 Railroad yard areas 0.20-0.40 13 Volume Summary unimproved areas 0.10.0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 32 ft' Concrete 0.95 Primary Treatment/Storage Basin V 286 fti Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 318 fti Fields:Sandy soil Soil Type Slope A 8 C 0 Flat:0-2% 0.04 0.07 0.22 0.: Average:2-6% 0-09 0,12 0.15 0.: Steep:>61y, 0-13 0.18 0.23 0.: Adapted from ASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,1:14 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin B-1 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 9,528 3,601 Acres 0.30 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avgl 0.72 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.40 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 537 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 467 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 54 fti Concrete 0,95 Primary Treatment/StorageBasin V 483 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 537 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:14 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin C-1 3 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 13,842 2,091 Acres 0.37 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.84 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.57 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 762 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 662 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 76 fti Concrete 0,95 Primary Treatment/StorageBasin V 686 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 762 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:15 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin D-1 4 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 3,730 3,136 Acres 0.16 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.56 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qeak 0.16 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 220 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 191 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 22 fti Concrete 0,95 Primary Treatment/StorageBasin V 198 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 220 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:15 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin E-1 5 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 3,937 Acres 0.09 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qeak 0.16 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 213 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 185 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 21 fti Concrete 0,95 Primary Treatment/StorageBasin V 192 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 213 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:15 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin F-1 6 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 5,600 Acres 0.13 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.23 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 303 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 264 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 30 fti Concrete 0,95 Primary Treatment/StorageBasin V 273 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 303 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:15 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin G-1 7 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 3,170 Acres 0.07 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qeak 0.13 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 172 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 149 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 17 fti Concrete 0,95 Primary Treatment/StorageBasin V 155 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 172 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:15 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin H-1 8 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 1,922 Acres 0.04 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.08 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 104 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 91 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 10 fti Concrete 0,95 Primary Treatment/StorageBasin V 94 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 104 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:15 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin 1-1 9 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 1,487 Acres 0.03 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc 1 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qeak 0.06 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 81 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 70 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 8 fti Concrete 0,95 Primary Treatment/StorageBasin V 73 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 81 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:15 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin J-1 10 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 3,862 Acres 0.09 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qeak 0.16 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 209 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 182 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 21 fti Concrete 0,95 Primary Treatment/StorageBasin V 188 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 209 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:15 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin K-1 11 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 1,634 Acres 0.04 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.07 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 89 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 77 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 9 fti Concrete 0,95 Primary Treatment/StorageBasin V 80 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 89 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:16 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. Steps for Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-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 100-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 11 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 5,620 2,397 Acres 0.18 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 Usercalculate min �10 Min. Estimated Runoff Coefficients for Various Surfau — Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc I 2.58 n hr Business owntown areas 0,70-0.95 (� D 9 Calculate the Post-Development peak discharge(ClPeak) QP.k 0.33 cfs urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0-50 10 Calculate total runoff vol(V)(for sizing primary storage) V 443 ft3 Multi-family o.6o-o.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 277 ft' Heavy areas 0.90 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,cemeteries a.10-o.25 Playgrounds 0.20.035 Railroad yard areas 0.20-0.40 13 Volume Summary unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 44 ft3 Concrete 0.95 Primary Treatment/Storage Basin V 398 ft3 Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 443 ft3 Fields:Sandy soil Soil Type Slope A 8 C 0 Flat:0-2% 0.04 0.07 0.22 0.: Average:2-6% 0-09 0,12 0.15 0.: Steep:>61y, 0-13 0.18 0.23 0.: Adapted from ASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,1:16 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 Peak Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin B-1 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 9,528 3,601 Acres 0.30 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avgl 0.72 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qeak 0.56 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 747 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 467 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 75 fti Concrete 0,95 Primary Treatment/StorageBasin V 672 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 747 ft Gravel 0,75 Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:17 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 Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin C-1 3 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 13,842 2,091 Acres 0.37 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.84 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.79 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,060 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 662 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 106 fti Concrete 0,95 Primary Treatment/StorageBasin V 954 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 1,060 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0.. Adapted from ASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:17 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 Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin D-1 4 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 3,730 3,136 Acres 0.16 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.56 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.23 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 306 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 191 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 31 fti Concrete 0,95 Primary Treatment/StorageBasin V 275 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 306 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:17 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 Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin E-1 5 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 3,937 Acres 0.09 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.22 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 297 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 185 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 30 fti Concrete 0,95 Primary Treatment/StorageBasin V 267 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 297 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:17 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 Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin F-1 6 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 5,600 Acres 0.13 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.32 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 422 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 264 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 42 fti Concrete 0,95 Primary Treatment/StorageBasin V 380 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 422 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:17 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 Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin G-1 7 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 3,170 Acres 0.07 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.18 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 239 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 149 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 24 fti Concrete 0,95 Primary Treatment/StorageBasin V 215 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 239 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:17 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 Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin H-1 8 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 1,922 Acres 0.04 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qeak 0.11 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 145 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 91 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 14 fti Concrete 0,95 Primary Treatment/StorageBasin V 130 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 145 ft Gravel 0,75 Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:18 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 Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin 1-1 9 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 1,487 Acres 0.03 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc 1 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.08 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 112 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 70 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 11 fti Concrete 0,95 Primary Treatment/StorageBasin V 101 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 112 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:18 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 Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin J-1 10 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 3,862 Acres 0.09 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.22 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 291 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 182 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 29 fti Concrete 0,95 Primary Treatment/StorageBasin V 262 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 291 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:18 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 Discharge Rate using the Rational Method calculated for post-development 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin K-1 11 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 Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 1,634 Acres 0.04 6 Determine the Weighted Runoff Coefficient(C) 0.95 C=[(ClxA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.95 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate — min [t0 Min. Estimated Runoff Coefficients for Various Surfac4 Type of Surface Runoff Coefficients"f 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0,70-0.95 y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.09 cfs Urban neighborhoods 0.50.0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 123 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0,40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th industrial and Commercial ( p ) 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 77 ft' Heavy areas 0.90 Parks,Cemeteries 0.20-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0,20-0.35 Railroad vard areas 0-20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 12 fti Concrete 0,95 Primary Treatment/StorageBasin V 111 ftj Brick 0.95 Subsurface Storage Roofs 0.95 Volume Without Sediment Factor(See BMP 20 Tab) V 123 ft Gravel 0,75j Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 C.: Average:2-6% 0.09 0.12 OAS 0- Stee :>6% 0.13 0.18 0.23 0- Adopted fromASCE P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xlsm 3/28/2023,1:18 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin A-1-SB#1(Private) 2 Enter number of Seepage Beds(25 max) 4 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.70 Link to Q'V J QV2 5 Area A(Acres) 0.18 acres QV3 6 Approved discharge rate(if applicable) 0.00 cfs QV4 Qvs _ 7 Is Seepage Bed in Common Lot? No V 553 ft3 25%Sediment 8 Set Total Design Width of All Drain Rock W 9.0 ft 9 Set Total Design Depth of All Drain Rock D 4.0 ft Rock Only,Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 11 Design Infiltration Rate(8 in/hr max) Perc 4.00 in/hr 12 Size of WQ Perf Pipe(Pert 180°) Dia pipe 18 in 13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Spf 17.6 ft3/ft 15 Calculate Design Length L 31 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 31 ft 17 Variable Infiltration Window W SWW 9.0 ft 18 Time to Drain 57 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 31 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 ft'/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft'/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:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:35 PM Version 10.5,November 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin B-1-SB#2(Private) 2 Enter number of Seepage Beds(25 max) 4 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.72 Link to: Q V J [ 5 Area A(Acres) 0.30 acres Qv3� 6 Approved discharge rate(if applicable) 0.00 cfs QV4 Qvs _ 7 Is Seepage Bed in Common Lot? No V 933 ft3 25%Sediment 8 Set Total Design Width of All Drain Rock W 9.0 ft 9 Set Total Design Depth of All Drain Rock D 4.0 ft Rock Only,Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 11 Design Infiltration Rate(8 in/hr max) Perc 4.00 in/hr 12 Size of WQ Perf Pipe(Pert 180°) Dia pipe 18 in 13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Spf 17.6 ft3/ft 15 Calculate Design Length L 53 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 53 ft 17 Variable Infiltration Window W SWW 9.0 ft 18 Time to Drain 5.7 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 53 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 ft'/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft'/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:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:40 PM Version 10.5,November 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin C-1-SB#3(Private) 2 Enter number of Seepage Beds(25 max) 4 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.84 Link to: Q V _ Qvz 5 Area A(Acres) 0.37 acres [QV3� 6 Approved discharge rate(if applicable) 0.00 cfs QV4 Qvs _ 7 Is Seepage Bed in Common Lot? No V 1,325 ft3 25%Sediment 8 Set Total Design Width of All Drain Rock W 9.0 ft 9 Set Total Design Depth of All Drain Rock D 4.5 ft Rock Only,Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 11 Design Infiltration Rate(8 in/hr max) Perc 4.00 in/hr 12 Size of WQ Perf Pipe(Pert 180°) Dia pipe 18 in 13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Spf 19.4 ft3/ft 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 9.0 ft 1 18 Time to Drain 5.8 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 ft'/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft'/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:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:42 PM Version 10.5,November 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 TM Creek Subdivision No.7 Roadways and Utilities-Basin D-1-SB#4(Private) 2 Enter number of Seepage Beds(25 max) 4 3 Design Storm 100 4 Weighted Runoff Coefficient 0.56 Link to: Qv J 5 Area A(Acres) 0.16 acres Qv3 6 Approved discharge rate(if applicable) 0.00 cfs 10M4� Qvs _ 7 Is Seepage Bed in Common Lot? No V 383 ft3 25%Sediment 8 Set Total Design Width of All Drain Rock W 6.0 ft 9 Set Total Design Depth of All Drain Rock D 5.0 ft Rock Only,Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 11 Design Infiltration Rate(8 in/hr max) Perc 4.00 in/hr 12 Size of WQ Perf Pipe(Pert 180°) Dia pipe 18 in 13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Spf 14.2 ft3/ft 15 Calculate Design Length L 27 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 27 ft 17 Variable Infiltration Window W SWW 6.0 ft 18 Time to Drain 6.4 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 27 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxJ(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 ft'/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft'/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:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:41 PM Version 10.5,November 2018 TEMPORARY POND CALCULATIONS ACHD Calculation Sheet for Sizing Basins 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. User input in yellow cells. 1 Project Name TM Creek Subdivision No.7 Roadways and Utilities-Basin E-1-Temporary Pond#1(Private) 2 Enter number of Basins(25 max) 7 3 Number of Cells(Forebay+primary=2,Primary Only=1) 1 4 Design Storm 300 do ON - 5 Weighted Runoff Coefficient C 0.95 QVz QV3 6 Area A(Acres) 0.09 acres QV4 0.00 cfs QV5 7 Approved Discharge Rate(if applicable) Q,V6 8 2-Primary Treatment/Storage V 297 ft3 QV7 Va Toggle between Forebay and Primary Basin,enter data and print for each SdeSIRe Z Sh Stops Z M54.. a � � w v stskrz s <..-L A-----------t--------a Sick SkpeZ <L 1 lapez Primary Basin 9 Select Primary Basin Shape 3-Rectangle 10 Width of Primary Basin Bottom W 12.0 ft 11 Length of Primary Basin Bottom RW L 12.0 ft 12 Side Slopes(H:1) H:1 3.00 13 Enter Bottom Elevation 2580.65 ft 14 Enter Top Bank Elevation 2582.65 ft 15 Enter Water Surface Elevation(WSE) 2582.15 ft 16 Distance Between Forebayand Primary Basin(blank if na) 0.00 ft 17 Enter Elevation Berm 0.00 ft 18 Enter High Groundwater Elevation 2573.40 ft 19 Min.Freeboard Requirement 0.50 20 Freeboard Provided 21 Infiltration Area for Primary/Storage Basin Infiltration? 4.00 in/hr Note:infiltration required if Design Infiltration Rate,Enter 0 for no infiltration bottom sloped%or 0 outflow 22 Infiltration Area for Primary Asa.d 144 ftz Enter 0 for no infiltration 23 Adjusted Storage Required 960i Duration i total Q Runoff Vol Perc Vol Pre-Dev Total Max Vol Discharge Discharge Reqd Hr in/hr cfs ft3ft3ft3ft3 ft31.00 0.96 0.08 297 48 0 48 249 24 Depth-Storage Relationship: Saved Surface Basin Basin Surface Surface Area A at Volume Saved Stage Side Slope Width at Length at Area A at Area A at Stage(ft') Below Stage (ft) New Stage(ft) (H:V) Stage(ft) Stage(ft) Stage(ft) Stage(ftz) OVERIDE (ft) 2580.65 2580.65 3.000 12.0 12.0 144 0 2582.15 3.000 21.0 21.0 441 439 1.50 ft depth for storage STORAGE OK 25 Does primary/storage basin have capacity? 26 Time to drain primary/storage basin 5.6 hours 90%volume in 48-hours minimum - P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:44 PM Version 10.5,November 2018 ACHD Calculation Sheet for Sizing Basins 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. User input in yellow cells. 1 Project Name TM Creek Subdivision No.7 Roadways and Utilities-Basin F-1-Temporary Pond#2(Private) 2 Enter number of Basins(25 max) 7 3 Number of Cells(Forebay+primary=2,Primary Only=1) 1 4 Design Storm 300 rCQV4 5 Weighted Runoff Coefficient C 0.95 6 Area A(Acres) 0.13 acres 0.00 cfs 7 Approved Discharge Rate(if applicable)8 2-PrimaryTreatment/Storage V 422 ft3 Toggle between Forebay and Primary Basin,enter data and print for each *L . StopsZ MOW z� �w<..- A-----------t--------a Sick SkpeZ <L 1 lapez Primary Basin 9 Select Primary Basin Shape 3-Rectangle 10 Width of Primary Basin Bottom W 12.0 ft 11 Length of Primary Basin Bottom RW L 12.0 ft 12 Side Slopes(H:1) H:1 3.00 13 Enter Bottom Elevation 2580.65 ft 14 Enter Top Bank Elevation 2582.65 ft 15 Enter Water Surface Elevation(WSE) 2582.15 ft 16 Distance Between Forebayand Primary Basin(blank if na) 0.00 ft 17 Enter Elevation Berm 0.00 ft 18 Enter High Groundwater Elevation 2573.40 ft 19 Min.Freeboard Requirement 0.50 20 Freeboard Provided 21 Infiltration Area for Primary/Storage Basin Infiltration? 4.00 in/hr Note:infiltration required if Design Infiltration Rate,Enter 0 for no infiltration bottom sloped%or 0 outflow 22 Infiltration Area for Primary Asa.d 144 ftz Enter 0 for no infiltration 23 Adjusted Storage Required 960i Duration i total Q Runoff Vol Perc Vol Pre-Dev Total Max Vol Discharge Discharge Reqd Hr in/hr cfs ft3ft3ft3ft3 ft31.00 0.96 0.12 422 48 0 48 374 24 Depth-Storage Relationship: Saved Surface Basin Basin Surface Surface Area A at Volume Saved Stage Side Slope Width at Length at Area A at Area A at Stage(ft') Below Stage (ft) New Stage(ft) (H:V) Stage(ft) Stage(ft) Stage(ft) Stage(ftz) OVERIDE (ft) 2580.65 2580.65 3.000 12.0 12.0 144 0 2582.15 3.000 21.0 21.0 441 439 1.50 ft depth for storage STORAGE OK 25 Does primary/storage basin have capacity? 26 Time to drain primary/storage basin 7.9 hours 90%volume in 48-hours minimum - P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:44 PM Version 10.5,November 2018 ACHD Calculation Sheet for Sizing Basins 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. User input in yellow cells. 1 Project Name TM Creek Subdivision No.7 Roadways and Utilities-Basin G-1-Temporary Pond#3(Private) 2 Enter number of Basins(25 max) 7 3 Number of Cells(Forebay+primary=2,Primary Only=1) 1 4 Design Storm 300 &QV4 - 5 Weighted Runoff Coefficient C 0.95 6 Area A(Acres) 0.07 acres 0.00 cfs 7 Approved Discharge Rate(if applicable)8 2-Primary Treatment/Storage V 239 ft3 Toggle between Forebay and Primary Basin,enter data and print for each *L . Sick54.z w<..- A-----------t--------a Sick SkpeZ <L 1 lapez Primary Basin 9 Select Primary Basin Shape 3-Rectangle 10 Width of Primary Basin Bottom W 12.0 ft 11 Length of Primary Basin Bottom L 12.0 ft 12 Side Slopes(H:1) H:1 3.00 13 Enter Bottom Elevation 2580.90 ft 14 Enter Top Bank Elevation 2582.90 ft 15 Enter Water Surface Elevation(WSE) 2582.40 ft 16 Distance Between Forebayand Primary Basin(blank if na) 0.00 ft 17 Enter Elevation Berm 0.00 ft 18 Enter High Groundwater Elevation 2573.40 ft 19 Min.Freeboard Requirement 0.50 20 Freeboard Provided 21 Infiltration Area for Primary/Storage Basin Infiltration? 4.00 in/hr Note:infiltration required if Design Infiltration Rate,Enter 0 for no infiltration bottom sloped%or 0 outflow 22 Infiltration Area for Primary Asa.d 144 ftz Enter 0 for no infiltration 23 Adjusted Storage Required 960i Duration i total Q Runoff Vol Perc Vol Pre-Dev Total Max Vol Discharge Discharge Reqd Hr in/hr cfs ft3ft3ft3ft3 ft31.00 0.96 0.07 239 48 0 48 191 24 Depth-Storage Relationship: Saved Surface Basin Basin Surface Surface Area A at Volume Saved Stage Side Slope Width at Length at Area A at Area A at Stage(ft') Below Stage (ft) New Stage(ft) (H:V) Stage(ft) Stage(ft) Stage(ft) Stage(ftz) OVERIDE (ft) 2580.90 2580.90 3.000 12.0 12.0 144 0 2582.40 3.000 21.0 21.0 441 439 1.50 ft depth for storage STORAGE OK 25 Does primary/storage basin have capacity? 26 Time to drain primary/storage basin 4.5 hours 90%volume in 48-hours minimum - P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:44 PM Version 10.5,November 2018 ACHD Calculation Sheet for Sizing Basins 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. User input in yellow cells. 1 Project Name TM Creek Subdivision No.7 Roadways and Utilities-Basin H-1-Temporary Pond#4(Private) 2 Enter number of Basins(25 max) 7 3 Number of Cells(Forebay+primary=2,Primary Only=1) 1 4 Design Storm 300 ILQV4 - 5 Weighted Runoff Coefficient C 0.95 6 Area A(Acres) 0.04 acres 0.00 cfs 7 Approved Discharge Rate(if applicable)8 2-PrimaryTreatment/Storage V 145 ft3 Toggle between Forebay and Primary Basin,enter data and print for each SdeSIRe Z S�Slope Z sac 54.. a pmw w, w v stsiemz sa s <..-L A-----------t--------a sideslwz <L 1 lapez Primary Basin 9 Select Primary Basin Shape 3-Rectangle 10 Width of Primary Basin Bottom W 12.0 ft 11 Length of Primary Basin Bottom L 12.0 ft 12 Side Slopes(H:1) H:1 3.00 13 Enter Bottom Elevation 2580.75 ft 14 Enter Top Bank Elevation 2582.75 ft 15 Enter Water Surface Elevation(WSE) 2582.25 ft 16 Distance Between Forebayand Primary Basin(blank if na) 0.00 ft 17 Enter Elevation Berm 0.00 ft 18 Enter High Groundwater Elevation 2573.40 ft 19 Min.Freeboard Requirement 0.50 20 Freeboard Provided 21 Infiltration Area for Primary/Storage Basin Infiltration? 4.00 in/hr Note:infiltration required if Design Infiltration Rate,Enter 0 for no infiltration bottom sloped%or 0 outflow 22 Infiltration Area for Primary Asa.d 144 ftz Enter 0 for no infiltration 23 Adjusted Storage Required 960i Duration i total Q Runoff Vol Perc Vol Pre-Dev Total Max Vol Discharge Discharge Reqd Hr in/hr cfs ft3ft3ft3ft3 ft31.00 0.96 0.04 145 48 0 48 97 24 Depth-Storage Relationship: Saved Surface Basin Basin Surface Surface Area A at Volume Saved Stage Side Slope Width at Length at Area A at Area A at Stage(ft') Below Stage (ft) New Stage(ft) (H:V) Stage(ft) Stage(ft) Stage(ft) Stage(ftz) OVERIDE (ft) 2580.75 2580.75 3.000 12.0 12.0 144 0 2582.25 3.000 21.0 21.0 441 439 1.50 ft depth for storage STORAGE OK 25 Does primary/storage basin have capacity? 26 Time to drain primary/storage basin 2.7 hours 90%volume in 48-hours minimum - P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:45 PM Version 10.5,November 2018 ACHD Calculation Sheet for Sizing Basins 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. User input in yellow cells. 1 Project Name TM Creek Subdivision No.7 Roadways and Utilities-Basin 1-1-Temporary Pond#5(Private) 2 Enter number of Basins(25 max) 7 3 Number of Cells(Forebay+primary=2,Primary Only=1) 1 4 Design Storm 300 QV6 - 5 Weighted Runoff Coefficient C 0.95 Q'V7 QV8 6 Area A(Acres) 0.03 acres QV9 0.00 cfs Qvi0 7 Approved Discharge Rate(if applicable) QVit 8 2-P ri m a ry Trea tm e n t/Sto rage V 112 ft3 QVTR55 Toggle between Forebay and Primary Basin,enter data and print for each *L . sac54.z w<..- A-----------t--------a Sick SkpeZ L lapez Primary Basin 9 Select Primary Basin Shape 3-Rectangle 10 Width of Primary Basin Bottom W 12.0 ft 11 Length of Primary Basin Bottom L 12.0 ft 12 Side Slopes(H:1) H:1 3.00 13 Enter Bottom Elevation 2581.00 ft 14 Enter Top Bank Elevation 2583.00 ft 15 Enter Water Surface Elevation(WSE) 2582.50 ft 16 Distance Between Forebayand Primary Basin(blank if na) 0.00 ft 17 Enter Elevation Berm 0.00 ft 18 Enter High Groundwater Elevation 2573.40 ft 19 Min.Freeboard Requirement 0.50 20 Freeboard Provided 21 Infiltration Area for Primary/Storage Basin Infiltration? 4.00 in/hr Note:infiltration required if Design Infiltration Rate,Enter 0 for no infiltration bottom sloped%or 0 outflow 22 Infiltration Area for Primary Asa.d 144 ftz Enter 0 for no infiltration 23 Adjusted Storage Required 960i Duration i total Q Runoff Vol Perc Vol Pre-Dev Total Max Vol Discharge Discharge Reqd Hr in/hr cfs ft3ft3ft3ft3 ft31.00 0.96 0.03 112 48 0 48 64 24 Depth-Storage Relationship: Saved Surface Basin Basin Surface Surface Area A at Volume Saved Stage Side Slope Width at Length at Area A at Area A at Stage(ft') Below Stage (ft) New Stage(ft) (H:V) Stage(ft) Stage(ft) Stage(ft) Stage(ftz) OVERIDE (ft) 2581.00 2581.00 3.000 12.0 12.0 144 0 2582.50 3.000 21.0 21.0 441 439 1.50 ft depth for storage STORAGE OK 25 Does primary/storage basin have capacity? 26 Time to drain primary/storage basin 2.1 hours 90%volume in 48-hours minimum - P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:45 PM Version 10.5,November 2018 ACHD Calculation Sheet for Sizing Basins 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. User input in yellow cells. 1 Project Name TM Creek Subdivision No.7 Roadways and Utilities-Basin J-1-Temporary Pond#6(Private) 2 Enter number of Basins(25 max) 7 3 Number of Cells(Forebay+primary=2,Primary Only=1) 1 4 Design Storm 300 lin It - 5 Weighted Runoff Coefficient C 0.95 6 Area A(Acres) 0.09 acres 0.00 cfs 7 Approved Discharge Rate(if applicable)8 2-PrimaryTreatment/Storage V 291 ft3 5 Toggle between Forebay and Primary Basin,enter data and print for each SdeSIRe Z S�Saope Z slat slope z a rmw w, w v sreskrz sa s <..-L A-----------t--------a SBe SlopeZ L lapez Primary Basin 9 Select Primary Basin Shape 3-Rectangle 10 Width of Primary Basin Bottom W 12.0 ft 11 Length of Primary Basin Bottom L 12.0 ft 12 Side Slopes(H:1) H:1 3.00 13 Enter Bottom Elevation 2581.00 ft 14 Enter Top Bank Elevation 2583.00 ft 15 Enter Water Surface Elevation(WSE) 2582.50 ft 16 Distance Between Forebayand Primary Basin(blank if na) 0.00 ft 17 Enter Elevation Berm 0.00 ft 18 Enter High Groundwater Elevation 2573.40 ft 19 Min.Freeboard Requirement 0.50 20 Freeboard Provided 21 Infiltration Area for Primary/Storage Basin Infiltration? 4.00 in/hr Note:infiltration required if Design Infiltration Rate,Enter 0 for no infiltration bottom sloped%or 0 outflow 22 Infiltration Area for Primary Asa.d 144 ftz Enter 0 for no infiltration 23 Adjusted Storage Required 960i Duration i total Q Runoff Vol Perc Vol Pre-Dev Total Max Vol Discharge Discharge Reqd Hr in/hr cfs ft3ft3ft3ft3 ft31.00 0.96 0.08 291 48 0 48 243 24 Depth-Storage Relationship: Saved Surface Basin Basin Surface Surface Area A at Volume Saved Stage Side Slope Width at Length at Area A at Area A at Stage(ft') Below Stage (ft) New Stage(ft) (H:V) Stage(ft) Stage(ft) Stage(ft) Stage(ftz) OVERIDE (ft) 2581.00 2581.00 3.000 12.0 12.0 144 0 2582.50 3.000 21.0 21.0 441 439 1.50 ft depth for storage STORAGE OK 25 Does primary/storage basin have capacity? 26 Time to drain primary/storage basin 5.5 hours 90%volume in 48-hours minimum - P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:45 PM Version 10.5,November 2018 ACHD Calculation Sheet for Sizing Basins 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. User input in yellow cells. 1 Project Name TM Creek Subdivision No.7 Roadways and Utilities-Basin K-1-Temporary Pond#7(Private) 2 Enter number of Basins(25 max) 7 3 Number of Cells(Forebay+primary=2,Primary Only=1) 1 4 Design Storm 300 Link QV5 - 5 Weighted Runoff Coefficient C 0.95 Q,V6 QV7 6 Area A(Acres) 0.04 acres Q.VB Q'7 Approved Discharge Rate(if applicable) 0.00 cfs QV9V70 8 2-Primary Treatment/Storage V 123 ft3 Q,vtt Q V TR55 Toggle between Forebay and Primary Basin,enter data and print for each SdeSIRe Z S�Slope Z sac Siege z a pmw w v stsiemz sa s <..-L A-----------t--------a side Slwz L lapez Primary Basin 9 Select Primary Basin Shape 3-Rectangle 10 Width of Primary Basin Bottom W 12.0 ft 11 Length of Primary Basin Bottom L 12.0 ft 12 Side Slopes(H:1) H:1 3.00 13 Enter Bottom Elevation 2582.50 ft 14 Enter Top Bank Elevation 2584.50 ft 15 Enter Water Surface Elevation(WSE) 2594.00 ft 16 Distance Between Forebayand Primary Basin(blank if na) 0.00 ft 17 Enter Elevation Berm 0.00 ft 18 Enter High Groundwater Elevation 2573.70 ft 19 Min.Freeboard Requirement 0.50 20 Freeboard Provided 21 Infiltration Area for Primary/Storage Basin Infiltration? 4.00 in/hr Note:infiltration required if Design Infiltration Rate,Enter 0 for no infiltration bottom sloped%or 0 outflow 22 Infiltration Area for Primary Asa.d 144 ftz Enter 0 for no infiltration 23 Adjusted Storage Required 960i Duration i total Q Runoff Vol Perc Vol Pre-Dev Total Max Vol Discharge Discharge Reqd Hr in/hr cfs ft3ft3ft3ft3 ft31.00 0.96 0.03 123 48 0 48 75 24 Depth-Storage Relationship: Saved Surface Basin Basin Surface Surface Area A at Volume Saved Stage Side Slope Width at Length at Area A at Area A at Stage(ft') Below Stage (ft) New Stage(ft) (H:V) Stage(ft) Stage(ft) Stage(ft) Stage(ftz) OVERIDE (ft) 2582.50 2582.50 3.000 12.0 12.0 144 0 2584.00 3.000 21.0 21.0 441 439 1.50 ft depth for storage STORAGE OK 25 Does primary/storage basin have capacity? 26 Time to drain primary/storage basin 2.3 hours 90%volume in 48-hours minimum - P:\23-004\Documents\Reports\Storm Drainage\Calcs\ACHD_SD_CALCS_112018.xism 3/28/2023,2:46 PM Version 10.5,November 2018 APPENDIX D - GEOTECHNICAL ENGINEERING REPORT - t p f �r r l • Afr OF G GEOTECHNICAL INVESTIGATION TEN MILE CREEK APARTMENTS 4 SWC of Franklin Road and Benchmark Road Meridian, ID PREPARED FOR: Mr. Nick Ploetz Brighton Corporation 2929 West Navigator Drirve Suite 400 Meridian, ID 83642 WWWOWPREPARED BY: Atlas Technical Consultants, LLC August 30, 2022 2791 South Victory View Way B221646g Boise, ID 83709 �TrT—G7T�J� 2791 South Victory View Way Boise, ID 83709 (208)376-4748 1 oneatlas.com August 30, 2022 Atlas No. B221646g Mr. Nick Ploetz Brighton Corporation 2929 West Navigator Drirve Suite 400 Meridian, ID 83642 Subject: Geotechnical Investigation Ten Mile Creek Apartments 4 SWC of Franklin Road and Benchmark Road Meridian, ID Dear Mr. Ploetz: 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 July 25 and 26 and August 25 and 26, 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. ��SS\ON NS FNc F Respectfully submitted, ��o Fo y a 14919 8-30-22 Gavin Marron, El Monica Saculles, PE OF � �``) Staff Engineer Senior Geotechnical En �SAOV Clinton Wyllie, PG Staff Geologist Page 1 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 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....................................................................................... 5 4.3 Soil and Sediment Profile........................................................................................... 5 4.4 Volatile Organic Scan................................................................................................. 6 5. SITE HYDROLOGY............................................................................................................ 6 5.1 Groundwater.............................................................................................................. 6 5.2 Soil Infiltration Rates .................................................................................................. 7 5.3 Infiltration Testing....................................................................................................... 7 6. LATERAL EARTH PRESSURES ....................................................................................... 8 6.1 Retaining Wall Backfill Materials................................................................................. 8 6.2 Retaining Wall Drainage............................................................................................10 7. FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS...........................11 7.1 Foundation Design Recommendations......................................................................11 7.2 Floor Slab-on-Grade..................................................................................................12 8. PAVEMENT DISCUSSION AND RECOMMENDATIONS..................................................13 8.1 Flexible Pavement Sections ......................................................................................13 8.2 Pavement Subgrade Preparation ..............................................................................14 8.3 Common Pavement Section Construction Issues......................................................14 9. CONSTRUCTION CONSIDERATIONS .............................................................................14 9.1 Earthwork..................................................................................................................15 9.2 Dry Weather..............................................................................................................15 9.3 Wet Weather.............................................................................................................16 9.4 Soft Subgrade Soils...................................................................................................16 9.5 Frozen Subgrade Soils..............................................................................................16 Atlas No. B221646g Page I i Copyright©2022 Atlas Technical Consultants 9.6 Structural Fill .............................................................................................................17 9.7 Backfill of Walls.........................................................................................................18 9.8 Excavations...............................................................................................................18 9.9 Groundwater Control.................................................................................................19 10. GENERAL COMMENTS..................................................................................................19 11. REFERENCES.................................................................................................................20 TABLES Table 1 — Seismic Design Values................................................................................................4 Table 2 — Groundwater Data.......................................................................................................6 Table 3— Infiltration Test Results................................................................................................7 Table 4— Lateral Earth Pressure Values for Native Soil..............................................................9 Table 5— Lateral Earth Pressure Values for Native Soil..............................................................9 Table 6— Lateral Earth Pressure Values for Fill Materials.........................................................10 Table 7 — Soil Bearing Capacity................................................................................................11 Table 8—AASHTO Flexible Pavement Specifications...............................................................13 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 AASHTO Pavement Design Appendix VII Important Information About This Geotechnical Engineering Report Atlas No. B221646g Page i ii Copyright©2022 Atlas Technical Consultants �TrT2 - T".ZJ--1 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 structures 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 southwestern portion of the City of Meridian, Ada County, ID, and occupies a portion of the NE%4NW%4 and NW%NE%of Section 14, Township 3 North, Range 1 West, Boise Meridian. This project is expected to consist of five 4-story apartment structures and a 2-story clubhouse structure with an associated pool. The site to be developed is approximately 9.0 acres. Total settlements are limited to 1 inch. Loads of up to 5,000 pounds per lineal foot for wall footings, and column loads of up to 100,000 pounds were assumed for settlement calculations. Additionally, assumptions have been made for traffic loading of pavements. Retaining walls in the form of pool walls are anticipated. 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. Nick Ploetz of Brighton Corporation to Jacob Schlador of Atlas Technical Consultants (Atlas), on July 11, 2022. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between Brighton Corporation and Atlas. Our scope of services for the proposed development has been provided in our proposal dated July 7, 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. ML Atlas No. B221646g Page 11 Copyright©2022 Atlas Technical Consultants �TrT2 _ T".ZJ__1 2. SITE DESCRIPTION 2.1 Site Access Access to the site may be gained via Interstate 84 to the Ten Mile Road exit. Proceed north on Ten Mile Road approximately 0.75 mile to its intersection with Franklin Road. From this intersection, proceed east on Franklin Road 0.56 mile to Benchmark Road. Continue south on Benchmark Road approximately 0.10 mile to the project site. The site is located on the west side of Benchmark 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 southern portion of the project site is underlain by "Sandy Alluvium of Side-Stream Valleys and Gulches" as mapped by Othberg and Stanford (1993). Locally, these deposits are composed of medium to coarse sand interbedded with silty fine sand and silt and are mostly derived from weathered granite and reworked Tertiary sediments of the Boise Foothills. The thickness of this unit is variable. Because of the relative youthfulness of these deposits they contain only minor pedogenic clay and calcium carbonate. The northern portion of the project site is underlain by the "Gravel of Whitney Terrace" as mapped by Othberg and Stanford (1993). Sediments of the Whitney terrace consist of sandy pebble and cobble gravel. The Whitney terrace is the second terrace above modern Boise River floodplain, is thickest toward its eastern extent, and is mantled with 2-6 feet of loes 2.3 General Site Characteristics The site to be developed is approximately 9.0 acres in size. Currently, the site is being used as a storage yard for a development being constructed to the west of the project. Tenmile Creek runs roughly east to west along the southern boundary of the property. The remainder of the site consists of vacant land. At the time of the field exploration, the majority of the site was stripped of organics. The western half of the site is currently under earthwork construction. In the eastern portion of the site, an approximately 15 foot tall stockpile of silty gravel with sand material is present. Along the southern property boundary is undeveloped land. To the east and north of the site are existing residential properties. Vegetation on the site consists primarily of sparse weeds and grasses. The site is relatively flat and level. Slopes along Tenmile Creek are approximately 2 feet horizontal to 1 foot vertical (2:1). Atlas No. 13221646g Page 12 Copyright©2022 Atlas Technical Consultants 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 present along West Franklin Road in the form of curbs, gutters, and drop inlets. 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 OF to 95°F, with daily extremes ranging from roughly -25°F to 111°F. 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 0.196 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, SMI, 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, SDI. Atlas No. B221646g Page 13 Copyright©2022 Atlas Technical Consultants 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). Table 1 —Seismic Design Values Seismic Design Parameter Design Value Site Class D "Default' Ss 0.287 (g) S1 0.105 (g) Fa 1.571 F 2.390 Sms 0.451 Smi 0.250 Sys 0.300 Sol 0.167 4. SOILS EXPLORATION 4.1 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 staked in the field by Brighton Corporation. Actual test pit sites were located in the field by means of a Global Positioning System (GPS) device and are reportedly accurate to within fifteen 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. Atlas No. B221646g Page 14 Copyright©2022 Atlas Technical Consultants 4.2 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 and Grain Size Analysis —ASTM C117/C136. 'nil 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. Silty gravel with sand fills and poorly graded gravel with silt and sand fills were found at ground surface in all of the test pits except test pits 1, 10, and 12. These materials were light brown, dry, and medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Organic debris was noted within these materials in test pit 21. Borderline sandy lean clay/clayey sand soils were encountered beneath fill materials in test pit 21. These soils were brown, dry, and stiff to very stiff/medium dense, with fine to medium-grained sand. Varying layers of sandy silts and silty sands were observed at ground surface in test pits 1, 10, and 12, underlying borderline sandy lean clay/clayey sand soils in test pit 21, and beneath fill materials in the remaining test pits. These soils were light brown, dry, and medium stiff to very stiff/medium dense to dense, with fine to coarse-grained sand. Organic materials were measured to depths of up to roughly 0.6 foot. Below silt/sand mixtures, poorly graded sands and gravels were exposed. These sediments were light brown, dry to slightly moist, and medium dense to dense. Fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles were noted throughout. At depth, poorly graded gravel with clay and sand sediments were encountered. These sediments were light brown, dry to slightly moist, and medium dense to very dense, with fine to coarse- grained sand, fine to coarse gravel, and 10-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. Atlas No. 13221646g Page 15 Copyright©2022 Atlas Technical Consultants 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 during test pit excavation. 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. 5.1 Groundwater During the initial field investigation conducted on July 25, 2022, groundwater was not encountered in test pits advanced to a maximum depth of 16.2 feet bgs. However, when Atlas advanced additional test pits on August 25, 2022, groundwater was measured in the previously placed piezometers at depths ranging from 14.0 to 15.1 feet bgs. Soil moistures in the test pits were generally dry to slightly moist. In the vicinity of the project site, groundwater levels are controlled in large part by commercial irrigation activity and leakage from nearby canals and Tenmile Creek. Maximum groundwater elevations likely occur during the later portion of the irrigation season. Atlas has previously performed 7 geotechnical investigations within 0.25 mile of the project site. Information from these investigations has been provided in the table below. Table 2 —Groundwater Data N&LateM Approximate Distance • - from bas A March 2017 0.05 West Not encountered to 16.8 March 2021 0.07 South 12.8 to 19.2* March 2021 0.10 South Not Encountered to 15.8 May 2021 0.14 East Not Encountered to 15.2 March 2021 0.16 East Not Encountered to 15.5 March 2020 0.20 Northeast Not Encountered to 16.8 November 2006 0.25 East Not Encountered to 14.9 *Site is approximately 8 feet lower in elevation than the project site. For construction purposes, groundwater depth can be assumed to remain greater than 12 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 test pits 1, 2, 7, 8, 11, 14, 15, 16, 18, 20, 22, and 23. If desired, Atlas is available to perform this monitoring. Atlas No. B221646g Page 16 Copyright©2022 Atlas Technical Consultants �TrT2 _ T".ZJ__1 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, borderline sandy lean clay/clayey 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. Poorly graded gravel with clay and sand sediments typically have infiltration rates ranging from 2 to 6 inches per hour. Silty sand sediments usually display rates of 4 to 8 inches per hour; though cementation may reduce this value to near zero. Poorly graded sand and gravel sediments typically exhibit infiltration values in excess of 12 inches per hour. 5.3 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. Testing was conducted on July 26 and August 26, 2022. Details and results of testing are as follows: Table 3—Infiltration Test Results Test Test Depth Stabilized Infiltration Design Infiltration Location (feet bgs) Soil Type Rate Rate (inches/hour) (inches per hour) TP-2 7.7 Poorly Graded Sand with >16.0 8.0 Gravel TP-17 6.3 Poorly Graded Sand with >16.0 8.0 Gravel TP-19 6.5 Poorly Graded Sand with >16.0 8.0 Gravel TP-24 9.7 Poorly Graded Gravel 5.4 2.7 with Clay and Sand TP-25 11.5 Poorly Graded Gravel 10.2 5.1 with Clay and Sand Poorly graded sand with -gravel sediments had measured infiltration rates in excess of 16 inches per hour. However, the underlying poorly graded gravel with clay and sand sediments may limit drainage. Atlas No. B221646g Page 17 Copyright©2022 Atlas Technical Consultants �TrT2 _ T".ZJ__1 In accordance with the ACHD Policy Manual, a factor of safety of 2 has been applied to the stabilized infiltration rates achieved during testing to obtain the design infiltration rates listed above. The reason for the decreased infiltration rate is to account for long term saturation of the soils and the potential for less permeable soils to settle into the bottom of the infiltration facilities. Atlas recommends that all infiltration facilities be constructed in accordance with the local municipality requirements. 6. LATERAL EARTH PRESSURES Retaining, below-grade, or basement walls will be subject to lateral earth pressures. The magnitude of earth pressure is a function of both type and compaction of backfill behind walls within the "active" zone, and allowable rotation of the top of the wall. The active zone is defined as the wedge of soil between the surface of the wall and a plane inclined 31 degrees from vertical passing through the base of the wall. All clayey soils must be completely removed from within the active zone. The following recommendations should be used when dealing with lateral earth pressures on a gravity block: 1) a sliding frictional coefficient of 0.35 is appropriate considering native silty sand/sandy silt soils and borderline sandy lean clay/clayey sand soils, and 2) a sliding frictional coefficient of 0.45 is appropriate considering granular structural fill under typical conditions. A state of plastic equilibrium is when the subject material is considered to be 1) homogeneous and unbounded and 2) at the point of incipient instability. This state is evaluated on the basis of unit weight, mechanical properties, and the definition of instability. For the purpose of this report, it is assumed that native relatively free draining soils and imported granular fill material will be the materials of concern regarding lateral earth pressures. If other materials are considered for use, Atlas must be contacted to provide alternate lateral earth pressure information. Furthermore, changes in natural soil moisture, such as can be imposed by site stormwater systems, can change the values listed below. Below-grade restrained walls, such as basement walls, should be designed based on at-rest pressures. Active pressures are appropriate under conditions where the wall moves or rotates away from the soil mass at failure. Passive pressures are used for conditions where the wall moves toward the soil mass at failure. Rotation, or lateral movement, of the top of the wall equal to 0.002 times the height of the wall will be necessary for on-site soil backfill to achieve an "active" loading condition. Lateral movement of the top of the wall equal to 0.001 times the height of the wall will be necessary for the "active" pressure condition for imported granular structural backfill. 6.1 Retaining Wall Backfill Materials For lateral earth pressure analysis, Atlas anticipates that the soils of interest will be the onsite native sandy silt soils and silty sand soils. Clayey soils are not suitable for use as backfill on the soil side of walls. Seismic lateral earth pressures have also been provided in the following tables, and were calculated per the Whitman method. For sandy silt and silty sand soils, the following values are applicable under non-surcharged, drained conditions. Atlas No. B221646g Page 18 Copyright©2022 Atlas Technical Consultants �TrTG7T�.�J� Table 4— Lateral Earth Pressure Values for Native Soil Soil Type: Sandy Silt/Silty Sand Internal Friction Angle: 28 ° Dry Unit Weight: 110 pcf Cohesion: 100 psf Bouyant Unit Weight: 73 pcf Natural Void Ratio: 0.7 Natural Moisture: 17 % Ground Acceleration2: 0.196 Backfill Slope: 0 ° At rest lateral earth pressure: 68 pcf' Ko= 0.53 Active lateral earth pressure: 46 pcf' Ka 0.36 Passive lateral earth pressure: 356 pcf' KP 2.77 Seismic active lateral earth pressure: 65 pcf' Kae= 0.51 Seismic passive lateral earth pressure: 287 pcf' e 2.23 'Lateral earth pressure values are in pounds per square foot,per foot of wall(psf/ft). Alternately,the values presented may also be considered as equivalent fluid with units of pounds per cubic foot(pcf). ZGround acceleration obtained from the USGS Seismic Design Maps. Table 5 — Lateral Earth Pressure Values for Native Soil Soil Type: Poorly Graded Sand with Gravel Internal Friction Angle: 30 ° Dry Unit Weight: 120 pcf Cohesion: N/A Bouyant Unit Weight: 83 pcf Natural Void Ratio: 0.7 Natural Moisture: 10 % Ground Acceleration2: 0.196 Backfill Slope: 0 ° At rest lateral earth pressure: 66 pcf' Ko= 0.50 Active lateral earth pressure: 44 pcf' Ka 0.33 Passive lateral earth pressure: 396 pcf' KP 3.00 Seismic active lateral earth pressure: 63 pcf' Kae 0.48 Seismic passive lateral earth pressure: 318 pcf' e 2.41 'Lateral earth pressure values are in pounds per square foot,per foot of wall(psf/ft). Alternately,the values presented may also be considered as equivalent fluid with units of pounds per cubic foot(pcf). ZGround acceleration obtained from the USGS Seismic Design Maps. Imported, compacted, structural material, which must be used to backfill the soil side of walls, must demonstrate the following characteristics: Atlas No. B221646g Page 19 Copyright©2022 Atlas Technical Consultants �TrTG7T�.�J� Table 6 — Lateral Earth Pressure Values for Fill Materials GradedSoil Type: Native Poorly . Internal Friction Angle: 35 ° Dry Unit Weight: 128 pcf Cohesion: N/A Bouyant Unit Weight: 83 pcf Natural Void Ratio: 0.4 Natural Moisture: 5 % Ground Acceleration2: 0.196 Backfill Slope: 0 ° At rest lateral earth pressure: 57 pcf' Ko= 0.43 Active lateral earth pressure: 36 pcf' Ka 0.27 Passive lateral earth pressure: 496 pcf' Kp= 3.69 Seismic active lateral earth pressure: 56 pcf' Kae= 0.42 Seismic passive lateral earth pressure: 399 pcf' e 2.97 'Lateral earth pressure values are in pounds per square foot,per foot of wall(psf/ft). Alternately,the values presented may also be considered as equivalent fluid with units of pounds per cubic foot(pcf). 2Ground acceleration obtained from the USGS Seismic Design Maps. Please note that the values for seismic lateral earth pressures are calculated using both the static and seismic coefficients. The effect of seismic conditions alone is the difference between the static and seismic lateral earth pressures presented above. In the case that another material is used for backfill, Atlas should be consulted for alternate lateral earth pressure values. Granular structural fill should consist of 4-inch-minus select, clean, granular soil with no more than 30 percent oversize (greater than %-inch) material and no more than 5 percent non-plastic fines (passing the No. 200 sieve). Retaining wall and basement backfill must be placed in accordance with recommendations in the Structural Fill section of this report and must be properly compacted and tested. Lateral earth pressure values do not incorporate specific factors of safety, and are only applicable for non-surcharged, drained conditions. Factors of safety, if applicable, should be integrated into the structural design of the wall. The preceding values are presented for idealized conditions relating to simple shallow structures. For complex structures, deep structures, or structures with significant perimeter landscaping, a soils engineer should be retained as part of the design team in developing appropriate project design parameters and construction specifications. 6.2 Retaining Wall Drainage Atlas recommends that a drainage system be incorporated into the retained soil mass. This can be accomplished by installing wall and toe drains as a part of each soil-supporting wall system. In areas where there is potential for significantly high soil moistures within the supported soil mass, installation of drains within the soil mass is recommended. Particular consideration of roof drain effluent and irrigation water must be made. Further, these drainage systems must be separate from other retaining wall/foundation systems. If the granular structural fill option to reduce lateral pressures is used, a compacted low permeability soil cap is recommended within the upper 2 feet of the surface to limit surface water infiltration behind the walls. Atlas No. B221646g Page110 Copyright©2022 Atlas Technical Consultants 7. FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS Various foundation types have been considered for support of the proposed structure. 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. Considering subsurface conditions and the proposed construction, it is recommended that the structure 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. 7.1 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 7—Soil Bearing Capacity Footing Depth ASTM D1557 Net Allowable Soil . . . .city 91 Footings must bear on competent, undisturbed, native sandy silt soils, silty sand sediments, borderline sandy lean clay/clayey sand soils, or Not Required for Native compacted structural fill. Existing organics and fill Soil 2,000 Ibs/ft2 materials must be completely removed from below foundation elements.' Excavation depths ranging 95% for Structural Fill from roughly 0.4 to 3.9 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, silty sand sediments, and borderline sandy lean clay/clayey sand soils, and 2) 0.45 for footings bearing on granular structural fill. A passive lateral earth pressure of 320 pounds per square foot per foot (psf/ft) should be used for borderline sandy lean clay/clayey sand soils. A passive lateral earth pressure of 356 pounds per square foot per foot (psf/ft) should be used for sandy silt/silty sand soils soils. For native poorly graded sand with gravel sediments, a passive lateral earth pressure of 396 psf/ft should be used. For native poorly graded gravel with sand sediments compacted sandy gravel fill, a passive lateral earth pressure of 496 psf/ft should be used. Atlas No. B221646g Page 111 Copyright©2022 Atlas Technical Consultants �TrT2 _ T".ZJ__1 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 'h 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 30 inches below finished grade. 7.2 Floor Slab-on-Grade Uncontrolled fill was encountered in portions of the site. Atlas recommends that these fill materials be removed to a depth of at least 1'/2 feet below existing grade. If fill materials remain after excavation, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D1557. The excavated fill materials can be replaced in accordance with the Structural Fill section provided that all organic material and/or debris is completely removed. Once final grades have been determined, Atlas is available to provide additional recommendations. 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. 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. ML Atlas No. B221646g Page112 Copyright©2022 Atlas Technical Consultants PAVEMENT DISCUSSION AND RECOMMENDATION'S Atlas has made assumptions for traffic loading variables based on the character of the proposed construction. The Client shall review and understand these assumptions to make sure they reflect intended use and loading of pavements both now and in the future. Based on experience with soils in the region, a subgrade California Bearing Ratio (CBR) value of 4 has been assumed for near-surface sandy silt soils on site. 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. 8.1 Flexible Pavement Sections The American Association of State Highway and Transportation Officials (AASHTO) design method has been used to calculate the following pavement sections. 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 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. Table 8 —AASHTO Flexible Pavement Specifications riveways and Parking 9r Driveways and Parkingl Pavement Section . . Asphaltic Concrete 2.5 Inches 3.0 Inches Crushed Aggregate Base 4.0 Inches 4.0 Inches Structural Subbase 10.0 Inches 12.0 Inches Compacted Subgrade See Pavement Subgrade See Pavement Subgrade Preparation Section Preparation 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. 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. Atlas No. B221646g Page113 Copyright©2022 Atlas Technical Consultants 8.2 Pavement Subgrade Preparation Uncontrolled fill was encountered in portions of the site. Atlas recommends that these fill materials be removed to a depth of at least 1'/2 feet below existing grade. If fill materials remain after excavation, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D698 for flexible pavements. The excavated fill materials can be replaced in accordance with the Structural Fill section provided that all organic material and/or debris is completely removed. However, the existing fill materials are not suitable for use as either the base or subbase components of the recommended pavement section. Once final grades have been determined, Atlas is available to provide additional recommendations. 8.3 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 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 recommends that rigid concrete pavement be provided for heavy garbage receptacles. This will eliminate damage caused by the considerable loading transferred through the small steel wheels onto asphaltic concrete. Rigid concrete pavement should consist of Portland Cement Concrete Pavement (PCCP) generally adhering to ITD specifications for Urban Concrete. PCCP should be 6 inches thick on a 4-inch drainage fill course (see Floor Slab-on-Grade section), and should be reinforced with welded wire fabric. Control joints must be on 12-foot centers or less. . CONSTRUCTION CONSIDERATIONS Recommendations in this report are based upon structural elements of the project being founded on competent, native sandy silt soils, silty sand sediments, borderline sandy lean clay/clayey sand soils, or compacted structural fill. Structural areas should be stripped to an elevation that exposes these soil types. Atlas No. B221646g Page114 Copyright©2022 Atlas Technical Consultants �TrT2 _ T".ZJ__1 9.1 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. Thick grasses with associated root systems were noted at the time of our investigation. 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. Stripping depths should be adjusted in the field to assure that the entire root zone or disturbed zone 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. 9.2 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. B221646g Page115 Copyright©2022 Atlas Technical Consultants �TrT2 _ T".ZJ__1 9.3 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. 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 11/ 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. Q r, 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. OL Atlas No. B221646g Page116 Copyright©2022 Atlas Technical Consultants �TrT2 _ T".ZJ__1 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. 9.6 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. B221646g Page117 Copyright©2022 Atlas Technical Consultants �TrT2 _ T".ZJ__1 The ASTM D1557 test method must be used for samples containing up to 40 percent oversize (greater than%-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. 9.7 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. 9.8 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 (1'h: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. 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. B221646g Page118 Copyright©2022 Atlas Technical Consultants �TrT2 - T".ZJ--1 9.9 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. 10. GENERAL COMMENTS Based on the subsurface conditions encountered during this investigation and available information regarding the proposed structures, 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 structure, 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. B221646g Page119 Copyright©2022 Atlas Technical Consultants �TrT2 - T".ZJ--1 11. REFERENCES American Association of State Highway and Transportation Officials(AASHTO) (1993). AASHTO Guide for Design of Pavement Structures 1993. Washington D.C.: AASHTO. American Concrete Institute (ACI) (2015). Guide for Concrete Floor and Slab Construction: ACI 302.1 R. Farmington Hills, MI: ACI. American Society of Civil Engineers (2021). ASCE 7 Hazards Tool: Web Interface [Online] Available: <https://asce7hazardtool.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-um (No. 200) Sieve in Mineral Aggregatesy 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) (2014). Standard Test Methods for California Bearing Ratio: ASTM D1883. 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). 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. B221646g Page 120 Copyright C 2022 Atlas Technical Consultants �TrTG7T�.�J� 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. Limitations It was anticipated that 32 test pits would be advanced onsite. Nineteen test pit locations were staked in the field. Atlas met onsite with Kameron Nauahi of Brighton Development and 6 locations were selected in the field. The remainder of the test pits were not advanced due to a large stockpile limiting access. Additionally, 16 piezometers were to be installed for future groundwater monitoring. Only 12 locations were selected by Brighton Development and 12 piezometers were installed. 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 n There is a distinct possibility that conditions may exist that could not be identified within the scope r 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. Atlas No. B221646g Page 121 Copyright©2022 Atlas Technical Consultants �TrT2 - T".ZJ--1 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 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. Atlas No. B221646g Page 122 Copyright©2022 Atlas Technical Consultants Vicinity Map Figure 1 3 n7r 4 27: = -. NJ z x m—Wj �y a - = ui -4 0 m MAP NOTES: is> { z x z v+x cn rn O < �' d �'� P� m d u, .� a N Delorme Street Atlas Y X'3 A z m -°�' RC 4� v~ U E WASHING7ON AVE_ = u a rn r D , <`n W CARLTONAVAVE Not to Scale X L n ¢ z c z �' W N n W STATE AVE iLU nl o rrr rn Q 0 uU- m � ut W EVAHO AVE ,� eu �' ��- `� LEGEND a rn V. E BROADWAY AVE Approximate Site z z 3 -4 "� Location rn ;1' E BOVIER ST Q I z _ E ADA AVE +n * - - E KING ST "j E KI v L WIWAMS AVE w FRANKLIN W FRANKLIN_RQ U'z_V=— —�,..�� -- —E.FR NKUN RfJ -- }. g N —1 t7 1 w 94 L Cn u71140 A Q V) 3 rn �7r Om m � _ F n n 3Ln v z a PENNWOOD 5T E WATER70WFR LN a- Sits= z W PINTAIL DR> � rn C — w p Location y 7 m r ry? F CORPORATE OR C C CC [-1 r in / ar m rn Of .. 7t r y:• w rC m f.ry• W WALTMAN ST . � n 2 G WALTMAN LN F 00 � rsit U^ $iTr p Ln sn N > a� ! 4A 7 a s c W VERBENA DR m >5 V7 7n < Q m �'C m a ;i „ W r F b r rn Ten Mile Creek Apartments 4 Near the SWC of Franklin Road and n y g _ E OVERLAND RI7 Benchmark Road ` z z 1 �q Meridian,ID 0���� z z 0 rACO I Modified from Delorme by:GJM rr z A. �' p�, 2E August 3,2022 �,p f $ 5 ZC � 1;►� oil.— 9� j�'s6� Drawing:6221646g CX I le 4 - �Of 2791 S.Victory View Way Phone: (208)376-4748 -' Boise,ID 83709 Fax: (208)322-6515 Web: oneatlas.com Site Map Figure 2 FRANKLIN ROAD TP-1 ® r I RI �I � I ________________Y TP-2 TP 5 -- - - ZI �_L.�. TP-4 _ TP-3 ..I-- � �I�flln�A Al � B4-srokw4 — \ U ZI g TP-8 TP-10 `e 4 TP-25 TP-17 _ ® 8 TP-18 ® TP-22 — —TP-23 TP-12 TP-19 I 2" TPn-14 [ �I .. TP-20 __ _ TP-24 TP-21 TEN MILE CREEK — — NOTES: LEGEND Ten Mile Creek Apartments 4 •Not to Scale Near the SWC of Franklin Road and _ram ■ ��_ Approximate Site Approximate Atlas Test Benchmark Road Boundary Pit Location ® Meridian,ID with Piezometer 2791 S.Victory View Way Phone: (208)376-4748 Approximate Atlas Test ® Modified by:GJM Boise,ID 83709 Fax: (208)322-6515 Pit Location August 3,2022 Web: oneatlas.wm Drawing:B221646g Appendix IV GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-1 Latitude: 43.604300 Date Advanced: July 25, 2022 Longitude: -116.425517 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.5 feet bgs Depth Field Description and USCS Soil and Sample Sample Depth Qp Lab • • Sediment Classification • bgs) Test I Sandy Silt(ML): Light brown, dry, medium stiff 0.0-5.1 to very stiff, with fine-grained sand. 1.0-2.5 --Organics encountered to 0.6 foot bgs. Silty Sand (SM): Light brown, dry, medium 5.1-8.0 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 8.0-10.0 brown, dry, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 10.0-15.5 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.5 feet bgs. Atlas No. 13221646g Page 125 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-2 Latitude: 43.604143 Date Advanced: July 25, 2022 Longitude: -116.425529 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 14.9 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs) Sediment Classification Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.2 brown, dry, medium dense,with fine to coarse- grained sand, fine to coarse gravel, and 4-inch minus cobbles. 1.2-2.4 Sandy Silt(ML): Light brown, dry, medium stiff 1.0-2.0 to very stiff, with fine-grained sand. Silty Sand (SM): Light brown, dry, medium 2.4-6.3 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 6.3-9.0 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 9.0-14.9 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 14.9 feet bgs. Infiltration testing conducted at a depth of 7.7 feet bgs. Atlas No. B221646g Page 126 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-3 Latitude: 43.603962 Date Advanced: July 25, 2022 Longitude: -116.425565 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 14.3 feet bgs Depth Field Description and USCS Soil and 7amp Tample D La !Q • (feet bgs) Sediment Classification Type (feet bgsj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.4 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. 1.4-4.9 Sandy Silt(ML): Light brown, dry, medium stiff 1.0-2.0 to very stiff, with fine-grained sand. Silty Sand (SM): Light brown, dry, medium 4.9-6.3 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 6.3-8.3 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 8.3-14.3 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Atlas No. B221646g Page 127 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-4 Latitude: 43.603897 Date Advanced: July 25, 2022 Longitude: -116.425085 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 14.7 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs) Sediment Classification Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-2.5 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. 2.5-5.1 Sandy Silt(ML): Light brown, dry, medium stiff 1.0-1.5 to stiff, with fine to medium-grained sand. Silty Sand (SM): Light brown, dry, medium 5.1-7.3 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 7 3-9 7 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 9.7-14.7 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Atlas No. B221646g Page 128 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-5 Latitude: 43.604091 Date Advanced: July 25, 2022 Longitude: -116.424487 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.4 feet bgs Depth Field Description and USCS Soil and 7amp Tample D La !Q • (feet bgs) Sediment Clas&Ltion Type (feet bgsj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-2.2 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 2.2-5.7 dense to dense, and fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 5.7-8.0 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 8.0-15.4 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Atlas No. B221646g Page 129 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-6 Latitude: 43.603912 Date Advanced: July 25, 2022 Longitude: -116.424472 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 14.6 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs)_ Sediment ClassQLtion Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.1 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. 1.1-5.5 Sandy Silt(ML): Light brown, dry, medium stiff 1.0-2.0 to very stiff, with fine-grained sand. Silty Sand (SM): Light brown, dry, medium 5.5-7.6 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 7.6-9.6 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 9.6-14.6 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Atlas No. B221646g Page 130 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-7 Latitude: 43.603638 Date Advanced: July 25, 2022 Longitude: -116.425430 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.1 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs) Sediment Clas&Ltion Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.9 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 1.9-5.8 dense to dense, with fine to medium-grained GS 2.2-2.7 A sand. Poorly Graded Sand with Gravel (SP): Light 5.8-9.1 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 9.1-15.1 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.1 feet bgs. Lab Test ID Moistur 0 P11 Sieve Analysis (% Passing) 00 #200 A 14.2 NP NP 90 81 42 27 21.9 Atlas No. B221646g Page 131 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-8 Latitude: 43.603628 Date Advanced: July 25, 2022 Longitude: -116.424758 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.5 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs)_ Sediment ClassQLtion Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-2.1 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. 2.1-5.9 Sandy Silt(ML): Light brown, dry, medium stiff 1.0-1.5 to stiff, with fine to medium-grained sand. Silty Sand (SM): Light brown, dry, medium 5.9-7.5 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 7.5-10.5 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 10.5-15.5 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.5 feet bgs. Atlas No. B221646g Page 132 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-9 Latitude: 43.603505 Date Advanced: July 25, 2022 Longitude: -116.423978 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.2 feet bgs Depth Keld=Description and UYSC S amp Tample D La (feet bgs innent Cla sificatioAft Ty 7pe (feet b)g'sj) 1 Test 11 Poorly Graded Gravel with Silt and Sand Fill 0.0-3.9 (GP-GM-FILL): Light brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 3.9-6.7 dense to dense, with fine to coarse-grained sand. Poorly Graded Gravel with Sand (GP): Light 6 7-8 2 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 8.2-15.2 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Atlas No. B221646g Page 133 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-10 Latitude: 43.603501 Date Advanced: July 25, 2022 Longitude: -116.424255 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.1 feet bgs - • - • • • • • - TS • - 1 - l !� •n •• dy Silt(ML). Light brown, dry, medium stiff 103.0-4.73totiff, with fine to medium-grained sand. 1.0-1.5 --Organics encountered to 0.4 foot bgs. Silty Sand (SM): Light brown, dry, medium 4.3-7.9 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 7.9-10.1 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 10.1-15.1 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 8-inch minus cobbles. Notes:See Site Map for test pit location. Atlas No. B221646g Page 134 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-11 Latitude: 43.603509 Date Advanced: July 25, 2022 Longitude: -116.425108 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 14.9 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs) Sediment Classification Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.4 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 1.4-6.4 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 6.4-11.0 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 11.0-14.9 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 14.9 feet bgs. Atlas No. B221646g Page 135 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-12 Latitude: 43.603194 Date Advanced: July 25, 2022 Longitude: -116.424222 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.2 feet bgs Depth • Description and USCS • . 'j 1 •le DI Lab i �� !� • (feet bgs)_ Sediment Classificatin Test I Silty Sand (SM): Light brown, dry, medium dense to dense, with fine to medium-grained 0.0-6.7 sand. --Organics encountered to 0.4 foot bgs. --Intermittent weak to moderate cementation encountered throughout. Poorly Graded Sand with Gravel (SP): Light 6.7-8.0 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 8.0-15.2 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Atlas No. B221646g Page 136 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-13 Latitude: 43.603006 Date Advanced: July 25, 2022 Longitude: -116.423942 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 14.5 feet bgs • • • • • • j '1 • 111171 Graded Gravel with Silt and Sand Fill 0.0-1.6 �(PGOP21VI-RILL): Light brown, dry, medium dense to dense, with fine to coarse-grained and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 1.6-7.8 dense to dense, with fine to coarse-grained GS 2.5-3.0 B sand. Poorly Graded Sand with Gravel (SP): Light 7.8-10.5 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 10.5-14.5 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Saileve Analysis (% Passing) B 16.0 N P N P 97 92 67 42 32.5 Atlas No. B221646g Page 137 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-14 Latitude: 43.602822 Date Advanced: July 25, 2022 Longitude: -116.424617 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.7 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs) Sediment ClassQLtion Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-2.2 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 2.2-5.2 dense to dense, with fine to coarse-grained GS 4.4-4.9 C sand. Poorly Graded Gravel with Sand (GP): Light 5.2-7.5 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 7.5-15.7 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.7 feet bgs. Groundwater measured at a depth of 15.1 feet bgs on August 25,2022. • Test ID Moisture LL Sieve Analysis (% Passing) 00 #200 C 8.5 N P N P 92 86 1 53 1 35 29.8 Atlas No. B221646g Page 138 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-15 Latitude: 43.602806 Date Advanced: July 25, 2022 Longitude: -116.424547 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.3 feet bgs Depth Field Description and USCS Soil and 7amp Tample D La !Q • (feet bgs) Sediment Classification Type (feet bgsj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.8 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 1.8-5.9 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 5.9-7.0 brown, dry, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 7.0-15.3 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.3 feet bgs. Groundwater measured at a depth of 14.0 feet bgs on August 25,2022. Atlas No. B221646g Page 139 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-16 Latitude: 43.603274 Date Advanced: July 25, 2022 Longitude: -116.425522 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.1 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs) Sediment ClassQLtion Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.2 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. 1.2-5.3 Silty Sand (SM): Light brown, dry, medium dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 5.3-8.0 brown, dry, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 8.0-15.1 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.1 feet bgs. Atlas No. B221646g Page 140 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-17 Latitude: 43.603201 Date Advanced: July 25, 2022 Longitude: -116.424883 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 6.3 feet bgs Depth Field Description and USCS Soil and = amp Tample D Qp La (feet •• 11 ' 1 • • •• 1 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.3 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. 1.3-5.6 Silty Sand (SM): Light brown, dry, medium dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 5.6-6.3 brown, dry, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 6.3 feet bgs. Atlas No. B221646g Page 141 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-18 Latitude: 43.603071 Date Advanced: July 25, 2022 Longitude: -116.424535 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.6 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs) Sediment ClassQLtion Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.8 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 1.8-7.7 dense to dense, with fine to medium-grained GS 3.1-3.6 D sand. Poorly Graded Sand with Gravel (SP): Light 7.7-10.0 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 10.0-15.6 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.6 feet bgs. Lab Test ID Moistur 0 P11 Sieve Analysis (% Passing) 00 #200 D 7.7 N P N P 90 82 47 30 24.1 Atlas No. B221646g Page 142 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-19 Latitude: 43.603225 Date Advanced: July 25, 2022 Longitude: -116.423947 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 14.8 feet bgs Poorly Graded Gravel with Silt and Sand Fill 0.0-0.9 (GP-GM): Light brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 0.9-6.1 dense to dense, with fine to coarse-grained sand. Poorly Graded Sand with Gravel (SP): Light 6.1-12.4 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Poorly Graded Gravel with Clay and Sand (GP-GC): Light brown, dry to slightly moist, 12.4-14.8 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 6.5 feet bgs. Atlas No. B221646g Page 143 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-20 Latitude: 43.602709 Date Advanced: July 25, 2022 Longitude: -116.423908 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.4 feet bgs T, �(PG0,Pc-GM-RLL): rly Graded gravel with Silt and Sand Fill . - . Light brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 1.2-4.7 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 4.7-6.5 brown, dry, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand 6.5-15.4 (GP-GC): Light brown, dry, 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 15.4 feet bgs. Groundwater measured at a depth of 14.5 feet bgs on August 25,2022. Atlas No. B221646g Page 144 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-21 Latitude: 43.602734 Date Advanced: July 25, 2022 Longitude: -116.422994 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.2 feet bgs !Q • •• JK= 11 ' 1 • . 7pe •• Poorly Graded Gravel with Silt and Sand Fill (GP-GM-FILL): Light brown, dry, medium 0.0-1.8 dense to dense, with fine to coarse-grained sand and fine to coarse gravel. --Organic debris encountered throughout. Borderline Sandy Lean Clay/Clayey Sand 1.8-5.0 (ML/SC): Brown, dry, stiff to very stiff/medium GS 3.3-3.8 E dense, with fine to medium-grained sand. Silty Sand (SM): Light brown, dry, medium dense to dense, with fine to coarse-grained 5.0-11.7 sand. --Weak to moderate cementation encountered from 9.1 to 11.7 feet bgs. Poorly Graded Sand with Gravel (SP): Light 11.7-14.1 brown, dry to slightly moist, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand 14.1-15.2 (GP-GC): Light brown, dry, very dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Passing)Sieve Analysisj% • Test ID Moisture 11 #200 E 12.4 28 18 98 94 72 59 50.9 Atlas No. B221646g Page 145 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-22 Latitude: 43.603066 Date Advanced: July 25, 2022 Longitude: -116.425603 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 16.2 feet bgs • • • •N • • • . 'jl • - 0 - a Poorly Graded Gravel with Silt and Sand Fill 0.0-1.2 (GP 1VI-FILL): Light brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. 1.2-4.6 Silty Sand (SM): Light brown, dry, medium dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 4.6-6.0 brown, dry to moist, medium dense to dense, with fine to coarse-grained sand,fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand 6.0-16.2 (GP-GC): Light brown, dry, dense to very dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Piezometer installed to a depth of 16.2 feet bgs. Groundwater measured at a depth of 14.9 feet bgs on August 25,2022. Atlas No. B221646g Page 146 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-23 Latitude: 43.602968 Date Advanced: July 25, 2022 Longitude: -116.425237 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Mason Allen Total Depth: 15.1 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La !Q • (feet bgs) Sediment ClassQLtion Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-2.4 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 2.4-7.3 dense to dense, with fine to medium-grained sand. Poorly Graded Gravel with Sand (GP): Light 7.3-8.5 brown, dry, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand 8.5-15.1 (GP-GC): Light brown, dry, 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 15.1 feet bgs. Groundwater measured at a depth of 14.7 feet bgs on August 25,2022. Atlas No. B221646g Page 147 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-24 Latitude: 43.602739 Date Advanced: August 25, 2022 Longitude: -116.423638 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Gavin Marron El Total Depth: 9.7 feet bgs Depth Field Description and USCS Soil and =mffarnp Tample D La e . (feet bgs) Sediment Clas&Ltion Ty 7pe (feet b)g'sj) 1 Test 11 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-1.9 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 1.9-5.7 dense to dense, with fine to medium-grained sand. Poorly Graded Gravel with Sand (GP): Light 5.7-7.0 brown, dry, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Poorly Graded Gravel with Clay and Sand 7 0-9 7 (GP-GC): Light brown, dry, medium dense to dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 9.7 feet bgs. Atlas No. B221646g Page 148 Copyright©2022 Atlas Technical Consultants GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-25 Latitude: 43.603968 Date Advanced: August 25, 2022 Longitude: -116.424047 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Gavin Marron El Total Depth: 11.5 feet bgs Depth Field Description and USCS Soil and amp Tample D Qp La (feet •• 11 ' 1 • • •• 1 Silty Gravel with Sand Fill (GM-FILL): Light 0.0-2.3 brown, dry, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand (SM): Light brown, dry, medium 2.3-4.6 dense to dense, with fine to medium-grained sand. Poorly Graded Sand with Gravel (SP): Light 4.6-6.9 brown, dry, medium dense,with fine to coarse- grained sand, fine to coarse gravel, and 4-inch minus cobbles. Poorly Graded Gravel with Clay and Sand 6.9-11.5 (GP-GC): Light brown, dry, dense to very dense, with fine to coarse-grained sand, fine to coarse gravel, and 10-inch minus cobbles. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 11.5 feet bgs. Atlas No. B221646g Page 149 Copyright©2022 Atlas Technical Consultants Appendix V GEOTECHNICAL GENERAL NOTES Unified Soil Classification System Ma-or 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 ravels; poorly-graded raded gravel/sand/clay mixtures 50% Y Y 9 p Y-9 9 Y passes Sand & Sandy SW Well-graded sands; ravel) sands with little or no fines No.200 Soils > 50% SP Poorly-graded sands; ravel) sands with little or no fines sieve coarse SM Silt sands; poorly-graded sand/gravel/silt mixtures 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 ravel) or 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 • • . Content • Classification Coarse-Grained Soils SPT Blow Counts N Description Field Test VeryLoose: <4 Dr Absence of moisture, dryto 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 Particle Size Acronym List Boulders: > 12 in. GS grab sample Cobbles: 12 to 3 in. LL Liquid Limit Gravel: 3 in. to 5 mm M moisture 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. B221646g Page 150 Copyright©2022 Atlas Technical Consultants �TrTG7T�.�J� Appendix VI AASHTO PAVEMENT DESIGN Pavement Section Design Location:Ten Mile Creek Apartments 4,Light Duty Average Daily Traffic Count: 300 All Lanes&Both Directions Design Life: 20 Years Percent of Traffic in Design Lane: 50% Terminal Seviceability Index(Pt): 2.5 Level of Reliability: 95 Subgrade CBR Value: 4 Subgrade Mr: 6,000 Calculation of Design-18 kip ESALs Daily Growth Load Design Traffic Rate Factors ESALs Passenger Cars: 125 2.0% 0.0008 887 Buses: 1 2.0% 0.6806 6,036 Panel&Pickup Trucks: 20 2.0% 0.0122 2,164 2-Axle,6-Tire Trucks: 3 2.0% 0.1890 5,028 Emergency Vehicles: 1.0 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: 150 Total Design Life 18-kip ESALs: 53,846 Actual Log(ESALs): 4.731 Trial SN: 2.49 Trial Log(ESALs): 4.739 Pavement Section Design SN: 2.61 Design Depth Structural Drainage Inches Coefficient Coefficient Asphaltic Concrete: 2.50 0.42 n/a Asphalt-Treated Base: 0.00 0.25 n/a Cement-Treated Base: 0.00 0.17 n/a Crushed Aggregate Base: 4.00 0.14 1.0 Subbase: 10.00 0.10 1.0 Special Aggregate Subgrade: 0.00 0.09 0.9 Atlas No. B221646g Page 151 Copyright©2022 Atlas Technical Consultants AASHTO PAVEMENT DESIGN Pavement Section Design Location:Ten Mile Creek Apartments 4,Heavy Duty Average Daily Traffic Count: 300 All Lanes&Both Directions Design Life: 20 Years Percent of Traffic in Design Lane: 50% Terminal Seviceability Index(Pt): 2.5 Level of Reliability: 95 Subgrade CBR Value: 4 Subgrade Mr: 6,000 Calculation of Design-18 kip ESALs Daily Growth Load Design Traffic Rate Factors ESALs Passenger Cars: 65 2.0% 0.0008 461 Buses: 1 2.0% 0.6806 6,036 Panel&Pickup Trucks: 56 2.0% 0.0122 6,059 2-Axle,6-Tire Trucks: 25 2.0% 0.1890 41,904 Emergency Vehicles: 1.0 2.0% 4.4800 39,731 Concrete/Dump Trucks: 1 2.0% 3.6300 32,193 Tractor Semi Trailer Trucks: 1 2.0% 2.3719 21,035 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: 150 Total Design Life 18-kip ESALs: 147,419 Actual Log(ESALs): 5.169 Trial SN: 2.94 Trial Log(ESALs): 5.173 Pavement Section Design SN: 3.02 Design Depth Structural Drainage Inches Coefficient Coefficient Asphaltic Concrete: 3.00 0.42 n/a Asphalt-Treated Base: 0.00 0.25 n/a Cement-Treated Base: 0.00 0.17 n/a Crushed Aggregate Base: 4.00 0.14 1.0 Subbase: 12.00 0.10 1.0 Special Aggregate Subgrade: 0.00 0.09 0.9 Atlas No. B221646g Page 152 Copyright©2022 Atlas Technical Consultants IMPOPIRRI InfOPM8110H Rhout GeolechnicalmEngineeping Subsurface problems are a principal e of construction . . ost overruns, claims, and . . While you cannot eliminate all such risks, you can manage them. The following information is provided to 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 may be 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 project ownership. and At Specific Times 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 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. DAM GEOPROFESSIONAL BUSINESS / - 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.