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CC - Drainage ReportGlobal Senior Housing, LLC Blakeslee DRAINAGE REPORT POST - CONSTRUCTION STORMWATER MANAGEMENT BLAKESLEE COMMONS SUBDIVISION 10/12/2017 Prepared For: Global Senior Housing, LLC Prepared By: ENGINEERING DEPENDABLE SOLUTIONS GROUNDED IN VALUE" 979 Osos St., Suite F4 San Luis Obispo, CA 93401 805.319.49 S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.dou 1 of 10 Global Senior Housing, LLC Blakeslee Table of Contents 1. Purpose.................................................................................................................................................3 2. Existing Site Features and Conditions...................................................................................................3 3. Opportunities and Constraints for Stormwater Control.......................................................................3 4. Design Criteria.......................................................................................................................................4 5. Hydrologic & Hydraulic Analysis...........................................................................................................4 6. Summary of Proposed Facilities............................................................................................................6 Appendices.................................................................................................................................................... 7 A: Pre and Post -Development Hydrology Exhibits................................................................................7 B: Storm and Sanitary Analysis Report..................................................................................................7 C: Geotechnical Engineering Investigation...........................................................................................7 S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.docx 2 of 10 Global Senior Housing, LLC 1. Purpose Blakeslee The Blakeslee Commons Subdivision is a residential development within the City of Meridian in the Ada County, Idaho. The project site is 12.01 acres located at 2545 East Ustick Road. Upon ultimate build -out of the proposed project, it is anticipated the site will include seventy-four residential homes and a clubhouse. The purpose of this report is to demonstrate how to mitigate runoff from stormwater in compliance with the local regulations discussed as Design Criteria in Section 4 of this report. The goal is to identify best management practices (BMPs) that provide compliance while best utilizing the project site and existing conditions. 2. Existing Site Features and Conditions The existing site topography gently slopes in the northwestern and southwestern directions at approximately 0.5 - 2%. There is a small ridge created by an irrigation ditch that cuts through the site, which separates the drainage tributary areas. The historical drainage path of the site's stormwater runoff travels to the northwest and ultimately discharges toward the Milk Lateral and Ustick Road, while the water that travels to the southwest discharges into Finch Lateral. According to the geotechnical report provided by STRATA, dated March 29, 2016, the surface soils consisted of near surface lean clay and silt overlying cemented silty sand and poorly graded gravel with sand and silt. Vegetation and organics were located up to approximately 12 inches below the ground surface. Below the surface material, lean clay with sand was found from approximately 2 to 5 feet deep across the site. Below the lean clay, cemented sandy silt and silty sand was found up to 5 feet in depth. Below 5 feet in depth, poorly -graded gravel with sand overlain with a limited thickness of silty gravel was discovered. Free groundwater was not encountered immediately following the drilling operations. Although groundwater was not found, seasonal high groundwater in the surrounding area typically occurs at approximate depth of 12 to 14 feet. Per the geotechnical report, the soil infiltrated at a rate of 20 inches per hour, but per the geotechnical engineer's recommendation an infiltration rate of 8 inches per hour was selected in order to provide a factor of safety greater than 2. The reader should reference the Project Geotechnical Engineering Investigation in Appendix C of this Report for further information. 3. Opportunities and Constraints for Stormwater Control The existing slope of the site towards Milk Lateral and Finch Lateral heavily influenced the location of the two proposed retention facilities. Open space parcels near the middle of the site and the southerly portion of the site created opportunities for retention basin locations while allowing for overland release of drainage in excess of the design storm events for conveyance along historical drainage paths. Additional opportunities for mitigation of stormwater include infiltration due to the nature of the native soils and adequate depth of groundwater discussed in the Existing Site Features and Conditions Section 2 of this Report above. S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.dou 3 of 10 Global Senior Housing, LLC 4. Design Criteria Blakeslee This project will comply with the City of Meridian's local regulations via ACHD's Section 8000 — Drainage and Stormwater Management requirements to control the volume and quality of stormwater. For peak rate control purposes, the project must mitigate the post -development peak runoff rates to no greater than pre -development peak runoff rates for the 2-, 5-, 10-, and 25 -year storm events. In addition to peak rate attenuation for the 2-, 5-, 10-, and 25 -year storms, the peak flow rate and maximum water surface elevations must be calculated for the 100 -year storm event. For runoff reduction purposes, this project must retain the first 0.6 inches of rainfall from a 24-hour event. For volume management purposes, the proposed facilities will need to manage a 100 -year, 1 -hour design storm. The overflow route shall direct the 100 -year post -developed flow safely towards the downstream conveyance system. In order to utilize infiltration BMPs, seasonal high groundwater must be three feet below the surface of the infiltration facility. Existing soil and groundwater conditions have been investigated in order to determine appropriate sizing of BM Ps for this site. 5. Hydrologic & Hydraulic Analysis In order to comply with the requirements, an impervious area analysis was completed for both the pre - development and post -development conditions (See Appendix A for Hydrology Exhibits). The hydrologic and hydraulic methodologies that will be utilized for this report conform to ACHD's Drainage and Stormwater Management Standards Section 8000. Pursuant to Section 8011.4 of the ACHD Standards, with pre -approval from the District, the method of determining volume and peak discharge with the Natural Resources Conservation Service (NRCS) Technical Release Number 55 (TR -55) for a 24-hour storm is acceptable. The district was consulted during the design process and the TR -55 was deemed acceptable given justification by the design engineer. As design engineer, it is deemed appropriate to utilize the NRCS TR -55 methodologies for this project as the site fits The NRCS (SCS) Urban Hydrology for Small Watersheds TR -55 Method has wide application for existing and developing urban watersheds up to 2,000 acres. The SCS TR -55 Method requires data similar to the Rational Method: drainage area, a runoff factor, time of concentration and rainfall. However, the SCS TR -55 method is more sophisticated in that it also considers the time distribution of the rainfall, the initial rainfall losses to interception and depression storage and an infiltration rate that decreases during the course of a storm. The fact that NRCS TR -55 Method accounts for cumulative rainfall at any point in time makes the methodology most suitable for volume dependent routing calculations on site with multiple watersheds or tributary areas. The NRCS (SCS) TR -55 Methodology with Type II 24-hour storm distribution and kinematic wave routing was used in conjunction with Autodesk's Storm and Sanitary Analysis (SSA) Program to determine the 2, 5-, 10-, and 25-, 100 -year, storm events and model the project hydrology and hydraulics. The total rainfall depths and maximum rainfall intensities of the model were compared to the intensity duration frequency curves of the ACHD manual and the model's rainfall amounts were deemed more conservative. The 0.6 inches of rainfall from a 24-hour storm event requirement was found to be non - governing due to the fact that the 2 -year design storm results in 1.21 inches which is greater than 0.6 inches. A summary of the calculations is below. Full calculations may be seen in the Storm and Sanitary Analysis Report as Appendix B of this Report. S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.docx 4 of 10 Global Senior Housing, LLC Table A: Input Parameters Blakeslee *Note: Curve Numbers (Coefficients) by Surface Type: Roof = 98.00, Hardscape = 98.00, Pavement = 98.00, Landscape (native soil) = 74.00, Composite Area & Weighted CN based on specific Drainage Management Areas (DMA). Lot coverage assumed to be 64% impervious for shared drive lots and 70% for front load lots. Final house plans shall be less than coverage noted herein. Table B.1: Summary of Results Pre -Development Post- Development SSA Inputs DMA 1 DMA 2 DMA 1 DMA 2 Time of Concentration (min.) 60 18.83 10 10 Weighted Curve Number* 74.72 74 89.74 89.49 Total Tributary Area (acres) 8.30 3.22 10.01 1.52 Infiltration Rate (in/hr) 8.0 8.0 8.0 8.0 Blakeslee *Note: Curve Numbers (Coefficients) by Surface Type: Roof = 98.00, Hardscape = 98.00, Pavement = 98.00, Landscape (native soil) = 74.00, Composite Area & Weighted CN based on specific Drainage Management Areas (DMA). Lot coverage assumed to be 64% impervious for shared drive lots and 70% for front load lots. Final house plans shall be less than coverage noted herein. Table B.1: Summary of Results Table B.2: Summary of Results Maximum Volume Stored (cf) Max Water Surface Depth (ft) Max Runoff (cfs) Design Storm Total Rainfall Depth (in.) Rainfall Intensity (in/hr) Forebay Basin 1 Basin 2 Post-Dev Outflow Pre-Dev Outflow 2 1.21 1.64 2.35 0.03 1.36 0 0.15 5 1.62 2.19 2.44 0.82 2.21 0 0.94 10 1.87 2.54 2.48 1.37 2.70 0 1.69 25 2.28 3.08 2.52 2.03 3.43 0 3.30 100 2.83 3.84 2.57 2.17 4.00 5.51 5.98 100 -yr, 1 -hr 0.97 1.32 1.71 0.00 0.80 0 0.03 Table B.2: Summary of Results Table B.3: Final Sizing Maximum Volume Stored (cf) Time to Empty (hrs) Design Storm Forebay Basin 1 Basin 2 Forebay Basin 1 Basin 2 2 5447 183 803 7.42 0.17 3.58 5 5750 4738 1561 9.74 1.58 5.92 10 5879 8371 2110 11.17 2.34 7.00 25 6018 13207 3059 12.67 3.75 8.83 100 6198 14400 3848 13.42 4.66 11.58 100 -yr, 1 -hr 3540 0 414 4.83 0 2.08 Table B.3: Final Sizing S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.dou 5 of 10 Seepage Basin Basin Capacity Bain Bottom Max 100 Year Storage Area (sf) Depth (ft.) Side Slope Volume (cf) Forebay 1450 3.9 3:1 6198 Basin 1 5250 2.6 4:1 14400 Basin 2 417 4.3 2:1 3848 S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.dou 5 of 10 Global Senior Housing, LLC Blakeslee 6. Summary of Proposed Facilities The retention basins will be constructed per ACHD BMP 11 to filter and retain storm water. The basins will be landscaped with vegetation, mulch and cobble to benefit the project aesthetically. The facilities have been designed to accommodate the retention volume requirements set forth for this project as calculated with the appropriate hydrology and hydraulic analysis. The basins were sized to capture the most conservative storm event associated with the project, which was the 100 year event in this case. Stormwater discharges resulting from storm events greater than the design storm events will be conveyed to the historical discharge point via storm drain pipes and overland release with adequate protection from erosion control. For overland release route, see the Post -Development Hydrology Exhibit in Appendix A. Since the design of the homes for the building permit are ongoing, the worst-case scenarios were used for impervious area calculations on the lots. This was done by fitting the largest possible floor plan within the desired setbacks. This ultimately resulted in an impervious are of 64% for the shared drive lots, and 70% for the front -loaded lots. Using AutoCAD SSA and known design storm, the basins were sized through an iterative process in order to meet ACHD requirements. The resulting analysis led to the final sizing shown in Table 13.3 in Section 5 of this Report. The sizes shown have been incorporated into the construction drawings for the site improvements. With seasonal high groundwater surface ranging from 12 to 14 below the surface, both basins have well over the 3' separation between the bottom of the basin and groundwater level required of infiltration facilities. Given the stormwater facilities are built per the construction drawings and this report, the project will be served with adequate drainage mitigation in compliance with requirements of the local jurisdiction. S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.dou 6 of 10 Global Senior Housing, LLC Appendices A: Pre and Post -Development Hydrology Exhibits B: Storm and Sanitary Analysis Report C: Geotechnical Engineering Investigation Blakeslee S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.docx 7 of 10 Global Senior Housing, LLC Blakeslee Appendix A: Pre and Post -Development Hydrology Exhibits 5:\Projects Eng\3016190_aungalows Meridian\Storm\Oralnage Reporttlocx 8 of 10 g3g 3 Qp�p�S g$, • : 6€i3��s€6G � 8 I° pp �o �n 4 I� to I� I� _1 11 \ Mgrs 11 �gg3e�A gyp} g� �1 €!� l:IN QE ¢ 4 110 3` a� avodNousn sp; -- -- -------------- -- — N LL O i N IM Nom aLH wow 00 Rd I b I I 4 b a I ? absa _ F F F Y I r I I Q Q i O I U) I I p ---------------- ----I m E" — o %5 I U z I ` I Z I O d x`08 I j O I I w� w: I U n —I w V I Y 01.01 I I m .. `s � I U ---- ---------------I F 3 w €g 'N Ste• T �_ a ocp Pp 6d �1 � Rgp�FF �3 hH / UI Al 5z I 4: I w ag E aaaa Global Senior Housing, LLC Appendix B: Storm and Sanitary Analysis Report Blakeslee S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.docx 9 of 10 Figure B-2 Approximate geographic boundaries for NRCS (SCS) rainfall distributions Rainfall data sources This section lists the most current 24-hour rainfall data published by the National Weather Service (NWS) for various parts of the country. Because NWS Technical Paper 40 (TP -40) is out of print, the 24-hour rainfall maps for areas east of the 105th meridian are included here as figures B-3 through B-8. For the area generally west of the 105th meridian, TP -40 has been superseded by NOAA Atlas 2, the Precipitation -Frequency Atlas of the Western United States, published by the National Ocean and Atmospheric Administration. East of 105th meridian Hershfield, D.M. 1961. Rainfall frequency atlas of the United States for durations from 30 minutes to 24 hours and return periods from 1 to 100 years. U.S. Dept. Commerce, Weather Bur. Tech. Pap. No. 40. Washington, DC. 155 p. West of 105th meridian Miller, J.F., R.H. Frederick, and R.J. Tracey. 1973. Precipitation -frequency atlas of the Western United States. Vol. I Montana; Vol. H, Wyoming; Vol III, Colo- rado; Vol. IV, New Mexico; Vol V, Idaho; Vol. VI, Utah; Vol. VII, Nevada; Vol. VIII, Arizona; Vol. IX, Washing- ton; Vol. X, Oregon; Vol. XI, California. U.S. Dept. of Commerce, National Weather Service, NOAA Atlas 2. Silver Spring, MD. Alaska Miller, John F. 1963. Probable maximum precipitation and rainfall -frequency data for Alaska for areas to 400 square miles, durations to 24 hours and return periods from 1 to 100 years. U.S. Dept. of Commerce, Weather Bur. Tech. Pap. No. 47. Washington, DC. 69 p. Hawaii Weather Bureau. 1962. Rainfall -frequency atlas of the Hawaiian Islands for areas to 200 square miles, dura- tions to 24 hours and return periods from 1 to 100 years. U.S. Dept. Commerce, Weather Bur. Tech. Pap. No. 43. Washington, DC. 60 p. Puerto Rico and Virgin Islands Weather Bureau. 1961. Generalized estimates of prob- able maximum precipitation and rainfall -frequency data for Puerto Rico and Virgin Islands for areas to 400 square miles, durations to 24 hours, and return periods from 1 to 100 years. U.S. Dept. Commerce, Weather Bur. Tech. Pap. No. 42. Washington, DC. 94 P. B_2 (210 -VI -TR -56, Second Ed., June 1986) 4 YE Y .N Z Q C,' ,.� N a c E 0 d 0 ... a Q Project Description File Name .....:........................................... Storm Water Analysis updated basin 1.SPF Project Options Flow Units ................................................... CFS Elevation Type ............................................ Elevation Hydrology Method ....................................... SCS TR -55 Time of Concentration (TOC) Method ........ SCS TR -55 Link Routing Method ................................... Kinematic Wave Enable Overflow Ponding at Nodes ............ YES Skip Steady State Analysis Time Periods ... YES Analysis Options Start Analysis On ........................................ Sep 01, 2017 00:00:00 End Analysis On .......................................... Sep 02, 2017 00:00:00 Start Reporting On ...................................... Sep 01, 2017 00:00:00 Antecedent Dry Days .................................. 0 days Runoff (Dry Weather) Time Step ................ 0 01:00:00 days hh:mm:ss Runoff (Wet Weather) Time Step ............... 0 00:05:00 days hh:mm:ss Reporting Time Step ................................... 0 00:05:00 days hh:mm:ss Routing Time Step ...................................... 30 seconds Number of Elements Qty Rain Gages ................................................. 1 Subbasins.................................................... 4 Nodes........................................................... 7 Junctions ............................................ 0 Outfalls............................................... 4 Flow Diversions .................................. 0 Inlets................................................... 0 Storage Nodes ................................... 3 Links............................................................. 3 Channels............................................ 1 Pipes.................................................. 1 Pumps................................................ 0 Orifices............................................... 0 Weirs.................................................. 1 Outlets................................................ 0 Pollutants.................................................... 0 LandUses ................................................... 0 Rainfall Details SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall ID Source ID Type Units Period Depth Distribution (years) (inches) 1 Time Series 2 -Year Intensity inches Idaho Ada 2 1.20 SCS Type II 24 -hr Subbasin Summary SN Subbasin Area Weighted Total Total Total Peak Time of ID Curve Rainfall Runoff Runoff Runoff Concentration Number Volume (ac) (in) (in) (ac -in) (cfs) (days hh:mm:ss) 1 POST 10.01 89.74 1.20 0.45 4.46 6.11 0 00:10:00 _DMA _1 2 POST _2 1.52 89.49 1.20 0.44 0.66 0.90 0 00:10:00 _DMA 3 PRE_DMA_1 8.30 74.72 1.20 0.07 0.58 0.11 0 01:00:00 4 PRE—DMA-2 3.22 74.00 1.20 0.06 0.20 0.05 0 00:18:49 Node Summary SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded Elevation Elevation Attained Depth Attained Flooding Volume Attained Occurrence (ft) (ft) (ft) (ft) UP) (cfs) (ft) (ft) (ft) (days hh:mm) (ac -in) (min) 1 Out -10 Outfall 0.00 0.00 0.00 2 OUTFALL Outfall 0.00 0.00 0.00 _POST _2 3 OUTFALL_PRE_1 Outfall 15.05 0.11 15.05 4 OUTFALL Outfall 9.32 0.05 9.32 _PRE _2 5 FOREBAY Storage Node 11.70 15.60 0.00 0.00 6.10 14.05 0.00 0.00 6 STORAGE BASIN Storage Node 13.00 15.60 0.00 0.00 1.82 13.03 0.00 0.00 7 STORAGE7_BASIN_2 Storage Node 10.70 14.70 0.00 0.00 0.90 12.06 0.00 0.00 Subbasin Hydrology Subbasin : POST -DMA -1 Input Data Area(ac)........................................................................ 10.01 Total Rainfall (in)............................................................ Weighted Curve Number .....- .................................. •. 89.74 0.45 RainGage ID................................................................. Rain Gage Weighted Curve Number ............................................... Composite Curve Number Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Area Soil Curve Soil/Surface Description (acres) Group Number Lot_ Impervious_(Roof+Hardscape) 4.49 98.00 Site_Hardscape 0.54 98.00 Pavement 1.54 98.00 Landscape 3.44 C 74.00 Composite Area & Weighted CN 10.01 89.74 Time of Concentration TOC Method: SCS TR -55 Sheet Flow Equation: ' Tc = (0.007 * ((n * Lf)A0.8)) / ((PA0.5) * (SfA0.4)) Where: Tc = Time of Concentration (hr) n = Manning's roughness Lf =Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (SfA0.5) (unpaved surface) V = 20.3282 * (SfA0.5) (paved surface) V = 15.0 * (SfA0.5) (grassed waterway surface) V = 10.0 * (SfA0.5) (nearly bare & untilled surface) V = 9.0(SfA0.5) (cultivated straight rows surface) V = 7.0' (SfA0.5) (short grass pasture surface) V = 5.0' (SfA0.5) (woodland surface) V = 2.5 * (SfA0.5) (forest w/heavy litter surface) Tc = (Lf / V) / (3600 sec/hr) Where Tc = Time of Concentration (hr) Lf = Flow Length (fl) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation : V = (1.49' (RA(2/3)) * (SfA0.5)) / n R =Aq/Wp Tc = (Lf / V) / (3600 sec/hr) Where Tc = Time of Concentration (hr) Lf = Flow Length (fl) R =Hydraulic Radius (ft) Aq = Flow Area (ft) Wp = Wetted Perimeter (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) n = Manning's roughness User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 1.20 Total Runoff (in)............................................................. 0.45 Peak Runoff (cfs)........................................................... 6.11 Weighted Curve Number ............................................... 89.74 Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Subbasin : POST DMA 1 Rainfall Intensity Graph .7 I i .4 - i .3 - - .2 1.1 .9 ).9- 1.7- ).6 ].6 - ].5 3.4 — i I i 3.2 - 3.1 1 2 3 4 5 6 7 tiy lu ll l2 "I.J 14 10 In v io la zu <i " Time (hrs) Runoff Hydrograph 7 5 i - 6 - - - - - I i I 5 I I � 4 i 3- 2- — - I i i i I II ' i 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b 16 v 1a ly zu n « Time (hrs) Subbasin : POST—DMA-2 1.20 Total Runoff (in)............................................................. Input Data Peak Runoff (cfs)......................................................... _ 0.90 Area(ac)........................................................................ 1.52 Time of Concentration (days hh:mm:ss) ........................ Weighted Curve Number ............................................... 89.49 RainGage ID................................................................. Rain Gage Composite Curve Number Area Soil Curve Soil/Surface Description (acres) Group Number Lot_ Impervious_(Roof+Hardscape) 0.65 98.00 Sile_Hardscape 0.10 98.00 Pavement 0.23 98.00 Landscape 0.54 C 74.00 Composite Area & Weighted CN 1.52 89.49 Time of Concentration User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 1.20 Total Runoff (in)............................................................. 0.44 Peak Runoff (cfs)......................................................... _ 0.90 Weighted Curve Number ............................................... 89.49 Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Subbasin : POST—DMA-2 Rainfall Intensity Graph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1b i ie is 2U ZI « Ia Time (hrs) Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ty 2u 21 22 2.i Time (hrs) I I i i I i I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1b i ie is 2U ZI « Ia Time (hrs) Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ty 2u 21 22 2.i Time (hrs) Subbasin : PRE—DMA-1 Input Data Area(ac)........................................................................ 8.30 Subarea Weighted Curve Number ,.... ......................... ..•••.••......... 74.72 C RainGage ID .......... .....,............. ............ ........................ Rain Gage 0.00 Composite Curve Number 669.2763 0.00 0.3 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 8.05 C 74.00 Paved parking & roofs 0.25 D 98.00 Composite Area & Weighted CN 8.30 74.72 Time of Concentration Sheet Flow Computations Manning's Roughness: Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................60.00 Subbasin Runoff Results Subarea Subarea Subarea A B C 0.03 0.025 0.00 300 669.2763 0.00 0.3 0.3 0.00 1.20 1.20 0.00 0.22 0.30 0.00 22.71 37.29 0.00 Total Rainfall (in)............................................................ 1.20 Total Runoff (in)............................................................. 0.07 Peak Runoff (cfs).................. ......................................... 0.11 Weighted Curve Number ............................................... 74.72 Time of Concentration (days hh:mm:ss) ........................ 0 01:00:00 t m Of Subbasin : PRE -DMA -1 Rainfall Intensity Graph .7 .4 - - .3 .2- ).9- ).6 2 1.9 - — - ).7 3.4 i 3.3 ).2- 3.1 I r I n , 9 a A F a 7 R A 1n 11 12 13 14 15 16 17 18 19 20 21 22 23 0.115 0.11 0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 00.065 0.06 00.055 0_ 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 Time (hrs) Runoff Hydrograph 0 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Lli - I - 1 I � I - - I � , , �-- 0 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Subbasin : PRE—DMA-2 Input Data Area(ac)........................................................................ 3.22 Subarea Weighted Curve Number ........... ..: ............ ................. 1— 74.00 C RainGage ID ...................... :................................ .......... Rain Gage 0.00 Composite Curve Number 178.2036 0.00 1.7 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 3.22 C 74.00 Composite Area & Weighted CN 3.22 74.00 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................18.83 Subarea Subarea Subarea A B C 0.03 0.03 0.00 300 178.2036 0.00 1.7 1.7 0.00 1.20 1.20 0.00 0.44 0.40 0.00 11.35 7.48 0.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 1.20 TotalRunoff (in)............................................................. 0.06 Peak Runoff (cfs)........................................................... 0.05 Weighted Curve Number ................................................ 74.00 Time of Concentration (days hh:mm:ss) .................... 0 00:18:50 Subbasin : PRE DMA 2 1.6 1.7 1.6 1.5 1.4 1.3 1.2 1.1 � 1 C 0.9 w 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 Rainfall Intensity Graph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 lb lb 11 lti is zu n tt zo Time (hrs) 0.05 0.048 0.046 0.044 0.042 0.04 0.036 0.036 0.034 0.032 0.03 0.028 .0.026 E0.024 CY0.022 0.02 0.018- 0.016 0.014- 0.012 0.01 0.006 0.006 0.004 0.002 Runoff Hydrograph 1-4 -11A--- - - - - - - i li I --- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 lb lb 11 lti is zu n tt zo Time (hrs) 0.05 0.048 0.046 0.044 0.042 0.04 0.036 0.036 0.034 0.032 0.03 0.028 .0.026 E0.024 CY0.022 0.02 0.018- 0.016 0.014- 0.012 0.01 0.006 0.006 0.004 0.002 Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) 1-4 -11A--- - - - - - - li I --- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Storage Nodes Storage Storage Node: FOREBAY Input Data Volume Invert Elevation (ft).................................................................. 11.70 Max (Rim) Elevation (ft)...........................................................15.60 0 Max (Rim) Offset (ft)................._............................................ 3.90 Initial Water Elevation (ft)........................................................0.00 2146 Initial Water Depth (ft)............................................................. -11.70 PondedArea (ft')..................................................................... 0.00 Evaporation Loss . ................................. ......:............. ...::..:....... 0.00 Infiltration/Exfiltration Exfiltration Rate (in/hr)............................................................. 8.0000 Storage Area Volume Curves Storage Curve: FOREBAY Stage Storage Storage Area Volume (ft) (fl') (ft') 0 1450 0.000 1 2146 1798.00 2 2970 4356.00 2.3 3242.16 5287.82 Storage Node: FOREBAY (continued) Outflow Weirs SN Element Weir Flap Crest Crest Length WeirTolal Discharge ID Type Gale Elevation Offset Height Coefficient (ft) (ft) (ft) 00 1 OVERFLOW—BERM Trapezoidal No 14.00 2.30 50.00 1.10 3.33 Output Summary Results Peak Inflow (cfs)...................................................................... 6.10 Peak Lateral Inflow (cfs).......................................................... 6.10 Peak Outflow (cfs)................................................................... 1.82 Peak Exfillration Flow Rate (cfm)............................................ 36.52 Max HGL Elevation Attained (ft) .............................................. 14.05 Max HGL Depth Attained (ft) ................................................... 2.35 Average HGL Elevation Attained (ft) ....................................... 12.14 Average HGL Depth Attained (ft) ............................................. 0.44 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:16 Total Exfillration Volume (1000-fP).......................................... 13.085 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ........................................................ 0 Total Retention Time (sec) ...................................................... 0:00 Storage Node: STORAGE—BASIN .......... _.............. 8.0000 Input Data Invert Elevation (ft).................................................................. 13.00 Max (Rim) Elevation (ft)................................_.........................15.60 Storage Max (Rim) Offset (ft)................................................................ 2.60 Initial Water Elevation (ft) ........................................................ 0.00 Initial Water Depth (fl)............................................................. -13.00 PondedArea (W)...................................................................... 0.00 Evaporation Loss..................................................................... 0.00 Infiltration/Exfiltration Exfiltration Rate (in/hr).................................. .......... _.............. 8.0000 Storage Area Volume Curves Storage Curve: STORAGE—BASIN Stage Storage Storage Area Volume (ft) (ft') (ft3) 0 5250 0.000 1 6474 5862.00 2 7826 13012.00 3 13087.2541 23468.63 3.1 13282.7596 24787.13 Storage Node: STORAGE—BASIN (continued) Output Summary Results Peak Inflow (cfs)...................................................................... 1.82 Peak Lateral Inflow (cfs).......................................................... 0.00 Peak Outflow (cfs)................................................................... 0.00 Peak Exfiltration Flow Rate (cfm)... ......................._................ 58.80 Max HGL Elevation Attained (ft) .............................................. 13.03 Max HGL Depth Attained (ft) ................................................... 0.03 Average HGL Elevation Attained (ft).......................................13.00 Average HGL Depth Attained (ft) ............................................. 0 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:21 Total Exfiltration Volume (1000-ft3).......................................... 0.991 Total Flooded Volume (ac -in) ....._ ........................................... 0 Total Time Flooded (min) ........................................................ 0 Total Retention Time (sec) ...................................................... 0.00 Storage Node: STORAGE—BASIN-2 Input Data Invert Elevation (ft)................................................................. 10.70 Max (Rim) Elevation (ft)..........................................................114.70 Max (Rim) Offset (ft)................................................................ 4.00 Initial Water Elevation (ft) ........................................................ 0.00 Initial Water Depth (ft)............................................................. -10.70 Ponded Area (ft')..................................................................... 0.00 Evaporation Loss..................................................................... 0.00 I nfI Itration/ExfI Itration Exfiltralion Rate (in/hr)....... ................ ...................................... 8.0000 Storage Area Volume Curves Storage Curve: STORAGE—BASIN-2 Stage Storage Storage Area Volume (ft) (ft') (fl') 0 416.86 0.000 1 667.79 542.33 2 960.03 1356.24 3 1297.28 2484.90 4.7 1520.63 4880.12 Storage Node: STORAGE_BASIN_2 (continued) Output Summary Results Peak Inflow (cfs)................................ ................ .... — ............. . 0.90 Peak Lateral Inflow (cfs)........ .................. ................................ 0.90 Peak Outflow (cfs).................. ....................... ................. .......,. 0.00 Peak Exfiltration Flow Rate (cfm)............................................ 8.59 Max HGL Elevation Attained (ft) .............................................. 12.06 Max HGL Depth Attained (ft) ................................................... 1.36 Average HGL Elevation Attained (ft) ....................................... 10.84 Average HGL Depth Attained (ft) ............................................. 0.14 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:31 Total Exfiltration Volume (1000-ft3).......................................... 1.801 Total Flooded Volume (ac-in).................................................. 0 Total Time Flooded (min)........................................................ 0 Total Retention Time (sec)...................................................... 0.00 Project Description File Name .................................................... Storm Water Analysis—updated basin 1.SPF Project Options FlowUnits ................................................... CFS Elevation Type ............................................ Elevation Hydrology Method ....................................... SCS TR -55 Time of Concentration (TOC) Method ........ SCS TR -55 Link Routing Method ................................... Kinematic Wave Enable Overflow Ponding at Nodes ............ YES Skip Steady Stale Analysis Time Periods ... YES Analysis Options Start Analysis On ........................................ Sep 01, 2017 00:00:00 End Analysis On .......................................... Sep 02, 2017 00:00:00 Start Reporting On ...................................... Sep 01, 2017 00:00:00 Antecedent Dry Days .................................. 0 days Runoff (Dry Weather) Time Step ................ 0 01:00:00 days hh:mm:ss Runoff (Wet Weather) Time Step... ............ 0 00:05:00 days hh:mm:ss Reporting Time Step ................................... 0 00:05:00 days hh:mm:ss Routing Time Step ...................................... 30 seconds Number of Elements Qty RainGages.. ........................... -- ................ 1 Subba s ins .................................................... 4 Nodes........................................................... 7 Junctions ............................................ 0 Outfalls............................................... 4 Flow Diversions .................................. 0 Inlets................................................... 0 Storage Nodes ................................... 3 Links............................................................. 3 Channels............................................ 1 Pipes.................................................. 1 Pumps................................................ 0 Orifices............................................... 0 Weirs.................................................. 1 Outlets................................................ 0 Pollutants..................................................... 0 LandUses ................................................... 0 Rainfall Details SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall ID Source ID Type Units Period Depth Distribution (years) (inches) 1 Time Series 5 -Year Intensity inches Idaho Ada 5 1.60 SCS Type II 24 -hr Subbasin Summary SN Subbasin Area Weighted Total Total Total Peak Time of ID Curve Rainfall Runoff Runoff Runoff Concentration Number Volume (ac) (in) (in) (ac -in) (cfs) (days hh:mm:ss) 1 POST _1 10.01 89.74 1.60 0.75 7.48 10.37 0 00:10:00 _DMA 2 POST 1.52 89.49 1.60 0.73 1.11 1.54 0 00:10:00 _DMA _2 3 PRE _1 8.30 74.72 1.60 0.20 1.64 0.55 0 01:00:00 _DMA 4 PRE—DMA-2 3.22 74.00 1.60 0.18 0.59 0.40 0 00:18:49 Node Summary SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded Elevation Elevation Attained Depth Attained Flooding Volume Attained Occurrence (ft) (ft) (ft) (ft) (ft') (cfs) (ft) (ft) (ft) (days hh:mm) (ac -in) (min) 1 Out -10 Outfall 0.00 0.00 0.00 2 OUTFALL Outfall 0.00 0.00 0.00 _POST _2 3 OUTFALPRE_1 Outfall 15.05 0.55 15.05 4 OUTFALL_PRE_2 Outfall 9.32 0.39 9.32 5 FOREBAY Storage Node 11.70 15.60 0.00 0.00 10.36 14.15 0.00 0.00 6 STORAGE BASIN Storage Node 13.00 15.60 0.00 0.00 9.43 13.82 0.00 0.00 7 STORAGE -BASIN -2 Storage Node 10.70 14.70 0.00 0.00 1.54 12.91 0.00 0.00 Subbasin Hydrology Subbasin: POST -DMA -1 Input Data Area(ac)........................................................................ 10.01 Weighted Curve Number .............................................. 89.74 RainGage ID ..........................:....................................... Rain Gage Composite Curve Number Area Soil Curve Soil/Surface Description (acres) Group Number Lot _Impervious_(Roof+Hardscape) 4.49 98.00 Sile_Hardscape 0.54 98.00 Pavement 1.54 98.00 Landscape 3.44 C 74.00 Composite Area & Weighted CN 10.01 89.74 Time of Concentration TOC Method: SCS TR -55 Sheet Flow Equation : Tc = (0.007 * ((n * Lf)10.8)) / ((P^0.5) * (Sf^0.4)) Where: Tc = Time of Concentration (hr) n = Manning's roughness Lf =Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (Sf^0.5) (unpaved surface) V = 20.3282 * (Sf^0.5) (paved surface) V = 15.0 * (Sf^0.5) (grassed waterway surface) V = 10.0 * (Sf^0.5) (nearly bare & unfilled surface) V = 9.0(Sf^0.5) (cultivated straight rows surface) V = 7.0' (Sf^0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V = 2.5 * (Sf^0.5) (forest w/heavy litter surface) Tc = (Lf / V) / (3600 sec/hr) Where Tc = Time of Concentration (hr) Lf = Flow Length (ft) V = Velocity (f /sec) Sf = Slope (ft/ft) Channel Flow Equation : V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n R =Aq/Wp Tc = (Lf / V) / (3600 sec/hr) Where: Tc = Time of Concentration (hr) Lf = Flow Length (ft) R =Hydraulic Radius (ft) Aq = Flow Area (ft) Wp = Wetted Perimeter (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) n = Manning's roughness User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 1.60 Total Runoff (in)............................................................ 0.75 Peak Runoff (cfs)........................................................... 10.37 Weighted Curve Number ............................................... 89.74 Time of Concentration (days hh:mm:ss) ........__......... .. 0 00:10:00 Subbasin : POST -DMA -1 Rainfall Intensity Graph 2.2 2.1 2 1.9 - — - — 1.7 1.6 - — - - 1.5 1.4 1.3 L c 1.2 � 1 m ch 0.9- 0.8- 0.7 .90.8 0.7 0.6 0.6 0.4- 0.3- 0.2- 01 .40.30.2 0.1 — _ I 0 1 2 3 4 5 6 7 8 9 10 it 12 13 14 1b lb it !n JU -,u n « <� Time (hrs) 11 10.5 10 9.5 9 8.5 8 7.5 7 6.5 w 6- 6.5- 5- 4.5 5.554.5 4- 3.5 3 2.5 2 1.5 1 0.5 Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) — I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Subbasin : POST—DMA-2 Input Data Area(ac)........................................................................ 1.52 Weighted Curve Number ............................................... 89.49 Rain Gage ID ............................................................. Rain Gage Composite Curve Number Area Soil Curve Soil/Surface Description (acres) Group Number Lot_ Impervious_(Roof+Hardscape) 0.65 98.00 Site_Hardscape 0.10 98.00 Pavement 0.23 98.00 Landscape 0.54 C 74.00 Composite Area & Weighted CN 1.52 89.49 Time of Concentration User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 1.60 TotalRunoff (in)............................................................. 0.73 Peak Runoff (cfs)........................................................... 1.54 Weighted Curve Number ............................................... 89.49 Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Subbasin : POST -DMA -2 2.3 2.2 2.1 2 1.9 1.6 1.7 1.6 1.5- 1.4 t 1.3- 1.2- 1.1 .31.21.1 I 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 1 0.9 c 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 Rainfall Intensity Graph I I i i - - i - I T-- - � I 01 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ( iu ita zu zi « 'o Time (hrs) i - - - - i 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ( iu ita zu zi « 'o Time (hrs) Subbasin : PRE—DMA-1 Input Data Area(ac)........................................................................ 8.30 Subarea Weighted Curve Number ............................................... 74.72 C RainGage ID................................................................. Rain Gage 0.00 Composite Curve Number 669.2763 0.00 0.3 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 8.05 C 74.00 Paved parking & roofs 0.25 D 98.00 Composite Area & Weighted CN 8.30 74.72 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (fUsec) : Computed Flow Time (min) : Total TOC (min) ..................60.00 Subbasin Runoff Results Subarea Subarea Subarea A B C 0.03 0.025 0.00 300 669.2763 0.00 0.3 0.3 0.00 1.20 1.20 0.00 0.22 0.30 0.00 22.71 37.29 0.00 Total Rainfall (in)............................................................ 1.60 Total Runoff (in)............................................................. 0.20 Peak Runoff (cfs)............. .................. .................. .......... 0.55 Weighted Curve Number ............................................... 74.72 Time of Concentration (days hh:mm:ss) ........................ 0 01:00:00 Subbasin : PRE -DMA -11 Rainfall Intensity Graph z- -----i 2I � — — -- 2 I - —F4 9 i- 8 -- -- 7 4 3 - _ - 2 -- - — -- — 0.56 0.54 0.52 0.5 0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34- 0.32 0.3 0 0.28 � 0.26- 0.24- 0.22- 0.2- 0.18-- 0.16 .260.240.220.20.180.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 A G a 7 a a 1n 11 19 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Runoff Hydrograph - - — I i 71< 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Subbasin : PRE—DMA-2 Input Data Area(ac)......................................................................... 3.22 Subarea Weighted Curve Number.. ............................................. 74.00 C RainGage ID................................................................. Rain Gage 0.00 Composite Curve Number 178.2036 0.00 1.7 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 3.22 C 74.00 Composite Area & Weighted CN 3.22 74.00 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................18.83 Subbasin Runoff Results Subarea Subarea Subarea A B C 0.03 0.03 0.00 300 178.2036 0.00 1.7 1.7 0.00 1.20 1.20 0.00 0.44 0.40 0.00 11.35 7.48 0.00 Total Rainfall (in)............................................................ 1.60 Total Runoff (in)............................................................. 0.18 PeakRunoff (cfs)........................................................... 0.40 Weighted Curve Number ................. .............................. 74.00 Time of Concentration (days hh:mm:ss) ........................ 0 00:18:50 Subbasin : PRE -DMA -2 Rainfall Intensity Graph 2.3 2.2 2.1 - - - - - -- - I I __ 2 _ 1.9 � - 1.8 - 1.7 1.5 1.4- 1.3- 1.2 .41.3 1.2 1 - 0.9- 0.7- 0.6- 0.5- 0.4 .90.70.60.4 - 0.3 0.21 0.1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b ib / lb iy to ci cl - Time (hrs) 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26- 0.24- 0.22- 0 .260.240.22 0.2- 0.18 0.16 0.14 012 0.1 0.08 0.06- 0.04 0.02 Runoff Hydrograph �I i i I � I � I � 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Storage Nodes Storage Node: FOREBAY Storage Input Data Invert Elevation (ft).................................................................. 11.70 Max (Rim) Elevation (ft)...........................................................15.60 (ft') Max (Rim) Offset (ft)................................................................ 3.90 Initial Water Elevation (ft).........................................................0.00 0.000 Initial Water Depth (ft)............................................................. -11.70 Ponded Area (ft')..................................................................... 0.00 Evaporation Loss ... .................. ...................... --- .................... 0.00 I nfi Itration/Exf iltratio n Exfiltration Rale (in/hr).................. .............................. ............. 8.0000 Storage Area Volume Curves Storage Curve: FOREBAY Stage Storage Storage Area Volume (ft) (ft') (ft') 0 1450 0.000 1 2146 1798.00 2 2970 4356.00 2.3 3242.16 5287.82 Storage Node: FOREBAY (continued) Outflow Weirs SN Element Weir Flap Crest Crest Length Weir Total Discharge ID Type Gate Elevation Offset Height Coefficient (ft) (ft) 00 (ft) 1 OVERFLOW—BERM Trapezoidal No 14.00 2.30 50.00 1.10 3.33 Output Summary Results Peak Inflow (cfs)...................................................................... 10.36 Peak Lateral Inflow (cfs).......................................................... 10.36 Peak Outflow (cfs)................................................................... 9.43 Peak Exflltration Flow Rate (cfm)............................................ 37.50 Max HGL Elevation Attained (ft) .............................................. 14.15 Max HGL Depth Attained (ft) ................................................... 2.45 Average HGL Elevation Attained (ft) ....................................... 12.30 Average HGL Depth Attained (ft) ............................................. 0.6 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:06 Total Exfiltration Volume (1000-f1') .......................................... 17.568 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ........................................................ 0 Total Retention Time (sec) ...................................................... 0.00 Storage Node: STORAGE—BASIN Storage Input Data Invert Elevation (ft)...........................................................•,..... 13.00 Max (Rim) Elevation (ft)...........................................................15.60 (ft') Max (Rim) Offset (fl)................................................................ 2.60 Initial Water Elevation (ft) ........................................................ 0.00 Initial Water Depth (f) ....................... ................ _................. .. -13.00 Ponded Area (ft) ........... .................... ................................... ... 0.00 Evaporation Loss..................................................................... 0.00 Infiltration/Exfiltration Exfiltration Rale (in/hr)...................... .................. :.................... 8.0000 Storage Area Volume Curves Storage Curve: STORAGE—BASIN Stage Storage Storage Area Volume (ft) (ft') (ft') 0 5250 0.000 1 6474 5862.00 2 7826 13012.00 3 13087.2541 23468.63 3.1 13282.7596 24787.13 Storage Node: STORAGE—BASIN (continued) Output Summary Results Peak Inflow (cfs)................ .:..:................................................. 9.43 Peak Lateral Inflow (cfs)..........................................................0.00 Peak Outflow (cfs)................................................................... 0.00 Peak Exfiltralion Flow Rate (cfm)............................................ 69.55 Max HGL Elevation Attained (ft) ............. --............................. 13.82 Max HGL Depth Attained (ft) ................................................... 0.82 Average HGL Elevation Attained (ft) ....................................... 13.04 Average HGL Depth Attained (ft) ............... :............. ................ 0.04 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:27 Total Exfiltralion Volume (1000 -ft) .......................................... 7.802 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ........................................................ 0 Total Retention Time (sec) ...................................................... 0.00 Storage Node: STORAGE—BASIN-2 Storage Input Data Invert Elevation (ft).................................................................. 10.70 Max (Rim) Elevation (ft)........................................................... 14.70 Max (Rim) Offset (ft)................................................................ 4.00 Initial Water Elevation (ft)........................................................0.00 0.000 Initial Water Depth (ft)............................................................. .10.70 Ponded Area (W)..................................................................... 0.00 Evaporation Loss ... ............ ..........--- .,................................... . 0.00 Infiltration/Exfiltration Exfiltration Rate (in/hr) ... Storage Area Volume Curves Storage Curve: STORAGE—BASIN-2 ............... 8.0000 Stage Storage Storage Area Volume (ft) (ft') (fl') 0 416.86 0.000 1 667.79 542.33 2 960.03 1356.24 3 1297.28 2464.90 4.7 1520.63 4880.12 Storage Node: STORAGE_BASIN_2 (continued) Output Summary Results PeakInflow (cis)...................................................................... 1.54 Peak Lateral Inflow (cis)..........................................................1.54 Peak Outflow (cis)................................................................... 0.00 Peak Exfiltralion Flow Rate (cfm).............................. .............. 11.44 Max HGL Elevation Attained (fl)....,..—............. ....................... 12.91 Max HGL Depth Attained (ft) ................................................... 2.21 Average HGL Elevation Attained (ft) ....................................... 11.04 Average HGL Depth Attained (fl)............................................. 0.34 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:36 Total Exfiltralion Volume (1000-ft3).......................................... 3.357 Total Flooded Volume (ac-in).................................................. 0 Total Time Flooded (min)........................................................ 0 Total Retention Time (sec)...................................................... 0.00 Project Description File Name ....................... ................... Storm Water Analysis—Updated basin 1.SPF Project Options FlowUnits ................................................... CFS Elevation Type ............................................ Elevation Hydrology Method ....................................... SCS TR -55 Time of Concentration (TOC) Method ........ SCS TR -55 Link Routing Method ................................... Kinematic Wave Enable Overflow Ponding at Nodes ............ YES Skip Steady State Analysis Time Periods ... YES Analysis Options Start Analysis On ........................................ Sep 01, 2017 00:00:00 End Analysis On .......................................... Sep 02, 2017 00:00:00 Start Reporting On ...................................... Sep 01, 2017 00:00:00 Antecedent Dry Days .................................. 0 days Runoff (Dry Weather) Time Step ................ 0 01:00:00 days hh:mm:ss Runoff (Wet Weather) Time Step ............... 0 00:05:00 days hh:mm:ss Reporting Time Step.. ........................... 0 00:05:00 days hh:mm:ss Routing Time Step ...................................... 30 seconds Number of Elements Qty Rain Gages ................................................. 1 Subbasi n s .................................................... 4 Nodes........................................................... 7 Junctions ............................................ 0 Outfalls............................................... 4 Flow Diversions .................................. 0 Inlets................................................... 0 Storage Nodes ................................... 3 Links............................................................. 3 Channels ............................................ 1 Pipes.................................................. 1 Pumps................................................ 0 Orifices............................................... 0 weirs.................................................. 1 Outlets................................................ 0 Pollutants.................................................... 0 LandUses ................................................... 0 Rainfall Details SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall ID Source ID Type Units Period Depth Distribution (years) (inches) 1 Time Series 10 -Year Intensity inches User Defined Subbasin Summary SN Subbasin Area Weighted Total Total Total Peak Time of ID Curve Rainfall Runoff Runoff Runoff Concentration Number Volume (ac) (in) (in) (ac -in) (cfs) (days hh:mm:ss) 1 POST _1 10.01 89.74 1.85 0.95 9.52 13.19 0 00:10:00 _DMA 2 POST _2 1.52 89.49 1.85 0.94 1.42 1.97 0 00:10:00 _DMA 3 PRE 8.30 74.72 1.85 0.30 2.51 0.98 0 01:00:00 _DMA _1 4 PRE DMA 2 3.22 74.00 1.85 0.28 0.91 0.75 0 00:18:49 Node Summary SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded Elevation Elevation Attained Depth Attained Flooding Volume Attained Occurrence (ft) (ft) (ft) (ft) (ft') (cfs) (ft) (ft) (ft) (days hh:mm) (ac -in) (min) 1 Out -10 Outfall 0.00 0.00 0.00 2 OUTFALL Outfall 0.00 0.00 0.00 _POST_2 3 OUTFALL Outfall 15.05 0.97 15.05 _PRE _1 4 OUTFALL PRE Outfall 9.32 0.72 9.32 _ _2 5 FOREBAY Storage Node 11.70 15.60 0.00 0.00 13.17 14.18 0.00 0.00 6 STORAGE BASIN Storage Node 13.00 15.60 0.00 0.00 12.52 14.37 0.00 0.00 7 STORAGE -BASIN -2 Storage Node 10.70 14.70 0.00 0.00 1.96 13.40 0.00 0.00 Subbasin Hydrology Subbasin: POST -DMA -1 Input Data Area(ac)........................................................................ 10.01 Weighted Curve Number ............................................... 89.74 RainGage ID ............................. .................... ................ Rain Gage Composite Curve Number Area Soil Curve Soil/Surface Description (acres) Group Number Lot_Impervious_(Roof+Hardscape) 4.49 98.00 Site_Hardscape 0.54 98.00 Pavement 1.54 98.00 Landscape 3.44 C 74.00 Composite Area & Weighted CN 10.01 89.74 Time of Concentration TOC Method: SCS TR -55 Sheet Flow Equation: Tc = (0.007 * ((n * Lf)A0.8)) / ((PA0.5) * (Sf"0.4)) Where: Tc = Time of Concentration (hr) n = Manning's roughness Lf =Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (SfA0.5) (unpaved surface) V = 20.3282 * (SfA0.5) (paved surface) V = 15.0 * (SfA0.5) (grassed waterway surface) V = 10.0 * (SfA0.5) (nearly bare & untilled surface) V = 9.0 * (SfA0.5) (cultivated straight rows surface) V = 7.0 * (SfA0.5) (short grass pasture surface) V = 5.0 * (SfA0.5) (woodland surface) V = 2.5 * (SfA0.5) (forest w/heavy litter surface) Tc = (Lf / V) / (3600 sec/hr) P,kFj, = Tc = Time of Concentration (hr) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation : V = (1.49 * (RA(2/3)) * (SfA0.5)) / n R =Aq/Wp Tc = (Lf / V) / (3600 sec/hr) Where : Tc = Time of Concentration (hr) Lf = Flow Length (ft) R = Hydraulic Radius (ft) Aq = Flow Area (fl) Wp = Welted Perimeter (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) n = Manning's roughness User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 1.85 Total Runoff (in)............................................................. 0.95 Peak Runoff (cfs)........................................................... 13.19 Weighted Curve Number ............................................... 89.74 Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Subbasin : POST -DMA -1 2. 2, 2. 2 2 2 1 1 1 1 L 1 � 1 - 1 m c 1 � 1 0 0 0 0 0 0 0 0 Rainfall Intensity Graph 4 -- -'- ---- -'- -'� -- t 3 - - - 2 - -- - - - - 2 - 9 - -- - - - 7- 6- 4- 3- 2 6 4 2 - - - 1 - 9 - -- - 8 - 71 -- 6 - — -- I 4 _ I 1 2 1 � I 14- 13.5 13 12.5 12 11.5 11 10.5 10 9.5 9 8.5 � 8 7.5 7 0 6.5- 6- 5.5- 5 .565.55 4.5- 4- 3.5- 3- 2-5- 2 .543.532.52 1.5- 1 0.5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 lb ib li iti is to n « l� Time (hrs) Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 Time (hrs) I I - i I J_ L 12 - 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 Time (hrs) Subbasin : POST—DMA-2 Input Data Area(ac) ................ .............. „.,....................................... 1.52 TotalRunoff (in)............................................................. Weighted Curve Number ............................................... 89.49 1.97 RainGage ID................................................................. Rain Gage Time of Concentration (days hh:mm:ss) ........................ Composite Curve Number Area Soil Curve Soil/Surface Description (acres) Group Number Lot_ Impervious_(Roof+Hardscape) 0.65 98.00 Site _Hardscape 0.10 98.00 Pavement 0.23 98.00 Landscape 0.54 C 74.00 Composite Area & Weighted CN 1.52 89.49 Time of Concentration User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results TotalRainfall (in)............................................................ 1.85 TotalRunoff (in)............................................................. 0.94 Peak Runoff (cfs).......................... ................ ................. 1.97 Weighted Curve Number ............................................... 89.49 Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Subbasin : POST -DMA -2 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2 1.9 1.B 1.7 1.6 c 1.5 _- 14 1.3 1.2 1.1 1 0. 0. 07 0.s 0.5 0. 0.3 0. 0.1 Rainfall Intensity Graph I - I - - - - aI F - - � r 2 i 2.1 2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 �- 1.1 0 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 1 2 3 4 5 6 7 8 9 10 11 12 la 14 15 lb itits is zu a cc z. Time (hrs) Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 Time (hrs) 1 I- i i I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 Time (hrs) Subbasin : PRE—DMA-1 Input Data Area(ac) ........................ .............. .................. ................ 8.30 Subarea Weighted Curve Number ............................................... 74.72 C RainGage ID................................................................. Rain Gage 0.00 Composite Curve Number 669.2763 0.00 0.3 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 8.05 C 74.00 Paved parking & roofs 0.25 D 98.00 Composite Area & Weighted CN 8.30 74.72 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................60.00 Subbasin Runoff Results Subarea Subarea Subarea A B C 0.03 0.025 0.00 300 669.2763 0.00 0.3 0.3 0.00 1.20 1.20 0.00 0.22 0.30 0.00 22.71 37.29 0.00 Total Rainfall (in)......_.................................................... 1.85 Total Runoff (in) ................................ .,............ ............... 0.30 Peak Runoff (cfs)............................ ............................... 0.98 Weighted Curve Number ................................................ 74.72 Time of Concentration (days hh:mm:ss) ........................ 0 01:00:00 Subbasin : PRE -DMA -1 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2 1c 1.E 1.7 1.E Ez 1c C 14 1.c of 1.1 1 0.f 0.E 0.i DA 0.! 0., 0 0.: 0.' Rainfall Intensity Graph i LLL - - - �- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b ib it io iu cu z « Time (hrs) 1.05 1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 N 0.6- a65- 0 .60.550 0.5 0_ 0.45- 0.4- 0.35 .450.40.35 0.3 0.25 0.2 0.15 0.1 0.05 Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) - - - �- -I -- -- - -� 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Subbasin : PRE—DMA-2 Input Data Area(ac)........................................................................ 3.22 Subarea Weighted Curve Number ............................................... 74.00 C RainGage ID.............................:.............:....:................ Rain Gage 0.00 Composite Curve Number 178.2036 0.00 1.7 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 3.22 C 74.00 Composite Area & Weighted CN 3.22 74.00 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................18.83 Subbasin Runoff Results Subarea Subarea Subarea A B C 0.03 0.03 0.00 300 178.2036 0.00 1.7 1.7 0.00 1.20 1.20 0.00 0.44 0.40 0.00 11.35 7.48 0.00 Total Rainfall (in) ............. .............................. ................. 1.85 Total Runoff (in)............................................................. 0.28 PeakRunoff (cfs)........................................................... 0.75 Weighted Curve Number ............................................... 74.00 Time of Concentration (days hh:mm:ss) ........................ 0 00:18:50 Subbasin : PRE -DMA -2 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2 19 18 1.7 1.6 1.5 1.4 @ 1.3 1.2 0'_ 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.8 0.75 0.7 0.65 0.6 0.55 0.5 N 0.45 -- 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.0' Rainfall Intensity Graph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b 1b v 10 1U <u n c< < Time (hrs) Runoff Hydrograph i _ I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b 1b v 10 1U <u n c< < Time (hrs) Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 11 14 1b 1b i( 10 1y <u Time (hrs) i 0 1 2 3 4 5 6 7 8 9 10 11 12 11 14 1b 1b i( 10 1y <u Time (hrs) Storage Nodes Storage Node: FOREBAY Input Data Invert Elevation (ft) .......................... Max (Rim) Elevation (ft) ................... Max (Rim) Offset (ft) ....................... Initial Water Elevation (ft) ................ Initial Water Depth (ft) ..................... Ponded Area (ft2) ............................. Evaporation Loss ........... I nfiltration/ExfI Itratio n Exfiltration Rate (in/hr) ... Storage Area Volume Curves Storage Curve: FOREBAY ................................ 11.70 —, ..............................15.60 ................................... 3.90 .......................................0.00 ....................................... -11.70 ........................................ 0.00 ....._ ................................1 0.00 Stage Storage Storage Area Volume (ft) (ft') UP) 0 1450 0.000 1 2146 1798.00 2 2970 4356.00 2.3 3242.16 5287.82 8.0000 Storage Node: FOREBAY (continued) Outflow Weirs SN Element Weir Flap Crest Crest Length Weir Total Discharge ID Type Gate Elevation Offset Height Coefficient (ft) (ft) (fl) (ft) 1 OVERFLOW—BERM Trapezoidal No 14.00 2.30 50.00 1.10 3.33 Output Summary Results Peak Inflow (cfs)...................................................................... 13.17 Peak Lateral Inflow (cfs).......................................................... 13.17 Peak Outflow (cfs)................................................................... 12.52 Peak Exfiltralion Flow Rate (cfm)............................................ 37.81 Max HGL Elevation Attained (ft) ..........................................:... 14.18 Max HGL Depth Attained (ft) ................................................... 2.48 Average HGL Elevation Attained (ft) ....................................... 12.41 Average HGL Depth Attained (ft) ............................................. 0.71 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:05 Total Exfiltralion Volume (1000-f 3) ..........._ ............................. 20.539 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ........................................................ 0 Total Retention Time (sec) ....................................................... 0.00 Storage Node: STORAGE—BASIN Input Data Invert Elevation (ft) ........................ -............................ ............ 13.00 Max (Rim) Elevation (fit)................................................_.........15.60 Max (Rim) Offset (ft)................................................................ 2.60 Initial Water Elevation (ft) ........................................................ 0.00 Initial Water Depth (ft)............................................................. .13.00 Ponded Area (ft').....................................................................0.00 0.000 Evaporation Loss..................................................................... 0.00 I nf1Itrati on/Exfi Itratio n Exfiltralion Rate (in/hr) ............................................................. 8.0000 Storage Area Volume Curves Storage Curve: STORAGE—BASIN Stage Storage Storage Area Volume (ft) (ft') (ft') 0 5250 0.000 1 6474 5862.00 2 7826 13012.00 3 13087.2541 23468.63 3.1 13282.7596 24787.13 Storage Node: STORAGE—BASIN (continued) Output Summary Results Peak Inflow (cfs)...................................................................... 12.52 Peak Lateral Inflow (cfs).......................................................... 0.00 Peak Outflow (cfs)................................................................... 0.00 Peak Exfillration Flow Rale (cfm)............................................ 77.54 Max HGL Elevation Attained (ft) .............................................. 14.37 Max HGL Depth Attained (ft) ................................................... 1.37 Average HGL Elevation Attained (ft) ....................................... 13.10 Average HGL Depth Attained (ft) ............................................. 0.1 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:31 Total Exfillration Volume (1000-ft3).......................................... 12.534 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ............ .................................... 0 Total Retention Time (sec) ............ ............ .:,:....... ......... :........ 0.00 Storage Node: STORAGE—BASIN-2 Input Data Invert Elevation (ft).................................................................. 10.70 Max (Rim) Elevation (ft)........................................................... 14.70 Max (Rim) Offset (ft) ........................ --............ .............. .......... 4.00 Initial Water Elevation (ft)........................................................0.00 (ftp) Initial Water Depth (ft)............................................................. .10.70 Ponded Area (ft')..................................................................... 0.00 Evaporation Loss ...... ...:........... .............................. ..... ............ 0.00 I nfi Itration/Exfi Itratio n Exfiltration Rate (in/hr).........:...::............. ............................... 8.0000 Storage Area Volume Curves Storage Curve: STORAGE_BASIN_2 Stage Storage Storage Area Volume (ft) (ftp) (f') 0 416.86 0.000 1 667.79 542.33 2 960.03 1356.24 3 1297.28 2484.90 4.7 1520.63 4880.12 Storage Node: STORAGE_BASIN_2 (continued) Output Summary Results PeakInflow (cfs)...................................................................... 1.96 Peak Lateral Inflow (cfs).......................................................... 1.96 Peak Outflow (cfs)...................................................................0.00 Peak Exfiltration Flow Rate (cfm)............................................ 13.29 Max HGL Elevation Attained (ft) .............................................. 13.40 Max HGL Depth Attained (ft) ................................................... 2.7 Average HGL Elevation Attained (fl)....................................... 11.20 Average HGL Depth Attained (ft) ............................................. 0.5 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:38 Total Exfiltration Volume (1000-f13).......................................... 4.491 Total Flooded Volume (ac-in).................................................. 0 Total Time Flooded (min)...................... ..........,....................... 0 Total Retention Time (sec)...................................................... 0.00 Project Description File Name .................................................... Storm Water Analysis—Updated basin 1.SPF Project Options FlowUnits . .............. .......:..:................... ...... CFS Elevation Type ............................................ Elevation Hydrology Method ........... ................ ........... SCS TR -55 Time of Concentration (TOC) Method ........ SCS TR -55 Link Routing Method ................................... Kinematic Wave Enable Overflow Ponding at Nodes ............ YES Skip Steady State Analysis Time Periods ... YES Analysis Options Start Analysis On ........................................ Sep 01, 2017 00:00:00 End Analysis On .......................................... Sep 02, 2017 00:00:00 Start Reporting On ...................................... Sep 01, 2017 00:00:00 Antecedent Dry Days .................................. 0 days Runoff (Dry Weather) Time Step ................ 0 01:00:00 days hh:mm:ss Runoff (Wet Weather) Time Step ............... 0 00:05:00 days hh:mm:ss Reporting Time Step ................................... 0 00:05:00 days hh:mm:ss Routing Time Step ...................................... 30 seconds Number of Elements Qty Rain Gages ................................................. 1 Subb asin s .................................................... 4 Nodes........................................................... 7 Junctions ............................................ 0 Outfalls............................................... 4 Flow Diversions .................................. 0 Inlets................................................... 0 Storage Nodes ................................... 3 Links............................................................. 3 Channels............................................ 1 Pipes.................................................. 1 Pumps................................................ 0 Orifices............................................... 0 weirs.................................................. 1 Outlets................................................. 0 Pollutants.................................................... 0 LandUses ................................................... 0 Rainfall Details SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall ID Source ID Type Units Period Depth Distribution (years) (inches) 1 Time Series 25 -Year Intensity inches Idaho Ada 25 2.25 SCS Type II 24 -hr Subbasin Summary SN Subbasin Area Weighted Total Total Total Peak Time of ID Curve Rainfall Runoff Runoff Runoff Concentration Number Volume (ac) (in) (in) (ac -in) (cfs) (days hh:mm:ss) 1 POST _1 10.01 89.74 2.25 1.29 12.92 17.86 0 00:10:00 _DMA 2 POST DMA 2 1.52 89.49 2.25 1.27 1.93 2.67 0 00:10:00 3 PRE 8.30 74.72 2.25 0.50 4.14 1.86 0 01:00:00 _DMA _1 4 PRE DMA 2 3.22 74.00 2.25 0.47 1.52 1.47 0 00:18:49 Node Summary SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded Elevation Elevation Attained Depth Attained Flooding Volume Attained Occurrence (ft) (ft) (ft) (ft) (ft') (cfs) (ft) (ft) (ft) (days hh:mm) (ac -in) (min) 1 Out -10 Outfall 0.00 3.25 0.08 2 OUTFALL Outfall 0,00 0.00 0.00 _POS7_2 3 OUTFALL Outfall 15,05 1.86 15.05 _PRE _1 4 OUTFALL_PRE_2 Outfall 9.32 1.44 9.32 5 FOREBAY Storage Node 11.70 15.60 0.00 0.00 17.78 14.22 0.00 0.00 6 STORAGE Storage Node 13.00 15.60 0.00 0.00 17.10 15.03 0.00 0.00 _BASIN 7 STORAGE -BASIN -2 Storage Node 10.70 14.70 0.00 0.00 2.66 14.13 0.00 0.00 Subbasin Hydrology Subbasin: POST -DMA -1 Input Data Area(ac)........................................................................ 10.01 Weighted Curve Number ............................................... 89.74 RainGage ID..........._..:............................................... Rain Gage Composite Curve Number Area Soil Curve Soil/Surface Description (acres) Group Number Lot_ Impervious_(Roof+Hardscape) 4.49 98.00 Site_Hardscape 0.54 98.00 Pavement 1.54 98.00 Landscape 3.44 C 74.00 Composite Area & Weighted CN 10.01 89.74 Time of Concentration TOC Method: SCS TR -55 Sheet Flow Equation: To = (0.007 * ((n * Lf)^0.B)) / ((P^0.5) * (Sf^0.4)) Where: To = Time of Concentration (hr) n = Manning's roughness Lf =Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (Sf^0.5) (unpaved surface) V = 20.3282 * (Sf^0.5) (paved surface) V = 15.0 * (Sf^0.5) (grassed waterway surface) V = 10.0 * (Sf^0.5) (nearly bare & untilled surface) V = 9.0 * (Sf^0.5) (cultivated straight rows surface) V = 7.0 * (Sf^0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V = 2.5 * (Sf^0.5) (forest w/heavy litter surface) To = (Lf / V) / (3600 sec/hr) Where To = Time of Concentration (hr) Lf = Flow Length (ft) V = Velocity (fUsec) Sf = Slope (ft/ft) Channel Flow Equation : V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n R =Aq/Wp To = (Lf / V) / (3600 sec/hr) Where: To = Time of Concentration (hr) Lf = Flow Length (ft) R =Hydraulic Radius (fl) Aq = Flow Area (ft') Wp = Wetted Perimeter (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) n = Manning's roughness User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Totat Rainfall (in)............................................................ 2.25 Total Runoff (in)............................................................. 1.29 Peak Runoff (cfs)........................................................... 17.86 Weighted Curve Number ............................................... 89.74 Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Subbasin : POST—DMA-11 ON 2.1 2.1 2. 2.: c 1. _ 1,1 (6 C 1. 0. 0. 0. 0. Rainfall Intensity Graph 1 I n a 7 a a 1n 11 17 13 14 15 16 17 18 19 20 21 22 23 19 18 17 16 16 14 31211 13- 12- 11 10 0 9- 8- 7- 6 876 6 4 3 2 1 Time (hrs) Runoff Hydrograph 0 1 2 3 4 6 6 7 B 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) I j i I -77 — I i 0 1 2 3 4 6 6 7 B 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Subbasin : POST—DMA-2 Total Rainfall (in)............................................................ Input Data Total Runoff (in)............................................................. 1.27 Area(ac)........................................................................ 1.52 Weighted Curve Number ............................................... Weighted Curve Number ............................................... 89.49 0 00:10:00 RainGage ID .. ................ ....................................... ........ Rain Gage Composite Curve Number Area Soil Curve Soil/Surface Description (acres) Group Number Lot_ Impervious_(Roof+Hardscape) 0.65 98.00 Sile_Hardscape 0.10 98.00 Pavement 0.23 98.00 Landscape 0.54 C 74.00 Composite Area & Weighted CN 1.52 89.49 Time of Concentration User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 2.25 Total Runoff (in)............................................................. 1.27 Peak Runoff (cfs)........................................................... 2.67 Weighted Curve Number ............................................... 89.49 Time of Concentration (days hh:mm:ss) ......................... 0 00:10:00 Subbasin : POST -DMA -2 Rainfall Intensity Graph 3.4- 3.2 - - - - - - - l_ I 3 2.8 2.6 2.4 I _ 0.8 I � 1 0.6 - fFL4iA 0.4 Wj 0.2- 1 2 3 4 5 6 / U a 1U n 1[ 13 iw is M it iu Time (hrs) Runoff Hydrograph - 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2 1.9 1.8 1.7 w 1.6 v 1.5 0 1.4 1.3 i; 1.2 1 1.1 1 0.9 0.8 0.7 0.6 0.5 -" 0.4 0.3 0.2 0.1 1 2 3 4 5 6 / U a 1U n 1[ 13 iw is M it iu Time (hrs) Runoff Hydrograph - I � i 0 1 2 3 4 5 6 7 B 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Subbasin : PRE—DMA-1 Input Data Area(ac)......................................,................................. 8.30 Subarea Weighted Curve Number ............ .................................. 74.72 C Rain Gage ID ................. ..,....,,.._................. ................... Rain Gage 0.00 Composite Curve Number 669.2763 0.00 0.3 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 8.05 C 74.00 Paved parking & roofs 0.25 D 98.00 Composite Area & Weighted CN 8.30 74.72 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................60.00 Subarea Subarea Subarea A B C 0.03 0.025 0.00 300 669.2763 0.00 0.3 0.3 0.00 1.20 1.20 0.00 0.22 0.30 0.00 22.71 37.29 0.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 2.25 Total Runoff (in)............................................................. 0.50 Peak Runoff (cfs)........................................................... 1.86 Weighted Curve Number ............................................... 74.72 Time of Concentration (days hh:mm:ss) ........................ 0 01:00:00 Subbasin : PRE—DMA-11 3. 3. 2. 2, 2 2 Rainfall Intensity Graph 0 0 0 0 2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 U 1.1 1 C 0.9 th O.E 0.7 O.E O.E 0.4 0.� 0.' 0.1 0 1 2 3 4 5 6 7 6 9 10 11 12 13 14 1b lb v ib y to a cz �I Time (hrs) Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 1:i 14 1b lb 1t ie 1� �U « < Time (hrs) I 0 1 2 3 4 5 6 7 8 9 10 11 12 1:i 14 1b lb 1t ie 1� �U « < Time (hrs) Subbasin : PRE—DMA-2 Input Data Area(ac)........................................................................ 3.22 Subarea Weighted Curve Number ............................................... 74.00 C Rain Gage ID................................................................. Rain Gage 0.00 Composite Curve Number 178.2036 0.00 1.7 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 3.22 C 74.00 Composite Area & Weighted CN 3.22 74.00 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................18.83 Subbasin Runoff Results Subarea Subarea Subarea A B C 0.03 0.03 0.00 300 178.2036 0.00 1.7 1.7 0.00 1.20 1.20 0.00 0.44 0.40 0.00 11.35 7.48 0.00 Total Rainfall (in)............................................................ 2.25 Total Runoff (in)............................................................. 0.47 Peak Runoff (cfs)........................................................... 1.47 Weighted Curve Number ............................................... 74.00 Time of Concentration (days hh:mm:ss) ........................ 0 00:18:50 Subbasin : PRE -DMA -2 2. 2. 2. 2. `6 1. C �m � 1 1 0. 0. 0. 0. Rainfall Intensity Graph V L Time (hrs) 1.55 1.5 1.45 1.4 1.35 1.3 1.25 1.2 1.15 1.1 1.05 1 0.95 0.9 0.85 0.8 6 0.75- 07 0.613- 0.6 .650.6 0.55 0.5- 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) I 1 1 1 I - i I - i 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) I 1 1 1 Storage Nodes Storage Node: FOREBAY Input Data Invert Elevation (ft)................................................................. 11.70 Max (Rim) Elevation (ft)...........................................................15.60 Max (Rim) Offset (ft) ........ .......................... ............................. 3.90 Initial Water Elevation (ft)........................................................0.00 (ft') Initial Water Depth (ft)..............................................................-11.70 0 Ponded Area (W) .......................... ........................ .:.................0.00 Evaporation Loss..................................................................... 0.00 Inf iltrationlExfi ltration Exfiltration Rate (in/hr)..........,,....... .............................. ............ 8.0000 Storage Area Volume Curves Storage Curve: FOREBAY Stage Storage Storage Area Volume (ft) (ft') (ft') 0 1450 0.000 1 2146 1798.00 2 2970 4356.00 2.3 3242.16 5287.82 Storage Node: FOREBAY (continued) Outflow Weirs SN Element Weir Flap Crest Crest Length Weir Total Discharge ID Type Gate Elevation Offset Height Coefficient (ft) (ft) (ft) (ft) 1 OVERFLOW—BERM Trapezoidal No 14.00 2.30 50.00 1.10 3.33 Output Summary Results Peak Inflow (cfs)........................ :................... .......................... 17.78 Peak Lateral Inflow (cfs).......................................................... 17.78 Peak Outflow (cfs)................................................................... 17.10 Peak Exfiltralion Flow Rale (cfm)............................................ 38.21 Max HGL Elevation Attained (ft) .............................................. 14.22 Max HGL Depth Attained (fl) ..... ..........._.................. ............... 2.52 Average HGL Elevation Attained (ft) ....................................... 12.57 Average HGL Depth Attained (ft) ............................................. 0.87 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:05 Total Exfiltration Volume (1000 -ft') .......................................... 23.751 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ........................................................ 0 Total Retention Time (sec) ...................................................... 0.00 Storage Node: STORAGE—BASIN Input Data Invert Elevation (ft).................................................................. 13.00 Max (Rim) Elevation (ft) ......................... .............. ....................15.60 Max (Rim) Offset (ft)................................................................ 2.60 Initial Water Elevation (ft) ......................................................... 0.00 Initial Water Depth (ft) ........................................ ..................... -13.00 PondedArea (ft) ............................................ ...................... ...0.00 Evaporation Loss....................................................................... 0.00 I of iltrati on/Exfiltratio n Exfiltration Rate (in/hr)............................................................. 8.0000 Storage Area Volume Curves Storage Curve: STORAGE—BASIN Stage Storage Storage Area Volume (ft) (ft') UP) 0 5250 0.000 1 6474 5862.00 2 7826 13012.00 3 13087.2541 23468.63 3.1 13282.7596 24787.13 Storage Node: STORAGE—BASIN (continued) Output Summary Results Peak Inflow (cfs)............... ........................................ ............... 17.10 Peak Lateral Inflow (cfs)..........................................................0.00 Peak Outflow (cfs)...................................................................3.26 Peak Exfiltralion Flow Rate (cfm)............................................ 88.75 Max HGL Elevation Attained (ft) .............................................. 15.03 Max HGL Depth Attained (ft) ................................................... 2.03 Average HGL Elevation Attained (ft) ....................................... 13.21 Average HGL Depth Attained (ft) ............................................. 0.21 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:18 Total Exfiltralion Volume (1000-ft3).......................................... 19.146 Total Flooded Volume (ac-in).................................................. 0 Total Time Flooded (min)........................................................ 0 Total Retention Time (sec)...................................................... 0.00 Storage Node: STORAGE—BASIN-2 Input Data Invert Elevation (ft).................................................................. 10.70 Max (Rim) Elevation (ft) .................. ................................ 14.70 Max (Rim) Offset (ft)................................................................ 4.00 Initial Water Elevation (ft)........................................................0.00 (ft') Initial Water Depth (ft) ............................................................. -10.70 PondedArea (ft')..................................................................... 0.00 EvaporationLoss ..................... ................. ................ .............. 0.00 I nfiltration/Exf iltratio n Exfiltration Rate (in/hr)............................................................. 8.0000 Storage Area Volume Curves Storage Curve: STORAGE_BASIN_2 Stage Storage Storage Area Volume (ft) (ft') (ft') 0 416.86 0.000 1 667.79 542.33 2 960.03 1356.24 3 1297.28 2484.90 4.7 1520.63 4880.12 Storage Node: STORAGE_BASIN_2 (continued) Output Summary Results PeakInflow (cfs).......................... :............................... ............ 2.66 Peak Lateral Inflow (cfs)..........................................................2.66 Peak Outflow (cfs)...................................................................0.00 Peak Extiiltration Flow Rate (cfm)............................................ 15.05 Max HGL Elevation Attained (ft) .............................................. 14.13 Max HGL Depth Attained (ft) ................................................... 3.43 Average HGL Elevation Attained (ft).......................................11.48 Average HGL Depth Attained (ft) ............................................. 0.78 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:44 Total Exiiillration Volume (1000-ft3).......................................... 6.396 Total Flooded Volume (ac-in).................................................. 0 Total Time Flooded (min)........................................................ 0 Total Retention Time (sec)...................................................... 0.00 Project Description File Name .................................................... Storm Water Analysis updated basin 1.SPF Project Options Flow Units .....................--- .......... ............. CFS Elevation Type ............................................ Elevation Hydrology Method ....................................... SCS TR -55 Time of Concentration (TOC) Method ........ SCS TR -55 Link Routing Method ................................... Kinematic Wave Enable Overflow Ponding at Nodes ............ YES Skip Steady State Analysis Time Periods ... YES Analysis Options Start Analysis On ........................................ Sep 01, 2017 00:00:00 End Analysis On .......................................... Sep 02, 2017 00:00:00 Start Reporting On ...................................... Sep 01, 2017 00:00:00 Antecedent Dry Days .................................. 0 days Runoff (Dry Weather) Time Step ................ 0 01:00:00 days hh:mm:ss Runoff (Wet Weather) Time Step ............... 0 00:05:00 days hh:mm:ss Reporting Time Step ................................... 0 00:05:00 days hh:mm:ss Routing Time Step ...................................... 30 seconds Number of Elements Qty RainGages ................................................. 1 Su bba sins .................................................... 4 Nodes........................................................... 7 Junctions ............................................ 0 Ouffalls............................................... 4 Flow Diversions .................................. 0 Inlets....................................... .....::..... 0 Storage Nodes ................................... 3 Links....... ............... .................. ....::.............. . 3 Channels.... ........................................ 1 Pipes.................................................. 1 Pumps................................................ 0 Orifices............................................... 0 Weirs.................................................. 1 Outlets................................................ 0 Pollutants.................................................... 0 LandUses ................................................... 0 Rainfall Details SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall ID Source ID Type Units Period Depth Distribution (years) (inches) 1 Time Series 100 -Year Intensity inches Idaho Ada 100 2.60 SCS Type II 24 -hr Subbasin Summary SN Subbasin Area Weighted Total Total Total Peak Time of ID Curve Rainfall Runoff Runoff Runoff Concentration Number Volume (ac) (in) (in) (ac -in) (cfs) (days hh:mm:ss) 1 POST 1 10.01 89.74 2.80 1.78 17.81 24.46 0 00:10:00 _DMA 2 POST_DMA__2 1.52 69.49 2.80 1.76 2.67 3.67 0 00:10:00 3 PRE_DMA_1 8.30 74.72 2.80 0.82 6.80 3.37 0 01:00:00 4 PRE DMA 2 3.22 74.00 2.80 0.78 2.53 2.66 0 00:18:49 Node Summary SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded Elevation Elevation Attained Depth Attained Flooding Volume Attained Occurrence R (ft) (ft) (ft) (f') (cfs) (ft) (ft) (ft) (days hh:mm) (ac -in) (min) 1 Out -10 Outfall 0.00 17.74 0.22 2 OUTFALL Outfall 0.00 0.00 0.00 _POST _2 3 OUTFALL_PRE_1 Outfall 15.05 3.34 15.05 4 OUTFALL Outfall 9.32 2.64 9.32 -PRE -2 5 FOREBAY Storage Node 11.70 15.60 0.00 0.00 24.30 14.27 0.00 0.00 6 STORAGE Storage Node 13.00 15.60 0.00 0.00 23.57 15.17 0.00 0.00 _BASIN 7 STORAGE -BASIN -2 Storage Node 10.70 14.70 0.00 0.00 3.65 14.70 0.21 47.00 Subbasin Hydrology Subbasin: POST -DMA -1 Input Data Area(ac)........................................................................ 10.01 Total Rainfall (in)............................................................ Weighted Curve Number ............................................... 89.74 1.78 Rain Gage ID................................................................. Rain Gage Weighted Curve Number ............................................... Composite Curve Number Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Area Soil Curve Soil/Surface Description (acres) Group Number Lot Impervious_(Roof+Hardscape) 4.49 98.00 Site _Hardscape 0.54 98.00 Pavement 1.54 98.00 Landscape 3.44 C 74.00 Composite Area & Weighted CN 10.01 89.74 Time of Concentration TOC Method: SCS TR -55 Sheet Flow Equation: To = (0.007 * ((n * Lf)A0.8)) / ((PA0.5) ` (SfA0.4)) Where: To = Time of Concentration (hr) n = Manning's roughness Lf = Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (SfA0.5) (unpaved surface) V = 20.3282 * (SfA0.5) (paved surface) V = 15.0 * (SfA0.5) (grassed waterway surface) V = 10.0 * (SfA0.5) (nearly bare & unlilled surface) V = 9.0 * (SfA0.5) (cultivated straight rows surface) V = 7.0 * (SfA0.5) (short grass pasture surface) V = 5.0 * (SfA0.5) (woodland surface) V = 2.5 * (SfA0.5) (forest w/heavy litter surface) To = (Lf / V) / (3600 sec/hr) Where To = Time of Concentration (hr) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation : V = (1.49 * (RA(2/3)) * (SfA0.5)) / n R =Aq/Wp To = (Lf / V) / (3600 sec/hr) Where To = Time of Concentration (hr) Lf = Flow Length (ft) R = Hydraulic Radius (ft) Aq = Flow Area (f 2) Wp = Wetted Perimeter (ft) V = Velocity (fUsec) Sf = Slope (ft/ft) n = Manning's roughness User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 2.80 Total Runoff (in)............................................................. 1.78 Peak Runoff (cfs)........................................................... 24.46 Weighted Curve Number ............................................... 89.74 Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Subbasin : POST -DMA -1 Rainfall Intensity Graph 4 3.8 3.6 - - --_ — - - -- 3.4 -- - - - - -- - - - 3.2-� - — - - - - -- - - 3i 2.8- 2.6 - 2.4 2.2- 2- 1.2 .2 2 1.2 - - 0.8 - — — � I 0.6 - - - i 0.4 �— - -- 0.2 I � I 01 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 Time (hrs) 2E 2E 24 2-- 22 21 2[ 1E 1E I? 1E N 1E 16 1� 0 � 11 1[ c Runoff Hydrocdraph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b lb v Iti is to n LL �o Time (hrs) r rf -- 1- - -- i - -- I --- — - �— -41 i 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b lb v Iti is to n LL �o Time (hrs) Subbasin : POST—DMA-2 Input Data Area(ac)........................................................................ 1.52 Weighted Curve Number ............................................... 89.49 RainGage ID................................................................. Rain Gage Composite Curve Number Area Soil Curve Soil/Surface Description (acres) Group Number Lot_ impervious_(Roof+Hardscape) 0.65 98.00 Site_Hardscape 0.10 98.00 Pavement 0.23 98.00 Landscape 0.54 C 74.00 Composite Area & Weighted CN 1.52 89.49 Time of Concentration User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 2.80 Total Runoff (in)............................................................. 1.76 Peak Runoff (cfs)........................................................... 3.67 Weighted Curve Number ............................................... 89.49 Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Subbasin : POST—DMA-2 4.2 4 3.E 3.E 3.4 3.2 2.E 2.E 2.2 c m c 1.E 1.E L� 1.: GA 0.1 0., 0.: Rainfall Intensity Graph 4 3.8 3.6 3.4 3.2 3 2.8 2.6 2.4 U 2.2 2 O 1.8 1.6 1.4 1.2 1 o.E 0.6 0.4 0.2 0 1 2 3 4 5 6 7 8 9 10 11 12 1:3 14 lb lb 1t It) IV zu n Time (hrs) Runoff Hydrocdraph i I _ _ i I I 1 -JX ' I I 4 3.8 3.6 3.4 3.2 3 2.8 2.6 2.4 U 2.2 2 O 1.8 1.6 1.4 1.2 1 o.E 0.6 0.4 0.2 0 1 2 3 4 5 6 7 8 9 10 11 12 1:3 14 lb lb 1t It) IV zu n Time (hrs) Runoff Hydrocdraph 0 1 2 3 4 5 6 7 8 9 10 11 12 1:i 14 lb 1b It io is zu a Time (hrs) I _ _ i I I 1 0 1 2 3 4 5 6 7 8 9 10 11 12 1:i 14 lb 1b It io is zu a Time (hrs) Subbasin : PRE—DMA-1 Input Data Area(ac) ........................... .....--- ......................... ..,..... 8.30 Subarea Weighted Curve Number ........... .............. ...................... 74.72 C RainGage ID................................................................. Rain Gage 0.00 Composite Curve Number 669.2763 0.00 0.3 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 8.05 C 74.00 Paved parking & roofs 0.25 D 98.00 Composite Area & Weighted CN 8.30 74.72 Time of Concentration Sheet Flow Computations Manning's Roughness: Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) : Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................60.00 Subbasin Runoff Results Subarea Subarea Subarea A B C 0.03 0.025 0.00 300 669.2763 0.00 0.3 0.3 0.00 1.20 1.20 0.00 0.22 0.30 0.00 22.71 37.29 0.00 Total Rainfall (in)............................................................ 2.80 Total Runoff (in)............................................................. 0.82 Peak Runoff (cfs)........................................................... 3.37 Weighted Curve Number ............................................... 74.72 Time of Concentration (days hh:mm:ss) ........................ 0 01:00:00 Subbasin : PRE—DMA-11 Rainfall Intensity Graph 4.2 4 3.8 3.6 3.4 3.2 3 2.8 2.6 L 2.4- 2.2- 2- 1.4 .42,221.4 1.2 1 0.8 0.6 0.4 0.2 3 3 2 2 2 2 0 1 � 1 1 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Runoff Hydrograph 0.8 .6 _ - 3 � I .6 .4 - - i .2 I i .4 .2 I 0.6 - -� --- -li - - - - - 1.2 -, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b ro if 10 iy zu ci « <. Time (hrs) I I I � i 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Runoff Hydrograph 0.8 .6 _ - 3 � I .6 .4 - - i .2 I i .4 .2 I 0.6 - -� --- -li - - - - - 1.2 -, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b ro if 10 iy zu ci « <. Time (hrs) Subbasin : PRE—DMA-2 Input Data Area(ac)........................................................................ 3.22 Subarea Weighted Curve Number ............................................... 74.00 C RainGage ID................................................................. Rain Gage 0.00 Composite Curve Number 178.2036 0.00 1.7 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 3.22 C 74.00 Composite Area & Weighted CN 3.22 74.00 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................18.83 Subarea Subarea Subarea A B C 0.03 0.03 0.00 300 178.2036 0.00 1.7 1.7 0.00 1.20 1.20 0.00 0.44 0.40 0.00 11.35 7.48 0.00 Subbasin Runoff Results Total Rainfall (in) ............................. — ............. ...,.......... 2.80 Total Runoff (in) .... ....................................... ............. ..... 0.78 Peak Runoff (cfs)........................................................_ 2.66 Weighted Curve Number ............................................... 74.00 Time of Concentration (days hh:mm:ss) ....................... 0 00:18:50 Subbasin : PRE -DMA -2 Rainfall Intensity Graph 4-2 3.8 3.6 3.4 3.2- 3- 2.6- 2.4- 2.2 .2 3 2.6 2.42.2 1.4 -- - - - -- - i 1-2 - 1 0.8 0.6- 0.4 0.211 - { � 1, j 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2 1.9- 11.B 1.7 w 1.6 1.5 0 1.4 1.3 D 1.2 1.1 1 0.9- 0-8- 0.7- 0.6 .90.80.70.6 0.5 0.4 0.3 0.2 0.1 1 2 3 4 5 6 7 8 9 lu 11 l2 73 14 to In It to la cu a ,c < Time (hrs) Runoff Hydrograph 0 1 2 3 4 5 6 7 B 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) I i - JIL 1 0 1 2 3 4 5 6 7 B 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Storage Nodes Storage Node: FOREBAY Storage Input Data Invert Elevation (ft).................................................................. 11.70 Max (Rim) Elevation (ft)........................................................... 15.60 Max (Rim) Offset (ft)................................................................ 3.90 Initial Water Elevation (ft) ........................................................ 0.00 Initial Water Depth (fl).............................................................-11.70 2146 Ponded Area (ft')..................................................................... 0.00 EvaporationLoss ................................................... ................. . 0.00 I nf1Itratio n/Exfiltratio n Exfiltralion Rate (in/hr)............................................................. 8.0000 Storage Area Volume Curves Storage Curve: FOREBAY Stage Storage Storage Area Volume (fl) (ftp) (fl') 0 1450 0.000 1 2146 1798.00 2 2970 4356.00 2.3 3242.16 5287.82 Storage Node: FOREBAY (continued) Outflow Weirs SN Element Weir Flap Crest Crest Length Weir Total Discharge ID Type Gale Elevation Offset Height Coefficient (ft) (ft) (ft) (ft) 1 OVERFLOW—BERM Trapezoidal No 14.00 2.30 50.00 1.10 3.33 Output Summary Results Peak Inflow (cfs)...................................................................... 24.30 Peak Lateral Inflow (cfs).......................................................... 24.30 Peak Outflow (cfs)................................................................... 23.57 Peak Exfltration Flow Rate (cfm)............................................ 38.73 Max HGL Elevation Attained (ft) .............................................. 14.27 Max HGL Depth Attained (ft) ................................................... 2.57 Average HGL Elevation Attained (ft) ....................................... 12.74 Average HGL Depth Attained (ft) ............................................. 1.04 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:05 Total Exfillration Volume (1000 -ft') .......................................... 26.595 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ................ ................ .................... .,. 0 Total Retention Time (sec) ..........::_ .....:................................. 0.00 Storage Node: STORAGE—BASIN Input Data Invert Elevation (ft).................................................................. 13.00 Max (Rim) Elevation (ft)........................................................... 15.60 Max (Rim) Offset (ft)................................................................ 2.60 Initial Water Elevation (ft) ........................................................ 0.00 Initial Water Depth (ft)............................................................. -13.00 PondedArea (ft)..................................................................... 0.00 EvaporationLoss.......................:........................................... 0.00 I nfi Itration/Exfi Itratio In Exfiltralion Rate (in/hr) ............................................................. 8.0000 Storage Area Volume Curves Storage Curve: STORAGE—BASIN Stage Storage Storage Area Volume (ft) (ft') UP) 0 5250 0.000 1 6474 5862.00 2 7826 13012.00 3 13087.2541 23468.63 3.1 13282.7596 24787.13 Storage Node: STORAGE—BASIN (continued) Output Summary Results Peak Inflow (cfs)...................................................................... 23.57 Peak Lateral Inflow (cfs).......................................................... 0.00 Peak Outflow (cfs).................................................................... 17.75 Peak Exflllration Flow Rate (cfm)............................................ 96.94 Max HGL Elevation Attained (ft) .............................................. 15.17 Max HGL Depth Attained (ft) ................................................... 2.17 Average HGL Elevation Attained (ft) ........................................ 13.26 Average HGL Depth Attained (ft) ............................................. 0.26 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:09 Total ExFltralion Volume (1000-ft3).......................................... 22.241 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ..................................................,..... 0 Total Retention Time (sec) ..........................................,,.......... 0.00 Storage Node: STORAGE—BASIN-2 Storage Input Data Invert Elevation (ft).................................................................. 10.70 Max (Rim) Elevation (ft)...........................................................14.70 (ft') Max (Rim) Offset (ft)................................................................ 4.00 Initial Water Elevation (ft) ................... ..................................... 0.00 Initial Water Depth (ft)............................................................. -10.70 Ponded Area (ft2) ........................... .................. :................. ...... 0.00 Evaporation Loss ....... .................................... ........................ :. 0.00 I nfi Itration/Exf iltration Exfiltration Rate (inthr)............................................................. 8.0000 Storage Area Volume Curves Storage Curve: STORAGE -BASIN -2 Stage Storage Storage Area Volume (ft) (ft') (fl') 0 416.86 0.000 1 667.79 542.33 2 960.03 1356.24 3 1297.28 2484.90 4.7 1520.63 4880.12 Storage Node: STORAGE—BASIN-2 (continued) Output Summary Results Peak Inflow (cfs)...................................................................... 3.65 Peak Lateral Inflow (cfs).......................................................... 3.65 Peak Outflow (cfs)...................................... .........._..... ........... . 0.00 Peak Exfiltration Flow Rate (cfm)...................................... 15.87 Max HGL Elevation Attained (ft)..............................................14.70 Max HGL Depth Attained (ft) ................................................... 4 Average HGL Elevation Attained (ft) ....................................... 11.82 Average HGL Depth Attained (ft) ............................................. 1.12 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:32 Total Exfiltration Volume (1000 -ft') .......................................... 8.502 Total Flooded Volume (ac -in) .................................................. 0.21 Total Time Flooded (min) ........................................................ 47 Total Retention Time (sec) ....................................................... 0.00 Project Description File Name ................ ............ ..............,.....,.;..,.....,..................... Storm Water Analysis—Updated basin 1.SPF Project Options FlowUnits ......................................... .................... ..................... CFS Elevation Type........................................................................... Elevation Hydrology Method...................................................................... SCS TR -55 Time of Concentration (TOC) Method ....................................... SCS TR -55 Link Routing Method.................................................................. Kinematic Wave Enable Overflow Ponding at Nodes ........................................... YES Skip Steady Stale Analysis Time Periods .................................. YES Analysis Options Start Analysis On....................................................................... Sep 01, 2017 00:00:00 End Analysis On........................................................................ Sep 02, 2017 00:00:00 Start Reporting On..................................................................... Sep 01, 2017 00:00:00 Antecedent Dry Days................................................................. 0 days Runoff (Dry Weather) Time Step ............................................... 0 01:00:00 days hh:mm:ss Runoff (Wet Weather) Time Step ............................................. 0 00:05:00 days hh:mm:ss Reporting Time Step.................................................................. 0 00:05:00 days hh:mm:ss Routing Time Step— ............................................................. 30 seconds Number of Elements Qty RainGages . ................... .................. ................ .......................... 1 Subbasins.................. ........................................... ...................... 4 Nodes......................................................................................... 7 Junctions........................................................................... 0 Outfalls.............................................................................. 4 FlowDiversions................................................................. 0 Inlets.................................................................................. 0 StorageNodes.................................................................. 3 Links..............................................._........................................... 3 Channels........................................................................... 1 Pipes................................................................................. 1 Pumps............................................................................... 0 Orifices.............................................. -- ................. ........... 0 Weirs................................................................................. 1 Outlets............................................................................... 0 Pollutants................................................................................... 0 LandUses.................................................................................. 0 Rainfall Details SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall ID Source ID Type Units Period Depth Distribution (years) (inches) 1 Time Series 100 -Year, 1 -Hour Rainfall Depth Cumulative inches 0.00 Subbasin Summary SN Subbasin Area Weighted Total Total Total Peak Time of ID Curve Rainfall Runoff Runoff Runoff Concentration Number Volume (ac) (in) (in) (ac -in) (cfs) (days hh:mm:ss) 1 POST DMA 10.01 89.74 0.96 0.29 2.85 3.82 0 00:10:00 _1 2 POST _2 1.52 89.49 0.96 0.28 0.42 0.56 0 00:10:00 _DMA 3 PRE 8.30 74.72 0.96 0.02 0.18 0.02 0 01:00:00 _DMA_1 4 PRE DMA 2 3.22 74.00 0.96 0.02 0.06 0.01 0 00:18:49 Node Summary SN Element Element Invert Ground/Rim Initial Surcharge Forded Peak Max HGL Max Min Time of Total Total Time ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded Elevation Elevation Attained Depth Attained Flooding Volume Attained Occurrence (ft) (ft) (ft) (ft) (ftp) (cfs) (ft) (ft) (ft) (days hh:mm) (ac -in) (min) 1 Out -10 Outfall 0.00 0.00 0.00 2 OUTFALL Outfall 0.00 0.00 0.00 _POST_2 3 OUTFALL Outfall 15.05 0.02 15.05 _PRE _1 4 OUTFALL Outfall 9.32 0.01 9.32 _PRE _2 5 FOREBAY Storage Node 11.70 15.60 0.00 0.00 3.79 13.41 0.00 0.00 6 STORAGE_BASIN Storage Node 13.00 15.60 0.00 0.00 0.00 13.00 0.00 0.00 7 STORAGE BASIN_2 Storage Node 10.70 14.70 0.00 0.00 0.55 11.50 0.00 0.00 Subbasin Hydrology Subbasin: POST -DMA -1 Input Data Area(ac)........................................................................ 10.01 Weighted Curve Number ............................................... 89.74 RainGage ID................................................................. Rain Gage Composite Curve Number Area Soil Curve Soil/Surface Description (acres) Group Number Lot_ Impervious_(Roof+Hardscape) 4.49 98.00 Site_Hardscape 0.54 98.00 Pavement 1.54 98.00 Landscape 3.44 C 74.00 Composite Area & Weighted CN 10.01 89.74 Time of Concentration TOC Method: SCS TR -55 Sheet Flow Equation: To = (0.007 * ((n * Lf)^0.8)) / ((P^0.5)(Sf^0.4)) Where: To = Time of Concentration (hr) n = Manning's roughness Lf =Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (Sf^0.5) (unpaved surface) V = 20.3282 * (Sf^0.5) (paved surface) V = 15.0 * (Sf^0.5) (grassed waterway surface) V = 10.0 * (Sf^0.5) (nearly bare & untitled surface) V = 9.0 * (Sf^0.5) (cultivated straight rows surface) V = 7.0 * (Sf^0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V = 2.5 * (Sf^0.5) (forest w/heavy litter surface) To = (Lf / V) / (3600 seclhr) Where To = Time of Concentration (hr) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation : V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n R =Aq/Wp To = (Lf / V) / (3600 sec/hr) Where: To = Time of Concentration (hr) Lf = Flow Length (ft) R = Hydraulic Radius (ft) Aq = Flow Area (ftp) Wp = Wetted Perimeter (ft) V = Velocity (fUsec) Sf = Slope (ftfft) n = Manning's roughness User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in) .... ........... --- ................ ....................... 0.96 Total Runoff (in)............................................................ 0.29 Peak Runoff (cfs)................................................... 3.82 3.82 Weighted Curve Number ............................................... 89.74 Time of Concentration (days hh:mm:ss) ......................- 0 00:10:00 Subbasin : POST -DMA -1 1.35 1.3 1.25 1.2 1.15 1.1 1.05 1 0.95 0.9 0.85 0.8 L 0.75 `c 0.7 0.65 0.6 0_ 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.0 Rainfall Intensity Graph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) 4 3.8 3.6 3.4 3.2 3 2.8 2.6- 2.4- 2.2- 2- 1.8- 1.6- 11.4- 1 , 2 .62.42.221.81.61.41.2 1 0.8 0.6 0.4 0.2 Runoff Hydrograph I ! i i t 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) 4 3.8 3.6 3.4 3.2 3 2.8 2.6- 2.4- 2.2- 2- 1.8- 1.6- 11.4- 1 , 2 .62.42.221.81.61.41.2 1 0.8 0.6 0.4 0.2 Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) I ! i I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Subbasin : POST—DMA-2 Input Data Area(ac).........................................................:.............. 1.52 Total Rainfall (in)............................................................ Weighted Curve Number ............................................... 69.49 0.28 RainGage ID................................................................. Rain Gage Weighted Curve Number ............................................... Composite Curve Number Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Area Soil Curve Soil/Surface Description (acres) Group Number Lot_Impervious_(Roof+Hardscape) 0.65 98.00 Site _Hardscape 0.10 98.00 Pavement 0.23 98.00 Landscape 0.54 C 74.00 Composite Area & Weighted CN 1.52 89.49 Time of Concentration User -Defined TOC override (minutes): 10.00 Subbasin Runoff Results Total Rainfall (in)............................................................ 0.96 Total Runoff (in)............................................................. 0.28 Peak Runoff (cfs)........................................................... 0.56 Weighted Curve Number ............................................... 89.49 Time of Concentration (days hh:mm:ss) ........................ 0 00:10:00 Subbasin : POST -DMA -2 1.4 1.35 1.3 1.25 1.2 1.15 1.1 1.05 1 0.95 0.9 0.85 L 0.8- 0-76- 0.7- 0.65 .60.750.70.65 16 0.6 o' 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 Rainfall Intensity Graph 01 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) 0.62- 0.6 0.58 0.56 0.54 0.52 0.5 0.48 0.46- 0.44 0.42- 0.4 0.38 0.36 0.34 F 0.32 0 0.3- 0.28 0.26- 0.24- 0.22- 0.2- 0.18 .260.240.220.20.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 Runoff Hydrograph i 14 _ -- I L J- - I _ i - I _ �- - I - - 01 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) 0.62- 0.6 0.58 0.56 0.54 0.52 0.5 0.48 0.46- 0.44 0.42- 0.4 0.38 0.36 0.34 F 0.32 0 0.3- 0.28 0.26- 0.24- 0.22- 0.2- 0.18 .260.240.220.20.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 Runoff Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) I 14 -- - I _ i - I i I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Subbasin : PRE—DMA-1 Input Data Area(ac)...................................................................<.... 8.30 Subarea Weighted Curve Number ............................................... 74.72 C RainGage ID . ..... --....................................................... Rain Gage 0.00 Composite Curve Number 669.2763 0.00 0.3 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 8.05 C 74.00 Paved parking & roofs 0.25 D 98.00 Composite Area & Weighted CN 8.30 74.72 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%): 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................60.00 Subbasin Runoff Results Subarea Subarea Subarea A B C 0.03 0.025 0.00 300 669.2763 0.00 0.3 0.3 0.00 1.20 1.20 0.00 0.22 0.30 0.00 22.71 37.29 0.00 Total Rainfall (in)............................................................ 0.96 Total Runoff (in)............................................................. 0.02 Peak Runoff (cfs)........................................................... 0.02 Weighted Curve Number ............................................... 74.72 Time of Concentration (days hh:mm:ss) ........................ 0 01:00:00 Subbasin : PRE–DMA-1 1.4 1.35 1.3 1.25 1.2 1.15 1.1 1.05 1 0.95 0.9 0.85 r 0.8 0.75 0.7 w � 0.65 O.E 0.55 0.5 0.45 0.4 0.35 0.� 0.25 0.� ME 0.1 0.05 Rainfall Intensity Graph —j - i I – - I _ i 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1b 1b 1! of ly 2u n « ca Time (hrs) 0.02 0.019- 0.016 0.017 0.016 0.015 0.014- 0.013 --0.012- ,`_'0.01 I -0.012.`_'0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0 001 Runoff Hydrograph 0 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) - i I 0 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Subbasin : PRE—DMA-2 Input Data Area(ac)........................................................................ 3.22 Subarea Weighted Curve Number ............................................... 74.00 C RainGage ID..................................:.:.:...::..................... Rain Gage 0.00 Composite Curve Number 178.2036 0.00 1.7 Area Soil Curve Soil/Surface Description (acres) Group Number > 75% grass cover, Good 3.22 C 74.00 Composite Area & Weighted CN 3.22 74.00 Time of Concentration Sheet Flow Computations Manning's Roughness Flow Length (ft) Slope (%) : 2 yr, 24 hr Rainfall (in) Velocity (ft/sec) : Computed Flow Time (min) : Total TOC (min) ..................18.83 Subbasin Runoff Results Subarea Subarea Subarea A B C 0.03 0.03 0.00 300 178.2036 0.00 1.7 1.7 0.00 1.20 1.20 0.00 0.44 0.40 0.00 11.35 7.48 0.00 Total Rainfall (in)............................................................ 0.96 TotalRunoff (in)............................................................. 0.02 Peak Runoff (cfs)........................................................... 0.01 Weighted Curve Number .............................................. 74.00 Time of Concentration (days hh:mm:ss) ........................ 0 00:18:50 Subbasin : PRE DMA 2 1.4 1.35 1.3 1.25 1.2 1.15 1.1 1.05 1 0.95- 0.9- -0.86. 0.85 `c 0.80.750.70.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0.006 0.006 0.006 0.006 0.006 0.005 0.005 0.005 0.005 0.005 0.004 0.004 Rainfall Intensity Graph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Runoff Hydrograph 00.004- 0.004 MO-003- Of0.003 - - - -- - - 0.003 --1 0.003 0.003- - - - - — - - -- — -� 0.002- .002 0.002- 0.002 0.002 0.002 - - .002 0.002- 0.002 0.002- 0.001 — 0.001 0.001 0 1 2 3 4 5 6 7 8 9 10 1I1 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Runoff Hydrograph 00.004- 0.004 MO-003- Of0.003 - - - -- - - 0.003 --1 0.003 0.003- - - - - — - - -- — -� 0.002- .002 0.002- 0.002 0.002 0.002 - - .002 0.002- 0.002 0.002- 0.001 — 0.001 0.001 0 1 2 3 4 5 6 7 8 9 10 1I1 12 13 14 15 16 17 18 19 20 21 22 23 Time (hrs) Storage Nodes Storage Node: FOREBAY Input Data Invert Elevation (ft).................................................................. 11.70 Max (Rim) Elevation (ft)...........................................................15.60 Max (Rim) Offset (ft)................................................................ 3.90 Initial Water Elevation (ft) ........................................................ 0.00 Initial Water Depth (ft)............................................................. -11.70 PondedArea (ft')..................................................................... 0.00 Evaporation Loss ....................................... -- ........ ................. 0.00 Infiltration/Exf filtration Exfiltration Rate (in/hr) ...........................: ............................. 8.0000 Storage Area Volume Curves Storage Curve : FOREBAY Stage Storage Storage Area Volume (ft) (ft') (ft') 0 1450 0.000 1 2146 1798.00 2 2970 4356.00 2.3 3242.16 5287.82 Storage Node: FOREBAY (continued) Outflow Weirs SN Element Weir Flap Crest Crest Length Weir Total Discharge ID Type Gate Elevation Offset Height Coefficient (ft) (ft) (ft) (ft) 1 OVERFLOW—BERM Trapezoidal No 14.00 2.30 50.00 1.10 3.33 Output Summary Results Peak Inflow (cfs)................................................................... 3.79 Peak Lateral Inflow (cfs).......................................................... 3.79 Peak Outflow (cfs)................................................................... 0.00 Peak Exfiltralion Flow Rate (cfm)............................................ 30.38 Max HGL Elevation Attained (ft) .............................................. 13.41 Max HGL Depth Attained (ft) ................................................... 1.71 Average HGL Elevation Attained (ft) ....................................... 11.93 Average HGL Depth Attained (ft) ............................................. 0.23 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:39 Total Exfiltration Volume (1000-ft3).......................................... 8.275 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ........................................................ 0 Total Retention Time (sec) ...................................................... 0.00 Storage Node: STORAGE—BASIN Input Data Invert Elevation (ft).................................................................. 13.00 Max (Rim) Elevation (ft)...........................................................15.60 Max (Rim) Offset (ft) ................................................................ 2.60 Initial Water Elevation (ft) ........................................................ 0.00 Initial Water Depth (ft)............................................................. .13.00 PondedArea (W) ............................ ........................................ . 0.00 EvaporationLoss ......... :.................. ..._.:................... ................ 0.00 Infi Itrati on/Exfi Itration Exfiltration Rate (in/hr) ............. Storage Area Volume Curves Storage Curve: STORAGE—BASIN Stage Storage Storage Area Volume (ft) (ftp) (ft') 0 5250 0.000 1 6474 5862.00 2 7826 13012.00 3 13087.2541 23468.63 3.1 13282.7596 24787.13 8.0000 Storage Node: STORAGE—BASIN (continued) Output Summary Results Peak Inflow (cfs)...................................................................... 0.00 Peak Lateral Inflow (cfs)..........................................................0.00 Peak Outflow (cfs)................................................................... 0.00 Peak Exfiltration Flow Rale (cfm)............................................ 58.33 Max HGL Elevation Attained (ft) .............................................. 13.00 Max HGL Depth Attained (ft) ................................................... 0 Average HGL Elevation Attained (ft) ....................................... 13.00 Average HGL Depth Attained (fl) ............................................. 0 Time of Max HGL Occurrence (days hh:mm) ......................... 0 00:00 Total Exfillration Volume (1000-ft3)........................................... 0.000 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ........................................................ 0 Total Retention Time (sec) ...................................................... 0.00 Storage Node: STORAGE—BASIN-2 Input Data Invert Elevation (ft).................................................................. 10.70 Max (Rim) Elevation (ft)...........................................................14.70 Max (Rim) Offset (ft)................................................................ 4.00 Initial Water Elevation (ft) ........................................................ 0.00 Initial Water Depth (fl)............................................................. -10.70 Ponded Area (ft')..................................................................... 0.00 Evaporation Loss .... .......:...:..:,:.--......................... ............... .. 0.00 Infiltration/Exfiltration Exfiltration Rate (in/hr)............ ..................... ::: ....................... 8.0000 Storage Area Volume Curves Storage Curve: STORAGE—BASIN-2 Stage Storage Storage Area Volume (ft) (ftp) UP) 0 416.86 0.000 1 667.79 542.33 2 960.03 1356.24 3 1297.28 2484.90 4.7 1520.63 4880.12 Storage Node: STORAGE_BASIN_2 (continued) Output Summary Results PeakInflow (cfs)...................................................................... 0.55 Peak Lateral Inflow (cfs).......................................................... 0.55 Peak Outflow (cfs)...................................................................0.00 Peak Exfillration Flow Rate (cfm)............................................6.86 Max HGL Elevation Attained (ft) .............................................. 11.50 Max HGL Depth Attained (ft) ................................................... 0.8 Average HGL Elevation Attained (ft) ....................................... 10.75 Average HGL Depth Attained (f) ............................................. 0.05 Time of Max HGL Occurrence (days hh:mm) ......................... 0 12:25 Total Exfiltration Volume (1000-ft3).......................................... 0.976 Total Flooded Volume (ac -in) .................................................. 0 Total Time Flooded (min) ........................................................ 0 Total Retention Time (sec) ...................................................... 0.00 Global Senior Housing, LLC Blakeslee Appendix C: Geotechnical Engineering Investigation S:\Projects_Eng\2016190_Bungalows_Meridian\Storm\Drainage Report.docx 10 of 10 4 A PROPESS}ONAI. �EUVICFS COPPORADON March 29, 2016 a-it-- c-�,-owtd Up File: B016014A Ms. Wendy Shrief, AICP Horrocks Engineers 5700 E. Franklin Road, Suite 160 Nampa, Idaho 83687 wendys@horrocks.com RE: Geotechnical Engineering Evaluation Walsh-Dixon Development Ustick Road and Wingate Lane Meridian Idaho Dear Wendy: STRATA, A Professional Services Corporation (STRATA) is pleased to present our authorized Geotechnical Engineering Evaluation for the proposed Walsh-Dixon Apartments development located southeast of the intersection of West Ustick Road and Wingate Lane in Meridian, Idaho. Our evaluation's purpose was to explore the subsurface conditions in the proposed development area and provide geotechnical recommendations to assist project planning, design and construction. The attached report summarizes our field and laboratory test results and presents our geotechnical engineering opinions and recommendations. The following report provides specific geotechnical recommendations for preparing the site, including earthwork activities, stormwater disposal and pavement section design. The project design, owner, and construction team must read, understand and implement this report in its entirety. Portions of the report cannot be relied upon individually without the supporting text of remaining sections, appendices and plates. Our opinion is the success of the proposed construction will depend on following the report recommendations, good construction practices, and providing the necessary construction monitoring, testing and consultation to verify that work has been constructed as recommended. We recommend STRATA be retained to provide monitoring, testing, and consultation services to verify our report recommendations. We appreciate the opportunity to work with Horrocks Engineers. We look forward to our continued involvement on this project throughout construction. Please do not hesitate to contact us if you have any questions or comments. Sincerely, STRATA iAL 'Y n Darnall F' ngineer �p of ael G. Woodworth i kmot<5Q gineering Manager MGW/js ftGE�3 \;Lfesi I«acicaifiore 01Ntc, raise, Idaho :?3709 Phone.Nlo."FYGX�00 Fw',.20' www.stratageotech.com Geotechnical Engineering Evaluation Walsh -Dixon Development Ustick Road and Wingate Lane Meridian, Idaho Prepared For: Ms. Wendy Shrief, AICP Horrocks Engineers 5700 E. Franklin Road, Suite 160 Nampa, Idaho 83687 HORROCKS Prepared By: Nihan Darnall Reviewed By: Michael G. Woodworth, P.E. STRATA, Inc. 8653 W. Hackamore Dr. Boise, Idaho 83709 P. 208.376.8200 F. 208.376.8201 March 29, 2016 TABLE OF CONTENTS INTRODUCTION............................... I ...................................... ................................... PROJECTUNDERSTANDING...................................................................................1 SUBSURFACE EVALUATION PROCEDURES..........................................................2 SUBSURFACECONDITIONS....................................................................................2 LABORATORYTESTING...........................................................................................2 GEOTECHNICAL OPINIONS AND RECOMMENDATIONS......................................3 Earthwork.................................................................................................................3 Excavation Characteristics...............................................................................I....3 EstablishingSubgrades.........................................................................................4 StructuralFill.........................................................................................................4 RequiredCompaction............................................................................................5 Wet WeatherMet Soil Construction......................................................................6 Utility Trench Construction....................................................................................6 Geotextiles............................................................................................................ 7 Pavement Subgrade Preparation and Section Design ............................................. 7 General.................................................................................................................. 7 Trafficand Subgrade.............................................................................................7 Asphalt, Aggregate Base Course and Subbase Materials....................................8 Pavement Section Thickness................................................................................9 Pavement Maintenance Considerations...............................................................9 SiteDrainage..........................................................................................................10 StormwaterDisposal...........................................................................................10 ExteriorGrading..................................................................................................10 ADDITIONAL RECOMMENDED SERVICES............................................................10 Geotechnical Design Continuity.............................................................................10 Plan and Specification Review...............................................................................11 Geotechnical Observation During Construction.....................................................11 EVALUATIONLIMITATIONS....................................................................................11 REPORT TABLES Table 1: Structural Fill Specifications and Allowable Use .......................................... 5 Table 2: Required Compaction for Designated Project Areas ................................... 6 Table 3: Geotextile Specifications............................................................................. 7 Table 5: Pavement Design Parameters..................................................................... 8 Table 6: Traffic Loading Assumptions....................................................................... 8 Table 7: Standard Asphalt Pavement Section Thickness ........................................ 9 REPORT PLATES & APPENDICES Plate 1: Exploration Location Plan Appendix A: Exploration Logs & Unified Soil Classification System (USCS) Appendix B: Summary Report 04 www.stratageotech.com 02GIG Uy Strata. A Professional Semites Corporation, All riglas reserved. Geotechnical Engineering Evaluation Walsh -Dixon Development Ustick Road and Wingate Lane Meridian, Idaho INTRODUCTION STRATA, A Professional Services Corporation (STRATA) has performed our geotechnical engineering evaluation for the proposed Walsh -Dixon Apartments development planned to be located southeast of the intersection of West Ustick Road and Wingate Lane in Meridian, Idaho. The project site location is illustrated on Plate 1, Exploration Location Plan. STRATA accomplished our services referencing the scope of services presented in our January 13, 2016 proposal. Our evaluation's purpose was to assess subsurface conditions within the proposed project area and to provide geotechnical recommendations to assist project planning, design, and construction. Below, we outline the services accomplished in providing our geotechnical engineering evaluation: 1. Coordinated exploration with the Idaho Utility Notification Center to help reduce the potential for damage to existing subsurface utilities due to exploration. 2. Accomplished subsurface exploration at the site via 6 exploratory test pits extending up to 14 feet below the existing ground surface. Approximate test pit locations are provided on the attached Plate 1. 3. Performed 2 infiltration tests referencing the Idaho Department of Environmental Quality Technical Guidance Manual. 4. Installed one piezometer for future ground water level readings. 5. Accomplished laboratory testing on select soil samples obtained during exploration i referencing ASTM International (ASTM) procedures. 6. Performed engineering analyses to provide geotechnical recommendations for the planned development, including earthwork, pavement and stormwater disposal recommendations. 7. Prepared and provided this geotechnical deliverable including our engineering opinions and recommendations, exploration and laboratory test results. Site exploration plans and illustrative schematics are also provided. PROJECT UNDERSTANDING i The proposed development area consists of agricultural land that is relatively flat and has i been previously cultivated in row crops. The site bounded by existing residential development to the E ( south and east, Wingate Lane to the west, and Ustick Road to the north. We understand the approximate 12.5 -acre site is to be developed with 23 residential apartment buildings, an in -ground pool and clubhouse structure. We understand the development will also include municipal and franchise utilities as well as private asphalt -paved drive aisles and parking. We understand stormwater will be retained and infiltrated on-site via subsurface infiltration beds. STRATA has not reviewed a grading plan for the development, but we anticipate grading will be limited, with cuts and fills of less than approximately 2 to 3 feet. 04 www.stratageotech.com 02,01E b2,• Str,Bi, A Professional Services Corporation. Ali rigW resorved. Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: BO16014A Page 2 SUBSURFACE EVALUATION PROCEDURES STRATA accomplished subsurface exploration on January 21, 2015 via 6 exploratory test pits extending up to approximately 14 feet below existing ground surface. The approximate exploration locations are illustrated on Plate 1, Exploration Location Plan, which also delineates the proposed development. We established test pit locations in the field by taping from existing site features. A staff engineer from our office visually evaluated the soil encountered in each test pit and logged the soil profile referencing the USCS. We provide a brief USCS explanation in Appendix A to help interpret the terms on the test pit logs. We also provide individual test pit logs in Appendix A. The test pits were loosely backfilled with the excavated material to the ground surface following the completion of the excavations. We performed in-situ infiltration testing to assist in evaluating stormwater disposal infiltration rates in the gravel subsoil. We accomplished infiltration testing referencing the Idaho Department of Environmental Quality Technical Guidance Manual infiltration test method. SUBSURFACE CONDITIONS Subsurface conditions encountered in test pits comprised near surface lean clay and silt overlying cemented silty sand and poorly graded gravel with sand and silt. We observed limited vegetation and organics in the exploratory test pit up to approximately 12 inches below the ground surface. Beneath the surficial vegetation and organics, we encountered 3 subsurface soil units: 14 Lean Clay with Sand: We observed lean clay with sand at the ground surface across the site. We noted the clay to be dark brown to brown, soft to firm, and moist. We observed clay soil to approximately 2 to 5 feet in the test pits. fit Cemented Sandy Silt (ML) and Silty Sand (SM): Underlying lean clay we encountered light brown to tan, moist, cemented sandy silt and silty sand. We noted moderate calcium carbonate cementation, with cemented soil extending to depths of approximately 5 feet in select test pit locations. ky Poorly -Graded Gravel with Sand (GP): Below depths of 5 feet, we encountered light brown to tan, moist, dense, poorly graded gravel alluvium. We observed cobbles of up to 6 to 10 inches in diameter in the gravel alluvium with varying amounts of silt. In select test pits, the poorly graded gravel alluvium is overlain by a limited thickness of silty gravel. Gravel alluvium extended through the termination depth of all test pits. We did not encounter groundwater during exploration. We installed a piezometer in TP -4 to allow for future groundwater monitoring at the project site. Infiltration tests were performed in TP -1 and TP -6. LABORATORY TESTING We tested select soil samples obtained during exploration referencing ASTM procedures. Laboratory test results are summarized on the Exploratory Logs in Appendix A and the Summary Report in Appendix B. We used test results to correlate soil design factors such as subgrade modulus and infiltration rates. #il www.stratageotech.com © 201fi by Sffato, A Professional Services Corporation. Ali rights reserved. Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: B01 6014A Page 3 GEOTECHNICAL OPINIONS AND RECOMMENDATIONS We present the following geotechnical recommendations to assist planning, design and construction of the proposed Walsh -Dixon Apartments development located southeast of the intersection of West Ustick Road and Wingate Lane in Meridian, Idaho as illustrated on Plate 1 attached to this report. This report provides geotechnical design criteria for the development which the structural and civil design and construction teams must review to verify the applicability to the planned structure as design is underway presently. We base our recommendations on the results of our field evaluation, laboratory testing, our experience with similar soil conditions and our understanding of the proposed construction. If design plans change or if the subsurface conditions encountered during construction vary from those observed during our field evaluation, we must be notified to review the report recommendations and make necessary revisions. Earthwork Excavation Characteristics We anticipate site soil may be excavated using conventional excavation techniques. Carefully plan and implement temporary excavations to be sloped, shored, or braced in accordance with the OSHA excavation regulations, Document 29, CFR Part 1926, Occupation Safety and Health Standards — Excavations; Final Rule. Regulations outlined by OSHA provide temporary construction slope requirements for various soil types and slopes up to 20 feet high. Based on our exploration results, we anticipate alluvium encountered at the site is typically classified as Type C soil, which can be temporarily sloped as steep as 1.5H:1 V (horizontal to vertical), when in a dry condition. Due to the potential for varying soil conditions during construction, we recommend earthwork contractors evaluate each slope configuration specific to OSHA guidelines and to seek appropriate professional guidance to create safe and stable excavations. Construction vibrations can cause excavations to slough or cave. We do not recommend stockpiling materials adjacent to or within 10 feet of excavations, which may cause a surcharge and contribute to excavation instability. Ultimately, the contractor is solely responsible for site safety and excavation configurations factoring in water infiltration, construction access, adjacent loading, and other factors that contribute to excavation stability. The earthwork contractor shall plan excavations with water collection points and utilize conventional sumps and pumps to remove nuisance water from runoff, seeps, or precipitation. If site soil excavations are not immediately backfilled, they may degrade when exposed to runoff and require over -excavation and replacement with granular structural fill. We recommend construction activities and excavation backfilling be performed as rapidly as possible following excavation to reduce the potential for subgrades to degrade under construction traffic. 0�01 www.stratageotech.com © 2016' by Sfreta, A. Professirna! Services Corporation. All rights reserved. Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: B016014A Page 4 Establishing Subgrades We provide the following recommendations for site preparation: 14 Excavate loose backfill from existing test pit locations and replace as structural fill for all test pits located below proposed buildings, flatwork or pavements. Irii Excavate the exposed subgrade to the project design elevations and tolerances. Existing vegetation and organic soil must be completely removed below all foundation, slab and pavement areas. We encountered roots to depths of up to approximately 12 inches during exploration, however, we anticipate stripping depths of 6 to 8 inches will be sufficient to remove significant vegetation and organic matter. 14 Scarify and moisture -condition the finished native subgrade below f pavement areas to within 3 percent of optimum moisture content to at least 8 inches prior to compaction effort. Moisture -conditioning may include aeration or adding moisture. Iliv To improve support characteristics, compact subgrade soil to at least 92 percent of ASTM D1557 (Modified Proctor). Earthwork contractors must expect substantial moisture -conditioning and compaction efforts to achieve proper subgrade moisture. If the subgrade is wet at the time of construction and compaction and moisture -conditioning is not practical, STRATA should be contacted to evaluate the use of a woven geotextile, as discussed in this report's Geosynthetics section. STRATA must observe and approve subgrade conditions and we recommend STRATA work with the earthwork and general contractors to help identify fill areas and provide quantity estimates. After preparing subgrades, it is the contractor's sole responsibility to protect subgrades from degradation, freezing, saturation, or other disturbance. Our opinion is careful construction and earthwork procedures will be critical to achieving adequate subgrade preparation and reducing over - excavation. Specifically, these procedures could include, but are not limited to, carefully staging equipment and/or stockpiles, routing construction equipment away from subgrades, and implementing aggressive site drainage procedures to help reduce saturating subgrades during wet weather conditions. As stated above, it is the contractor's responsibility to protect subgrades throughout construction. Subgrade disturbance that occurs due to the contractor's means and methods must be repaired at no cost to the owner. STRATA will remain available to consult with the project team and the contractor as the project moves forward regarding subgrade preparation procedures. Structural Fill All fill for this project must be placed as structural fill. Site soil (excluding topsoil containing vegetation and organics) may be re -used as General Structural Fill for site grading provided it meets the requirements in this report. Various imported fill materials will also be required throughout construction. Our recommended material requirements for structural fill are provided, referencing the latest Idaho Standards for Public Works Construction (ISPWC) specifications. Project structural fill products are described in Table 1, below. Oki www.stratageotech.com 0 206 by Strata. A professional Services Corporation. /kit rights resented. Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: B016014A Page 5 Table 1: Structural Fill Soecifications and Allowable Use Soil Fill Product Allowable Use Material Specifications • Soil must be classified as silt, sand, or gravel (GP, GM, GW, SP, SM, SW, or ML) according to the USCS. • Soil may not contain particles larger than 6 -inches in General • Site grading, temporary median diameter. Structural Fill haul/access roads . Soil must consist of inert earth materials with less than 3 percent organics or other deleterious substances wood, metal, plastic, waste, etc . Is Over -excavations, soil Granular improvements, temporary , 6 -inch minus granular subbase meeting the latest Structural Fill haul roads, temporary requirements in ISPWC' Section 801 -Uncrushed (Granular platforms, Granular Aggregates. Subbase) subbase, general structural fill Aggregate Base . Asphalt pavement section • Type 1 Crushed Aggregate meeting the latest Course aggregate, general requirements in 1SPWC' Section 802— Crushed structural fill Aggregates. Pipe Bedding • Utility pipe bedding within • Soil meeting requirements for Type 1 bedding as stated in the latest edition of the 1SPWC', Section 305 6 inches of the pipe invert _ Pipe Bedding. • Aggregate meeting the latest requirements for 3 -inch Drainage . Infiltration features Drain Rock in ISPWC' Section 809 -Uncrushed Aggregate Aggregates. • Soil classified as MH, OH, CL, CH, OL, or PT may not be used at the project site. • Excess moisture does not render a soil unsatisfactory. Contractors must attempt moisture Unsatisfactory conditioning (i.e. wetting or drying) prior to soil disposal. • NONE However, soil not moisture conditioned to within 3% of Soil optimum during compaction is unsatisfactory soil and requires additional moisture conditioning. . Any soil containing more than 3 percent (by weight) of organics, vegetation, wood, metal, plastic or other deleterious substances. 'Idaho Standards for Public WorKs Uonstruction Other than topsoil and clay encountered, the site soil is expected to be suitable for reuse as general structural fill, providing it can meet the criteria presented in Table 1 above and can be properly moisture conditioned for compaction. Required Compaction Place structural fill only over subgrades reviewed and approved by STRATA. Never place structural fill over frozen, saturated, or soft subgrades. Fill placed exclusively in landscape areas, not including fill embankments, can be placed as non-structural fill (i.e. landscape fill) providing there are no structures (sidewalk, curbs, utilities, signs, etc.) or embankments planned directly above the landscape fill. Structural fill products must be moisture conditioned to near optimum moisture content as defined by ASTM D1557 and placed in maximum 10 -inch -thick, loose lifts. This lift thickness requires compaction equipment with energy ratings of at least 5 tons. If smaller or lighter compaction 04 www.stratageotech.com 01016 by Sera Ia. A Prolesstonal Semites Corporation. Ali rights rescrveo. Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: B016014A Page 6 equipment is used, reduce the lift thickness to meet the compaction and moisture content requirements presented in Table 2: Required Compaction for Designated Project Areas. Table 2: Required Compaction for Designated Project Areas Project Area Required Structural Fill Product Compaction Requirement' • In-situ subgrades below the . Existing Native Soil 92% planned structural fill areas • Pavement aggregates • General structural fill • Site grading • Granular subbase 95% e Trench backfilling 1 • Aggregate base 'Relative compaction and moisture content requirement compared to the maximum dry density of the soil as determined by ASTM D1557 (Modified Proctor). Wet Weather/Wet Soil Construction Once the subgrade elevation is achieved, it is the contractor's responsibility to protect the soil from degrading under construction traffic, freezing and/or wet weather. The condition of the subgrade and careful construction procedures are critical to embankment and subsequent foundation and slab stability and long-term performance. We strongly recommend earthwork construction take place during dry weather conditions. The majority of the near surface on-site soil will be susceptible to pumping or rutting from heavy loads such as rubber -tired equipment or vehicles any time of the year. If construction commences before soil can dry after precipitation or during wet periods of the year (November through April), the contractor must be prepared to achieve project requirements with respect to subgrades and structural fill placement. This may require earthwork to be completed by low pressure, track -mounted equipment that spreads and reduces vehicle load, or other means and methods. Utility Trench Construction Structural fill for utility trench backfill must be placed and compacted to the structural fill requirements presented herein. Loose soil must be removed from the base of utility trenches prior to placing pipe bedding. In addition, if water is encountered, it must be removed from the base of the utility trench before placing pipe bedding. We recommend utility pipes be placed on at least 4 inches of bedding conforming to Table 9 — Pipe Bedding, placed over undisturbed native soil, structural fill or otherwise supported according to the pipe manufacturer's specifications. After bedding the pipe, place structural fill and compact it from the pipe invert to 1 foot above the top of the pipe with tamping bars and/or plate compactors to render the backfill in a firm and unyielding condition. Thoroughly place and compact bedding below pipe haunches or the zone between the pipe invert and the spring line. To accomplish backfilling, the distance between the side of the pipe at the spring line and the trench wall should be at least 12 inches. The remainder of the utility trench should be backfilled in accordance with this report's Structural Fill section. 04 www.stratageotech.com 2OU Lyr Strata, h Aro/cssinna! Services Corporation. /t/1 rigtds reserved. Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: B016014A Page 7 Geotextiles Non -woven geosynthetics are required for drainage facility construction. Additionally, geosynthetic fabrics can facilitate constructability over soft, wet subgrades. If, or where required, geotextiles shall meet the minimum properties shown in Table 3 below: Table 3: Geotextile Specifications Geosynthetic Type Use Minimum Material Specifications • Grab tensile strength: 120 pounds (ASTM D4632) • Non -Woven • Surrounding drain e Puncture resistance: 3100 pounds (ASTM D6241) Geosynthetic rock in infiltration Apparent opening size: US Sieve #70 ASTM D4751 pp p g ( ) facilities 1 • Permittivity: 1.7 seconds (ASTM D4491) • Woven • Soft subgrade • Grab tensile strength: 350 pounds (ASTM D4632) Geosynthetic conditions • Puncture resistance: 1000 pounds (ASTM D6241) Apply geosynthetics directly on approved subgrades, taut, free of wrinkles, and over -lapped at least 12 inches. Consult STRATA to review geosynthetic applications or other subgrade improvement alternatives. Pavement Subgrade Preparation and Section Design General The following flexible asphalt pavement section design is provided referencing the American Association of State Highway and Transportation Officials (AASHTO) Guide for Design of Pavement Structures (1993). STRATA estimated traffic loading and design parameters based on our proposed construction and traffic understanding, results from laboratory testing and our understanding of the subsurface conditions. Traffic and Subgrade The tables continued on the next page present our traffic loading estimates, geotechnical design parameters, and references as well as the resulting flexible pavement section design recommendations. 04 www.stratageotech.com 0 2016 by Str, to, k Pralessional Sen•ices Corporation. M/ rights rese-ed. Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: B016014A Page 8 Table 5: Pavement Design Parameters Design Parameter Value Used References ' Reliability R 90% Estimated Standard Deviation S 0.45 AASHTO 1993 Initial Serviceability PSI; 4.2 Typical regional values Terminal Serviceability PSIZ 2.1 Typical regional values Traffic Loading 33,000 ESALS' See Table 6 below Design Life 20 years Assumed Resilient Modulus (Mr) 6,000 ps12 Assumed based on R -value correlations (see paragraph below As halt Layer Coefficient a, 0.42 Figure 2.5 AASHTO 1993 Aggregate Base Course Layer Coefficient az 0.12 Figure 2.6 AASHTO 1993 Aggregate Base Course Drainage Coefficient mz 1.0 Table 2.4 AASHTO 1993 for "fair" drainage, 1 to 8 percent saturation Granular Subbase Course Layer Coefficient az 0.10 Figure 2.6 AASHTO 1993 Granular Subbase Course Drainage Coefficient mz 1.0 Table 2.4 AASHTO 1993 for "fair" drainage, 1 to 8 percent saturation 'Equivalent Single Axle Loads (ESALS). 2Pounds per square inch (psi). Table 6: Traffic Loading Assumptions Pavement Section Area Traffic Loading Parameters Frequency', or Value Used EALF2 ESALS Standard -Duty Section (parking areas) Passenger Vehicles 200 trips per day 0.004 7,000 Garbage, Mid Range GVW Trucks 4 trips per day 0.75 26,000 Annual Growth Factor 2.0% Construction Traffc3 **None** 'One trip is one complete pass by the vehicle. 2Equivalent Axle Load Factor; Loading by one vehicle trip. 3Construction traffic is not included in design. From correlations to index laboratory testing, we estimate the subgrade for proposed asphalt areas will have a resilient modulus (Mr) correlation of approximately 6,000 psi. To help improve subgrade characteristics, the pavement subgrade should be prepared as recommended in this report's Site Preparation section. Subgrades must be shaped (crowned) and graded to facilitate positive drainage and inverted crowns must be avoided. Asphalt Aggregate Base Course and Subbase Materials Crushed aggregate base course and granular subbase shall conform to the Structural Fill requirements section, and be placed directly over a properly prepared subgrade. A woven geotextile is an option for constructability during wet and inclement weather and to increase performance at the subgrade and should have material properties and be placed as outlined in this report's Geosynthetics section. We recommend STRATA observe final subgrade preparations, geotextile placement and all aggregate placements. 04 www.stratageotech.com G 2016 by Shata. A. Professional Services Corporation. All rig Mr. reserved Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: B016014A Page 9 Compact asphalt concrete to between 92 and 96 percent of the maximum density for Superpave mix design. The final traveling surface of asphalt concrete shall meet ISPWC %2 or '/- inch asphalt mix design requirements. Asphalt mix designs and all appropriate aggregate source certificates should be accepted by STRATA at least 5 days prior to initiating asphalt paving. Asphalt construction and final surface smoothness, joints and density should meet ITD specifications. If subgrade conditions appear significantly different during construction, traffic loading conditions change or traffic volumes increase, STRATA should be notified to amend our design accordingly. Pavement Section Thickness STRATA evaluated the pavement sections utilizing the AASHTO pavement design methodology, soil -engineering parameters from previous field and laboratory testing and the estimated traffic -loading conditions. Based on the above pavement design parameters, Table 7 below provides our flexible pavement design recommendations. If traffic loading or subgrade i conditions change as design is finalized or during construction, STRATA must review our pavement analyses and resulting sections. Table 7: Standard Asphalt Pavement Section Thickness The above pavement section assumes the subgrade will be prepared as clescrioed in the Establishing Subgrades and Structural Fill report sections. Pavement Maintenance Considerations We recommend crack maintenance be accomplished on all pavement surfaces every 3 to 5 years to reduce the potential for surface water infiltration into the underlying pavement subgrade. Slurry seals and chip seals can extend flexible pavement life and reduce water infiltration to the subgrade. As asphalt pavements age, brittle/thermal cracking and isolated areas of distress and deterioration are normal and commensurate with pavement design assumptions. Identifying soil fines seeping through cracks can identify subgrade areas that may retain water. These distressed areas should be sealed to help reduce water infiltration. Pavement maintenance and reducing water infiltration to pavement subgrades will slow pavement distress and may extend pavement life. Surface and subgrade drainage are extremely important to the performance of the pavement section. Therefore, we recommend the subgrade, aggregate and pavement surfaces slope at no less than 2 percent to an appropriate stormwater disposal system or other appropriate daylight location that does not impact adjacent properties; higher subgrade slopes improve drainage and pavement performance. Surface irrigation overspray, ponded water, or other water infiltrating the pavement surface must be avoided to the maximum extent practical. Pavement performance will depend upon achieving adequate drainage throughout the section and especially at the subgrade. Water that #4 www.stratageotech.com ©i07C by Strata. A Pro/essinna! Serrlces Corpora lion. All rig61s rc,erved. Asphalt Pavement Application Asphalt Concrete inches Aggregate Base inches Granular Subbase inches Standard Duty Section — Parking 2.5 4 8 The above pavement section assumes the subgrade will be prepared as clescrioed in the Establishing Subgrades and Structural Fill report sections. Pavement Maintenance Considerations We recommend crack maintenance be accomplished on all pavement surfaces every 3 to 5 years to reduce the potential for surface water infiltration into the underlying pavement subgrade. Slurry seals and chip seals can extend flexible pavement life and reduce water infiltration to the subgrade. As asphalt pavements age, brittle/thermal cracking and isolated areas of distress and deterioration are normal and commensurate with pavement design assumptions. Identifying soil fines seeping through cracks can identify subgrade areas that may retain water. These distressed areas should be sealed to help reduce water infiltration. Pavement maintenance and reducing water infiltration to pavement subgrades will slow pavement distress and may extend pavement life. Surface and subgrade drainage are extremely important to the performance of the pavement section. Therefore, we recommend the subgrade, aggregate and pavement surfaces slope at no less than 2 percent to an appropriate stormwater disposal system or other appropriate daylight location that does not impact adjacent properties; higher subgrade slopes improve drainage and pavement performance. Surface irrigation overspray, ponded water, or other water infiltrating the pavement surface must be avoided to the maximum extent practical. Pavement performance will depend upon achieving adequate drainage throughout the section and especially at the subgrade. Water that #4 www.stratageotech.com ©i07C by Strata. A Pro/essinna! Serrlces Corpora lion. All rig61s rc,erved. Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: B016014A Page 10 ponds at the pavement subgrade surface reduces pavement support, can induce heaving during the freeze -thaw process and create pavement distress. Site Drainage Stormwater Disposal We performed infiltration testing in TP -1 and TP -6 within native, poorly graded gravel with sand encountered at depth across the site. We measured an infiltration rate of approximately 20 inches per hour during testing. Considering the relatively permeable gravel soil, we recommend all infiltration facilities extend a minimum of 1 foot into native, poorly graded gravel soil. Approximate excavation depths of 3.5 to 6 feet below existing grade should be anticipated to expose native gravel alluvium. We recommend all subsurface infiltration facilities that extend into poorly graded gravel with silt be designed using an allowable infiltration rate of 8 inches per hour, which includes a factor of safety of 2 or greater. We did not encounter groundwater during our investigation. Groundwater in the site vicinity is primarily related to irrigation, and will fluctuate seasonally. Based on our experience in the area, we estimate typical seasonal high groundwater may occur at an approximate depth of 12 to 14 feet. STRATA will continue to accomplish groundwater monitoring during the irrigation season to evaluate the potential for groundwater fluctuation. Exterior Grading Other than areas governed by ADA requirements, we recommend the ground surface outside of any structure be sloped a minimum of 5 percent away for 10 feet to rapidly convey surface water or roof runoff away from foundations. Remaining landscapes should slope at least 2 percent away from structures. Roof downspouts must be provided and connected to a solid pipe placed away from structures and not allowed to infiltrate into the soil underlying the structure. Stormwater should be routed away from disturbed soil areas and should be disposed of in stormwater disposal facilities located at least 20 feet from the proposed building foundations. Irrigation within 10 feet of the buildings is discouraged. ADDITIONAL RECOMMENDED SERVICES Geotechnical Design Continuity The information contained in this report is based on anticipated structural loads and current development plans provided the design team, The final floor elevation, floor configuration, loading conditions, as well as site geometry, can significantly alter our opinions and design recommendations. Specifically, changes in structural design loads and planned site grading may require additional foundation and earthwork evaluations specific to the actual anticipated construction conditions. We should be contacted once final designs are completed to review our opinions and design recommendations contained herein. www.stratageotech.com -- C) 201C by Strata, A Professional Smime , Corporation. All righls reaen•ed. �'I Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: B016014A Page 11 Plan and Specification Review We recommend STRATA be retained by the project owner to review geotechnical related plan and specification sections prior to issuance of the construction documents for bidding. It has been our experience that having the geotechnical consultants from the design team review the construction documents reduces the potential for errors, and reduces costly changes to the contract during construction. Geotechnical Observation During Construction We recommend STRATA be retained to provide construction observation and testing to document the report recommendations have been followed. Providing these services during construction will help to identify potential earthwork and foundation construction issues, thus allowing the contractor to proactively remedy problems and reduce the potential for errors and omissions. If STRATA is not retained to provide these design verification services during construction, then we will no longer have geotechnical engineer -of -record continuity and cannot be responsible for design or construction errors or omissions. Consistent with the standard of care in the industry, the firm retained to accomplish this work will assume the responsibility as the geotechnical engineer -of - record. EVALUATION LIMITATIONS This geotechnical engineering report has been prepared to assist in planning, design, and construction for the proposed Walsh -Dixon Apartments development located southeast of the intersection of West Ustick Road and Wingate Lane in Meridian, Idaho. Our scope does not include an engineering evaluation for proposed structures, including shallow or deep foundations, slab -on - grade design, concrete pavement section design, or shoring design. Variation in subsurface conditions may exist between or beyond our exploration locations, which can necessitate changes to the geotechnical recommendations in this report. Also, changes to the planned development can significantly affect our recommendations. If the improvement plans change from those described herein, we must be notified so that we may make modifications to our recommendations with respect to the modified improvements. If unforeseen conditions are encountered during earthwork, STRATA must be afforded the opportunity to review our recommendations and provide necessary consultation, revision, or modifications to information contained herein. We recommend STRATA be retained to review the final project plans and specifications, to provide geotechnical continuity throughout construction, and to identify any soil variations which could impact our recommendations. Exploration allows observing only a small portion of the site's subsurface conditions. Subsurface variations may not be apparent until construction. We recommend STRATA be retained to provide continuity throughout project design and construction to review site preparations, specifically slab and foundation excavations to verify the conditions encountered in exploration and relied on for design exist in the field and to identify any undocumented fill not encountered during �0 www.stratageotech.com 0 201C by Strata, R Prolcsslonal Sendces Corporation. All rights reserved. Geotechnical Engineering Evaluation Walsh -Dixon Development— Meridian, ID File: BO16014A Page 12 exploration. If subsurface variations exist, they may impact the opinions and recommendations presented in this report, as well as construction timing and costs. This report was prepared for the exclusive use of Horrocks Engineering, the project owner, and their project design team, for the specific project referenced herein. STRATA cannot be held responsible for unauthorized duplication or reliance upon this report or its contents without written authorization. The geotechnical recommendations provided herein are based on the premise that an adequate program of tests and observations will be conducted by STRATA during construction in order to verify compliance with our recommendations and to confirm conditions between exploration locations. Subsurface conditions may vary from the locations explored and the extent of variation may only be known at the time of construction. Where variations occur, it is critical STRATA be afforded the opportunity to modify our report to reflect the site conditions exposed. This acknowledgment is in lieu of all warranties either express or implied. The following plates accompany this report. Plate 1: Exploration Location Plan Appendix A: Exploration Logs and Unified Soil Classification System (USCS) Appendix B: Summary Report �4 www.stratageotech.com © 2016 by SvO;a, A Protessionaf Smices Corporation. All reohYs reserved. z o C E 0 CL v W.. 0, un.1 2 P C 2 0 5 Cie0L m T W EZ 20 0 -j IA Wul R .3 ti ya -29 Exploration Logs & USCS I" USCS Description V5 -6 E Eg, > 6 'T 016 D 2 26 j 42 -E Remarks Note: BGS = Below 'L562 U) U) z 'a 0 0 Ground Surface 0 0 a. LL PI 00 LEAN CLAY WITH SAND, (CL) brown, soft, moist Vegetation and Organics to 12". SK 71.0 21.9 36 15 CL 2.5 POORLY GRADED SAND, (SP) light brown, medium dense, moist SP — 5.0 POORLY GRADED GRAVEL, With Sand, (GP) light brown, dense, moist GP Op 7.6 O. Infiltration rate greater than 20" /hr. Test Pit Terminated at 8.0 Feet. Client: Horrocks Engineers Test Pit Number: TP -1 STRaT EXPLORATORY TEST PIT LOG Project: 8016014A Date Excavated: 01-21-2016 Backhoe: CASE 580 Bucket Width: 3' Depth to Groundwater: N.E, Logged By: ND Sheet 1 Of 1 USCS Description 0 T M o o N o 2::,. s d 6" 21 £ E - Remarks Note: BGS = Below U ") ~ ° Z o n°. ¢ J Ground Surface LL PI LEAN CLAY WITH SAND, (CL) brown, soft, 0,0 moist . Vegetation and Organics to 12". CL BK µ 2.5 y SILT, (ML) tan, dense, moderate cementation ML SILTY SAND, (SM) brown, medium dense, moist e� SM 5'0 POORLY GRADED GRAVEL, With Sand, (GP) light brown, dense, moist q GP Test Pit Terminated at 6.0 Feet. Client: Horrocks Engineers Test Pit Number: TP -2 STRaTa rreui„r,oma, s„-,c�«;K•�., `'"`' ' EXPLORATORY TEST PIT LOG Project: B016014A Date Excavated: 01-21-2016 Backhoe: CASE 580 Bucket Width: 3' Depth to Groundwater: N.E. Logged By: ND"'"`'"'r" Sheet 1 Of 1 LEAN CLAY WITH SAND, (CL) dark brown to light brown, soft to firm, moist 2.5 1 CL POORLY GRADED GRAVEL, With Sand And 5.0 Cobbles, (GP) tan, medium dense, moist at 10.0 MM 7.5 1 GP [o 3.o a�< BK 68.0 35.8 Remarks Note: BGS = Below Ground Surface Vegetation and Organics to 12". 1 Client: Horrocks Engineers w n Project: B016014A Date Excavated: 01-21-2016 STRaTa `1 o N LA USCS Description v Depth to Groundwater: N.E. a E� o o a o d w y E N.. '62 L) (n azo no o o aJ LEAN CLAY WITH SAND, (CL) dark brown to light brown, soft to firm, moist 2.5 1 CL POORLY GRADED GRAVEL, With Sand And 5.0 Cobbles, (GP) tan, medium dense, moist at 10.0 MM 7.5 1 GP [o 3.o a�< BK 68.0 35.8 Remarks Note: BGS = Below Ground Surface Vegetation and Organics to 12". 1 Client: Horrocks Engineers Test Pit Number: TP -3 EXPLORATORY Project: B016014A Date Excavated: 01-21-2016 STRaTa TEST PIT LOG Backhoe: CASE 580 Bucket Width: 3' n Sf�W"" co,,�x=,�, Depth to Groundwater: N.E. Logged By: NO i"'`'"'' " " `` '" ' Sheet 1 Of 1 USCS Description U - of 2 o E W2 ❑.� m y0 j a o-2 o a o °' y N .— Remarks Note: BGS = Below U) U o Z o 0 a ¢ Ground Surface LL PI 0'0 LEAN CLAY WITH SAND, (CL) dark brown, soft, moist CL Vegetation and Organics to 12". 2.5 `• SILT, (ML) tan, dense, moist, moderate cementation ML 5.0 POORLY GRADED GRAVEL, With Sand And Cobbles, (GP) tan, dense, moist J. . �. Q. •. • o.•a. o a' T5 0 A' ap o D:• 0 GP Q . aD�. 10.0 oQ a' b d' gad' (?: 12.5 O �A. o �• Piezometer installed at 14'. o �o Test Pit Terminated at 14.0 Feet. Client: Horrocks Engineers Test Pit Number: TP -4 STRaZ' n..„......n, `'' `''"""+' EXPLORATORY TEST PIT LOG Project: 8016014A Date Excavated: 01-212016 i Backhoe: CASE 580 Bucket Width: 3' Depth to Groundwater N.E. Logged By: ND Sheet 1 Of 1 USCS Description (6 -6 E -i'. E P .. 15 Remarks Note: BGS = Below >1 U) M U) (T 0 , z Ground Surface LL PI 0.0 LEAN CLAY WITH SAND, (CL) brown, soft, moist CL Vegetation and Organics to 12". BK E. SILTY SAND, (SM) light brown, medium dense, moist 2.5 SM FI -5.0 IJ 1. 11 POORLY GRADED GRAVEL WITH SILT AND SAND, With Cobbles, (GP -GM) tan, OC, K dense, moist 'Q GP - 0C( GM 3' < 7.5 0C Test Pit Terminated at 8.0 Feet. Client: Horrocks Engineers Test Pit Number: TP -5 .45 -r FR & ra 5, EXPLORATORY TEST PIT LOG Project: B016014A Date Excavated: 01-21-2016 Backhoe: CASE 580 Bucket Width: 3' Depth to Groundwater; N.E. Logged By: ND Sheet 1 Of 1 I. a ° CL M o c S a a «. m a.... 21 . z Remarks USCS Description p aa� U m v� E T E a m P m N a d �, p a aC 'o d "N ° E Note: BGS = Below o � �' U Z o � v a ¢ LL PI Ground Surface 0.0 LEAN CLAY WITH SAND, (CL) dark brown, soft, moist Vegetation and Organics to 12". CIL �ti '° BK 78.0 18.9 2.5 ,. SILTY SAND, (SM) light brown, medium rt1 r dense, moist E f " SM �f f 1 t �C C F 5.0 � POORLY GRADED GRAVEL WITH SILT AND SAND, With Cobbles, (GP -GM) tan, ° dense, moist o 0 O GP- 0 o GM 0 0 7.5 0 P Infiltration rate greater than oa 20"/hr. 0 Test Pit Terminated at 8.0 Feet. Client: Horrocks Engineers Test Pit Number: TP -6 r, S,ar,as Cowv r ;; ,, '"'''"'' "`"''" ' °""` EXPLORATORY TEST PIT LOG Project: B016014A Date Excavated: 01-21-2016 Backhoe: CASE 580 Bucket Width: 3' Depth to Groundwater: N.E. Logged By: ND Sheet 1 Of 1 Ii:\CAUU Standards\B.,decs\Baring I _.g2014Ag, 5/23/2014 11:40:05 A'Al, DIVG To pUF.p6 UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GRAPH SYMBOL LETTER SYMBOL TYPICAL NAMES (7-3-07) Indicates Date of [BIK Bulk Sample Reading GW Well -Graded Gravel, Groundwater [RIG Ring Sample CLEAN =_ at Time of Drilling Gravel -Sand Mixtures. O GP Poorly -Graded Gravel, GRAVEL Gravel -Sand Mixtures. GRAVEL Silty Gravel, Gravel - GRAVEL GM Sand -Silt Mixtures. WITH Clayey Gravel, Gravel- COARSE FINES GC Mixtures. GRAINEDSand-Clay Well -Graded Sand, SOIL CLEAN `' ` �� �- C C � SW Gravelly Sand. Sand, SANDPoorly-Graded ` `f� SP Gravelly Sand. SAND Silty Sand, SAND r SM Sand -Silt Mixtures. WITH Clayey Sand, FINES GE` SC Sand -Clay Mixtures. Inorganic Silt, Sandy ML or Clayey Silt. SILT AND CLAY Inorganic Clay of Low CL to Medium Plasticity, LIQUID LIMIT �'�� �`� �� Sandy or Silty Clay. LESS THAN 50% I Organic Silt and Clay I i OL of Low Plasticity. FINE Inorganic Silt, Mica - GRAINED MH ceous Silt, Plastic SOIL Silt. SILT AND CLAY Inorganic Clay of High CH Plasticity, Fat Clay. LIQUID LIMIT GREATER THAN 50% OH Organic Clay of Medium to High Plasticity. Peat, Muck and Other PT Highly Organic Soil. BORING LOG SYMBOLS GROUNDWATER SYMBOLS TEST PIT LOG SYMBOLS Standard 2 -Inch OD Split -Spoon Sample -Groundwater - After 24 Hours [BG Baggie Sample California Modified 3 -Inch OD Split -Spoon Sample (7-3-07) Indicates Date of [BIK Bulk Sample Reading 'I Rock Core Groundwater [RIG Ring Sample =_ at Time of Drilling Shelby Tube 3 -Inch OD _ Undisturbed Sample Shorthand Notation: BGS = Below Existing Ground Surface N.E. = None Encountered Summary Report $ kC) /\ L: ƒ Ec k ] E k(D < @ §� R \0 \0 \y 7± CO \ \ \ � � \ \ � \ % i I \ / \ � \ ( \ � � \ w � $ kC) /\ L: ƒ Ec k ] E k(D < @ §� R \0 \0 \y 7± CO f a ON _ f a ON