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Drainage Narrative - 07-22-2020 Drainage Narrative for Berrospid Addition – Chanhassen, MN Revised July 22, 2020 Completed by Eric Fagerberg, PE License # 53772 James R. Hill, Inc. 2999 County Rd. 42 W, #100 Burnsville, MN 55306 Existing Conditions The proposed 2.02-acre project site is situated just West of Frontier Trail in Chanhassen, Minnesota. Currently, there is a single family home situated on the West side of the site. Generally, the site drains West to East. Upstream drainage passes through the site, directed by an 18” culvert. This runoff is then directed on the North side of the existing driveway to a culvert adjacent to Frontier Trail. Although this runoff bypasses a majority of the site, it was included in the modeling for completeness sake. Geotechnical reports indicate poorly draining underlying soils, primarily sandy lean clays (CL, which falls is HSG D). No evidence of groundwater was found in the soil boring, however, when a double ring infiltration test was attempted on April 22, 2020, the test pit that was excavated for the test began to fill with water from the saturated soils in the vicinity. Groundwater was observed at elevation 918.2 at the test pit location. Proposed Conditions The proposed plat will ultimately add 2 single family homes to the site, bringing the total number of homes to 3. With the 2 additional homes, impervious area totals 18,318 square feet. The initial approach for stormwater management was to design a rain garden at the south portion of Lot 1. Given the elevation of the groundwater in the test pit, and the proximity of the proposed rain garden from the existing home to the south, the rain garden approach was ruled out. The current proposed stormwater management BMP is an underground infiltration chamber, located on the east side yard of Lot 1. The chamber serves to attenuate the peak flow and to provide infiltration of a portion of the required volume control. The new paved driveway, together with the storm sewer, will convey the majority of the runoff to the chamber for treatment. This conveyance system will route existing upstream runoff as well as newly developed runoff to the proposed stormwater chamber. The system design will bypass the flow when the chamber reaches full capacity. Volume Control On April 22, 2020, an attempt was made at conducting a double ring infiltrometer test within the proposed basin area. Shortly after the excavation was performed, the pit began filling with water seeping from surrounding soils. The water surface appeared to become static approximately 15" below existing surface, or elevation 918.2. Due to the underlying soils falling in HSG D, as well as the inundation discovered during the double ring test attempt, RPBCWD classifies this site as a “Restricted Site”, which allows the volume reduction requirement to be reduced to 0.55” over the impervious surface, amounting to a required reduction of 840 cubic feet. The infiltration capacity of the underground chamber is limited by the rate of the underlying D soils, within a 48-hour period. The full storage capacity of the chamber system is 1,713cubic feet. The 48-hour volume, located within the 7.2 inch base layer of washed stone, is 414 cubic feet. The chamber system is located behind a proposed retaining wall. The wall serves the purpose of providing a defined edge for the chamber system and to create a more desirable and usable side and rear yard for Lot 1. This also allows for the low area at the southern portion of Lot 1 to remain mostly unchanged, preserving existing vegetation and flood storage. We believe the chamber’s horizontal footprint is at its practicable limit, given that the feature is located on a single-family lot and that the use of the yard above the system is limited (i.e. no structures, no tree planting, no footings, etc.) and the cost of constructing the stormwater management system is approaching the feasible limit for the value of the lots. Increased footprint size will begin to impact the building pad size, again reducing lot value. The plans also specify that the existing topsoil be amended prior to placement of the final sod, in order to reduce the soil Curve Number, which should result in reduced runoff. p8 Modeling A p8 model was produced to show that the proposed stormwater management system is capable of removing 71.4% to Total Phosphorus (TP) and 90.1% of Total Suspended Solids (TSS). The following is a summary table of the removal efficiencies of the system: Variable OVERALL Sediment Swale Upstream Swale Ditch Check 3 Driveway Swale P0% 42.0 29.8 6.9 4.8 4.5 P10% 66.2 57.0 8.1 1.2 13.8 P30% 87.8 81.3 32.3 2.0 33.2 P50% 96.6 93.9 62.2 4.5 58.0 P80% 99.8 99.3 92.7 21.1 93.9 TSS 90.1 86.2 57.6 3.4 43.1 TP 71.4 63.4 25.4 3.2 21.1 TKN 67.3 58.7 22.6 3.5 18.3 CU 76.7 70.4 42.0 4.1 27.0 PB 85.4 80.7 52.0 3.7 36.7 ZN 67.3 58.7 22.6 3.5 18.3 HC 85.4 80.7 52.0 3.7 36.7 The p8 model indicates that the proposed stormwater management system is capable of removing 71.4% TP and 90.1% TSS Rate Control The Riley Purgatory Bluff Creek Watershed District requires that, at a minimum, detention basins should maintain existing flow rates for the 2, 10, 100 Year 24-Hour rainfalls as well as the 10 Day Snow Melt. The following is a summary table of the existing and proposed runoff flow rates: Event Existing (1S) Proposed North (7L) 2 Year (2.87”) 3.27 cfs 2.61 cfs 10 Year (4.27”) 6.24 cfs 6.23 cfs 100 Year (7.89”) 12.22 cfs 11.85 cfs 10 Day Snow Melt 0.39 cfs 0.38 cfs The proposed improvements reduce total runoff rates for all analyzed rainfall events. Low Floor Evaluation The proposed improvements include the construction of an infiltration basin at the SE corner of the property. Just south of the proposed basin is an existing home (7460 Frontier Trail), of which there is a concern about the low floor in proximity to local ground water. The low floor elevation of the adjacent property was obtained by looking at the lot certificate from when the home was constructed (see appendix). The LFE is 918.50 and the GFE is 921.50, per the City’s record. Using our surveyed GFE of 922.28, the LFE was adjusted 0.78’, the difference between the lot certificate and surveyed elevation, up to an elevation of 919.28. Soil Boring SB-1 has an elevation of 928.1, and groundwater was not encountered at a depth of 16 feet, setting a conservative groundwater elevation of 912.10, minimum. However, the discovery of groundwater at an elevation of 918.2 during the attempted infiltrometer test indicates a perched groundwater condition. In order to ensure there will be no influence on groundwater mounding from the proposed underground basin, it was designed with two constraints: a maximum bounce of two feet, and an existing groundwater separation of approximately one foot (919.28-918.20=1.08’). Utilizing Plot 2, a minimum distance from the basement of 7460 Frontier Trail was determined to be approximately 100 feet. The proposed underground system is bounded by native material to a two foot depth, and is also controlled by the upstream structure which begins to bypass the system at a two foot depth. The proposed system is also located ~120’ from the closest basement corner of the adjacent structure. Stream Power Index After initial review of the project, Riley Purgatory Bluff Creek Watershed District staff identified the swale/culvert system upstream of the proposed project as a potential high risk erosion area. Conversations with staff led to a decision to examine the stream power index at two locations; one at the culvert inlet, and one where the two waterways combine and flow alongside the driveway. The examination determined that the Stream Power Index, as defined by the watershed, at both locations was below 3. That, in conjunction with a lack of recent erosion evidence indicates that although the area was identified as a high risk erosion area, the actual stream power is below the threshold for requiring a protective and restrictive buffer. See the attached exhibit for detailed stream power calculations. Summary The proposed project was designed in accordance with the project objectives from the Riley Purgatory Bluff Creek Watershed District. Runoff from the project area is reduced due to the proposed stormwater management system. Infiltration is accomplished to the standard imposed upon restricted sites, and water quality requirements are met. If you have any questions, please feel free to contact me at efagerberg@jrhinc.com or 952-890-6044. Sincerely, Eric Fagerberg, PE #53772 Appendices: Drainage Maps Existing HydroCAD Proposed HydroCAD P8 Model Inputs Geotechnical Report Double Ring Attempt Report 7460 Frontier Trail – Lot Cert for LFE Evaluation Stream Power Index Exhibit DRI-1 SB-1 DRI-1 SB-1 1S Existing Routing Diagram for 23520 06-19-2020 Prepared by James R. Hill, Inc, Printed 6/23/2020 HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link Existing Conditions 23520 06-19-2020 Printed 6/23/2020Prepared by James R. Hill, Inc Page 2HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 0.172 98 Unconnected roofs, HSG D (1S) 1.850 82 Woods/grass comb., Fair, HSG D (1S) 2.022 83 TOTAL AREA Existing Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 06-19-2020 Printed 6/23/2020Prepared by James R. Hill, Inc Page 3HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Runoff = 3.27 cfs @ 12.22 hrs, Volume= 0.235 af, Depth= 1.39" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-2 Year 2y 24hr Rainfall=2.87" Area (ac) CN Description 1.850 82 Woods/grass comb., Fair, HSG D 0.172 98 Unconnected roofs, HSG D 2.022 83 Weighted Average 1.850 82 91.49% Pervious Area 0.172 98 8.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.5 116 0.1200 0.16 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 0.2 61 0.0710 6.29 4.94 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.025 Corrugated metal 2.9 277 0.1000 1.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 15.6 454 Total Subcatchment 1S: Existing Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)3 2 1 0 RPBCWD-2 Year 2y 24hr Rainfall=2.87" Runoff Area=2.022 ac Runoff Volume=0.235 af Runoff Depth=1.39" Flow Length=454' Tc=15.6 min CN=82/98 3.27 cfs Existing Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 06-19-2020 Printed 6/23/2020Prepared by James R. Hill, Inc Page 4HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Runoff = 0.39 cfs @ 121.35 hrs, Volume= 1.173 af, Depth= 6.96" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=4 Area (ac) CN Adj Description 1.850 82 Woods/grass comb., Fair, HSG D 0.172 98 Unconnected roofs, HSG D 2.022 83 98 Weighted Average, AMC Adjusted 1.850 82 98 91.49% Pervious Area, AMC Adjusted 0.172 98 98 8.51% Impervious Area, AMC Adjusted Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.5 116 0.1200 0.16 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 0.2 61 0.0710 6.29 4.94 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.025 Corrugated metal 2.9 277 0.1000 1.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 15.6 454 Total Subcatchment 1S: Existing Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20" AMC=4 Runoff Area=2.022 ac Runoff Volume=1.173 af Runoff Depth=6.96" Flow Length=454' Tc=15.6 min AMC Adjusted CN=98/98 0.39 cfs Existing Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 06-19-2020 Printed 6/23/2020Prepared by James R. Hill, Inc Page 5HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Runoff = 6.24 cfs @ 12.21 hrs, Volume= 0.433 af, Depth= 2.57" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-10 Year 10y 24hr Rainfall=4.27" Area (ac) CN Description 1.850 82 Woods/grass comb., Fair, HSG D 0.172 98 Unconnected roofs, HSG D 2.022 83 Weighted Average 1.850 82 91.49% Pervious Area 0.172 98 8.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.5 116 0.1200 0.16 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 0.2 61 0.0710 6.29 4.94 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.025 Corrugated metal 2.9 277 0.1000 1.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 15.6 454 Total Subcatchment 1S: Existing Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)6 5 4 3 2 1 0 RPBCWD-10 Year 10y 24hr Rainfall=4.27" Runoff Area=2.022 ac Runoff Volume=0.433 af Runoff Depth=2.57" Flow Length=454' Tc=15.6 min CN=82/98 6.24 cfs Existing Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 06-19-2020 Printed 6/23/2020Prepared by James R. Hill, Inc Page 6HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Runoff = 12.22 cfs @ 12.21 hrs, Volume= 0.920 af, Depth= 5.46" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-100 Year 100y 24hr Rainfall=7.41" Area (ac) CN Description 1.850 82 Woods/grass comb., Fair, HSG D 0.172 98 Unconnected roofs, HSG D 2.022 83 Weighted Average 1.850 82 91.49% Pervious Area 0.172 98 8.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.5 116 0.1200 0.16 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 0.2 61 0.0710 6.29 4.94 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.025 Corrugated metal 2.9 277 0.1000 1.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 15.6 454 Total Subcatchment 1S: Existing Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)13 12 11 10 9 8 7 6 5 4 3 2 1 0 RPBCWD-100 Year 100y 24hr Rainfall=7.41" Runoff Area=2.022 ac Runoff Volume=0.920 af Runoff Depth=5.46" Flow Length=454' Tc=15.6 min CN=82/98 12.22 cfs 2S Proposed 6S Fugitive 1P CBMH 101 AND CHAMBER 7L Proposed Total Routing Diagram for 23520 07-21-2020 Prepared by James R. Hill, Inc, Printed 7/22/2020 HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link Proposed Conditions 23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 2HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 0.405 82 Compost Blended HSG D Soil (2S, 6S) 0.302 98 Paved parking, HSG D (2S, 6S) 0.118 98 Unconnected roofs, HSG D (2S) 1.196 82 Woods/grass comb., Fair, HSG D (2S, 6S) 2.022 85 TOTAL AREA Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 3HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Runoff = 2.41 cfs @ 12.22 hrs, Volume= 0.178 af, Depth= 1.67" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-2 Year 2y 24hr Rainfall=2.87" Area (sf) CN Description 11,010 98 Paved parking, HSG D * 29,845 82 Woods/grass comb., Fair, HSG D 5,155 98 Unconnected roofs, HSG D * 9,417 82 Compost Blended HSG D Soil 55,427 87 Weighted Average 39,262 82 70.84% Pervious Area 16,165 98 29.16% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.5 116 0.1200 0.16 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 0.2 61 0.0710 6.29 4.94 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.025 Corrugated metal 2.9 277 0.1000 1.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 15.6 454 Total Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 4HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Subcatchment 2S: Proposed Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)2 1 0 RPBCWD-2 Year 2y 24hr Rainfall=2.87" Runoff Area=55,427 sf Runoff Volume=0.178 af Runoff Depth=1.67" Flow Length=454' Tc=15.6 min CN=82/98 2.41 cfs Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 5HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Fugitive Runoff = 1.05 cfs @ 12.27 hrs, Volume= 0.085 af, Depth= 1.37" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-2 Year 2y 24hr Rainfall=2.87" Area (sf) CN Description 2,153 98 Paved parking, HSG D * 22,254 82 Woods/grass comb., Fair, HSG D * 8,242 82 Compost Blended HSG D Soil 32,649 83 Weighted Average 30,496 82 93.41% Pervious Area 2,153 98 6.59% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.7 200 0.1300 0.18 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 1.2 125 0.1300 1.80 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 19.9 325 Total Subcatchment 6S: Fugitive Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)1 0 RPBCWD-2 Year 2y 24hr Rainfall=2.87" Runoff Area=32,649 sf Runoff Volume=0.085 af Runoff Depth=1.37" Flow Length=325' Slope=0.1300 '/' Tc=19.9 min CN=82/98 1.05 cfs Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 6HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: CBMH 101 AND CHAMBER Inflow Area = 1.272 ac, 29.16% Impervious, Inflow Depth = 1.67" for 2y 24hr event Inflow = 2.41 cfs @ 12.22 hrs, Volume= 0.178 af Outflow = 1.67 cfs @ 12.36 hrs, Volume= 0.178 af, Atten= 31%, Lag= 8.8 min Discarded = 0.00 cfs @ 12.13 hrs, Volume= 0.014 af Primary = 1.52 cfs @ 12.36 hrs, Volume= 0.163 af Secondary = 0.15 cfs @ 12.36 hrs, Volume= 0.000 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-280.00 hrs, dt= 0.01 hrs / 9 Peak Elev= 923.97' @ 12.36 hrs Surf.Area= 1,743 sf Storage= 1,741 cf Flood Elev= 923.80' Surf.Area= 1,743 sf Storage= 1,738 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 145.5 min ( 948.6 - 803.1 ) Volume Invert Avail.Storage Storage Description #1A 921.20' 1,077 cf 23.00'W x 64.00'L x 2.35'H Field A 3,458 cf Overall - 766 cf Embedded = 2,691 cf x 40.0% Voids #2A 921.80' 576 cf ADS N-12 15" x 24 Inside #1 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf 24 Chambers in 8 Rows #3 922.50' 114 cf Custom Stage Data (Prismatic) Listed below (Recalc) #4 921.20' 60 cf Custom Stage Data (Prismatic) Listed below (Recalc) 151 cf Overall x 40.0% Voids 1,827 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 922.50 19 0 0 928.50 19 114 114 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 921.20 252 0 0 921.80 252 151 151 Device Routing Invert Outlet Devices #1 Discarded 921.20'0.060 in/hr Exfiltration over Surface area #2 Primary 921.80'6.1" Round Culvert L= 19.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 921.80' / 921.13' S= 0.0353 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.20 sf #3 Secondary 923.80'21.0" Round Culvert L= 53.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 923.80' / 923.34' S= 0.0087 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 2.41 sf Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 7HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.00 cfs @ 12.13 hrs HW=922.51' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=1.52 cfs @ 12.36 hrs HW=923.95' TW=0.00' (Dynamic Tailwater) 2=Culvert (Barrel Controls 1.52 cfs @ 7.47 fps) Secondary OutFlow Max=0.13 cfs @ 12.36 hrs HW=923.96' TW=0.00' (Dynamic Tailwater) 3=Culvert (Barrel Controls 0.13 cfs @ 1.86 fps) Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 8HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Pond 1P: CBMH 101 AND CHAMBER - Chamber Wizard Field A Chamber Model = ADS N-12 15" (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf 18.0" Wide + 12.0" Spacing = 30.0" C-C Row Spacing 3 Chambers/Row x 20.00' Long = 60.00' Row Length +24.0" End Stone x 2 = 64.00' Base Length 8 Rows x 18.0" Wide + 12.0" Spacing x 7 + 24.0" Side Stone x 2 = 23.00' Base Width 7.2" Base + 18.0" Chamber Height + 3.0" Cover = 2.35' Field Height 24 Chambers x 24.0 cf = 576.0 cf Chamber Storage 24 Chambers x 31.9 cf = 766.2 cf Displacement 3,457.6 cf Field - 766.2 cf Chambers = 2,691.4 cf Stone x 40.0% Voids = 1,076.6 cf Stone Storage Chamber Storage + Stone Storage = 1,652.6 cf = 0.038 af Overall Storage Efficiency = 47.8% Overall System Size = 64.00' x 23.00' x 2.35' 24 Chambers 128.1 cy Field 99.7 cy Stone Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 9HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Pond 1P: CBMH 101 AND CHAMBER Inflow Outflow Discarded Primary Secondary Hydrograph Time (hours) 280260240220200180160140120100806040200Flow (cfs)2 1 0 Inflow Area=1.272 ac Peak Elev=923.97' Storage=1,741 cf 2.41 cfs 1.67 cfs 0.00 cfs 1.52 cfs 0.15 cfs Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 10HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 921.20 1,724 0 921.22 1,724 14 921.24 1,724 28 921.26 1,724 41 921.28 1,724 55 921.30 1,724 69 921.32 1,724 83 921.34 1,724 97 921.36 1,724 110 921.38 1,724 124 921.40 1,724 138 921.42 1,724 152 921.44 1,724 165 921.46 1,724 179 921.48 1,724 193 921.50 1,724 207 921.52 1,724 221 921.54 1,724 234 921.56 1,724 248 921.58 1,724 262 921.60 1,724 276 921.62 1,724 290 921.64 1,724 303 921.66 1,724 317 921.68 1,724 331 921.70 1,724 345 921.72 1,724 359 921.74 1,724 372 921.76 1,724 386 921.78 1,724 400 921.80 1,724 414 921.82 1,724 425 921.84 1,724 435 921.86 1,724 445 921.88 1,724 454 921.90 1,724 464 921.92 1,724 473 921.94 1,724 482 921.96 1,724 494 921.98 1,724 506 922.00 1,724 520 922.02 1,724 534 922.04 1,724 548 922.06 1,724 563 922.08 1,724 578 922.10 1,724 594 922.12 1,724 610 922.14 1,724 626 922.16 1,724 642 922.18 1,724 659 922.20 1,724 676 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 922.22 1,724 693 922.24 1,724 710 922.26 1,724 727 922.28 1,724 745 922.30 1,724 763 922.32 1,724 780 922.34 1,724 798 922.36 1,724 816 922.38 1,724 834 922.40 1,724 852 922.42 1,724 871 922.44 1,724 889 922.46 1,724 907 922.48 1,724 926 922.50 1,743 944 922.52 1,743 963 922.54 1,743 982 922.56 1,743 1,000 922.58 1,743 1,019 922.60 1,743 1,038 922.62 1,743 1,057 922.64 1,743 1,076 922.66 1,743 1,094 922.68 1,743 1,113 922.70 1,743 1,131 922.72 1,743 1,150 922.74 1,743 1,168 922.76 1,743 1,187 922.78 1,743 1,205 922.80 1,743 1,223 922.82 1,743 1,241 922.84 1,743 1,259 922.86 1,743 1,277 922.88 1,743 1,295 922.90 1,743 1,312 922.92 1,743 1,329 922.94 1,743 1,346 922.96 1,743 1,363 922.98 1,743 1,380 923.00 1,743 1,396 923.02 1,743 1,412 923.04 1,743 1,427 923.06 1,743 1,443 923.08 1,743 1,457 923.10 1,743 1,472 923.12 1,743 1,485 923.14 1,743 1,498 923.16 1,743 1,510 923.18 1,743 1,520 923.20 1,743 1,529 923.22 1,743 1,539 Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 11HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 923.24 1,743 1,549 923.26 1,743 1,559 923.28 1,743 1,570 923.30 1,743 1,581 923.32 1,743 1,594 923.34 1,743 1,606 923.36 1,743 1,618 923.38 1,743 1,630 923.40 1,743 1,642 923.42 1,743 1,654 923.44 1,743 1,667 923.46 1,743 1,679 923.48 1,743 1,691 923.50 1,743 1,703 923.52 1,743 1,715 923.54 1,743 1,727 923.56 1,743 1,733 923.58 1,743 1,734 923.60 1,743 1,734 923.62 1,743 1,734 923.64 1,743 1,735 923.66 1,743 1,735 923.68 1,743 1,735 923.70 1,743 1,736 923.72 1,743 1,736 923.74 1,743 1,737 923.76 1,743 1,737 923.78 1,743 1,737 923.80 1,743 1,738 923.82 1,743 1,738 923.84 1,743 1,739 923.86 1,743 1,739 923.88 1,743 1,739 923.90 1,743 1,740 923.92 1,743 1,740 923.94 1,743 1,740 923.96 1,743 1,741 923.98 1,743 1,741 924.00 1,743 1,742 924.02 1,743 1,742 924.04 1,743 1,742 924.06 1,743 1,743 924.08 1,743 1,743 924.10 1,743 1,743 924.12 1,743 1,744 924.14 1,743 1,744 924.16 1,743 1,745 924.18 1,743 1,745 924.20 1,743 1,745 924.22 1,743 1,746 924.24 1,743 1,746 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 924.26 1,743 1,746 924.28 1,743 1,747 924.30 1,743 1,747 924.32 1,743 1,748 924.34 1,743 1,748 924.36 1,743 1,748 924.38 1,743 1,749 924.40 1,743 1,749 924.42 1,743 1,750 924.44 1,743 1,750 924.46 1,743 1,750 924.48 1,743 1,751 924.50 1,743 1,751 924.52 1,743 1,751 924.54 1,743 1,752 924.56 1,743 1,752 924.58 1,743 1,753 924.60 1,743 1,753 924.62 1,743 1,753 924.64 1,743 1,754 924.66 1,743 1,754 924.68 1,743 1,754 924.70 1,743 1,755 924.72 1,743 1,755 924.74 1,743 1,756 924.76 1,743 1,756 924.78 1,743 1,756 924.80 1,743 1,757 924.82 1,743 1,757 924.84 1,743 1,758 924.86 1,743 1,758 924.88 1,743 1,758 924.90 1,743 1,759 924.92 1,743 1,759 924.94 1,743 1,759 924.96 1,743 1,760 924.98 1,743 1,760 925.00 1,743 1,761 925.02 1,743 1,761 925.04 1,743 1,761 925.06 1,743 1,762 925.08 1,743 1,762 925.10 1,743 1,762 925.12 1,743 1,763 925.14 1,743 1,763 925.16 1,743 1,764 925.18 1,743 1,764 925.20 1,743 1,764 925.22 1,743 1,765 925.24 1,743 1,765 925.26 1,743 1,765 Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 12HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 925.28 1,743 1,766 925.30 1,743 1,766 925.32 1,743 1,767 925.34 1,743 1,767 925.36 1,743 1,767 925.38 1,743 1,768 925.40 1,743 1,768 925.42 1,743 1,769 925.44 1,743 1,769 925.46 1,743 1,769 925.48 1,743 1,770 925.50 1,743 1,770 925.52 1,743 1,770 925.54 1,743 1,771 925.56 1,743 1,771 925.58 1,743 1,772 925.60 1,743 1,772 925.62 1,743 1,772 925.64 1,743 1,773 925.66 1,743 1,773 925.68 1,743 1,773 925.70 1,743 1,774 925.72 1,743 1,774 925.74 1,743 1,775 925.76 1,743 1,775 925.78 1,743 1,775 925.80 1,743 1,776 925.82 1,743 1,776 925.84 1,743 1,777 925.86 1,743 1,777 925.88 1,743 1,777 925.90 1,743 1,778 925.92 1,743 1,778 925.94 1,743 1,778 925.96 1,743 1,779 925.98 1,743 1,779 926.00 1,743 1,780 926.02 1,743 1,780 926.04 1,743 1,780 926.06 1,743 1,781 926.08 1,743 1,781 926.10 1,743 1,781 926.12 1,743 1,782 926.14 1,743 1,782 926.16 1,743 1,783 926.18 1,743 1,783 926.20 1,743 1,783 926.22 1,743 1,784 926.24 1,743 1,784 926.26 1,743 1,784 926.28 1,743 1,785 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 926.30 1,743 1,785 926.32 1,743 1,786 926.34 1,743 1,786 926.36 1,743 1,786 926.38 1,743 1,787 926.40 1,743 1,787 926.42 1,743 1,788 926.44 1,743 1,788 926.46 1,743 1,788 926.48 1,743 1,789 926.50 1,743 1,789 926.52 1,743 1,789 926.54 1,743 1,790 926.56 1,743 1,790 926.58 1,743 1,791 926.60 1,743 1,791 926.62 1,743 1,791 926.64 1,743 1,792 926.66 1,743 1,792 926.68 1,743 1,792 926.70 1,743 1,793 926.72 1,743 1,793 926.74 1,743 1,794 926.76 1,743 1,794 926.78 1,743 1,794 926.80 1,743 1,795 926.82 1,743 1,795 926.84 1,743 1,796 926.86 1,743 1,796 926.88 1,743 1,796 926.90 1,743 1,797 926.92 1,743 1,797 926.94 1,743 1,797 926.96 1,743 1,798 926.98 1,743 1,798 927.00 1,743 1,799 927.02 1,743 1,799 927.04 1,743 1,799 927.06 1,743 1,800 927.08 1,743 1,800 927.10 1,743 1,800 927.12 1,743 1,801 927.14 1,743 1,801 927.16 1,743 1,802 927.18 1,743 1,802 927.20 1,743 1,802 927.22 1,743 1,803 927.24 1,743 1,803 927.26 1,743 1,803 927.28 1,743 1,804 927.30 1,743 1,804 Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 13HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 927.32 1,743 1,805 927.34 1,743 1,805 927.36 1,743 1,805 927.38 1,743 1,806 927.40 1,743 1,806 927.42 1,743 1,807 927.44 1,743 1,807 927.46 1,743 1,807 927.48 1,743 1,808 927.50 1,743 1,808 927.52 1,743 1,808 927.54 1,743 1,809 927.56 1,743 1,809 927.58 1,743 1,810 927.60 1,743 1,810 927.62 1,743 1,810 927.64 1,743 1,811 927.66 1,743 1,811 927.68 1,743 1,811 927.70 1,743 1,812 927.72 1,743 1,812 927.74 1,743 1,813 927.76 1,743 1,813 927.78 1,743 1,813 927.80 1,743 1,814 927.82 1,743 1,814 927.84 1,743 1,815 927.86 1,743 1,815 927.88 1,743 1,815 927.90 1,743 1,816 927.92 1,743 1,816 927.94 1,743 1,816 927.96 1,743 1,817 927.98 1,743 1,817 928.00 1,743 1,818 928.02 1,743 1,818 928.04 1,743 1,818 928.06 1,743 1,819 928.08 1,743 1,819 928.10 1,743 1,819 928.12 1,743 1,820 928.14 1,743 1,820 928.16 1,743 1,821 928.18 1,743 1,821 928.20 1,743 1,821 928.22 1,743 1,822 928.24 1,743 1,822 928.26 1,743 1,822 928.28 1,743 1,823 928.30 1,743 1,823 928.32 1,743 1,824 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 928.34 1,743 1,824 928.36 1,743 1,824 928.38 1,743 1,825 928.40 1,743 1,825 928.42 1,743 1,826 928.44 1,743 1,826 928.46 1,743 1,826 928.48 1,743 1,827 928.50 1,743 1,827 Proposed Conditions RPBCWD-2 Year 2y 24hr Rainfall=2.87"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 14HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Link 7L: Proposed Total Inflow Area = 2.022 ac, 20.80% Impervious, Inflow Depth = 1.48" for 2y 24hr event Inflow = 2.61 cfs @ 12.36 hrs, Volume= 0.249 af Primary = 2.61 cfs @ 12.36 hrs, Volume= 0.249 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-280.00 hrs, dt= 0.01 hrs Link 7L: Proposed Total Inflow Primary Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)2 1 0 Inflow Area=2.022 ac 2.61 cfs 2.61 cfs Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 15HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Runoff = 0.24 cfs @ 121.35 hrs, Volume= 0.738 af, Depth= 6.96" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=4 Area (sf) CN Adj Description 11,010 98 Paved parking, HSG D * 29,845 82 Woods/grass comb., Fair, HSG D 5,155 98 Unconnected roofs, HSG D * 9,417 82 Compost Blended HSG D Soil 55,427 87 98 Weighted Average, AMC Adjusted 39,262 82 98 70.84% Pervious Area, AMC Adjusted 16,165 98 98 29.16% Impervious Area, AMC Adjusted Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.5 116 0.1200 0.16 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 0.2 61 0.0710 6.29 4.94 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.025 Corrugated metal 2.9 277 0.1000 1.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 15.6 454 Total Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 16HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Subcatchment 2S: Proposed Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20" AMC=4 Runoff Area=55,427 sf Runoff Volume=0.738 af Runoff Depth=6.96" Flow Length=454' Tc=15.6 min AMC Adjusted CN=98/98 0.24 cfs Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 17HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Fugitive Runoff = 0.14 cfs @ 121.41 hrs, Volume= 0.435 af, Depth= 6.96" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=4 Area (sf) CN Adj Description 2,153 98 Paved parking, HSG D * 22,254 82 Woods/grass comb., Fair, HSG D * 8,242 82 Compost Blended HSG D Soil 32,649 83 98 Weighted Average, AMC Adjusted 30,496 82 98 93.41% Pervious Area, AMC Adjusted 2,153 98 98 6.59% Impervious Area, AMC Adjusted Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.7 200 0.1300 0.18 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 1.2 125 0.1300 1.80 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 19.9 325 Total Subcatchment 6S: Fugitive Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20" AMC=4 Runoff Area=32,649 sf Runoff Volume=0.435 af Runoff Depth=6.96" Flow Length=325' Slope=0.1300 '/' Tc=19.9 min AMC Adjusted CN=98/98 0.14 cfs Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 18HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: CBMH 101 AND CHAMBER Inflow Area = 1.272 ac, 29.16% Impervious, Inflow Depth = 6.96" for 10 DAY SM event Inflow = 0.24 cfs @ 121.35 hrs, Volume= 0.738 af Outflow = 0.24 cfs @ 121.46 hrs, Volume= 0.736 af, Atten= 0%, Lag= 6.3 min Discarded = 0.00 cfs @ 10.03 hrs, Volume= 0.054 af Primary = 0.24 cfs @ 121.46 hrs, Volume= 0.682 af Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-280.00 hrs, dt= 0.01 hrs / 9 Peak Elev= 922.07' @ 121.46 hrs Surf.Area= 1,724 sf Storage= 569 cf Flood Elev= 923.80' Surf.Area= 1,743 sf Storage= 1,738 cf Plug-Flow detention time= 207.4 min calculated for 0.736 af (100% of inflow) Center-of-Mass det. time= 188.6 min ( 7,579.4 - 7,390.8 ) Volume Invert Avail.Storage Storage Description #1A 921.20' 1,077 cf 23.00'W x 64.00'L x 2.35'H Field A 3,458 cf Overall - 766 cf Embedded = 2,691 cf x 40.0% Voids #2A 921.80' 576 cf ADS N-12 15" x 24 Inside #1 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf 24 Chambers in 8 Rows #3 922.50' 114 cf Custom Stage Data (Prismatic) Listed below (Recalc) #4 921.20' 60 cf Custom Stage Data (Prismatic) Listed below (Recalc) 151 cf Overall x 40.0% Voids 1,827 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 922.50 19 0 0 928.50 19 114 114 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 921.20 252 0 0 921.80 252 151 151 Device Routing Invert Outlet Devices #1 Discarded 921.20'0.060 in/hr Exfiltration over Surface area #2 Primary 921.80'6.1" Round Culvert L= 19.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 921.80' / 921.13' S= 0.0353 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.20 sf #3 Secondary 923.80'21.0" Round Culvert L= 53.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 923.80' / 923.34' S= 0.0087 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 2.41 sf Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 19HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.00 cfs @ 10.03 hrs HW=921.27' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.24 cfs @ 121.46 hrs HW=922.07' TW=0.00' (Dynamic Tailwater) 2=Culvert (Inlet Controls 0.24 cfs @ 2.20 fps) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=921.20' TW=0.00' (Dynamic Tailwater) 3=Culvert ( Controls 0.00 cfs) Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 20HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Pond 1P: CBMH 101 AND CHAMBER - Chamber Wizard Field A Chamber Model = ADS N-12 15" (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf 18.0" Wide + 12.0" Spacing = 30.0" C-C Row Spacing 3 Chambers/Row x 20.00' Long = 60.00' Row Length +24.0" End Stone x 2 = 64.00' Base Length 8 Rows x 18.0" Wide + 12.0" Spacing x 7 + 24.0" Side Stone x 2 = 23.00' Base Width 7.2" Base + 18.0" Chamber Height + 3.0" Cover = 2.35' Field Height 24 Chambers x 24.0 cf = 576.0 cf Chamber Storage 24 Chambers x 31.9 cf = 766.2 cf Displacement 3,457.6 cf Field - 766.2 cf Chambers = 2,691.4 cf Stone x 40.0% Voids = 1,076.6 cf Stone Storage Chamber Storage + Stone Storage = 1,652.6 cf = 0.038 af Overall Storage Efficiency = 47.8% Overall System Size = 64.00' x 23.00' x 2.35' 24 Chambers 128.1 cy Field 99.7 cy Stone Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 21HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Pond 1P: CBMH 101 AND CHAMBER Inflow Outflow Discarded Primary Secondary Hydrograph Time (hours) 280260240220200180160140120100806040200Flow (cfs)0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=1.272 ac Peak Elev=922.07' Storage=569 cf 0.24 cfs 0.24 cfs 0.00 cfs 0.24 cfs 0.00 cfs Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 22HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 921.20 1,724 0 921.22 1,724 14 921.24 1,724 28 921.26 1,724 41 921.28 1,724 55 921.30 1,724 69 921.32 1,724 83 921.34 1,724 97 921.36 1,724 110 921.38 1,724 124 921.40 1,724 138 921.42 1,724 152 921.44 1,724 165 921.46 1,724 179 921.48 1,724 193 921.50 1,724 207 921.52 1,724 221 921.54 1,724 234 921.56 1,724 248 921.58 1,724 262 921.60 1,724 276 921.62 1,724 290 921.64 1,724 303 921.66 1,724 317 921.68 1,724 331 921.70 1,724 345 921.72 1,724 359 921.74 1,724 372 921.76 1,724 386 921.78 1,724 400 921.80 1,724 414 921.82 1,724 425 921.84 1,724 435 921.86 1,724 445 921.88 1,724 454 921.90 1,724 464 921.92 1,724 473 921.94 1,724 482 921.96 1,724 494 921.98 1,724 506 922.00 1,724 520 922.02 1,724 534 922.04 1,724 548 922.06 1,724 563 922.08 1,724 578 922.10 1,724 594 922.12 1,724 610 922.14 1,724 626 922.16 1,724 642 922.18 1,724 659 922.20 1,724 676 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 922.22 1,724 693 922.24 1,724 710 922.26 1,724 727 922.28 1,724 745 922.30 1,724 763 922.32 1,724 780 922.34 1,724 798 922.36 1,724 816 922.38 1,724 834 922.40 1,724 852 922.42 1,724 871 922.44 1,724 889 922.46 1,724 907 922.48 1,724 926 922.50 1,743 944 922.52 1,743 963 922.54 1,743 982 922.56 1,743 1,000 922.58 1,743 1,019 922.60 1,743 1,038 922.62 1,743 1,057 922.64 1,743 1,076 922.66 1,743 1,094 922.68 1,743 1,113 922.70 1,743 1,131 922.72 1,743 1,150 922.74 1,743 1,168 922.76 1,743 1,187 922.78 1,743 1,205 922.80 1,743 1,223 922.82 1,743 1,241 922.84 1,743 1,259 922.86 1,743 1,277 922.88 1,743 1,295 922.90 1,743 1,312 922.92 1,743 1,329 922.94 1,743 1,346 922.96 1,743 1,363 922.98 1,743 1,380 923.00 1,743 1,396 923.02 1,743 1,412 923.04 1,743 1,427 923.06 1,743 1,443 923.08 1,743 1,457 923.10 1,743 1,472 923.12 1,743 1,485 923.14 1,743 1,498 923.16 1,743 1,510 923.18 1,743 1,520 923.20 1,743 1,529 923.22 1,743 1,539 Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 23HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 923.24 1,743 1,549 923.26 1,743 1,559 923.28 1,743 1,570 923.30 1,743 1,581 923.32 1,743 1,594 923.34 1,743 1,606 923.36 1,743 1,618 923.38 1,743 1,630 923.40 1,743 1,642 923.42 1,743 1,654 923.44 1,743 1,667 923.46 1,743 1,679 923.48 1,743 1,691 923.50 1,743 1,703 923.52 1,743 1,715 923.54 1,743 1,727 923.56 1,743 1,733 923.58 1,743 1,734 923.60 1,743 1,734 923.62 1,743 1,734 923.64 1,743 1,735 923.66 1,743 1,735 923.68 1,743 1,735 923.70 1,743 1,736 923.72 1,743 1,736 923.74 1,743 1,737 923.76 1,743 1,737 923.78 1,743 1,737 923.80 1,743 1,738 923.82 1,743 1,738 923.84 1,743 1,739 923.86 1,743 1,739 923.88 1,743 1,739 923.90 1,743 1,740 923.92 1,743 1,740 923.94 1,743 1,740 923.96 1,743 1,741 923.98 1,743 1,741 924.00 1,743 1,742 924.02 1,743 1,742 924.04 1,743 1,742 924.06 1,743 1,743 924.08 1,743 1,743 924.10 1,743 1,743 924.12 1,743 1,744 924.14 1,743 1,744 924.16 1,743 1,745 924.18 1,743 1,745 924.20 1,743 1,745 924.22 1,743 1,746 924.24 1,743 1,746 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 924.26 1,743 1,746 924.28 1,743 1,747 924.30 1,743 1,747 924.32 1,743 1,748 924.34 1,743 1,748 924.36 1,743 1,748 924.38 1,743 1,749 924.40 1,743 1,749 924.42 1,743 1,750 924.44 1,743 1,750 924.46 1,743 1,750 924.48 1,743 1,751 924.50 1,743 1,751 924.52 1,743 1,751 924.54 1,743 1,752 924.56 1,743 1,752 924.58 1,743 1,753 924.60 1,743 1,753 924.62 1,743 1,753 924.64 1,743 1,754 924.66 1,743 1,754 924.68 1,743 1,754 924.70 1,743 1,755 924.72 1,743 1,755 924.74 1,743 1,756 924.76 1,743 1,756 924.78 1,743 1,756 924.80 1,743 1,757 924.82 1,743 1,757 924.84 1,743 1,758 924.86 1,743 1,758 924.88 1,743 1,758 924.90 1,743 1,759 924.92 1,743 1,759 924.94 1,743 1,759 924.96 1,743 1,760 924.98 1,743 1,760 925.00 1,743 1,761 925.02 1,743 1,761 925.04 1,743 1,761 925.06 1,743 1,762 925.08 1,743 1,762 925.10 1,743 1,762 925.12 1,743 1,763 925.14 1,743 1,763 925.16 1,743 1,764 925.18 1,743 1,764 925.20 1,743 1,764 925.22 1,743 1,765 925.24 1,743 1,765 925.26 1,743 1,765 Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 24HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 925.28 1,743 1,766 925.30 1,743 1,766 925.32 1,743 1,767 925.34 1,743 1,767 925.36 1,743 1,767 925.38 1,743 1,768 925.40 1,743 1,768 925.42 1,743 1,769 925.44 1,743 1,769 925.46 1,743 1,769 925.48 1,743 1,770 925.50 1,743 1,770 925.52 1,743 1,770 925.54 1,743 1,771 925.56 1,743 1,771 925.58 1,743 1,772 925.60 1,743 1,772 925.62 1,743 1,772 925.64 1,743 1,773 925.66 1,743 1,773 925.68 1,743 1,773 925.70 1,743 1,774 925.72 1,743 1,774 925.74 1,743 1,775 925.76 1,743 1,775 925.78 1,743 1,775 925.80 1,743 1,776 925.82 1,743 1,776 925.84 1,743 1,777 925.86 1,743 1,777 925.88 1,743 1,777 925.90 1,743 1,778 925.92 1,743 1,778 925.94 1,743 1,778 925.96 1,743 1,779 925.98 1,743 1,779 926.00 1,743 1,780 926.02 1,743 1,780 926.04 1,743 1,780 926.06 1,743 1,781 926.08 1,743 1,781 926.10 1,743 1,781 926.12 1,743 1,782 926.14 1,743 1,782 926.16 1,743 1,783 926.18 1,743 1,783 926.20 1,743 1,783 926.22 1,743 1,784 926.24 1,743 1,784 926.26 1,743 1,784 926.28 1,743 1,785 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 926.30 1,743 1,785 926.32 1,743 1,786 926.34 1,743 1,786 926.36 1,743 1,786 926.38 1,743 1,787 926.40 1,743 1,787 926.42 1,743 1,788 926.44 1,743 1,788 926.46 1,743 1,788 926.48 1,743 1,789 926.50 1,743 1,789 926.52 1,743 1,789 926.54 1,743 1,790 926.56 1,743 1,790 926.58 1,743 1,791 926.60 1,743 1,791 926.62 1,743 1,791 926.64 1,743 1,792 926.66 1,743 1,792 926.68 1,743 1,792 926.70 1,743 1,793 926.72 1,743 1,793 926.74 1,743 1,794 926.76 1,743 1,794 926.78 1,743 1,794 926.80 1,743 1,795 926.82 1,743 1,795 926.84 1,743 1,796 926.86 1,743 1,796 926.88 1,743 1,796 926.90 1,743 1,797 926.92 1,743 1,797 926.94 1,743 1,797 926.96 1,743 1,798 926.98 1,743 1,798 927.00 1,743 1,799 927.02 1,743 1,799 927.04 1,743 1,799 927.06 1,743 1,800 927.08 1,743 1,800 927.10 1,743 1,800 927.12 1,743 1,801 927.14 1,743 1,801 927.16 1,743 1,802 927.18 1,743 1,802 927.20 1,743 1,802 927.22 1,743 1,803 927.24 1,743 1,803 927.26 1,743 1,803 927.28 1,743 1,804 927.30 1,743 1,804 Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 25HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 927.32 1,743 1,805 927.34 1,743 1,805 927.36 1,743 1,805 927.38 1,743 1,806 927.40 1,743 1,806 927.42 1,743 1,807 927.44 1,743 1,807 927.46 1,743 1,807 927.48 1,743 1,808 927.50 1,743 1,808 927.52 1,743 1,808 927.54 1,743 1,809 927.56 1,743 1,809 927.58 1,743 1,810 927.60 1,743 1,810 927.62 1,743 1,810 927.64 1,743 1,811 927.66 1,743 1,811 927.68 1,743 1,811 927.70 1,743 1,812 927.72 1,743 1,812 927.74 1,743 1,813 927.76 1,743 1,813 927.78 1,743 1,813 927.80 1,743 1,814 927.82 1,743 1,814 927.84 1,743 1,815 927.86 1,743 1,815 927.88 1,743 1,815 927.90 1,743 1,816 927.92 1,743 1,816 927.94 1,743 1,816 927.96 1,743 1,817 927.98 1,743 1,817 928.00 1,743 1,818 928.02 1,743 1,818 928.04 1,743 1,818 928.06 1,743 1,819 928.08 1,743 1,819 928.10 1,743 1,819 928.12 1,743 1,820 928.14 1,743 1,820 928.16 1,743 1,821 928.18 1,743 1,821 928.20 1,743 1,821 928.22 1,743 1,822 928.24 1,743 1,822 928.26 1,743 1,822 928.28 1,743 1,823 928.30 1,743 1,823 928.32 1,743 1,824 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 928.34 1,743 1,824 928.36 1,743 1,824 928.38 1,743 1,825 928.40 1,743 1,825 928.42 1,743 1,826 928.44 1,743 1,826 928.46 1,743 1,826 928.48 1,743 1,827 928.50 1,743 1,827 Proposed Conditions RPBCWD-10 Day SM 10 DAY SM Rainfall=7.20", AMC=423520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 26HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Link 7L: Proposed Total Inflow Area = 2.022 ac, 20.80% Impervious, Inflow Depth = 6.63" for 10 DAY SM event Inflow = 0.38 cfs @ 121.41 hrs, Volume= 1.117 af Primary = 0.38 cfs @ 121.41 hrs, Volume= 1.117 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-280.00 hrs, dt= 0.01 hrs Link 7L: Proposed Total Inflow Primary Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=2.022 ac 0.38 cfs 0.38 cfs Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 27HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Runoff = 4.30 cfs @ 12.21 hrs, Volume= 0.308 af, Depth= 2.90" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-10 Year 10y 24hr Rainfall=4.27" Area (sf) CN Description 11,010 98 Paved parking, HSG D * 29,845 82 Woods/grass comb., Fair, HSG D 5,155 98 Unconnected roofs, HSG D * 9,417 82 Compost Blended HSG D Soil 55,427 87 Weighted Average 39,262 82 70.84% Pervious Area 16,165 98 29.16% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.5 116 0.1200 0.16 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 0.2 61 0.0710 6.29 4.94 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.025 Corrugated metal 2.9 277 0.1000 1.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 15.6 454 Total Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 28HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Subcatchment 2S: Proposed Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)4 3 2 1 0 RPBCWD-10 Year 10y 24hr Rainfall=4.27" Runoff Area=55,427 sf Runoff Volume=0.308 af Runoff Depth=2.90" Flow Length=454' Tc=15.6 min CN=82/98 4.30 cfs Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 29HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Fugitive Runoff = 2.03 cfs @ 12.27 hrs, Volume= 0.159 af, Depth= 2.54" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-10 Year 10y 24hr Rainfall=4.27" Area (sf) CN Description 2,153 98 Paved parking, HSG D * 22,254 82 Woods/grass comb., Fair, HSG D * 8,242 82 Compost Blended HSG D Soil 32,649 83 Weighted Average 30,496 82 93.41% Pervious Area 2,153 98 6.59% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.7 200 0.1300 0.18 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 1.2 125 0.1300 1.80 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 19.9 325 Total Subcatchment 6S: Fugitive Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)2 1 0 RPBCWD-10 Year 10y 24hr Rainfall=4.27" Runoff Area=32,649 sf Runoff Volume=0.159 af Runoff Depth=2.54" Flow Length=325' Slope=0.1300 '/' Tc=19.9 min CN=82/98 2.03 cfs Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 30HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: CBMH 101 AND CHAMBER Inflow Area = 1.272 ac, 29.16% Impervious, Inflow Depth = 2.90" for 10y 24hr event Inflow = 4.30 cfs @ 12.21 hrs, Volume= 0.308 af Outflow = 4.32 cfs @ 12.21 hrs, Volume= 0.308 af, Atten= 0%, Lag= 0.0 min Discarded = 0.00 cfs @ 12.01 hrs, Volume= 0.014 af Primary = 1.69 cfs @ 12.21 hrs, Volume= 0.249 af Secondary = 2.63 cfs @ 12.21 hrs, Volume= 0.045 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-280.00 hrs, dt= 0.01 hrs / 9 Peak Elev= 924.53' @ 12.21 hrs Surf.Area= 1,743 sf Storage= 1,752 cf Flood Elev= 923.80' Surf.Area= 1,743 sf Storage= 1,738 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 88.1 min ( 871.8 - 783.7 ) Volume Invert Avail.Storage Storage Description #1A 921.20' 1,077 cf 23.00'W x 64.00'L x 2.35'H Field A 3,458 cf Overall - 766 cf Embedded = 2,691 cf x 40.0% Voids #2A 921.80' 576 cf ADS N-12 15" x 24 Inside #1 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf 24 Chambers in 8 Rows #3 922.50' 114 cf Custom Stage Data (Prismatic) Listed below (Recalc) #4 921.20' 60 cf Custom Stage Data (Prismatic) Listed below (Recalc) 151 cf Overall x 40.0% Voids 1,827 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 922.50 19 0 0 928.50 19 114 114 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 921.20 252 0 0 921.80 252 151 151 Device Routing Invert Outlet Devices #1 Discarded 921.20'0.060 in/hr Exfiltration over Surface area #2 Primary 921.80'6.1" Round Culvert L= 19.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 921.80' / 921.13' S= 0.0353 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.20 sf #3 Secondary 923.80'21.0" Round Culvert L= 53.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 923.80' / 923.34' S= 0.0087 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 2.41 sf Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 31HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.00 cfs @ 12.01 hrs HW=922.52' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=1.69 cfs @ 12.21 hrs HW=924.53' TW=0.00' (Dynamic Tailwater) 2=Culvert (Barrel Controls 1.69 cfs @ 8.35 fps) Secondary OutFlow Max=2.62 cfs @ 12.21 hrs HW=924.53' TW=0.00' (Dynamic Tailwater) 3=Culvert (Barrel Controls 2.62 cfs @ 4.10 fps) Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 32HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Pond 1P: CBMH 101 AND CHAMBER - Chamber Wizard Field A Chamber Model = ADS N-12 15" (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf 18.0" Wide + 12.0" Spacing = 30.0" C-C Row Spacing 3 Chambers/Row x 20.00' Long = 60.00' Row Length +24.0" End Stone x 2 = 64.00' Base Length 8 Rows x 18.0" Wide + 12.0" Spacing x 7 + 24.0" Side Stone x 2 = 23.00' Base Width 7.2" Base + 18.0" Chamber Height + 3.0" Cover = 2.35' Field Height 24 Chambers x 24.0 cf = 576.0 cf Chamber Storage 24 Chambers x 31.9 cf = 766.2 cf Displacement 3,457.6 cf Field - 766.2 cf Chambers = 2,691.4 cf Stone x 40.0% Voids = 1,076.6 cf Stone Storage Chamber Storage + Stone Storage = 1,652.6 cf = 0.038 af Overall Storage Efficiency = 47.8% Overall System Size = 64.00' x 23.00' x 2.35' 24 Chambers 128.1 cy Field 99.7 cy Stone Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 33HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Pond 1P: CBMH 101 AND CHAMBER Inflow Outflow Discarded Primary Secondary Hydrograph Time (hours) 280260240220200180160140120100806040200Flow (cfs)4 3 2 1 0 Inflow Area=1.272 ac Peak Elev=924.53' Storage=1,752 cf 4.30 cfs 4.32 cfs 0.00 cfs 1.69 cfs 2.63 cfs Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 34HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 921.20 1,724 0 921.22 1,724 14 921.24 1,724 28 921.26 1,724 41 921.28 1,724 55 921.30 1,724 69 921.32 1,724 83 921.34 1,724 97 921.36 1,724 110 921.38 1,724 124 921.40 1,724 138 921.42 1,724 152 921.44 1,724 165 921.46 1,724 179 921.48 1,724 193 921.50 1,724 207 921.52 1,724 221 921.54 1,724 234 921.56 1,724 248 921.58 1,724 262 921.60 1,724 276 921.62 1,724 290 921.64 1,724 303 921.66 1,724 317 921.68 1,724 331 921.70 1,724 345 921.72 1,724 359 921.74 1,724 372 921.76 1,724 386 921.78 1,724 400 921.80 1,724 414 921.82 1,724 425 921.84 1,724 435 921.86 1,724 445 921.88 1,724 454 921.90 1,724 464 921.92 1,724 473 921.94 1,724 482 921.96 1,724 494 921.98 1,724 506 922.00 1,724 520 922.02 1,724 534 922.04 1,724 548 922.06 1,724 563 922.08 1,724 578 922.10 1,724 594 922.12 1,724 610 922.14 1,724 626 922.16 1,724 642 922.18 1,724 659 922.20 1,724 676 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 922.22 1,724 693 922.24 1,724 710 922.26 1,724 727 922.28 1,724 745 922.30 1,724 763 922.32 1,724 780 922.34 1,724 798 922.36 1,724 816 922.38 1,724 834 922.40 1,724 852 922.42 1,724 871 922.44 1,724 889 922.46 1,724 907 922.48 1,724 926 922.50 1,743 944 922.52 1,743 963 922.54 1,743 982 922.56 1,743 1,000 922.58 1,743 1,019 922.60 1,743 1,038 922.62 1,743 1,057 922.64 1,743 1,076 922.66 1,743 1,094 922.68 1,743 1,113 922.70 1,743 1,131 922.72 1,743 1,150 922.74 1,743 1,168 922.76 1,743 1,187 922.78 1,743 1,205 922.80 1,743 1,223 922.82 1,743 1,241 922.84 1,743 1,259 922.86 1,743 1,277 922.88 1,743 1,295 922.90 1,743 1,312 922.92 1,743 1,329 922.94 1,743 1,346 922.96 1,743 1,363 922.98 1,743 1,380 923.00 1,743 1,396 923.02 1,743 1,412 923.04 1,743 1,427 923.06 1,743 1,443 923.08 1,743 1,457 923.10 1,743 1,472 923.12 1,743 1,485 923.14 1,743 1,498 923.16 1,743 1,510 923.18 1,743 1,520 923.20 1,743 1,529 923.22 1,743 1,539 Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 35HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 923.24 1,743 1,549 923.26 1,743 1,559 923.28 1,743 1,570 923.30 1,743 1,581 923.32 1,743 1,594 923.34 1,743 1,606 923.36 1,743 1,618 923.38 1,743 1,630 923.40 1,743 1,642 923.42 1,743 1,654 923.44 1,743 1,667 923.46 1,743 1,679 923.48 1,743 1,691 923.50 1,743 1,703 923.52 1,743 1,715 923.54 1,743 1,727 923.56 1,743 1,733 923.58 1,743 1,734 923.60 1,743 1,734 923.62 1,743 1,734 923.64 1,743 1,735 923.66 1,743 1,735 923.68 1,743 1,735 923.70 1,743 1,736 923.72 1,743 1,736 923.74 1,743 1,737 923.76 1,743 1,737 923.78 1,743 1,737 923.80 1,743 1,738 923.82 1,743 1,738 923.84 1,743 1,739 923.86 1,743 1,739 923.88 1,743 1,739 923.90 1,743 1,740 923.92 1,743 1,740 923.94 1,743 1,740 923.96 1,743 1,741 923.98 1,743 1,741 924.00 1,743 1,742 924.02 1,743 1,742 924.04 1,743 1,742 924.06 1,743 1,743 924.08 1,743 1,743 924.10 1,743 1,743 924.12 1,743 1,744 924.14 1,743 1,744 924.16 1,743 1,745 924.18 1,743 1,745 924.20 1,743 1,745 924.22 1,743 1,746 924.24 1,743 1,746 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 924.26 1,743 1,746 924.28 1,743 1,747 924.30 1,743 1,747 924.32 1,743 1,748 924.34 1,743 1,748 924.36 1,743 1,748 924.38 1,743 1,749 924.40 1,743 1,749 924.42 1,743 1,750 924.44 1,743 1,750 924.46 1,743 1,750 924.48 1,743 1,751 924.50 1,743 1,751 924.52 1,743 1,751 924.54 1,743 1,752 924.56 1,743 1,752 924.58 1,743 1,753 924.60 1,743 1,753 924.62 1,743 1,753 924.64 1,743 1,754 924.66 1,743 1,754 924.68 1,743 1,754 924.70 1,743 1,755 924.72 1,743 1,755 924.74 1,743 1,756 924.76 1,743 1,756 924.78 1,743 1,756 924.80 1,743 1,757 924.82 1,743 1,757 924.84 1,743 1,758 924.86 1,743 1,758 924.88 1,743 1,758 924.90 1,743 1,759 924.92 1,743 1,759 924.94 1,743 1,759 924.96 1,743 1,760 924.98 1,743 1,760 925.00 1,743 1,761 925.02 1,743 1,761 925.04 1,743 1,761 925.06 1,743 1,762 925.08 1,743 1,762 925.10 1,743 1,762 925.12 1,743 1,763 925.14 1,743 1,763 925.16 1,743 1,764 925.18 1,743 1,764 925.20 1,743 1,764 925.22 1,743 1,765 925.24 1,743 1,765 925.26 1,743 1,765 Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 36HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 925.28 1,743 1,766 925.30 1,743 1,766 925.32 1,743 1,767 925.34 1,743 1,767 925.36 1,743 1,767 925.38 1,743 1,768 925.40 1,743 1,768 925.42 1,743 1,769 925.44 1,743 1,769 925.46 1,743 1,769 925.48 1,743 1,770 925.50 1,743 1,770 925.52 1,743 1,770 925.54 1,743 1,771 925.56 1,743 1,771 925.58 1,743 1,772 925.60 1,743 1,772 925.62 1,743 1,772 925.64 1,743 1,773 925.66 1,743 1,773 925.68 1,743 1,773 925.70 1,743 1,774 925.72 1,743 1,774 925.74 1,743 1,775 925.76 1,743 1,775 925.78 1,743 1,775 925.80 1,743 1,776 925.82 1,743 1,776 925.84 1,743 1,777 925.86 1,743 1,777 925.88 1,743 1,777 925.90 1,743 1,778 925.92 1,743 1,778 925.94 1,743 1,778 925.96 1,743 1,779 925.98 1,743 1,779 926.00 1,743 1,780 926.02 1,743 1,780 926.04 1,743 1,780 926.06 1,743 1,781 926.08 1,743 1,781 926.10 1,743 1,781 926.12 1,743 1,782 926.14 1,743 1,782 926.16 1,743 1,783 926.18 1,743 1,783 926.20 1,743 1,783 926.22 1,743 1,784 926.24 1,743 1,784 926.26 1,743 1,784 926.28 1,743 1,785 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 926.30 1,743 1,785 926.32 1,743 1,786 926.34 1,743 1,786 926.36 1,743 1,786 926.38 1,743 1,787 926.40 1,743 1,787 926.42 1,743 1,788 926.44 1,743 1,788 926.46 1,743 1,788 926.48 1,743 1,789 926.50 1,743 1,789 926.52 1,743 1,789 926.54 1,743 1,790 926.56 1,743 1,790 926.58 1,743 1,791 926.60 1,743 1,791 926.62 1,743 1,791 926.64 1,743 1,792 926.66 1,743 1,792 926.68 1,743 1,792 926.70 1,743 1,793 926.72 1,743 1,793 926.74 1,743 1,794 926.76 1,743 1,794 926.78 1,743 1,794 926.80 1,743 1,795 926.82 1,743 1,795 926.84 1,743 1,796 926.86 1,743 1,796 926.88 1,743 1,796 926.90 1,743 1,797 926.92 1,743 1,797 926.94 1,743 1,797 926.96 1,743 1,798 926.98 1,743 1,798 927.00 1,743 1,799 927.02 1,743 1,799 927.04 1,743 1,799 927.06 1,743 1,800 927.08 1,743 1,800 927.10 1,743 1,800 927.12 1,743 1,801 927.14 1,743 1,801 927.16 1,743 1,802 927.18 1,743 1,802 927.20 1,743 1,802 927.22 1,743 1,803 927.24 1,743 1,803 927.26 1,743 1,803 927.28 1,743 1,804 927.30 1,743 1,804 Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 37HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 927.32 1,743 1,805 927.34 1,743 1,805 927.36 1,743 1,805 927.38 1,743 1,806 927.40 1,743 1,806 927.42 1,743 1,807 927.44 1,743 1,807 927.46 1,743 1,807 927.48 1,743 1,808 927.50 1,743 1,808 927.52 1,743 1,808 927.54 1,743 1,809 927.56 1,743 1,809 927.58 1,743 1,810 927.60 1,743 1,810 927.62 1,743 1,810 927.64 1,743 1,811 927.66 1,743 1,811 927.68 1,743 1,811 927.70 1,743 1,812 927.72 1,743 1,812 927.74 1,743 1,813 927.76 1,743 1,813 927.78 1,743 1,813 927.80 1,743 1,814 927.82 1,743 1,814 927.84 1,743 1,815 927.86 1,743 1,815 927.88 1,743 1,815 927.90 1,743 1,816 927.92 1,743 1,816 927.94 1,743 1,816 927.96 1,743 1,817 927.98 1,743 1,817 928.00 1,743 1,818 928.02 1,743 1,818 928.04 1,743 1,818 928.06 1,743 1,819 928.08 1,743 1,819 928.10 1,743 1,819 928.12 1,743 1,820 928.14 1,743 1,820 928.16 1,743 1,821 928.18 1,743 1,821 928.20 1,743 1,821 928.22 1,743 1,822 928.24 1,743 1,822 928.26 1,743 1,822 928.28 1,743 1,823 928.30 1,743 1,823 928.32 1,743 1,824 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 928.34 1,743 1,824 928.36 1,743 1,824 928.38 1,743 1,825 928.40 1,743 1,825 928.42 1,743 1,826 928.44 1,743 1,826 928.46 1,743 1,826 928.48 1,743 1,827 928.50 1,743 1,827 Proposed Conditions RPBCWD-10 Year 10y 24hr Rainfall=4.27"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 38HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Link 7L: Proposed Total Inflow Area = 2.022 ac, 20.80% Impervious, Inflow Depth = 2.68" for 10y 24hr event Inflow = 6.23 cfs @ 12.23 hrs, Volume= 0.452 af Primary = 6.23 cfs @ 12.23 hrs, Volume= 0.452 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-280.00 hrs, dt= 0.01 hrs Link 7L: Proposed Total Inflow Primary Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)6 5 4 3 2 1 0 Inflow Area=2.022 ac 6.23 cfs 6.23 cfs Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 39HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Proposed Runoff = 8.01 cfs @ 12.20 hrs, Volume= 0.620 af, Depth= 5.85" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-100 Year 100y 24hr Rainfall=7.41" Area (sf) CN Description 11,010 98 Paved parking, HSG D * 29,845 82 Woods/grass comb., Fair, HSG D 5,155 98 Unconnected roofs, HSG D * 9,417 82 Compost Blended HSG D Soil 55,427 87 Weighted Average 39,262 82 70.84% Pervious Area 16,165 98 29.16% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.5 116 0.1200 0.16 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 0.2 61 0.0710 6.29 4.94 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.025 Corrugated metal 2.9 277 0.1000 1.58 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 15.6 454 Total Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 40HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Subcatchment 2S: Proposed Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)8 7 6 5 4 3 2 1 0 RPBCWD-100 Year 100y 24hr Rainfall=7.41" Runoff Area=55,427 sf Runoff Volume=0.620 af Runoff Depth=5.85" Flow Length=454' Tc=15.6 min CN=82/98 8.01 cfs Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 41HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: Fugitive Runoff = 4.01 cfs @ 12.27 hrs, Volume= 0.339 af, Depth= 5.42" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-280.00 hrs, dt= 0.01 hrs RPBCWD-100 Year 100y 24hr Rainfall=7.41" Area (sf) CN Description 2,153 98 Paved parking, HSG D * 22,254 82 Woods/grass comb., Fair, HSG D * 8,242 82 Compost Blended HSG D Soil 32,649 83 Weighted Average 30,496 82 93.41% Pervious Area 2,153 98 6.59% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.7 200 0.1300 0.18 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.87" 1.2 125 0.1300 1.80 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 19.9 325 Total Subcatchment 6S: Fugitive Runoff Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)4 3 2 1 0 RPBCWD-100 Year 100y 24hr Rainfall=7.41" Runoff Area=32,649 sf Runoff Volume=0.339 af Runoff Depth=5.42" Flow Length=325' Slope=0.1300 '/' Tc=19.9 min CN=82/98 4.01 cfs Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 42HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: CBMH 101 AND CHAMBER Inflow Area = 1.272 ac, 29.16% Impervious, Inflow Depth = 5.85" for 100y 24hr event Inflow = 8.01 cfs @ 12.20 hrs, Volume= 0.620 af Outflow = 8.01 cfs @ 12.20 hrs, Volume= 0.620 af, Atten= 0%, Lag= 0.0 min Discarded = 0.00 cfs @ 11.58 hrs, Volume= 0.014 af Primary = 1.83 cfs @ 12.20 hrs, Volume= 0.416 af Secondary = 6.18 cfs @ 12.20 hrs, Volume= 0.189 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-280.00 hrs, dt= 0.01 hrs / 9 Peak Elev= 925.00' @ 12.20 hrs Surf.Area= 1,743 sf Storage= 1,760 cf Flood Elev= 923.80' Surf.Area= 1,743 sf Storage= 1,738 cf Plug-Flow detention time= 47.7 min calculated for 0.620 af (100% of inflow) Center-of-Mass det. time= 47.8 min ( 815.9 - 768.1 ) Volume Invert Avail.Storage Storage Description #1A 921.20' 1,077 cf 23.00'W x 64.00'L x 2.35'H Field A 3,458 cf Overall - 766 cf Embedded = 2,691 cf x 40.0% Voids #2A 921.80' 576 cf ADS N-12 15" x 24 Inside #1 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf 24 Chambers in 8 Rows #3 922.50' 114 cf Custom Stage Data (Prismatic) Listed below (Recalc) #4 921.20' 60 cf Custom Stage Data (Prismatic) Listed below (Recalc) 151 cf Overall x 40.0% Voids 1,827 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 922.50 19 0 0 928.50 19 114 114 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 921.20 252 0 0 921.80 252 151 151 Device Routing Invert Outlet Devices #1 Discarded 921.20'0.060 in/hr Exfiltration over Surface area #2 Primary 921.80'6.1" Round Culvert L= 19.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 921.80' / 921.13' S= 0.0353 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.20 sf #3 Secondary 923.80'21.0" Round Culvert L= 53.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 923.80' / 923.34' S= 0.0087 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 2.41 sf Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 43HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.00 cfs @ 11.58 hrs HW=922.50' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=1.83 cfs @ 12.20 hrs HW=925.00' TW=0.00' (Dynamic Tailwater) 2=Culvert (Barrel Controls 1.83 cfs @ 9.00 fps) Secondary OutFlow Max=6.18 cfs @ 12.20 hrs HW=925.00' TW=0.00' (Dynamic Tailwater) 3=Culvert (Barrel Controls 6.18 cfs @ 4.98 fps) Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 44HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Pond 1P: CBMH 101 AND CHAMBER - Chamber Wizard Field A Chamber Model = ADS N-12 15" (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf 18.0" Wide + 12.0" Spacing = 30.0" C-C Row Spacing 3 Chambers/Row x 20.00' Long = 60.00' Row Length +24.0" End Stone x 2 = 64.00' Base Length 8 Rows x 18.0" Wide + 12.0" Spacing x 7 + 24.0" Side Stone x 2 = 23.00' Base Width 7.2" Base + 18.0" Chamber Height + 3.0" Cover = 2.35' Field Height 24 Chambers x 24.0 cf = 576.0 cf Chamber Storage 24 Chambers x 31.9 cf = 766.2 cf Displacement 3,457.6 cf Field - 766.2 cf Chambers = 2,691.4 cf Stone x 40.0% Voids = 1,076.6 cf Stone Storage Chamber Storage + Stone Storage = 1,652.6 cf = 0.038 af Overall Storage Efficiency = 47.8% Overall System Size = 64.00' x 23.00' x 2.35' 24 Chambers 128.1 cy Field 99.7 cy Stone Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 45HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Pond 1P: CBMH 101 AND CHAMBER Inflow Outflow Discarded Primary Secondary Hydrograph Time (hours) 280260240220200180160140120100806040200Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=1.272 ac Peak Elev=925.00' Storage=1,760 cf 8.01 cfs 8.01 cfs 0.00 cfs 1.83 cfs 6.18 cfs Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 46HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 921.20 1,724 0 921.22 1,724 14 921.24 1,724 28 921.26 1,724 41 921.28 1,724 55 921.30 1,724 69 921.32 1,724 83 921.34 1,724 97 921.36 1,724 110 921.38 1,724 124 921.40 1,724 138 921.42 1,724 152 921.44 1,724 165 921.46 1,724 179 921.48 1,724 193 921.50 1,724 207 921.52 1,724 221 921.54 1,724 234 921.56 1,724 248 921.58 1,724 262 921.60 1,724 276 921.62 1,724 290 921.64 1,724 303 921.66 1,724 317 921.68 1,724 331 921.70 1,724 345 921.72 1,724 359 921.74 1,724 372 921.76 1,724 386 921.78 1,724 400 921.80 1,724 414 921.82 1,724 425 921.84 1,724 435 921.86 1,724 445 921.88 1,724 454 921.90 1,724 464 921.92 1,724 473 921.94 1,724 482 921.96 1,724 494 921.98 1,724 506 922.00 1,724 520 922.02 1,724 534 922.04 1,724 548 922.06 1,724 563 922.08 1,724 578 922.10 1,724 594 922.12 1,724 610 922.14 1,724 626 922.16 1,724 642 922.18 1,724 659 922.20 1,724 676 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 922.22 1,724 693 922.24 1,724 710 922.26 1,724 727 922.28 1,724 745 922.30 1,724 763 922.32 1,724 780 922.34 1,724 798 922.36 1,724 816 922.38 1,724 834 922.40 1,724 852 922.42 1,724 871 922.44 1,724 889 922.46 1,724 907 922.48 1,724 926 922.50 1,743 944 922.52 1,743 963 922.54 1,743 982 922.56 1,743 1,000 922.58 1,743 1,019 922.60 1,743 1,038 922.62 1,743 1,057 922.64 1,743 1,076 922.66 1,743 1,094 922.68 1,743 1,113 922.70 1,743 1,131 922.72 1,743 1,150 922.74 1,743 1,168 922.76 1,743 1,187 922.78 1,743 1,205 922.80 1,743 1,223 922.82 1,743 1,241 922.84 1,743 1,259 922.86 1,743 1,277 922.88 1,743 1,295 922.90 1,743 1,312 922.92 1,743 1,329 922.94 1,743 1,346 922.96 1,743 1,363 922.98 1,743 1,380 923.00 1,743 1,396 923.02 1,743 1,412 923.04 1,743 1,427 923.06 1,743 1,443 923.08 1,743 1,457 923.10 1,743 1,472 923.12 1,743 1,485 923.14 1,743 1,498 923.16 1,743 1,510 923.18 1,743 1,520 923.20 1,743 1,529 923.22 1,743 1,539 Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 47HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 923.24 1,743 1,549 923.26 1,743 1,559 923.28 1,743 1,570 923.30 1,743 1,581 923.32 1,743 1,594 923.34 1,743 1,606 923.36 1,743 1,618 923.38 1,743 1,630 923.40 1,743 1,642 923.42 1,743 1,654 923.44 1,743 1,667 923.46 1,743 1,679 923.48 1,743 1,691 923.50 1,743 1,703 923.52 1,743 1,715 923.54 1,743 1,727 923.56 1,743 1,733 923.58 1,743 1,734 923.60 1,743 1,734 923.62 1,743 1,734 923.64 1,743 1,735 923.66 1,743 1,735 923.68 1,743 1,735 923.70 1,743 1,736 923.72 1,743 1,736 923.74 1,743 1,737 923.76 1,743 1,737 923.78 1,743 1,737 923.80 1,743 1,738 923.82 1,743 1,738 923.84 1,743 1,739 923.86 1,743 1,739 923.88 1,743 1,739 923.90 1,743 1,740 923.92 1,743 1,740 923.94 1,743 1,740 923.96 1,743 1,741 923.98 1,743 1,741 924.00 1,743 1,742 924.02 1,743 1,742 924.04 1,743 1,742 924.06 1,743 1,743 924.08 1,743 1,743 924.10 1,743 1,743 924.12 1,743 1,744 924.14 1,743 1,744 924.16 1,743 1,745 924.18 1,743 1,745 924.20 1,743 1,745 924.22 1,743 1,746 924.24 1,743 1,746 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 924.26 1,743 1,746 924.28 1,743 1,747 924.30 1,743 1,747 924.32 1,743 1,748 924.34 1,743 1,748 924.36 1,743 1,748 924.38 1,743 1,749 924.40 1,743 1,749 924.42 1,743 1,750 924.44 1,743 1,750 924.46 1,743 1,750 924.48 1,743 1,751 924.50 1,743 1,751 924.52 1,743 1,751 924.54 1,743 1,752 924.56 1,743 1,752 924.58 1,743 1,753 924.60 1,743 1,753 924.62 1,743 1,753 924.64 1,743 1,754 924.66 1,743 1,754 924.68 1,743 1,754 924.70 1,743 1,755 924.72 1,743 1,755 924.74 1,743 1,756 924.76 1,743 1,756 924.78 1,743 1,756 924.80 1,743 1,757 924.82 1,743 1,757 924.84 1,743 1,758 924.86 1,743 1,758 924.88 1,743 1,758 924.90 1,743 1,759 924.92 1,743 1,759 924.94 1,743 1,759 924.96 1,743 1,760 924.98 1,743 1,760 925.00 1,743 1,761 925.02 1,743 1,761 925.04 1,743 1,761 925.06 1,743 1,762 925.08 1,743 1,762 925.10 1,743 1,762 925.12 1,743 1,763 925.14 1,743 1,763 925.16 1,743 1,764 925.18 1,743 1,764 925.20 1,743 1,764 925.22 1,743 1,765 925.24 1,743 1,765 925.26 1,743 1,765 Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 48HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 925.28 1,743 1,766 925.30 1,743 1,766 925.32 1,743 1,767 925.34 1,743 1,767 925.36 1,743 1,767 925.38 1,743 1,768 925.40 1,743 1,768 925.42 1,743 1,769 925.44 1,743 1,769 925.46 1,743 1,769 925.48 1,743 1,770 925.50 1,743 1,770 925.52 1,743 1,770 925.54 1,743 1,771 925.56 1,743 1,771 925.58 1,743 1,772 925.60 1,743 1,772 925.62 1,743 1,772 925.64 1,743 1,773 925.66 1,743 1,773 925.68 1,743 1,773 925.70 1,743 1,774 925.72 1,743 1,774 925.74 1,743 1,775 925.76 1,743 1,775 925.78 1,743 1,775 925.80 1,743 1,776 925.82 1,743 1,776 925.84 1,743 1,777 925.86 1,743 1,777 925.88 1,743 1,777 925.90 1,743 1,778 925.92 1,743 1,778 925.94 1,743 1,778 925.96 1,743 1,779 925.98 1,743 1,779 926.00 1,743 1,780 926.02 1,743 1,780 926.04 1,743 1,780 926.06 1,743 1,781 926.08 1,743 1,781 926.10 1,743 1,781 926.12 1,743 1,782 926.14 1,743 1,782 926.16 1,743 1,783 926.18 1,743 1,783 926.20 1,743 1,783 926.22 1,743 1,784 926.24 1,743 1,784 926.26 1,743 1,784 926.28 1,743 1,785 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 926.30 1,743 1,785 926.32 1,743 1,786 926.34 1,743 1,786 926.36 1,743 1,786 926.38 1,743 1,787 926.40 1,743 1,787 926.42 1,743 1,788 926.44 1,743 1,788 926.46 1,743 1,788 926.48 1,743 1,789 926.50 1,743 1,789 926.52 1,743 1,789 926.54 1,743 1,790 926.56 1,743 1,790 926.58 1,743 1,791 926.60 1,743 1,791 926.62 1,743 1,791 926.64 1,743 1,792 926.66 1,743 1,792 926.68 1,743 1,792 926.70 1,743 1,793 926.72 1,743 1,793 926.74 1,743 1,794 926.76 1,743 1,794 926.78 1,743 1,794 926.80 1,743 1,795 926.82 1,743 1,795 926.84 1,743 1,796 926.86 1,743 1,796 926.88 1,743 1,796 926.90 1,743 1,797 926.92 1,743 1,797 926.94 1,743 1,797 926.96 1,743 1,798 926.98 1,743 1,798 927.00 1,743 1,799 927.02 1,743 1,799 927.04 1,743 1,799 927.06 1,743 1,800 927.08 1,743 1,800 927.10 1,743 1,800 927.12 1,743 1,801 927.14 1,743 1,801 927.16 1,743 1,802 927.18 1,743 1,802 927.20 1,743 1,802 927.22 1,743 1,803 927.24 1,743 1,803 927.26 1,743 1,803 927.28 1,743 1,804 927.30 1,743 1,804 Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 49HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: CBMH 101 AND CHAMBER (continued) Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 927.32 1,743 1,805 927.34 1,743 1,805 927.36 1,743 1,805 927.38 1,743 1,806 927.40 1,743 1,806 927.42 1,743 1,807 927.44 1,743 1,807 927.46 1,743 1,807 927.48 1,743 1,808 927.50 1,743 1,808 927.52 1,743 1,808 927.54 1,743 1,809 927.56 1,743 1,809 927.58 1,743 1,810 927.60 1,743 1,810 927.62 1,743 1,810 927.64 1,743 1,811 927.66 1,743 1,811 927.68 1,743 1,811 927.70 1,743 1,812 927.72 1,743 1,812 927.74 1,743 1,813 927.76 1,743 1,813 927.78 1,743 1,813 927.80 1,743 1,814 927.82 1,743 1,814 927.84 1,743 1,815 927.86 1,743 1,815 927.88 1,743 1,815 927.90 1,743 1,816 927.92 1,743 1,816 927.94 1,743 1,816 927.96 1,743 1,817 927.98 1,743 1,817 928.00 1,743 1,818 928.02 1,743 1,818 928.04 1,743 1,818 928.06 1,743 1,819 928.08 1,743 1,819 928.10 1,743 1,819 928.12 1,743 1,820 928.14 1,743 1,820 928.16 1,743 1,821 928.18 1,743 1,821 928.20 1,743 1,821 928.22 1,743 1,822 928.24 1,743 1,822 928.26 1,743 1,822 928.28 1,743 1,823 928.30 1,743 1,823 928.32 1,743 1,824 Elevation (feet) Surface (sq-ft) Storage (cubic-feet) 928.34 1,743 1,824 928.36 1,743 1,824 928.38 1,743 1,825 928.40 1,743 1,825 928.42 1,743 1,826 928.44 1,743 1,826 928.46 1,743 1,826 928.48 1,743 1,827 928.50 1,743 1,827 Proposed Conditions RPBCWD-100 Year 100y 24hr Rainfall=7.41"23520 07-21-2020 Printed 7/22/2020Prepared by James R. Hill, Inc Page 50HydroCAD® 10.00-25 s/n 00744 © 2019 HydroCAD Software Solutions LLC Summary for Link 7L: Proposed Total Inflow Area = 2.022 ac, 20.80% Impervious, Inflow Depth = 5.61" for 100y 24hr event Inflow = 11.85 cfs @ 12.22 hrs, Volume= 0.944 af Primary = 11.85 cfs @ 12.22 hrs, Volume= 0.944 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-280.00 hrs, dt= 0.01 hrs Link 7L: Proposed Total Inflow Primary Hydrograph Time (hours) 2802702602502402302202102001901801701601501401301201101009080706050403020100Flow (cfs)13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=2.022 ac 11.85 cfs 11.85 cfs P8 Urban Catchment Model, Version 3.5 Run Date 07/23/20 Case 23520 HSG D 7-21-2020.p8c FirstDate 06/01/09 Precip(in) 297.3 Title Berospid LastDate 12/31/18 Rain(in) 267.67 PrecFile MSP4918.pcp Events 735 Snow(in) 29.62 PartFile nurp50.p8p TotalHrs 83895 TotalYrs 9.57 Case Title Berospid Case Data File 23520 HSG D 7-21-2020.p8c Path F:\_Civil 3D Projects\23520\CLIENT\p8\ Case Notes: Storm Data File MSP4918.pcp Particle File nurp50.p8p Air Temp File File MSP4918.tem Time Steps Per Hour 5 Minimum Inter-Event Time (hrs) 10 Maximum Continuity Error % 2 Rainfall Breakpoint (inches) 0.8 Precipitation Scale Factor 1 Air Temp Offset (deg-F)0 Loops Thru Storm File 1 Simulation Dates Start 6/1/2008 Keep 6/1/2009 Stop 12/31/2018 Max Snowfall Temperature (deg-f) 32.0 SnowMelt Temperature (deg-f) 32.0 Snowmelt Coef (in/degF-Day) 0.06 Soil Freeze Temp (deg-F) 32.0 Snowmelt Abstraction Factor 1.00 Evapo-Trans. Calibration Factor 1.00 Growing Season Start Month 5 Growing Season End Month 10 5-Day Antecedent Rainfall + Runoff (inches) CN Antecedent Moisture Condition AMC-II AMC-III Growing Season 1.40 2.10 NonGrowing Season 0.50 1.10 Watershed Data Watershed Name 2S 6S 2S UpstreamDriveway Swale Area Runoff to Device Underground InfiltrationSediment Swale Upstream Swale Driveway Swale Infiltration to Device Watershed Area 0.81 0.75 0.42 0.036 SCS Curve Number (Pervious) 82 74 82 82 Scale Factor for Pervious Runoff Load 1 1 1 1 Indirectly Connected Imperv Fraction 0 0 0 0 UnSwept Impervious Fraction 0.42 0.066 0 0.3 UnSwept Depression Storage (inches) 0.02 0.02 0.02 0.02 UnSwept Imperv. Runoff Coefficient 1 1 1 1 UnSwept Scale Factor for Particle Loads 1 1 1 1 Swept Impervious Fraction 0 0 0 0 Swept Depression Storage (inches) 0.02 0.02 0.02 0.02 Swept Imperv. Runoff Coefficient 1 1 1 1 Swept Scale Factor for Particle Loads 1 1 1 1 Sweeping Frequency 0 0.5 0.5 0.5 Sweeping Efficiency 1 1 1 1 Sweeping Start Date (MMDD) 101 101 101 101 Sweeping Stop Date (MMDD) 1231 1231 1231 1231 Device Data Device Name Sediment SwaleFrontier Trail Sediment SwaleUnderground InfiltrationDitch Check 1 Ditch Check 2 Upstream Swale Device Type SWALE SWALE POND POND POND SWALE Infiltration Outlet Normal Outlet Ditch Check 1Frontier Trail Sediment SwaleDitch Check 2 Ditch Check 3 Spillway Outlet Ditch Check 1Frontier Trail Sediment SwaleDitch Check 2 Ditch Check 3 Particle Removal Scale Factor 1 1 1 1 1 1 Bottom Elevation (ft)919 918 921.2 922 920 942 Bottom Area (acres)0.042 0.0006 0.0006 Permanent Pool Area (acres)0.042 0.0006 0.0006 Permanent Pool Volume (ac-ft)0.01 0.0003 0.0003 Perm Pool Infilt Rate (in/hr)0.06 0.06 0.06 Flood Pool Area (acres)0.042 0.0006 0.0006 Flood Pool Volume (ac-ft)0.05 0.0003 0.0003 Flood Pool Infilt Rate (in/hr) 0.06 0.06 0.06 0.06 0.06 0.06 Infilt Basin Void Fraction (%) Detention Pond Outlet Parameters Outlet Type ORIFICE NONE NONE Outlet Orifice Diameter (in)6 Orifice Discharge Coef 0.6 Outlet Weir Length (ft) Weir Discharge Coef Perforated Riser Height (ft) Number of Holes in Riser Holes Diameter Flood Pool Drain Time (hrs) Swale Parameters Length of Flow Path (ft) 240 170 125 Slope of Flow Path %5 2.8 12 Bottom Width (ft)40 16 6 Side Slope (ft-v/ft-h)10 5 5 Maximum Depth of Flow (ft) 1 1 1 Mannings n Constant 0.4 0.4 0.4 Hydraulic Model 0 0 0 Pipe, Splitter, Aquifer Parameter Hydraulic Res. Time (hrs) Particle Data Particle File nurp50.p8p Particle Class P0% P10% P30% P50% P80% Filtration Efficiency (%) 90 100 100 100 100 Settling Velocity (ft/hr) 0 0.03 0.3 1.5 15 First Order Decay Rate (1/day) 0 0 0 0 0 2nd Order Decay (1/day-ppm) 0 0 0 0 0 Impervious Runoff Conc (ppm) 1 0 0 0 0 Pervious Runoff Conc (ppm) 1 100 100 100 200 Pervious Conc Exponent 0 1 1 1 1 Accum. Rate (lbs-ac-day) 0 1.75 1.75 1.75 3.5 Particle Removal Rate (1/day) 0 0.25 0.25 0.25 0.25 Washoff Coefficient 0 20 20 20 20 Washoff Exponent 0 2 2 2 2 Sweeper Efficiency 0 0 0 5 15 Water Quality Component Data Component Name TSS TP TKN CU PB ZN HC Water Quality Criteria (ppm) Level 1 5 0.025 2 2 0.02 5 0.1 Level 2 10 0.05 1 0.0048 0.014 0.0362 0.5 Level 3 20 0.1 0.5 0.02 0.15 0.38 1 Content Scale Factor 1 1 1 1 1 1 1 Particle Composition (mg/kg) P0%0 99000 600000 13600 2000 64000 250000 P10% 1000000 3850 15000 340 180 1600 22500 P30% 1000000 3850 15000 340 180 1600 22500 P50% 1000000 3850 15000 340 180 1600 22500 P80% 1000000 0 0 340 180 0 22500 December 6, 2019 HGTS Project Number: 19-1053 Mr. Luis Berrospid 7406 Frontier Trail Chanhassen, MN 55317 Re: Geotechnical Exploration Report, Proposed Residential Development, Chanhassen, Minnesota Dear Mr. Berrospid: We have completed the geotechnical exploration report for the project at 7406 Frontier Trail in Chanhassen, Minnesota. We understand the existing lot will be split and a new home constructed on each of the newly split parcels. One (1) soil boring was completed on the project site that encountered about 4 feet of topsoil that was underlain by native glacial till soils consisting of sandy lean clay that extended to the termination depth of the soil boring. The glacial till had a soft consistency from a depth of about 7 to 12 below the ground surface. Groundwater was not encountered in the soil boring while drilling and sampling or after removing of the augers from the borehole. We do not anticipate that groundwater will be encountered during construction. The vegetation and topsoil are not suitable for foundation or utility support and will need to be removed from below these areas and replaced with suitable compacted fill. In our opinion, the underlying denser and stiffer glacial soils are generally suitable for the construction of the proposed residential development. However, as noted above, some softer clays were encountered in the borings which will likely need to be removed and replaced with suitable compacted engineered fill or dried and re-compacted. Specific details regarding our procedures, results and recommendations follow in the attached geotechnical exploration report. Thank you for the opportunity to assist you on this project. If you have any questions or need additional information, please contact Paul Gionfriddo at 612-271-8185. Sincerely, HAUGO GEOTECHNICAL SERVICES, LLC Paul Gionfriddo, P.E. Senior Engineer GEOTECHNICAL EXPLORATION REPORT PROJECT: Residential Development 7406 Frontier Tail Chanhassen, Minnesota PREPARED FOR: Mr. Luis Berrospid 7406 Frontier Trail Chanhassen, MN 55317 PREPARED BY: Haugo GeoTechnical Services 2825 Cedar Avenue South Minneapolis, Minnesota 55407 Haugo GeoTechnical Services Project: 19-1053 December 6, 2019 I hereby certify that this plan, specification, or report was prepared by me or under my direct supervision and that I am a duly Registered Professional Engineer under the laws of the State of Minnesota. Paul Gionfriddo, P.E. Senior Engineer License Number 23093 Expires June 2020 Table of Contents 1.0 INTRODUCTION 1 1.1 Project Description 1 1.2 Purpose 1 1.3 Site Description 1 1.4 Scope of Services 1 1.5 Documents Provided 2 1.6 Locations and Elevations 2 2.0 FIELD PROCEDURES 2 3.0 RESULTS 3 3.1 Soil Conditions 3 3.2 Groundwater 3 3.3 Laboratory Tests 3 3.4 OSHA Soil Classification 4 4.1 Proposed Construction 4 4.2 Discussion 5 4.4 Dewatering 7 4.5 Interior Slabs 7 4.6 Below Grade Walls 7 4.7 Exterior Slabs 8 4.9 Utilities 9 4.10 Rain Gardens/Infiltration Rates 9 5.0 CONSTRUCTION CONSIDERATIONS 10 5.1 Excavation 10 5.2 Observations 10 5.3 Backfill and Fills 10 5.4 Testing 10 5.5 Winter Construction 11 6.0 PROCEDURES 11 6.1 Soil Classification 11 6.2 Groundwater Observations 11 7.0 GENERAL 11 7.1 Subsurface Variations 11 7.2 Review of Design 12 7.3 Groundwater Fluctuations 12 7.4 Use of Report 12 7.5 Level of Care 12 Soil Boring Location Sketch, Figure 1 Soil Boring Logs, SB-1 Descriptive Terminology 1 1.0 INTRODUCTION 1.1 Project Description We understand that Mr. Luis Berrospid is proposing to split the lot at 7406 Frontier Trail in Chanhassen, Minnesota to accommodate two (2) lots for single family homes. The project will also include improving the existing driveway and installing the associated underground utilities and a rain garden. 1.2 Purpose Haugo GeoTechnical Services (HGTS) was retained to perform a geotechnical exploration to evaluate the suitability of site soil and groundwater conditions to support the anticipated residential structures and underground utilities and provide recommendation for foundation design and construction. 1.3 Site Description The project site is located at 7406 Frontier Trail in Chanhassen, Minnesota. The site is situated west of Frontier Trail, and south of Highland Drive. At the time of exploration, the west/southwest portion of the site contained an existing house, garage and a driveway. Most of the project site was wooded with some open areas especially near the home. The site generally sloped downward to the southeast with the ground surface elevations ranging from about 972 on the west end of the property to about 920 on the east/southeast portion of the lot. The ground surface elevation at the boring location was about 922 feet above mean sea level (MSL). 1.4 Scope of Services Our services were performed in accordance with the HGTS proposal 19-1053 dated October 29, 2019. Our scope of services was performed under the terms of our General Conditions and limited to the following tasks: • Completing one (1) standard penetration test soil boring and extending the boring to a nominal depth of 14 ½ feet. • Sealing the borehole in accordance with MDH requirements. • Visually/manually classifying the samples recovered from the soil borings. • Performing one (1) double ring infiltration test. • Performing laboratory tests on selected samples. • Preparing soil boring logs describing the materials encountered and the results of groundwater level measurements. • Preparing an engineering report describing soil and groundwater conditions and recommendations for foundation and pavement design and construction. 2 1.5 Documents Provided We were provided with a Grading Plan prepared by James R. Hill, Inc. dated March 5, 2019. The Plan showed the existing site conditions and the location of the proposed houses, associated street/driveway and pond. We were not provided with any specific architectural or structural engineering documents or drawings for the proposed homes. 1.6 Locations and Elevations The soil boring location and double ring infiltrometer test location were selected and staked in the field by James R. Hill, Inc. The approximate locations of the soil boring and double ring infiltrometer test location are shown on Figure 1, “Soil Boring Location Sketch,” in the Appendix. The sketch was prepared by HGTS using an aerial image from Google Earth as a base. Ground surface elevations at the boring locations were obtained by HGTS using GPS measuring equipment. Elevations were based on the MN County Coordinates System (Carver County) mean sea level. GPS coordinates at the boring location are also provided in Figure 1 in the Appendix. 2.0 FIELD PROCEDURES One (1) standard penetration test boring was advanced on November 14, 2019 by HGTS with a rotary drilling rig, using continuous flight augers to advance the boreholes. Representative samples were obtained from the borings, using the split-barrel sampling procedures in general accordance with ASTM Specification D-1586. In the split-barrel sampling procedure, a 2-inch O.D. split-barrel spoon is driven into the ground with a 140-pound hammer falling 30 inches. The number of blows required to drive the sampling spoon the last 12 inches of an 18-inch penetration is recorded as the standard penetration resistance value, or "N" value. The results of the standard penetration tests are indicated on the boring log. The samples were sealed in containers and provided to the HGTS office for testing and soil classification. A field log of the boring was prepared by the HGTS drill crew. The logs contained visual classifications of the soil materials encountered during drilling, as well as the driller's interpretation of the subsurface conditions between samples and water observation notes. The final boring logs included with this report represent an interpretation of the field logs and include modifications based on visual/manual method observation of the samples. The soil boring logs, general terminology for soil description and identification and classification of soils for engineering purposes are also included in the appendix. The soil boring logs identify and describe the materials encountered, the relative density or consistency based on the Standard Penetration resistance (N-value, “blows per foot”) and groundwater observations. 3 The strata changes were inferred from the changes in the samples and auger cuttings. The depths shown as changes between strata are only approximate. The changes are likely transitions, variations can occur beyond the location of the boring. 3.0 RESULTS 3.1 Soil Conditions The soil boring encountered about 4 feet of sandy lean clay topsoil at the surface that was black in color. Beneath the topsoil, the soil boring encountered native glacial till soils that extended to the termination depths of the borings. The glacial till consisted of sandy lean clay that was brown and grey in color. Penetration resistance values (N-Values) within the clayey glacial till (sandy lean clay) ranged from 3 to 7 bpf, indicating the glacial till soils had a soft to medium consistency. 3.2 Groundwater Groundwater was not encountered in the soil borings while drilling and sampling or after removing of the augers from the boreholes. Groundwater appears to be below the depths explored by our borings. Water levels were measured on the dates as noted on the boring logs and the period of water level observations was relatively short. Given the cohesive nature of portions of the soils encountered, it is possible that insufficient time was available for groundwater to seep into the borings and rise to its hydrostatic level. Groundwater monitoring wells or piezometers in conjunction with deeper soil boring(s) would be required to more accurately determine water levels. Seasonal and annual fluctuations in the groundwater levels should be expected. 3.3 Laboratory Tests Laboratory moisture content tests were performed on selected samples recovered from the soil borings. Table 1 below summarizes the results of the laboratory tests. Results of the laboratory moisture content tests are shown on the boring logs adjacent to the sample tested. Table 1. Summary of Laboratory Tests Boring Number Sample Number Depth (feet) Moisture Content (%)* SB-1 SS-4 7 ½ 33 SB-1 SS-6 12 ½ 22 *Moisture Content tests were rounded to the nearest ½ percent. 4 3.4 OSHA Soil Classification The soils encountered in the soil boring at the anticipated excavation depths consisted of sandy lean clay generally corresponding to the ASTM classification of CL. The sandy lean clay soil will generally be Type B soils under Department of Labor Occupational Safety and Health Administration (OSHA) guidelines. Temporary excavations should be constructed at a minimum of 1 foot horizontal to every 1 foot vertical within excavations. Slopes constructed in this manner may still exhibit surface sloughing. If site constraints do not allow the construction of slopes with these dimensions, then temporary shoring may be required. 4.0 DISCUSSION AND RECOMMENDATIONS 4.1 Proposed Construction A single-family home exists of the approximate west half of the property which we understand will remain. We understand the approximate east half of the property will be split to accommodate to 2 single family homes, preparing the house pads for those homes, improving the existing driveway and constructing the associated rain garden and underground utilities. Specific architectural or structural engineering documents or drawings for the proposed homes were not available at the time of this evaluation. Based on the grading plan provided we anticipate the new homes will have a rear walk-out style foundation. We anticipate that new homes will include one or two stories above grade with cast-in-place concrete or masonry block foundation walls supported on concrete spread footings. We anticipate above grade construction to consist of wood framing, a pitched roof and asphalt shingles. Based on the assumed construction we estimate wall loadings will range from about 1 to 2 kips (1,000 to 2,000 pounds) per lineal foot and column loads, if any, will be less than 50 kips (50,000 pounds). Based on proposed floor grades provided on the grading plan we anticipate the home on Lot 1 will have a basement/lowest floor grade at or near elevation 926.5 feet. With the ground surface at or near elevation 920 we anticipate that Fills on the order of 6 ½ feet will be required to attain design grades. The home on Lot 2 will have a lowest floor grade at or near elevation 934. With the ground surface on Lot 2 within the proposed house pad ranging from about elevation 928 to 940 we anticipate Cuts and Fills on the order of 6 feet to attain site grades If the proposed loads exceed these values, the proposed grades differ by more than 2 feet from the assumed values or if the design or location of the proposed development changes, we should be informed. Additional analyses and revised recommendations may be necessary. 5 4.2 Discussion The vegetation and topsoil are not suitable for foundation, driveway or utility support and will need to be removed from below these areas and the oversize areas and replaced with suitable compacted fill. Some softer clayey soils were encountered in soil boring SB-1 from about 7 to 12 feet below the ground surface. Soft clays if encountered will need to be removed and replaced with suitable compacted engineered fill or removed, moisture conditioned (dried) and recompacted. The laboratory moisture contents of the clayey soils generally ranged from about 22 to 33 percent indicating they were likely above their estimated optimum soil moisture content based on the standard Proctor test. Clayey soil that will be reused ad fill or backfill will likely require significant moisture conditioning (drying) to meet the recommended compaction levels. Summer months are typically more favorable for drying wet clays. In our opinion, the underlying denser and stiffer glacial soils are generally suitable for foundation support. Groundwater was not encountered in the soil borings while drilling and sampling or after removing of the augers from the boreholes. We do not anticipate that groundwater will be encountered during construction. The following sections provide recommendations for site development. 4.3 Grading Recommendations Excavation We recommend that all vegetation, topsoil and soft/loose soils be removed from below the proposed building and oversize areas. Soils disturbed during construction activities should be surface compacted to increase their density and uniformity or removed and replaced with suitable compacted fill. Table 2 below summarizes the anticipated excavation depths at the soil boring locations. A limited number of borings were completed for this project and because of that, excavation depths will likely vary and could be deeper. Table 2. Anticipated Excavation Depths Boring Number Surface Elevation (feet) Anticipated Excavation Depth (feet)* Anticipated Excavation Elevation (feet)* SB-1 921.9 4 - 12 918 - 910 *Excavation depths and elevations were rounded to the nearest ½ foot. Oversizing In areas where the excavations extend below the proposed footing elevations, the excavation requires oversizing. We recommend the perimeter of the excavation be extended a foot outside the proposed footprint for every foot below footing grade (1H:1V oversizing). The purpose of the oversizing is to provide lateral support of the foundation. Fill Material Fill required to attain site grades may consist of any debris-free, non-organic mineral soil. The exception being within 3 feet of the groundwater table, if encountered, where 6 granular soil with less than 5 percent passing the number 200 sieve and at least 50 percent retained on the number 40 sieve should be used. The native glacial till soils generally appear suitable for reuse as structural fill. As discussed above the laboratory moisture contents of the clayey soils ranged from about 22 to 33 percent indicating they were likely above their estimated optimum soil moisture content based on the standard Proctor test. Clayey soil that will be reused ad fill or backfill will likely require significant moisture conditioning (drying) to meet the recommended compaction levels. Summer months are typically more favorable for drying wet clays. The topsoil and other soils that are black in color are not suitable for re-use as fill or backfill. It may be possible to re-use these materials in “green areas” on the site such as landscaping berms. Backfilling Prior to placing additional fill and/or the footings, we recommend any loose or disturbed soils be surface compacted to increase their density and uniformity with a large self- propelled vibratory compactor. We recommend that backfill placed to attain site grades be compacted to a minimum of 95 percent of its standard Proctor density (ASTM D 698), except the upper 3 feet of pavement areas, where the compaction level should be increased to a minimum of 100 percent. Granular fill classified as SP or SP-SM, if used, should be placed within 65 percent to 105 percent of its optimum moisture content as determined by the standard Proctor. Remaining fill soils should be placed within 3 percentage points above and 1 percentage point below its optimum moisture content as determined by the standard Proctor. All fill should be placed in thin lifts and be compacted with a large self-propelled vibratory compactor operating in vibratory mode. In areas where fill depths will exceed 10 feet, if any, we recommend that compaction levels be increased to a minimum of 98 percent of standard Proctor density. Even with the increased compaction levels a construction delay may be required to allow for post construction settlement of the fill mass. Fill and backfill placed on slopes, if any, must be “benched” into the underlying suitable soil to reduce the potential for slip planes to develop between the fill and underlying soil. We recommend “benching” or excavating into the slope at 5 feet vertical intervals to key the fill into the slope. We recommend each bench be a minimum of 10 feet wide. Foundations We recommend the perimeter footings bear a minimum of 42 inches below the exterior grade for frost protection. Interior footings may be placed immediately below the slab provided construction does not occur during below freezing weather conditions. Foundation elements in unheated areas should bear at least 5 feet below exterior grade for frost protection. We anticipate the foundations and floor slabs will bear on compacted engineered fill or glacial soils. With the building pads prepared as recommended it is our opinion the footings can be designed for a net allowable bearing pressure up to 2,000 pounds per square foot (psf). We anticipate total and differential settlement of the foundations will be less than 1 inch and ½ inch, respectively across an approximate 30-foot span. 7 4.4 Dewatering Groundwater was not encountered in the soil borings while drilling or sampling or after removing of the augers from the boreholes. We do not anticipate that groundwater will be encountered during construction and do not anticipate that dewatering will be required. Perched water, if encountered, can likely be controlled with sumps and pumps. If groundwater is encountered in “clean” sand soils (poorly graded sand or poorly graded sand with silt) more aggressive dewatering techniques could be required. Where dewatering is required, we recommend the groundwater level be temporarily lowered to a minimum of 2 feet below the lowest anticipated excavation elevation to allow for construction. In sand soils we do not recommend attempting to dewater from within the excavation. Upward seepage will loosen and disturb the excavation, resulting in a “quick condition". Rather, we recommend groundwater be drawn down below the anticipated excavation bottom. If dewatering is required, we recommend that a dewatering contractor be consulted to review the soil boring logs, develop a dewatering plan and evaluate the impact of dewatering on adjacent structures. 4.5 Interior Slabs The anticipated floor subgrade will consist of compacted engineered fill or native clayey glacial till soils. It is our opinion a modulus of subgrade reaction, k, of 200 pounds per square inch of deflection (psi) be used to design the floor. If floor coverings or coatings less permeable than the concrete slab will be used, we recommend that a vapor retarder or vapor barrier be placed immediately beneath the slab. Some contractors prefer to bury the vapor barrier or vapor retarder beneath a layer of sand to reduce curling and shrinkage, but this practice often traps water between the slab and vapor retarder or barrier. Regardless of where the vapor retarder or vapor barrier is placed, we recommend consulting the floor covering manufacturer regarding the appropriate type, use and installation of the vapor retarder or vapor barrier to preserve the warranty. We recommend following all state and local building codes with regards to a radon mitigation plan beneath interior slabs. 4.6 Below Grade Walls Foundation walls or below grade (basement) walls will have lateral loads from the surrounding soil transmitted to them. We recommend general waterproofing of the below grade walls even with the use of free-draining backfill because of the potential cost impacts related to seepage after construction. Unless a drainage composite is placed against the backs of the exterior perimeter below-grade walls we recommend that backfill placed within 2 feet of those wall consist of sand having less than 50 percent of the particles by weight passing the #40 sieve and less than 5 percent of the particles by weight passing the #200 sieve. We recommend the balance of the backfill for the walls consist of sand however the sand may contain up to 20 percent of the particles by weight passing the #200 sieve. 8 We recommend installing drain tile behind the below grade walls, adjacent to the wall footing and below the slab elevation. Preferably the drain tile should consist of perforated pipe embedded in gravel. A geotextile filter fabric should encase the pipe and gravel. The drain tile should be routed to a storm sewer, sump pump or other suitable disposal site. Active earth pressures can be used to design the below grade walls if the walls are allowed to rotate slightly. If wall rotation cannot be tolerated, then below grade wall design should be based on at-rest earth pressures. We recommend the following soil parameters be used for below grade/retaining wall design, shown in Table 3. These design parameters are based on the assumptions that the walls are drained, there are no surcharge loads within a horizontal distance equal to the height of the wall and the backfill is level. Table 3. Soil Parameters Soil Type Estimated Unit Weight (pcf) Estimated Friction Angle (degrees) At-Rest Pressure (pcf) Active Soil Pressure (pcf) Passive Soil Pressure (pcf) Sand (SP & SP-SM) 125 32 55 35 400 Other Soils (CL, SC, SM) 135 28 70 50 375 Resistance to lateral earth pressures will be provided by passive resistance against the wall footings and by sliding resistance along the bottom of the wall footings. We recommend a sliding coefficient of 0.35. This value does not include a factor of safety. 4.7 Exterior Slabs The exterior slabs will likely be underlain by clayey soils which are considered moderately to highly frost susceptible. If these soils become saturated and freeze, frost heave may occur. This heave can be a nuisance in front of doors and at other critical grade areas. One way to help reduce the potential for heaving is to remove the frost-susceptible soils below the slabs down to bottom of footing grades and replace them with non-frost-susceptible backfill consisting of sand having less than 5 percent of the particles by weight passing the number 200 sieve. If this approach is used and the excavation bottoms terminate in non-free draining granular soil, we recommend a drain tile be installed along the bottom outer edges of the excavation to collect and remove any water that may accumulate within the sand. The bottom of the excavation should be graded away from the building. If the banks of the excavations to remove the frost-susceptible soils are not sloped, abrupt transitions between the frost-susceptible and non-frost-susceptible backfill will exist along which unfavorable amounts of differential heaving may occur. Such transitions could exist between exterior slabs and sidewalks, between exterior slabs and pavements and along the slabs themselves if the excavations are confined to only the building entrances. To address this issue we recommend sloping the excavations to remove frost-susceptible soils at a minimum 3:1 (horizontal:vertical) gradient. 9 Another alternative for reducing frost heave is to support the slabs on frost depth footings. A void space of at least 4 inches should be provided between the slab and the underlying soil to allow the soil to heave without affecting the slabs. 4.8 Site Grading and Drainage We recommend the site be graded to provide positive run-off away from the proposed buildings. We recommend landscaped areas be sloped a minimum of 6 inches within 10 feet of the building and slabs be sloped a minimum of 2 inches. In addition, we recommend downspouts with long splash blocks or extensions for each house. We recommend the lowest floor grades be constructed to maintain at least a 4-foot separation between the lowest floor slab and observed groundwater and at least a 2-foot separation between the lowest floor slab and 100-year flood levels of any adjacent surface water features such as wetlands, creeks, ponds or ditches. 4.9 Utilities We anticipate that the utilities will be supported on compacted engineered fill or native glacial deposits. In our opinion, these soils are generally suitable for pipe support. We recommend removing all topsoil, soft/loose or other unsuitable soils, if encountered, beneath utilities prior to placement. We recommend bedding material be thoroughly compacted around the pipes. We recommend trench backfill above the pipes be compacted to a minimum of 95 percent beneath slabs and pavements, the exception being within 3 feet of the proposed pavement subgrade, where 100 percent of standard Proctor density is required. In landscape areas, we recommend a minimum compaction of 90 percent. Groundwater was not encountered in the soil borings. We do anticipate that groundwater will be encountered during utility construction and do not anticipate that dewatering will be required. Perched water, if encountered, can likely be controlled with sumps and pumps. See Section 4.4 for additional details regarding dewatering. 4.10 Rain Gardens/Infiltration Rates On November 20, 2019 we attempted to complete the double ring infiltrometer test. We mobilized a “mini” backhoe to the site and excavated to an elevation of about 917 corresponding to the approximate elevation of the bottom of the rain garden. Soil conditions at that elevation consisted of “black” organic soil which are generally not well suited for rain gardens or infiltration. Because of that we extended the excavation to depth of about 10 feet below the ground surface corresponding to about elevation 910. Soil conditions at that elevation also consisted of black organic material and we excavated additional pits in an effort to identify or encounter non-organic soils. The additional test pits also encountered “black” organic soil conditions and as a result the double ring infiltrometer test was not performed. Soil boring SB-1 taken within a proposed house pad encountered sandy lean clay at an approximate elevation of 917. Soils classified as sandy lean clay generally meet the ASTM Classification CL. The “Minnesota Storm Water Manual”, provides a design infiltration rate 10 of 0.06 inches per hour for sandy lean clay soil. A summary of the estimated design infiltration rates for various soils is presented in Table 4. These values were obtained from the Minnesota Stormwater Manual. Table 4. Design Infiltration Rates In-situ soils Soil Description Design Infiltration Rate (in/hr) SP, SP-SM Poorly Graded Sand 0.8 SM Silty Sand 0.45 SC, SC-SM Clayey Sand 0.06 CL Sandy Lean Clay 0.06 5.0 CONSTRUCTION CONSIDERATIONS 5.1 Excavation The soils encountered in the soil boring at the anticipated excavation depths consisted of sandy lean clay generally corresponding to the ASTM classification of CL. The sandy lean clay soil will generally be Type B soils under Department of Labor Occupational Safety and Health Administration (OSHA) guidelines. Temporary excavations should be constructed at a minimum of 1 foot horizontal to every 1 foot vertical within excavations. Slopes constructed in this manner may still exhibit surface sloughing. If site constraints do not allow the construction of slopes with these dimensions, then temporary shoring may be required. 5.2 Observations A geotechnical engineer should observe the excavation subgrade to evaluate if the subgrade soils are similar to those encountered in the borings and adequate to support the proposed construction. 5.3 Backfill and Fills Site soils that will be excavated and reused as backfill and fill appear to be below and above their assumed optimum moisture content. We anticipate it will be necessary to moisture condition (dry or wet) these soils to achieve the recommended compaction. We recommend that fill and backfill be placed in lifts not exceeding 4 to 12 inches, depending on the size of the compactor and materials used. 5.4 Testing We recommend density tests of backfill and fills placed for the new house pads. Samples of the proposed materials should be submitted to our laboratory prior to placement for evaluation of their suitability and to determine their optimum moisture content and maximum dry density (Standard Proctor). 11 5.5 Winter Construction If site grading and construction is anticipated to proceed during cold weather, all snow and ice should be removed from cut and fill areas prior to additional grading and placement of fill. No fill should be placed on frozen soil and no frozen soil should be used as fill or backfill. Concrete delivered to the site should meet the temperature requirements of ASTM and/or ACI. Concrete should not be placed on frozen soil. Concrete should be protected from freezing until the necessary strength is obtained. Frost should not be permitted to penetrate below the footings. 6.0 PROCEDURES 6.1 Soil Classification The drill crew chief visually and manually classified the soils encountered in the borings in general accordance with ASTM D 2488, “Description and Identification of Soils (Visual- Manual Procedure).” Soil terminology notes are included in the Appendix. The samples were returned to our laboratory for review of the field classification by a soils engineer. Samples will be retained for a period of 30 days. 6.2 Groundwater Observations Immediately after taking the final samples in the bottom of the borings, the holes were checked for the presence of groundwater. Immediately after removing the augers from the borehole the holes were once again checked and the depth to water and cave-in depths were noted. 7.0 GENERAL 7.1 Subsurface Variations The analyses and recommendations presented in this report are based on data obtained from a limited number of soil borings. Variations can occur away from the borings, the nature of which may not become apparent until additional exploration work is completed or construction is conducted. A reevaluation of the recommendations in this report should be made after performing on-site observations during construction to note the characteristics of any variations. The variations may result in additional foundation costs and it is suggested that a contingency be provided for this purpose. It is recommended that we be retained to perform the observation and testing program during construction to evaluate whether the design is as expected, if any design changes have affected the validity of our recommendations, and if our recommendations have been correctly interpreted and implemented in the designs, specifications and construction methods. This will allow correlation of the soil conditions encountered during construction to the soil borings and will provide continuity of professional responsibility. 12 7.2 Review of Design This report is based on the design of the proposed development as related to us for preparation of this report. It is recommended that we be retained to review the geotechnical aspects of the design and specifications. With the review, we will evaluate whether any changes have affected the validity of the recommendations and whether our recommendations have been correctly interpreted and implemented in the design and specifications. 7.3 Groundwater Fluctuations We made water level measurements in the borings at the times and under the conditions stated on the boring logs. The data was interpreted in the text of this report. The period of observation was relatively short and fluctuations in the groundwater level may occur due to rainfall, flooding, irrigation, spring thaw, drainage and other seasonal and annual factors not evident at the time the observations were made. Design drawings and specifications and construction planning should recognize the possibility of fluctuations. 7.4 Use of Report This report is for the exclusive use of Mr. Luis Berrospid and his design team to use to design the proposed structure and prepare construction documents. In the absence of our written approval, we make no representation and assume no responsibility to other parties regarding this report. The data, analysis and recommendations may not be appropriate for other structures or purposes. We recommend that parties contemplating other structures or purposes contact us. 7.5 Level of Care Haugo GeoTechnical Services, LLC has used the degree of skill and care ordinarily exercised under similar circumstance by members of the profession currently practicing in this locality. No warranty expressed or implied is made. APPENDIX Haugo GeoTechnical Services, LLC 2825 Cedar Avenue S. Minneapolis, MN 55407 Figure #: 1 Drawn By: RD Date: 11/15/19 Scale: None Project #: 19-1053 Soil Boring Location Sketch 7406 Frontier Trail Chanhassen, Minnesota GPS Boring Locations Boring Number Elevation (US Survey Feet) Northing Coordinate Easting Coordinate SB-1 928.1 183614.041 561466.401 Referencing Minnesota County Coordinates Basis – Carver County (GEOID09 Conus model) Legend Approximate Soil Boring Location DRI = Double Ring Infiltration Test SB-1 DRI-1 Sandy Lean Clay, black, moist. (Topsoil) (CL) Sandy Lean Clay, brown and grey, trace rust staining, moist, soft to medium. (Glacial Till) Bottom of borehole at 16.0 feet. AU 1 SS 2 SS 3 SS 4 SS 5 SS 6 SS 7 1-3-5 (8) 1-3-3 (6) 1-2-1 (3) 1-2-1 (3) 2-3-4 (7) 1-3-4 (7) 33 22 NOTES GROUND ELEVATION 928.1 ft LOGGED BY NA DRILLING METHOD Hollow Stem Auger/Split Spoon DRILLING CONTRACTOR HGTS - 750 GROUND WATER LEVELS: CHECKED BY PG DATE STARTED 11/14/19 COMPLETED 11/14/19 AT TIME OF DRILLING --- Not Encountered AT END OF DRILLING --- Not Encountered AFTER DRILLING --- Not Encountered HOLE SIZE 3 1/4 inches FINES CONTENT (%) 20 40 60 80 20 40 60 80 PL LLMC DEPTH(ft)0.0 2.5 5.0 7.5 10.0 12.5 15.0 GRAPHICLOGMATERIAL DESCRIPTION SAMPLE TYPENUMBERRECOVERY %(RQD)BLOWCOUNTS(N VALUE) SPT N VALUE 20 40 60 80 MOISTURE CONT.(%)NOTESPAGE 1 OF 1 BORING NUMBER SB-1 CLIENT Luis Berrospid PROJECT NUMBER 19-1053 PROJECT NAME 7406 Frontier Trail PROJECT LOCATION Chanhassen, MN GEOTECH BH PLOTS - GINT STD US LAB.GDT - 12/6/19 09:41 - C:\USERS\PUBLIC\DOCUMENTS\BENTLEY\GINT\PROJECTS\19-1053 7406 FRONTIER TRAIL.GPJHaugo GeoTechnical Services 2825 Cedar Ave South MN 55105 Telephone: 612-729-2959 Fax: 763-445-2238