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Draft Grant Street Feasibility Study part oneCITY OF SHOREWOOD FEASIBILITY REPORT GRANT STREET DRAINAGE PROJECT JANUARY 2019 Prepared for: City of Shorewood 5755 Country Club Road Shorewood, MN 55331 WSB PROJECT NO. 12046 -000 Mum FEASIBILITY REPORT GRANT STREET DRAINAGE PROJECT For: CITY OF SHOREWOOD JANUARY 2019 Prepared By: wsb CERTIFICATION I hereby certify that this plan, specification, or report was prepared by me or under my direct supervision and that I am a duly licensed Professional Engineer under the laws of the State of Minnesota. William Alms, PE Reg. No. 54301 GRANT STREET DRAINAGE FEASIBILITY REPORT CERTIFICATION City of Shorewood, MN WSB Project No. 12046 -000 TABLE OF CONTENTS 1. INTRODUCTION AND BACKGROUND ............................................................. ..............................1 2. EXISTING CONDITIONS .................................................................................... ..............................2 3. PROPOSED IMPROVEMENTS .......................................................................... ..............................3 3.1. Option 1: Pre - Watermain Project Conveyance .............................................. ............................... 3 3.2. Option 2: North Dry Pond and Lowered Park Street ....................................... ..............................4 3.3. Option 3: New Outlet Pipe with North Dry Pond ............................................ ............................... 5 3.4. Option 4: New Outlet Pipe with South Dry Pond ............................................. ..............................6 3.5. Option 5: New Outlet Pipe to College Lake .................................................... ..............................7 4. FINANCING ......................................................................................................... ..............................8 4.1. Cost Estimates ............................................................................................... ............................... 8 4.2. Funding ........................................................................................................... ..............................8 5. PROJECT SCHEDULE ...................................................................................... ............................... 9 5.1. Permitting Considerations ............................................................................... ..............................9 5.2. Schedule ......................................................................................................... ..............................9 6. RECOMMENDATION ........................................................................................ .............................11 LIST OF TABLES Table 1: Summary of Impacts Table 2: Existing Conditions Table 3: Impacts of Pre - Watermain Conveyance Table 4: Impacts of North Dry Pond and Lowered Park Street Table 5: Impacts of New Outlet Pipe with North Dry Pond Table 6: Impacts of New Outlet Pipe with South Dry Pond Table 7: Impacts of New Outlet Pipe to College Lake Table 8: Cost Estimate Summary APPENDICES Appendix A — Figures Figure 1: Drainage Areas Figure 2: Existing Cross Section Figure 3: 2018 Existing Conditions Survey Figure 4: Pre - Watermain Conveyance (Option 1) Figure 5: North Dry Pond and Lowered Park Street (Option 2) Figure 6: New Outlet Pipe with North Dry Pond (Option 3) Figure 7: New Outlet Pipe with South Dry Pond (Option 4) Figure 8: New Outlet Pipe to College Lake (Option 5) Appendix B — Problem Areas Report Appendix C — HydroCAD Reports Existing Pre - Watermain, As Built Proposed North Pond and Lowered Park Street Proposed North Pond Proposed South Pond Proposed Outlet Pipe to College Lake GRANT STREET DRAINAGE FEASIBILITY REPORT TABLE OF CONTENTS City of Shorewood, MN WSB Project No. 12046 -000 Appendix D — Or Option 1 Option 2 Option 3 Option 4 Option 5 TABLE OF CONTENTS inions of Probable Cost Pre - Watermain Conveyance North Dry Pond and Lowered Park Street New Outlet Pipe with North Dry Pond New Outlet Pipe with South Dry Pond New Outlet Pipe to College Lake GRANT STREET DRAINAGE FEASIBILITY REPORT TABLE OF CONTENTS City of Shorewood, MN WSB Project No. 12046 -000 EXECUTIVE SUMMARY Five options were investigated as solutions to the existing, historic flooding problem at the intersection of Grant Street and Park Street in Shorewood, MN. This area is a localized low point that outlets to the Minnesota Department of Transportation (MnDOT) right -of -way (ROW) along TH -7 and ultimately to College Lake in Excelsior. The proposed solutions had to consider flood protection for the structures at this low point, 5915 and 5925 Grant Street, discharge rates to the MnDOT ROW and across the municipal boundary into the City of Excelsior and impacts to downstream structures and College Lake. The proposed solutions range from an option with minimal impact that does not meet City standards to one that complies with City requirements for all structures adjacent to the Grant Street and Park Street intersection. Option 1 presents the minimal impact option — to return the drainage conveyance under Park Street to pre - watermain project conditions. This includes installing a 15 -inch reinforced concrete (RC) pipe with lower invert elevations as shown in Figure 4, Appendix A. The affected properties will still be subject to flooding in events less than the 100 -year event. Option 2 presents the maximum flood protection in terms of providing freeboard (separation between the high water level (HWL) and the lowest opening of a structure) and an emergency overflow (EOF) for all the properties along Grant Street. This includes a buyout of 5915 and 5925 Grant Street to turn the existing low area into a dry pond with an upsized outlet through the existing channel and lowering Park Street approximately 0.25 feet to provide an EOF for 5905 Grant Street as shown in Figure 6, Appendix A. Option 3 presents a compromise option that increases freeboard to 5915 Grant Street and provides a piped emergency overflow route from the low area. This includes a buyout of 5925 Grant Street to construct a dry pond in the low area as well as a new outlet pipe through the existing channel as shown in Figure 6, Appendix A. Option 4 presents a compromise option that increases freeboard to 5915 and 5925 Grant Street without requiring a buyout of 5925 Grant Street. It includes improved inlets and a new outlet pipe from the low area to a dry pond on the northern portion of 5965 Grant Street as shown in Figure 6, Appendix A. This would require easement acquisition rather than property buyout. Option 5 presents a compromise option that increases freeboard to 5915 and 5925 Grant Street, slightly increases discharge rates into the City of Excelsior, and maintains the existing HWL of College Lake. It includes improved inlets and a new outlet pipe from the low point to College Lake as shown in Figure 8, Appendix A. The City of Excelsior is planning road and utility reconstruction along Academy Avenue and Pleasant Street in 2019, which provides a unique partnership opportunity that makes this project much more financially feasible than if the City of Excelsior were not completing such a project. The impacts of Options 1 -5 are summarized in Table 1. Green highlighted cells indicate that City requirements are met. GRANT STREET DRAINAGE FEASIBILITY REPORT EXECUTIVE SUMMARY City of Shorewood, MN WSB Project No. 12046 -000 Cl) v W F- D 1 U w X W U E O L E O co r E co c a� E a� � L O � L 0 T U U v co E L co co U Q U co 0) L 0 0) �!E co a) Q a) E 0 O U �0 0 Q Z } a cn W U W X W H 0 CL LU } H J m U) LLI LL w (7 °o a o zZ� ZE v � N w z° LU U) �a O n L Z o m a a U) (7 U � O O O O O O O O O O O O O O O O O O O O +, y O O O O O O (� i CN .1 M Ln 0) Ln a0 (fl a0 0) Lo N N 'a L N O i 'y r U m co W V w 3 U N O N N N Am V 0 O Z O Z O Z � co c •v � m to 3 co N U D� N L L }r w y U i 0 �+ d v 0 E O O O z O z N "O O z O z �ao-i @ Q O o o L L O Z 00 0 O L r CO O O a W a) c� Q. 0 0 O O y J N O M ch z z a) a) O O C o Z Z LL co o N 2 cm 0 J t O O N O Z U) V�I O LC = = c CL CL CL d r c r_ aO X00 O O E •a O `� L L d d d i O w w tnz OD- �Z Z Z cm O N i M -4 LC! O O= O y O O O O 'a O Y 0-0 O -a O L O O Q O Q Q Q O Q U w OUOa00a a O E co c a� E a� � L O � L 0 T U U v co E L co co U Q U co 0) L 0 0) �!E co a) Q a) E 0 O U �0 0 Q Z } a cn W U W X W H 0 CL LU } H J m U) LLI LL w (7 °o a o zZ� ZE v � N w z° LU U) �a O n L Z o m a a U) (7 U � SECTION 1 INTRODUCTION AND BACKGROUND There is a localized low point in the northeast quadrant of the Grant Street and Park Street intersection in Shorewood, Minnesota at 5925 Grant Street. There are 7.4 acres draining to this low point; runoff is conveyed south under Park Street in a 12 -inch reinforced concrete (RC) pipe to a channel through a wooded area and eventually to a ditch in Minnesota Department of Transportation (MnDOT) right -of -way (ROW) along TH -7 (Figure 1, Appendix A). There have been historic reports of flooding at this property. The home at 5925 Grant Street and many surrounding it, were built in the 1950s. The City did not have the same stormwater management rules in place at that time as it does now. Currently, the structures in this area are not in compliance with City stormwater management standards for adequate outlet capacity, structure freeboard, and emergency overflows. The existing 12 -inch storm sewer under Park Street, which serves as the primary outlet for the area, only provides approximately 25% of the City's typical 10 -year design capacity for storm sewer. The low openings of 5925 Grant Street and 5915 Grant Street (the property to the north) are below the elevation at which water will overtop Park Street and flow into the channel as shown in Figure 2, Appendix A. Neither an adequate emergency overflow nor the required freeboard to structures are provided in this area. A letter in the property file indicates that a storm in August 1977 caused basement flooding at 5925 Grant Street and that there had been previous flooding issues there. In September and October of 2005, Shorewood experienced two strong storms that highlighted several drainage problem areas, including flooding at 5925 and 5915 Grant Street. See Appendix B for the relevant pages from a 2006 report on these drainage problem areas. In 2017, a trunk watermain extension project was completed in Shorewood. At the intersection of Grant Street and Park Street, the project included the replacement of several drainage structures and intersection siting improvements. See Figure 3, Appendix A for existing conditions survey data of the intersection. After the project was completed, the owner of 5925 Grant Street reported flooding through cracks in their foundation, specifically due to a rain event on August 16 -17, 2017. Although a rain gauge was not present at the exact project location, the Chanhassen weather station registered 3.3 inches of rain during this storm and observations from staff in the area indicated a rainfall intensity similar to that of one between a 10 -year and 25 -year event. Based on the historic accounts of flooding and this recent occurrence, the City decided to study the issue further. This feasibility report investigates the existing conditions that have contributed to the flooding and proposes solutions to alleviate it and protect structures. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 1 SECTION 2 2. EXISTING CONDITIONS A HydroCAD model was developed for the area around 5915 and 5925 Grant Street. An MSE 3, 24 -hour storm distribution was used with Atlas 14 rainfall depths for the 1 -, 2 -, 10 -, and 100 -year storm events. The model was checked against the August 16 rain event; flooding of the structures at 5915 and 5925 Grant Street occurs between the 10- and 25 -year events. See Figure 1, Appendix A for the drainage area delineations. Storm sewer under Park Street conveys water from the area around 5925 Grant Street to a channel that parallels Grant Street and ultimately outlets through a wooded area to a ditch in the MnDOT ROW along TH -7. The HydroCAD model includes the offsite area that drains to the TH -7 ditch. This ditch drains northeast, across the municipal boundary with Excelsior, MN, to a culvert under Academy Avenue and into College Lake. See Appendix C for the HydroCAD summary. Full modeling results are available upon request. Existing conditions high water levels (HWLs) are shown in Table 2. Table 2: Existing Conditions GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 2 Discharge Rate Across the Municipal High Water Level (ft) Boundary with Excelsior cfs 1 -year 2 -year 10 -year 100 -year 6916/6926 Grant TH -7 Ditch College Lake Street E2P EOffWP COL1 Existing 8.01 12.10 31.86 78.98 965.35 953.47 946.77 GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 2 SECTION 3 3. PROPOSED IMPROVEMENTS Each potential solution involves numerous modifications and improvements to the existing drainage system to address flooding on the east side of Grant Street, while managing discharge rates to the MnDOT ROW along TH -7 and across the municipal boundary with Excelsior. The proposed conditions were also modeled in HydroCAD, see Appendix C for results summaries. All existing conditions results in this section reflect the as- built, pre - watermain discharge and HWL conditions. Each potential solution was evaluated for the following desired outcomes: • Flood prevention and freeboard • Providing an emergency overflow • Maintaining discharge rates across the municipal boundary 3.1. Option 1: Pre - Watermain Project Conveyance In Option 1, the City would return the stormwater system conveyance to pre - watermain project capacity. This is the minimal impact option in terms of cost and flood reduction. The City would replace the existing 12 -inch RC pipe under Park Street with a 15 -in RC pipe with lower invert elevations and excavate and clear the downstream channel as shown in Figure 4, Appendix A. Table 3 shows the impacts of this option on the discharge rate across the municipal boundary with the City of Excelsior and the 100 -year HWLs at the structures east of Grant Street, in the TH- 7 ditch, and at College Lake. The elevation of the shoulder of TH -7 is approximately 954.0. Table 3: Impacts of Pre - Watermain Conveyance Summary of Option 1: Pre - Watermain Convevance Flood prevention and freeboard • -0.70 feet freeboard to the low opening at 5925 Grant Street • -1.06 feet freeboard to the low opening at 5915 Grant Street • 0.51 feet freeboard to the TH -7 shoulder. Emergency overflow • Not provided for structures along Grant Street. Discharge rates to the City of Excelsior • Match pre - watermain conditions in all events. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 3 Discharge Rate Across the Municipal High Water Level (ft) Bou dary with Excelsior cfs 1 -year 2 -year 10 -year 100 -year 6916/6926 Grant TH -7 Ditch College Lake Street (E2P) (EOffWP COL1 Pre - Watermain 8.41 12.47 35.71 80.98 965.04 953.49 946.81 Summary of Option 1: Pre - Watermain Convevance Flood prevention and freeboard • -0.70 feet freeboard to the low opening at 5925 Grant Street • -1.06 feet freeboard to the low opening at 5915 Grant Street • 0.51 feet freeboard to the TH -7 shoulder. Emergency overflow • Not provided for structures along Grant Street. Discharge rates to the City of Excelsior • Match pre - watermain conditions in all events. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 3 SECTION 3 3.2. Option 2: North Dry Pond and Lowered Park Street In Option 2, the City would purchase the properties at 5915 and 5925 Grant Street to utilize as a dry pond and would acquire easement over the northern portion of the property at 5965 Grant Street as shown in Figure 5, Appendix A. This option meets the City standards for freeboard and EOF routing. For stormwater ponding areas, the City of Shorewood requires at least two feet of separation between the 100 -year HWL of a stormwater pond and the low opening of adjacent structures and at least 1 foot of separation between the low opening of adjacent structures and the EOF. The low opening of the structure to the north of the acquired properties, 5905 Grant Street, is 965.72 and would require a HWL less than or equal to 963.72 and an EOF less than or equal to 964.72. To achieve these requirements, inlets would be improved from the dry pond and a 15 -inch RC pipe would be installed to convey water from the low point under the existing channel. Table 4 shows the impacts of this option. Table 4: Impacts of North Dry Pond and Lowered Park Street Summary of Option 2: North Dry Pond and Lowered Park Street Flood prevention and freeboard • 2.19 feet freeboard to the low opening at 5905 Grant Street • 0.53 feet freeboard to the TH -7 shoulder. Emergency overflow • Provided at north dry pond by lowering Park Street. Discharge rates to the City of Excelsior • Below pre - watermain conditions in all events. An option to meet the City standards for freeboard and EOF routing without the purchase of the properties at 5915 and 5925 Grant Street was considered. This option would require lowering the Park Street profile more than two feet. Due to the utility conflicts in this corridor and the extensive regrading of the roads and driveways in the area, this option was not investigated in depth. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 4 Discharge Rate Across the Municipal High Water Level (ft) Bou dary with Excelsior cfs 5915/5925 Grant TH -7 Ditch College Lake 1 -year 2 -year 10 -year 100 -year Street (E2P) (EOffWP COL1 Pre - Watermain 8.41 12.47 35.71 80.98 965.04 953.49 946.81 Proposed 1 7.46 11.83 31.42 79.20 1 963.53 953.47 946.82 Summary of Option 2: North Dry Pond and Lowered Park Street Flood prevention and freeboard • 2.19 feet freeboard to the low opening at 5905 Grant Street • 0.53 feet freeboard to the TH -7 shoulder. Emergency overflow • Provided at north dry pond by lowering Park Street. Discharge rates to the City of Excelsior • Below pre - watermain conditions in all events. An option to meet the City standards for freeboard and EOF routing without the purchase of the properties at 5915 and 5925 Grant Street was considered. This option would require lowering the Park Street profile more than two feet. Due to the utility conflicts in this corridor and the extensive regrading of the roads and driveways in the area, this option was not investigated in depth. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 4 SECTION 3 3.3. Option 3: New Outlet Pipe with North Dry Pond In Option 3, the City would purchase the property at 5925 Grant Street to utilize it as a dry stormwater pond and would acquire easement over the northern portion of the property at 5965 Grant Street as shown in Figure 6, Appendix A. For stormwater ponding areas, the City of Shorewood requires at least two feet of separation between the 100 -year HWL of a stormwater pond and the low opening of adjacent structures. The low opening of the structure to the north of this property, 5915 Grant Street, is 963.98 and would require a HWL less than or equal to 961.98. While an overland EOF is not feasible for this option, a piped EOF is provided. This outlet needs to convey three times the 100 -year peak discharge rate from the dry pond, which would require a 36 -inch equivalent pipe under the existing channel. Table 5 shows the impacts of this option. Table 5: Impacts of New Outlet Pipe with North Dry Pond Summary of Option 3: New Outlet Pioe with North Pondina Flood prevention and freeboard • 2.02 feet freeboard to the low opening at 5915 Grant Street • 0.37 feet freeboard to the TH -7 shoulder. Emergency overflow • No overland EOF, piped EOF provided. Discharge rates to the City of Excelsior • Above pre - watermain conditions in all events. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 5 Discharge Rate Across the Municipal High Water Level (ft) Boundary with Excelsior (cfs) 1 -year 2 -year 10 -year 100 -year 5915/5925 Grant TH -7 Ditch College Lake Street (E2P) (EOffWP COL1 Pre - Watermain 8.41 12.47 35.71 80.98 965.04 953.49 946.81 Proposed 1 8.93 13.91 35.92 95.84 1 961.96 953.63 946.84 Summary of Option 3: New Outlet Pioe with North Pondina Flood prevention and freeboard • 2.02 feet freeboard to the low opening at 5915 Grant Street • 0.37 feet freeboard to the TH -7 shoulder. Emergency overflow • No overland EOF, piped EOF provided. Discharge rates to the City of Excelsior • Above pre - watermain conditions in all events. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 5 SECTION 3 3.4. Option 4: New Outlet Pipe with South Dry Pond In Option 4, inlets and draintile would be improved at 5925 Grant Street and a larger piped outlet (30 -inch equivalent) would convey drainage to a new dry pond. To improve the inlets and install the new draintile (upsized to 15 -inch RC pipe), a large tree and row of lilac bushes along the south property line would need to be removed at 5925 Grant Street. The existing channel would be maintained at a shallower depth to allow drainage conveyance from properties on the south side of Park Street to the TH -7 ROW. Raising the bottom of the channel 1.0 feet would allow for cover over the pipe that would convey drainage from the north side of Park Street to the dry pond and ultimately to the TH -7 ROW. The proposed outlet pipe has an invert elevation more than 2.0 feet lower than the existing invert. The channel could not be lowered this amount while maintaining adequate side slopes within the 30 -foot width. The City would acquire easement over the northern portion of the property at 5965 Grant Street to create the dry pond as shown in Figure 7, Appendix A. Table 6 shows the impacts of this option. Table 6: Impacts of New Outlet Pipe with South Dry Pond Because there is not adequate freeboard to 5915 and 5925 Grant Street, the properties' low openings should be floodproofed and options reviewed to reduce infiltration of stormwater through cracks in the foundation. Summary of Option 4: New Outlet Pioe with South Dry Pond Flood prevention and freeboard • 0.43 feet freeboard to the low opening at 5925 Grant Street. • 0.07 feet freeboard to the low opening at 5915 Grant Street. • 0.35 feet freeboard to the TH -7 shoulder. Emergency overflow • Not provided for structures along Grant Street. Discharge rates to the City of Excelsior • Above pre - watermain conditions in all events except the 10 -year event GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 6 Discharge Rate Across the Municipal High Water Level (ft) Bou dary with Excelsior cfs 6916/6926 Grant TH -7 Ditch College Lake 1 -year 2 -year 10 -year 100 -year Street (E2P) (EOffWP COL1 Pre - Watermain 8.41 12.47 35.71 80.98 965.04 953.49 946.81 Proposed 1 9.32 13.77 34.51 98.29 1 963.91 953.65 946.83 Because there is not adequate freeboard to 5915 and 5925 Grant Street, the properties' low openings should be floodproofed and options reviewed to reduce infiltration of stormwater through cracks in the foundation. Summary of Option 4: New Outlet Pioe with South Dry Pond Flood prevention and freeboard • 0.43 feet freeboard to the low opening at 5925 Grant Street. • 0.07 feet freeboard to the low opening at 5915 Grant Street. • 0.35 feet freeboard to the TH -7 shoulder. Emergency overflow • Not provided for structures along Grant Street. Discharge rates to the City of Excelsior • Above pre - watermain conditions in all events except the 10 -year event GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 6 SECTION 3 3.6. Option 6: New Outlet Pipe to College Lake In Option 5, the City would construct a new storm sewer system to convey water from the area around 5925 Grant Street to College Lake. The City of Excelsior is planning road and utility reconstruction along Academy Avenue and Pleasant Street in 2019, which provides a unique opportunity for partnership. For this option, the City would install 24 -inch RC pipe under Park and Pleasant Streets, with improved inlets around 5925 Grant Street. The City would increase the size of the planned storm sewer in the City of Excelsior to 30 -inch RC pipe, from the intersection of Pleasant Street and Academy Avenue into College Lake. The City would reconstruct the Park Street to the municipal boundary. The City of Excelsior is planning to reconstruct Pleasant Street and Academy Avenue as part of their 2019 road and utility reconstruction project. Table 7 shows the impacts of this option. Table 7: New Outlet Pipe to College Lake Because there is not adequate freeboard to 5915 and 5925 Grant Street, the properties' low openings should be floodproofed and options reviewed to reduce infiltration of stormwater through cracks in the foundation. Summary of Option 6: New Outlet Pioe to Colleae Lake Flood prevention and freeboard • 0.68 feet freeboard to the low opening at 5925 Grant Street. • 0.32 feet freeboard to the low opening at 5915 Grant Street. • 0.56 feet freeboard to the TH -7 shoulder. Emergency overflow • Not provided for structures along Grant Street. Discharge rates to the City of Excelsior • Above pre - watermain conditions in the 2- and 100 -year events GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 7 Discharge Rate Across the Municipal High Water Level (ft) Boundary with Excelsior (cfs) 1 -year 2 -year 10 -year 100 -year 6916/6926 Grant TH -7 Ditch College Lake Street (E2P) (EOffWP COL1 Pre - Watermain 8.41 12.47 35.71 80.98 965.04 953.49 946.81 Proposed 1 8.23 12.75 32.40 89.06 1 963.66 953.44 946.80 Because there is not adequate freeboard to 5915 and 5925 Grant Street, the properties' low openings should be floodproofed and options reviewed to reduce infiltration of stormwater through cracks in the foundation. Summary of Option 6: New Outlet Pioe to Colleae Lake Flood prevention and freeboard • 0.68 feet freeboard to the low opening at 5925 Grant Street. • 0.32 feet freeboard to the low opening at 5915 Grant Street. • 0.56 feet freeboard to the TH -7 shoulder. Emergency overflow • Not provided for structures along Grant Street. Discharge rates to the City of Excelsior • Above pre - watermain conditions in the 2- and 100 -year events GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 7 SECTION 4 4. FINANCING 4.1. Cost Estimates Detailed opinions of probable cost are given in Appendix D for Options 1 -5 and summarized in Table 8. The opinions of cost include 15% contingency and 25% for related indirect costs (legal, administrative, engineering, and financing) based on the construction costs (not including property acquisition). Table 8: Cost Estimate Summary Based on 2018 Land value (PID: 3411723310041). Assume 35% of property value. 2 Based on 2018 Tax Market value (PID: 3411723420015). 3 Based on 2018 Tax Market value (PID: 3411723420016). 4.2. Funding The project will be funded by assessment, the City's Stormwater Utility, grant funds, or a combination of these. A Flood Damage Reduction Grant from the Minnesota Department of Natural Resources might be available to cover 50% of the cost of the property acquisition for Options 2, 3, and 4. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 8 stimated Total Cost Option 1: Pre - Watermain Conveyance Total $71,440.00 Option 2: North Dry Pond and Lowered Park Street Construction $285,710.00 Property / Easement Acquisition 1,2,3 $648,000.00 Option 2 Total $933,710.00 Option 3: New Outlet Pipe with North Pond Construction $257,460.00 Property / Easement Acquisition 1 2 $337,000.00 Option 3 Total $694,460.00 k. Option 4: New Outlet Pipe with South Dry Pond Construction $239,950.00 Easement Acquisition 1 $45,000.00 Option 4 Total $284,960.00 Option 6: New Outlet Pipe to College Lake Total $286,680.00 Based on 2018 Land value (PID: 3411723310041). Assume 35% of property value. 2 Based on 2018 Tax Market value (PID: 3411723420015). 3 Based on 2018 Tax Market value (PID: 3411723420016). 4.2. Funding The project will be funded by assessment, the City's Stormwater Utility, grant funds, or a combination of these. A Flood Damage Reduction Grant from the Minnesota Department of Natural Resources might be available to cover 50% of the cost of the property acquisition for Options 2, 3, and 4. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 8 SECTION 5 5. PROJECT SCHEDULE 5.1. Permitting Considerations The lead time to acquire the appropriate permits will have an impact on the project schedule. The permits described below will likely be required from regulatory agencies. Minnesota Department of Transportation A drainage permit is required for changes in drainage to the MnDOT ROW. On July 24, 2018, representatives from WSB & Associates, Inc. met with Brian Kelly, a Project Manager in MnDOT's Metro Water Resources Engineering Group. He confirmed that runoff to the TH -7 ditch in the project area drains to College Lake and eventually to Galpin Lake. He indicated that there have not been reports of flooding issues in the area and stated that increased discharge resulting in a small rise in the HWL in the ditch would be acceptable. Minnehaha Creek Watershed District (MCWD) Erosion Control — An erosion control permit is required when disturbing more than 5,000 square feet or grading, excavating, or filling more than 50 cubic yards of earth. Stormwater Management — A stormwater management permit is required when changing the contours of a parcel in a way that affects the direction, peak rate, volume, or water quality of runoff from a parcel. Minnesota Pollution Control Agency (MPCA) A National Pollutant Discharge Elimination System ( NPDES) Construction Activity permit is required for activities that result in one acre or more of land disturbance. Depending on the final design, this project may or may not require an NPDES permit. 5.2. Schedule If the City Council wishes to proceed with the Grant Street Drainage Improvements project, a proposed schedule with the earliest start dates is below. This may be adjusted based on the decision of the City Council regarding preferred timeline and funding sources (use of assessments may impact the timeline). City Council Accepts Feasibility Report ....................... Public Hearing /City Council Authorizes Improvements 60% Plans /Permitting /Property Acquisition ................. Final Plans and Specs /Advertisement for Bid .............. Open Bids /City Council Awards Contract .................... Begin Construction ........................ ............................... Substantial Completion ................. ............................... ... January 2019 ... January 2019 ...February 2019 .......... May 2019 ......... June 2019 ...........July 2019 September 2019 If the City Council wishes to proceed with Option 5, the proposed schedule will need to be adjusted to correlate with the City of Excelsior's schedule for their 2019 Street and Utility Improvements Project in this area (see following). GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 9 SECTION 5 Public Improvement Hearing /Order Project ....................... ............................... December 17, 2018 OpenBids ............................................................ ............................... .......................February 2019 AwardContract ................................................................................ ............................... March 2019 Begin Construction .................................................. ............................... .........................Spring 2019 Substantial Completion ............................................................. ............................... November 2019 Final Completion ................................................... ............................... ......................June /July 2020 GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 10 SECTION 6 6. RECOMMENDATION While all preceding options are feasible, WSB recommends proceeding with Option 5: New Outlet Pipe to College Lake. This option is feasible, necessary, and cost - effective from an engineering perspective. Option 5: New Outlet Pipe to College Lake is recommended based on the cost of the project, the ability to maintain private ownership of the lots at 5925 and 5915 Grant Street, and the added flood protection. The overall feasibility will be determined by the City Council. The Council may consider economic and permitting feasibility in their final determination, as well as the participation and permission required from the City of Excelsior for the recommended option. GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 Page 11 APPENDIX A APPENDIX A Figures GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 APPENDIX A 0¢.—.t Path: KkOlM &8001GIMM. s \Grain. eA ,R ure...d Date S.vetl: 12118120181: 2657 PM 1bOF � L o O o V / m O E E O O O E c O N m d 944 9'46 998 J - Z66 � 6 988 6 8E 9s 96 86 -�o, .• _ Zbb ggA 60 � ° _ � 066 _ ,, m rn s gss 6' S6 OS v M� 0 • ZS6 a � 9.0 m _ 0 0 0 N gab g74 96, AS s o o s o gi4 b96 �0 86 m rn m 0�O 9� 296' m 0 � 66 988 gg2 6 086 � `�s o � 066 rn GS °o° m • °mss SbO cu 10 QC6 O 1� gg8 oo°'' OOl A O o � 6 a0'C °0 066 tics R s N N _ _ a 2 L gA m`O rno, m a N LL 8 0 a) z g O. �� ^, bl ZsOOL r�0� 100- rn 0) f4 C C 'O O 0 O O off` 7 O A 066 Z.b0l �� LL CD U bL l �, 1002 1 _ 'OJU MTV, r� N C A .2- V � N � � .w N n N n O � U li z c rn m Ia m °O W `O ra N � s U) � � O E2 .w LL (7 U 8 oa ��s 1 U U O � O i LL I i LL N O J <-I rn rn rn J I -o I 'o I � Z rvo rvo .V li .V li � W W W v W p[ � N (fl � Q Z a � I I T 4J C C L U I rn rn rn rn rn ^ V ^ I� rn rn rn rn rn r� N C A .2- V � N � � .w N n N n O � U li z c rn m Ia m °O W `O ra N � s U) � � O E2 .w LL (7 U 8 oa ��s 1 U U O � O i LL I i LL O _ U O O � do 00 o .w \J &° U O SNOISIA38 400M32JOHS 30.1110 w' 52 zo w w X > w o � S1181HX3 . z 1S 1NV2JS Q 1S Ni ]Vd LL N o O J a lu U 0 0 Z Z m» uL se s} o LU cn J — — I 3� iAfr �e 06 �>6 sv lei g e v e — 3 & — w — H » �» y Z w �LL 4 W C W >� e � _ m s> I H �m z m= a o — _ r I W 0 s K a m� _ I Q H Z 09 q I 9 _ 5915 Grant Street Low opening = 963.98 5925 Grant Street Low opening = 964.34 A 16 -A ,, 15 -in storm sewer at pre - watermain project elevations 100 -year HWL = 965.04 l 0) rn Excavated and cleared channel 962 r 00 (Legend � Proposed Storm Sewer � Existing Storm Sewer Figure 4: Pre - Watermain Conveyance (Option 1) ■ Grant Street Drainage Feasibility Study N � 6 1 A s b CITY OF City of Shorewood, MN Feet V V SHOREWOOn A 1 inch = 60 feet '0V o 5905 Grant Street ► , w rr. Low opening = 965.72 , P. •. k< d d c� n 15 -in. pipe beneath shallower channel M 1100 -year HWL = 963.53 Park Street lowered to provide EOF for 5905 Grant Street Legend Proposed Storm Sewer P Proposed Dry Pond Easement to Acquire 5965 Grant Street V MnDOT ROW 100 -year HWL = 953.47 Parcel to Acquire ' Existing Storm Sewer Figure 5: North Dry Pond and Lowered Park Street (Option 2) Grant Street Drainage Feasibility Study N 1 A s City f Shorewood, M o 6o V V J CITY OF y N Feet SHOREWOOD A 1 inch = 60 feet 5915 Grant Street Low opening = 963.98 i 10 Ep"r i� ear HWL = 961.96 ��Piped EOF Option: Lower Park Street 2 ft to 36 -in equiv. pipe beneath shallower channel 11 e overland EOF Legend Proposed Storm Sewer Proposed Dry Pond Easement to Acquire 5965 Grant Street MnDOT ROW 100 -year HWL = 953.63 Parcel to Acquire ' Existing Storm Sewer Figure 6: New Outlet Pipe with North Dry Pond (Option 3) Grant Street Drainage Feasibility Study N 1 A s City f Shorewood, M o 6o V V J CITY OF y N Feet SHOREWOOD A 1 inch = 60 feet v 5915 Grant Street Low opening = 963.98 5925 Grant Street Low opening = 964.34 1201d. 100 -year HWL = 963.91 '=-in nlets and ► storm sewer 30 -in equiv. pipe beneath shallower channel 1Q 5965 Grant Street rn 5$ g55 9� 9 100 -year HWL = 958.04 RUN', =MnDOT O W 11 00_ WL = 953.65 r Legend ► Proposed Storm Sewer Proposed Dry Pond Easement to Acquire ► Existing Storm Sewer Figure 7: New Outlet Pipe with South Dry Pond (Option 4) . Grant Street Drainage Feasibility Study N o 60 wsbo Cirrar City of Shorewood , MN mmmmmmm===== Feet SHOREW(X-)D A 1 inch = 60 feet n i L rt+ rt+ i ,L^ V HWL = 963.66 Academy Avenue IL d L y 5915 Grant Street Low opening = 963.98 5925 Grant Street Low opening = 964.34 lb cp Improved inlets and ��� 24 -in storm sewer Storm sewer installed as part of the Excelsior road reconstruction project. Unsized to 30 -in. o� rn h Legend ► Proposed Storm Sewer Road to Reconstruct ► Existing Storm Sewer Figure 8: New Outlet Pipe to College Lake (Option 5) . Grant Street Drainage Feasibility Study N o goo wsbo Cirrar City of Shorewood , MN mommomm== Feet SHOREW(X-)D A 1 inch = 100 feet '''��' `=' '•' " '�` College Lake n� m 0) L rt+ rt+ i ,L^ V HWL = 963.66 Academy Avenue IL d L y 5915 Grant Street Low opening = 963.98 5925 Grant Street Low opening = 964.34 lb cp Improved inlets and ��� 24 -in storm sewer Storm sewer installed as part of the Excelsior road reconstruction project. Unsized to 30 -in. o� rn h Legend ► Proposed Storm Sewer Road to Reconstruct ► Existing Storm Sewer Figure 8: New Outlet Pipe to College Lake (Option 5) . Grant Street Drainage Feasibility Study N o goo wsbo Cirrar City of Shorewood , MN mommomm== Feet SHOREW(X-)D A 1 inch = 100 feet APPENDIX B APPENDIX B Problem Areas Report GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 APPENDIX B ANALYSIS OF DRAINAGE PROBLEM AREAS WITHIN THE CITY OF SHOREWOOD PREPARED FOR THE CITY OF SHOREWOOD, MINNESOTA January 23, 2006 Prepared By: WSB & Associates, Inc. 701 Xenia Avenue South, Suite 300 Minneapolis, MN 55416 (763) 541 -4800 (763) 541 -1700 (Fax) I. INTRODUCTION On September 4', 2005 a strong thunderstorm developed over the City of Shorewood. In the course of approximately three hours, close to six inches of rain fell within the City. During this time, large hail also was observed, stripping leaves from trees and adding to the general debris that was present within the storm sewer system. The City experienced a second storm on October 4t', 2005. This storm produced approximately 4.5 inches of rain within a four hour period. The City requested WSB & Associates, Inc. look at the various drainage problem areas. The preliminary findings of this investigation are outlined within this report. To aid the City in planning for projects that will reduce the number of flood problem areas, we have ranked the problem areas based on a modified classification system. In order to maintain some consistency with the City's system previously established, we used the same categories with limited modifications. The criteria outlined in the Capital Improvement Program (1997 — 2001) were modified as follows: • Split "Private Nuisance" areas into two categories, one in which the City may share in the responsibility for the project and one that is entirely the responsibility of the private property owner and / or their neighbors. Added a new category consisting of areas where no additional work is recommended. The various categories are outlined below: 1) PUBLIC SAFETY AND HEALTH Primary attention will be paid to those projects that impact the public health or safety. These projects would include ice problems on the road, erosion that is causing a hazardous structural problem (i.e. undermining a road), or storm water that is causing a significant health problem (such as flooding the sanitary system). 2) SUBSTANTIAL FINANCIAL IMPACT TO THE CITY This category will include those projects that, while not endangering the public health, will still have a negative impact on the residents as a whole. Projects in this category include minor infrastructure replacement that cannot be funded cost effectively by other means. Other potential projects include erosion causing property damage and minor structure replacement. 3) PUBLIC NUISANCE This category includes those projects that cannot be considered a substantial hazard, are not likely to cause a financial loss to the City, but are a public nuisance. These projects include standing water in the roadway, unwanted flooding in public parks, and minor erosion projects. Analysis ofDrainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 1 WSB Project No. 1459 -04 4) PRIVATE NUISANCE WITH LINHTED CITY RESPONSIBILITY This category includes projects that are a nuisance to a single residence or small group of residences that the City Council deems that the City has some responsibility to help correct. These projects include those instances where a large drainage area is causing a problem to a small area or where a substantial portion of the runoff is generated within the City's Right -of -Way. In order for the City to participate, the homeowner(s) must be willing to provide a right - of -entry to City crews and provide Drainage and Utility Easement over improvements without cost. 5) PRIVATE NUISANCE WITH NO CITY RESPONSIBILTY This category includes projects that are a nuisance to a single residence or small group of residences that the City Council deems that the City has no responsibility to help correct. These projects include those instances where a limited drainage area, consisting of private property, is causing a problem to a small area. The nuisance problem will involve little or no runoff that is generated from City Right -of -Way. 6) NO FURTHER ACTION REQUIRED This category includes projects that are under way, or have been addressed through various means, such as individual homeowners correcting the problem himself or herself or City crews fixing the problem. The problem areas are all evaluated and a category assigned so that the City Council can begin to prioritize the problem areas. Tables 1 -6 contain a list of the problem areas for each category along with a preliminary ranking of the areas within in each category. This ranking, along with the preliminary cost estimates, can be used by the City Council to determine the priority for fixing the problem areas. Analysis ofDrainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 2 WSB Project No. 1459 -04 Problem Area Number 7 — 5925 Grant Vreet Description of Problem: This residence is located at the lowest point of a subwatershed that includes a portion of the City of Excelsior. A series of culverts are located in the roadway ditch in the front of the yard. To alleviate standing water in the low backyard area, a 4 -inch PVC drain file was installed to convey runoff from this lowpoint to the storm sewer located in the street Right -of -Way. The inlet to this drain tile consists of a small hole dug into the yard supported by landscape bricks. A screened grate was placed over the bricks. During the September rainfall event, this area flooded resulting in water in the basement of the residence. It was observed that the landscape bricks that supported the grate had collapsed, partially blocking the drain tile line. The storm sewer system crosses below Park Street and discharges to a drainage ditch located within the City's Right -of -Way. At the end of the ditch, adjacent to the TH -7 Right -of -Way, a resident has constructed a horseshoe shaped berm in an attempt to block runoff from flowing across his property. The height of this berm is approximately 3-4 feet high. Based on review of the City's 1 -foot contour information, it appears that there is approximately 7 feet of fall from the outlet of the storm sewer system to the top of this berm. Therefore, it is unlikely that the berm is creating any tailwater impacts on the Grant Street storm sewer system. The City has an existing sewer easement across the property containing the berm. It is recommended that the City instruct the homeowner at 5965 Grant Street to remove the berm. Hydrologic Information: • Tributary Area: 1.7 ac* (direct), 8.9 ac total (tributary to Park St. storm sewer) • Impervious Surface: 9% (direct), 25% (total area) • Peak 10 -year Flow Rate: 19.7 cfs • Peak 100 -year Flow Rate: 34.3 cfs *Area within City of Excelsior has been estimated based on field visit. Possible Alternatives: Constructing a larger storm sewer system with additional capacity would reduce the flooding potential in this area. It is anticipated the construction costs associated with this work will be approximately $42,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since the runoff involves City Right -of -Way and a portion of the storm sewer system is a City owned system. It is recommended that additional analysis be undertaken to design a comprehensive system in this area. Analysis ofDrainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 10 WSB Project No. 1459 -04 Problem Area Number 21 — 5915 Grant Vreet Description of Problem: The property owner experienced flooding in her yard. This residence is adjacent to 5925 Grant Street. The description of the problem, hydrologic information, and possible alternatives are the same for this property as those outlined in Problem Area Number 7. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since the runoff involves City Right -of -Way and a portion of the storm sewer system is a City owned system. It is recommended that additional analysis be undertaken to design a comprehensive system in this area. Analysis ofDrainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 27 WSB Project No. 1459 -04 W. 4j PQ Ez N N O ca U ca i Q _0 T2 0 CL O E cn N ca i Q CL N 0 w U 2:, O J U as Z 0 .i CL vi 0) c 0 0) c O O 0 0 C N x a� co co a) co a� V) co 2 co O) 0) so O .Q O a� "2 O N C N E E O 0 N L y-+ D L co v) U N O ^L LL LW r U 0 co co O O N co r O O O O O O O O O N O I-- O O O O O O M O O O O O N O N O N LO 0 0 I� O 0 CN 4 O K3 O C Ef} 0 V M 6 cvi M o O o� o o °o o� o °oo °o 0 0 0 0 0 0 0 0 0 — O O — O O M O C C C C O O C O 0 0 0 0 0 O 0 N N N N M N N 0) N O N N c N L co co co ++ O O c O E —_ N L-0 �, (n (n N co O co N O 0 L 0 0 — — "O Y 0 3 N O— co L c c co 0 6 0 ch iC) wQ � 200CD "" -0= N co(n� JLO L .a 0LO w Ln 00LO M Ln O O Ln Ln Ln O O r— O M O O O O O W N— M W co I— O� Q M N M N M N M N co N (O O O M— N (O 2 I— co N O N vi 0) c 0 0) c O O 0 0 C N x a� co co a) co a� V) co 2 co O) 0) so O .Q O a� "2 O N C N E E O 0 N L y-+ D L co v) U N O ^L LL LW r U 0 co co O O N co r Appendix A Opinion of Probable Cost Problem Area 7 - 5925 Grant Street A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $3,500.00 $3,500.00 2 Remove Bituminous Pavement 200 SY $5.00 $1,000.00 3 Storm Sewer (12" RCP) 80 L $35.00 $2,800.00 4 Storm Sewer (15" RCP) 90 L $40.00 $3,600.00 5 Storm Sewer (27" RCP) 70 LF $85.00 $5,950.00 6 Catch Basins and Manholes 5 EA $1,250.00 $6,250.00 7 Salvage and Reinstall Base Course Aggregate 35 CY $12.00 $420.00 8 Bituminous Pavement 45 TN $150.00 $6,750.00 9 Turf Establishment 1500 SY $2.00 $3,000.00 Subtotal $33,270.00 +25% Contingencies $8,318.00 Total $41,588.00 1/18/2006 PA 7 � � � c @ � � Z-1 � E � @ U c � c � c � � @ � c @ E E 0 U @ � O J .a f / ± \ } E \ .g / / % 3 \ IT � � 0 \ / .E § / E o / ) ° ) 2 \ § e / E o / / e (D = (D f 2 E cn E a) _ ') E 5 = ) _ §\ \ \_ \ƒ\ \ § \ \ 0 (D Cl § \ \ \ _ ( © f 0 % \ \ \ \ \ £ f _ \ a E 2 $ § E \ bb\ < _ $ $ $ ) \ ± $ 5 2 » oon�= o� =< _ _ )) [ / \ C: / o < / ° { { cn k % 2 ©/ e§ k 2 a \ $ } £ 0- f / ƒ. 2 / \ # \ E f °+ \\\ E E* e E E 3 e e g#\# CO * e � 2 5 n o # 2 % E ® ƒ / cn \ § / \ \ 3 z _ $ \ k\\ f 2 2 / \/ n t/ - - 3» a) ��= 4 4 = t u t or o (n (_ - - o ®0®%J (n _ _ /E o §//±77 $ $ $ / $ $ $ � $ / 2 0 2 o 2/ n o 2 o.g 2\ o 2)\ J o= 2/ �EEEEEOEaa6EE § 0 D = e $ o 2 E = 2222«/= eS \ 7/ 2= f (n � 2 m —M< ƒ/2 c (D Of e -i < e \ /\ \\ / / / \\ <ratoaaar LO k®2 /%%\ /7 \9 � 2 .a f / ± \ } E \ .g / / % 3 \ IT � APPENDIX C APPENDIX C HydroCAD Reports GRANT STREET DRAINAGE FEASIBILITY REPORT City of Shorewood, MN WSB Project No. 12046 -000 APPENDIX C E1.5 E2 E1.5P \ 2 E1 1 P �D E2Pipe E4 4P / /E3 E6 E5 -p 1R O O Ch4el / \\\ SSS E-- [:� to MnDOT R MN -7 Ditch EOffW EOFFE -N Frontier ectric - N EOFFE -S �/ EoFFE -sP Subcat Reach on Link Electric - S Existing_21NIode MSE 24 -hr 3 1 -Year Rainfall= 2.48" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 2 Time span =0.00 -60.00 hrs, dt =0.01 hrs, 6001 points x 2 Runoff by SCS TR -20 method, UH =SCS, Weighted -CN Reach routing by Dyn -Stor -Ind method - Pond routing by Dyn -Stor -Ind method SubcatchmentE1: Runoff Area =1.419 ac 40.52% Impervious Runoff Depth = 0.68" Flow Length =542' Tc =14.7 min CN =76 Runoff =1.18 cfs 0.081 of SubcatchmentE1.5: Runoff Area =2.424 ac 31.35% Impervious Runoff Depth = 0.56" Flow Length =411' Tc =10.1 min CN =73 Runoff =1.88 cfs 0.112 of SubcatchmentE2: Runoff Area =3.518 ac 41.76% Impervious Runoff Depth = 0.68" Flow Length =832' Tc =25.0 min CN =76 Runoff =2.19 cfs 0.200 of SubcatchmentE3: Runoff Area =0.456 ac 51.75% Impervious Runoff Depth = 0.88" Tc =10.0 min CN =80 Runoff =0.61 cfs 0.033 of SubcatchmentE4: Runoff Area =0.318 ac 60.69% Impervious Runoff Depth= 1.04" Tc =10.0 min CN =83 Runoff =0.51 cfs 0.028 of SubcatchmentE5: Runoff Area =1.832 ac 19.27% Impervious Runoff Depth = 0.38" Flow Length =615' Tc =14.5 min CN =68 Runoff =0.68 cfs 0.058 of SubcatchmentE6: Runoff Area =0.681 ac 12.04% Impervious Runoff Depth= 0.24" Tc =10.0 min CN =63 Runoff =0.13 cfs 0.013 of SubcatchmentEOFFE -N: Runoff Area= 1.710 ac 47.78% Impervious Runoff Depth = 0.82" Flow Length =320' Tc =8.0 min CN =79 Runoff =2.35 cfs 0.117 of SubcatchmentEOFFE -S: Runoff Area= 1.865 ac 26.81% Impervious Runoff Depth = 0.48" Flow Length =490' Tc =17.5 min CN =71 Runoff =0.89 cfs 0.075 of SubcatchmentEOffW: Runoff Area= 19.973 ac 29.71% Imperious Runoff Depth = 0.52" Flow Length= 1,890' Tc =36.2 min CN =72 Runoff =7.01 cfs 0.863 of Reach 1R: Channel Avg. Flow Depth =0.47' Max Vet =1.21 fps Inflow =2.97 cfs 0.487 of n =0.100 L= 100.0' S= 0.0246 T Capacity= 114.91 cfs Outflow =2.94 cfs 0.487 of Pond E1.5P: Peak Elev= 965.21' Storage =0.018 of Inflow =1.88 cfs 0.112 of Outflow =1.66 cfs 0.099 of Pond E1 P: Peak Elev= 965.42' Storage =0.003 of Inflow =1.18 cfs 0.081 of Primary=1.18 cfs 0.078 of Secondary=0.00 cfs 0.000 of Outflow =1.18 cfs 0.078 of Pond E21P: Peak Elev= 963.69' Storage =0.122 of Inflow =3.30 cfs 0.299 of Primary=0.00 cfs 0.000 of Secondary=0.64 cfs 0.294 of Tertiary=0.00 cfs 0.000 of Outflow =0.64 cfs 0.294 of Pond E2Pipe: Peak Elev= 962.98' Storage =0.002 of Inflow =1.43 cfs 0.372 of Primary=1.43 cfs 0.371 of Secondary=0.00 cfs 0.000 of Outflow =1.43 cfs 0.371 of Pond E4P: Peak Elev= 965.96' Storage =0.004 of Inflow =0.51 cfs 0.028 of Primary=0.50 cfs 0.025 of Secondary=0.00 cfs 0.000 of Outflow =0.50 cfs 0.025 of Existing_21NIode MSE 24 -hr 3 1 -Year Rainfall= 2.48" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 3 Pond EOFFE -NP: Frontier Electric- N Peak EIev= 947.07' Storage =0.012 of Inflow =8.51 cfs 1.490 of Primary=8.50 cfs 1.489 of Secondary=0.00 cfs 0.000 of Outflow =8.50 cfs 1.489 of Pond EOFFE -SP: Frontier Electric- S Peak EIev= 949.96' Storage =0.039 of Inflow =8.37 cfs 1.374 of Primary=7.48 cfs 1.359 of Secondary=0.73 cfs 0.013 of Outflow =8.21 cfs 1.372 of Pond EOffWP: MN -7 Ditch Peak EIev= 952.40' Storage =0.170 of Inflow =8.71 cfs 1.363 of Outflow =8.01 cfs 1.299 of Rii1mlnr•wiIi1exid: eavyI Inflow =3.07 cfs 0.500 of Primary=3.07 cfs 0.500 of Total Runoff Area = 34.196 ac Runoff Volume = 1.580 of Average Runoff Depth = 0.55" 68.07% Pervious = 23.277 ac 31.93% Impervious = 10.919 ac Existing_21NIode MSE 24 -hr 3 2 -Year Rainfall= 2.86" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 4 Time span =0.00 -60.00 hrs, dt =0.01 hrs, 6001 points x 2 Runoff by SCS TR -20 method, UH =SCS, Weighted -CN Reach routing by Dyn -Stor -Ind method - Pond routing by Dyn -Stor -Ind method SubcatchmentE1: Runoff Area =1.419 ac 40.52% Impervious Runoff Depth = 0.92" Flow Length =542' Tc =14.7 min CN =76 Runoff =1.64 cfs 0.109 of SubcatchmentE1.5: Runoff Area =2.424 ac 31.35% Impervious Runoff Depth = 0.77" Flow Length =411' Tc =10.1 min CN =73 Runoff =2.74 cfs 0.156 of SubcatchmentE2: Runoff Area =3.518 ac 41.76% Impervious Runoff Depth = 0.92" Flow Length =832' Tc =25.0 min CN =76 Runoff =3.06 cfs 0.270 of SubcatchmentE3: Runoff Area =0.456 ac 51.75% Impervious Runoff Depth= 1.15" Tc =10.0 min CN =80 Runoff =0.81 cfs 0.044 of SubcatchmentE4: Runoff Area =0.318 ac 60.69% Impervious Runoff Depth= 1.33" Tc =10.0 min CN =83 Runoff =0.66 cfs 0.035 of SubcatchmentE5: Runoff Area= 1.832 ac 19.27% Impervious Runoff Depth = 0.56" Flow Length =615' Tc =14.5 min CN =68 Runoff =1.12 cfs 0.085 of SubcatchmentE6: Runoff Area =0.681 ac 12.04% Impervious Runoff Depth= 0.38" Tc =10.0 min CN =63 Runoff =0.27 cfs 0.021 of SubcatchmentEOFFE -N: Runoff Area= 1.710 ac 47.78% Impervious Runoff Depth= 1.09" Flow Length =320' Tc =8.0 min CN =79 Runoff =3.14 cfs 0.155 of SubcatchmentEOFFE -S: Runoff Area= 1.865 ac 26.81% Impervious Runoff Depth = 0.68" Flow Length =490' Tc =17.5 min CN =71 Runoff =1.35 cfs 0.106 of SubcatchmentEOffW: Runoff Area= 19.973 ac 29.71% Imperious Runoff Depth = 0.73" Flow Length= 1,890' Tc =36.2 min CN =72 Runoff =10.39 cfs 1.209 of Reach 1R: Channel Avg. Flow Depth =0.57' Max Vet =1.35 fps Inflow =4.25 cfs 0.674 of n =0.100 L= 100.0' S=0.0246'/' Capacity= 114.91 cfs Outflow =4.22 cfs 0.674 of Pond E1.5P: Peak Elev= 965.24' Storage =0.019 of Inflow =2.74 cfs 0.156 of Outflow =2.62 cfs 0.143 of Pond E1 P: Peak Elev= 965.45' Storage =0.003 of Inflow =1.64 cfs 0.109 of Primary=1.64 cfs 0.106 of Secondary=0.00 cfs 0.000 of Outflow =1.64 cfs 0.106 of Pond E21P: Peak Elev= 963.91' Storage =0.196 of Inflow =4.72 cfs 0.413 of Primary=0.00 cfs 0.000 of Secondary=0.71 cfs 0.408 of Tertiary=0.00 cfs 0.000 of Outflow =0.71 cfs 0.408 of Pond E2Pipe: Peak Elev= 963.12' Storage =0.002 of Inflow =1.94 cfs 0.514 of Primary=1.94 cfs 0.513 of Secondary=0.00 cfs 0.000 of Outflow =1.94 cfs 0.513 of Pond E4P: Peak Elev= 965.97' Storage =0.004 of Inflow =0.66 cfs 0.035 of Primary=0.65 cfs 0.033 of Secondary=0.00 cfs 0.000 of Outflow =0.65 cfs 0.033 of Existing_21NIode MSE 24 -hr 3 2 -Year Rainfall= 2.86" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 5 Pond EOFFE -NP: Frontier Electric- N Peak Elev= 947.54' Storage =0.017 of Inflow =12.98 cfs 2.099 of Primary=12.97 cfs 2.099 of Secondary=0.00 cfs 0.000 of Outflow =12.97 cfs 2.099 of Pond EOFFE -SP: Frontier Electric- S Peak EIev= 950.22' Storage =0.053 of Inflow =12.69 cfs 1.946 of Primary=8.44 cfs 1.808 of Secondary=4.12 cfs 0.136 of Outflow =12.56 cfs 1.945 of Pond EOffWP: MN -7 Ditch Peak EIev= 952.53' Storage =0.198 of Inflow =12.69 cfs 1.904 of Outflow =12.10 cfs 1.840 of Rii1mlnr•wiIi1exid: eavyI Inflow =4.47 cfs 0.695 of Primary=4.47 cfs 0.695 of Total Runoff Area = 34.196 ac Runoff Volume = 2.190 of Average Runoff Depth = 0.77" 68.07% Pervious = 23.277 ac 31.93% Impervious = 10.919 ac 609S --p sos GL GL E1.5 E2 E4 A4 YI E5 -p 1R Ch.1 C ,® 301 S 302S COL 1 - EDIT �COL2 01 C 1 606 60625 �GL� sos � 605S GL6 6061 S 604 GL 5 GL 5 603 GL 6B `Qj� � 3 603S 1 a� I �3 GL 611S 604S CHAN GI-4 612S Frontier ectnc - N CHAN 1 EoFFE -N EOFFE -S h Electnc - S Subcat Reach on Link Existing MSE 24 -hr 3 10 -Year Rainfall= 4.26" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 2 Time span =0.00 -60.00 hrs, dt =0.01 hrs, 6001 points x 2 Runoff by SCS TR -20 method, UH =SCS, Weighted -CN Reach routing by Dyn -Stor -Ind method - Pond routing by Dyn -Stor -Ind method Subcatchment301S: COL 1 -EDITED RunoffArea= 24.783 ac 0.00% Impervious Runoff Depth= 2.18" Tc =30.0 min CN =79 Runoff =48.41 cfs 4.495 of Subcatchment302S: COL 2 Runoff Area =1.989 ac 0.00% Impervious Runoff Depth= 2.78" Tc =20.0 min CN =86 Runoff =6.17 cfs 0.461 of Subcatchment603S: GL 3 RunoffArea= 36.364 ac 0.00% Impervious Runoff Depth= 1.51" Tc =21.0 min CN =70 Runoff =57.72 cfs 4.564 of Subcatchment604S: GL 4 RunoffArea= 27.582 ac 0.00% Impervious Runoff Depth= 1.57" Tc =18.0 min CN =71 Runoff =50.10 cfs 3.620 of Subcatchment605S: GL 5 Runoff Area =5.097 ac 0.00% Impervious Runoff Depth= 1.79" Tc =20.0 min CN =74 Runoff =10.08 cfs 0.760 of Subcatchment609S: GL 9 RunoffArea =8.595 ac 0.00% Impervious Runoff Depth= 1.31" Tc =15.0 min CN =67 Runoff= 13.94 cfs 0.937 of Subcatchment611S: CHAN RunoffArea= 49.667 ac 0.00% Impervious Runoff Depth= 2.10" Tc =40.0 min CN =78 Runoff =78.40 cfs 8.676 of Subcatchment612S: CHAN 1 RunoffArea= 34.133 ac 0.00% Impervious Runoff Depth= 1.72" Tc =40.0 min CN =73 Runoff =43.33 cfs 4.883 of Subcatchment6061S: GL 6B RunoffArea= 27.178 ac 0.00% Impervious Runoff Depth= 2.10" Tc =42.0 min CN =78 Runoff =41.39 cfs 4.748 of Subcatchment6062S: GL 6A Runoff Area =1.181 ac 0.00% Impervious Runoff Depth= 2.51" Tc =20.0 min CN =83 Runoff =3.33 cfs 0.247 of SubcatchmentE1: RunoffArea =1.419 ac 40.52% Impervious Runoff Depth= 1.94" Flow Length =542' Tc =14.7 min CN =76 Runoff =3.58 cfs 0.229 of SubcatchmentE1.5: RunoffArea =2.424 ac 31.35% Impervious Runoff Depth= 1.72" Flow Length =411' Tc =10.1 min CN =73 Runoff =6.43 cfs 0.347 of SubcatchmentE2: RunoffArea =3.518 ac 41.76% Impervious Runoff Depth= 1.94" Flow Length =832' Tc =25.0 min CN =76 Runoff =6.75 cfs 0.569 of SubcatchmentE3: RunoffArea =0.456 ac 51.75% Impervious Runoff Depth= 2.26" Tc =10.0 min CN =80 Runoff =1.60 cfs 0.086 of SubcatchmentE4: RunoffArea =0.318 ac 60.69% Impervious Runoff Depth= 2.51" Tc =10.0 min CN =83 Runoff= 1.24 cfs 0.067 of SubcatchmentES: Runoff Area= 1.832 ac 19.27% Impervious Runoff Depth= 1.37" Flow Length =615' Tc =14.5 min CN =68 Runoff =3.17 cfs 0.210 of Existing MSE 24 -hr 3 10 -Year Rainfall= 4.26" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 3 SubcatchmentE6: Runoff Area =0.681 ac 12.04% Impervious Runoff Depth= 1.06" Tc =10.0 min CN =63 Runoff =1.04 cfs 0.060 of SubcatchmentEOFFE -N: Runoff Area= 1.710 ac 47.78% Impervious Runoff Depth= 2.18" Flow Length =320' Tc =8.0 min CN =79 Runoff =6.33 cfs 0.310 of SubcatchmentEOFFE -S: Runoff Area= 1.865 ac 26.81% Impervious Runoff Depth= 1.57" Flow Length =490' Tc =17.5 min CN =71 Runoff =3.44 cfs 0.245 of SubcatchmentEOffW: Runoff Area= 19.973 ac 29.71% Imperious Runoff Depth= 1.65" Flow Length= 1,890' Tc =36.2 min CN =72 Runoff =25.62 cfs 2.738 of Reach 1R: Channel Avg. Flow Depth =0.87' Max Vet =1.69 fps Inflow =9.18 cfs 1.490 of n =0.100 L= 100.0' S=0.0246'/' Capacity= 114.91 cfs Outflow =9.16 cfs 1.490 of Pond 301 P: COL 1 Peak Elev= 945.86' Storage= 14.795 of Inflow= 108.41 cfs 27.512 of Outflow =10.36 cfs 23.723 of Pond 603P: GL 3 Peak Elev= 966.35' Storage =7.511 of Inflow =88.01 cfs 9.447 of Outflow =2.40 cfs 6.675 of Pond 604P: GL 4 Peak EIev= 960.65' Storage =6.931 of Inflow= 106.01 cfs 18.970 of 24.0" Round Culvert n =0.014 L= 150.0' S=0.0050'/' Outflow =18.15 cfs 18.294 of Pond 605P: GL 5 Peak EIev= 987.33' Storage =0.581 of Inflow =10.08 cfs 0.760 of 18.0" Round Culvert n =0.024 L =50.0' S=0.0050'/' Outflow =0.26 cfs 0.509 of Pond 606P: GL 6 Peak EIev= 946.67' Storage =1.050 of Inflow =57.05 cfs 23.798 of Primary=35.27 cfs 16.986 of Secondary=7.81 cfs 6.812 of Outflow =43.08 cfs 23.798 of Pond 609P: GL 9 Peak EIev= 983.34' Storage =0.618 of Inflow =13.94 cfs 0.937 of Outflow =0.61 cfs 0.792 of Pond E1.5P: Peak EIev= 965.35' Storage =0.026 of Inflow =6.43 cfs 0.347 of Outflow =6.25 cfs 0.333 of Pond E1 P: Peak EIev= 965.57' Storage =0.001 of Inflow =3.58 cfs 0.229 of Primary=3.58 cfs 0.229 of Secondary=0.00 cfs 0.000 of Outflow =3.58 cfs 0.229 of Pond E21P: Peak EIev= 964.27' Storage =0.360 of Inflow =14.47 cfs 1.131 of Primary=4.56 cfs 1.131 of Secondary=0.00 cfs 0.000 of Outflow =4.56 cfs 1.131 of Pond E41P: Peak EIev= 966.00' Storage =0.004 of Inflow =1.24 cfs 0.067 of Primary=1.22 cfs 0.064 of Secondary=0.00 cfs 0.000 of Outflow =1.22 cfs 0.064 of Pond EOFFE -NP: Frontier Electric- N Peak EIev= 949.94' Storage =0.119 of Inflow =34.20 cfs 4.778 of Primary=31.61 cfs 4.778 of Secondary=0.00 cfs 0.000 of Outflow =31.61 cfs 4.778 of Pond EOFFE -SP: Frontier Electric- S Peak EIev= 950.74' Storage =0.101 of Inflow =33.41 cfs 4.470 of Primary=9.72 cfs 2.866 of Secondary=25.21 cfs 1.602 of Outflow =33.18 cfs 4.468 of Existing MSE 24 -hr 3 10 -Year Rainfall= 4.26" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 4 Pond EOFFWP: MN -7 Ditch Peak Elev= 952.92' Storage =0.303 of Inflow =32.48 cfs 4.289 of Outflow =31.86 cfs 4.225 of Rii1n w[r•wiIi1exid: eavyI Inflow =10.10 cfs 1.551 of Primary=10.10 cfs 1.551 of Total Runoff Area = 250.765 ac Runoff Volume = 38.251 of Average Runoff Depth = 1.83" 95.65% Pervious = 239.846 ac 4.35% Impervious = 10.919 ac Existing MSE 24 -hr 3 100 -Year Rainfall= 7.32 Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 5 Time span =0.00 -60.00 hrs, dt =0.01 hrs, 6001 points x 2 Runoff by SCS TR -20 method, UH =SCS, Weighted -CN Reach routing by Dyn -Stor -Ind method - Pond routing by Dyn -Stor -Ind method Subcatchment301S: COL 1 -EDITED RunoffArea= 24.783 ac 0.00% Impervious Runoff Depth= 4.88" Tc =30.0 min CN =79 Runoff = 107.95 cfs 10.075 of Subcatchment302S: COL 2 Runoff Area =1.989 ac 0.00% Impervious Runoff Depth = 5.67" Tc =20.0 min CN =86 Runoff =12.25 cfs 0.940 of Subcatchment603S: GL 3 RunoffArea= 36.364 ac 0.00% Impervious Runoff Depth= 3.89" Tc =21.0 min CN =70 Runoff = 154.34 cfs 11.776 of Subcatchment604S: GL 4 RunoffArea= 27.582 ac 0.00% Impervious Runoff Depth= 3.99" Tc =18.0 min CN =71 Runoff = 130.27 cfs 9.181 of Subcatchment605S: GL 5 Runoff Area =5.097 ac 0.00% Impervious Runoff Depth= 4.32" Tc =20.0 min CN =74 Runoff =24.71 cfs 1.836 of Subcatchment609S: GL 9 RunoffArea =8.595 ac 0.00% Impervious Runoff Depth= 3.56" Tc =15.0 min CN =67 Runoff =39.85 cfs 2.553 of Subcatchment611S: CHAN RunoffArea= 49.667 ac 0.00% Impervious Runoff Depth= 4.77" Tc =40.0 min CN =78 Runoff = 178.17 cfs 19.726 of Subcatchment612S: CHAN 1 RunoffArea= 34.133 ac 0.00% Impervious Runoff Depth= 4.21" Tc =40.0 min CN =73 Runoff= 108.69 cfs 11.982 of Subcatchment6061S: GL 6B RunoffArea= 27.178 ac 0.00% Impervious Runoff Depth= 4.77" Tc =42.0 min CN =78 Runoff =94.51 cfs 10.794 of Subcatchment6062S: GL 6A RunoffArea =1.181 ac 0.00% Impervious Runoff Depth = 5.33" Tc =20.0 min CN =83 Runoff =6.92 cfs 0.525 of SubcatchmentE1: RunoffArea =1.419 ac 40.52% Impervious Runoff Depth= 4.54" Flow Length =542' Tc =14.7 min CN =76 Runoff =8.37 cfs 0.537 of SubcatchmentE1.5: RunoffArea =2.424 ac 31.35% Impervious Runoff Depth= 4.21" Flow Length =411' Tc =10.1 min CN =73 Runoff= 15.82 cfs 0.851 of SubcatchmentE2: RunoffArea =3.518 ac 41.76% Impervious Runoff Depth= 4.54" Flow Length =832' Tc =25.0 min CN =76 Runoff =15.91 cfs 1.332 of SubcatchmentE3: RunoffArea =0.456 ac 51.75% Impervious Runoff Depth= 4.99" Tc =10.0 min CN =80 Runoff =3.47 cfs 0.190 of SubcatchmentE4: RunoffArea =0.318 ac 60.69% Impervious Runoff Depth = 5.33" Tc =10.0 min CN =83 Runoff =2.55 cfs 0.141 of SubcatchmentES: Runoff Area= 1.832 ac 19.27% Impervious Runoff Depth= 3.67" Flow Length =615' Tc =14.5 min CN =68 Runoff =8.84 cfs 0.560 of Existing MSE 24 -hr 3 100 -Year Rainfall= 7.32 Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 6 SubcatchmentE6: Runoff Area =0.681 ac 12.04% Impervious Runoff Depth= 3.14" Tc =10.0 min CN =63 Runoff =3.32 cfs 0.178 of SubcatchmentEOFFE -N: Runoff Area= 1.710 ac 47.78% Impervious Runoff Depth= 4.88" Flow Length =320' Tc =8.0 min CN =79 Runoff= 13.86 cfs 0.695 of SubcatchmentEOFFE -S: Runoff Area= 1.865 ac 26.81% Impervious Runoff Depth= 3.99" Flow Length =490' Tc =17.5 min CN =71 Runoff =8.96 cfs 0.621 of SubcatchmentEOM: Runoff Area= 19.973 ac 29.71% Imperious Runoff Depth= 4.10" Flow Length= 1,890' Tc =36.2 min CN =72 Runoff =65.93 cfs 6.829 of Reach 1R: Channel Avg. Flow Depth= 1.25' Max Vet =2.06 fps Inflow =18.40 cfs 3.595 of n =0.100 L= 100.0' S=0.0246'/' Capacity= 114.91 cfs Outflow= 18.35 cfs 3.595 of Pond 301 P: COL 1 Peak Elev= 946.77' Storage= 20.017 of Inflow= 237.63 cfs 68.309 of Outflow =66.73 cfs 63.264 of Pond 603P: GL 3 Peak Elev= 967.87' Storage= 15.382 of Inflow= 231.38 cfs 23.758 of Outflow =30.94 cfs 19.501 of Pond 604P: GL 4 Peak Elev= 964.57' Storage= 22.209 of Inflow= 254.95 cfs 48.409 of 24.0" Round Culvert n =0.014 L= 150.0' S=0.0050'/' Outflow =31.76 cfs 47.478 of Pond 605P: GL 5 Peak Elev= 987.73' Storage =1.284 of Inflow =24.71 cfs 1.836 of 18.0" Round Culvert n =0.024 L =50.0' S=0.0050'/' Outflow =1.29 cfs 1.535 of Pond 606P: GL 6 Peak Elev= 949.35' Storage =4.163 of Inflow= 121.95 cfs 60.331 of Primary=46.76 cfs 43.053 of Secondary=13.24 cfs 17.218 of Outflow =59.39 cfs 60.270 of Pond 609P: GL 9 Peak EIev= 984.03' Storage =1.605 of Inflow =39.85 cfs 2.553 of Outflow =2.71 cfs 2.389 of Pond E1.5P: Peak EIev= 965.54' Storage =0.041 of Inflow =15.82 cfs 0.851 of Outflow =15.42 cfs 0.837 of Pond E1 P: Peak EIev= 966.28' Storage =0.020 of Inflow =8.37 cfs 0.537 of Primary=4.90 cfs 0.487 of Secondary=3.27 cfs 0.050 of Outflow =7.92 cfs 0.537 of Pond E21P: Peak EIev= 965.35' Storage =1.070 of Inflow =34.37 cfs 2.706 of Primary=5.81 cfs 2.420 of Secondary=5.08 cfs 0.287 of Outflow =10.85 cfs 2.706 of Pond E41P: Peak EIev= 966.08' Storage =0.005 of Inflow =2.55 cfs 0.141 of Primary=2.39 cfs 0.138 of Secondary=0.14 cfs 0.001 of Outflow =2.54 cfs 0.139 of Pond EOFFE -NP: Frontier Electric- N Peak EIev= 951.26' Storage =0.427 of Inflow =84.96 cfs 11.853 of Primary=38.39 cfs 9.823 of Secondary=46.49 cfs 2.030 of Outflow =84.89 cfs 11.853 of Pond EOFFE -SP: Frontier Electric- S Peak EIev= 951.39' Storage =0.198 of Inflow =82.81 cfs 11.160 of Primary=9.36 cfs 4.383 of Secondary=79.74 cfs 6.775 of Outflow =82.75 cfs 11.158 of Existing MSE 24 -hr 3 100 -Year Rainfall= 7.32 Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 7 Pond EOFFWP: MN -7 Ditch Peak Elev= 953.47' Storage =0.492 of Inflow =80.00 cfs 10.603 of Outflow =78.98 cfs 10.539 of Rii1n w[r•wiIi1exid: eavyI Inflow =21.43 cfs 3.773 of Primary=21.43 cfs 3.773 of Total Runoff Area = 250.765 ac Runoff Volume = 91.323 of Average Runoff Depth = 4.37" 95.65% Pervious = 239.846 ac 4.35% Impervious = 10.919 ac OE1.5 � EoFFE_NP EOFFE -N \ E2 Frontier ectric - N zJ 1.5P 2P E1 1P E2Pipe / fl FE-S EoFFE -sa E4 —� 4P / E3 1R E5 Cleared Chase 1L to MnDOT R6 EOffW Subcat Reach on Link MN -7 Ditch ier Electric - S Pre- Watermain_ClearedChannel_2Node MSE 24 -hr 3 1 -Year Rainfall= 2.48" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 2 Time span =0.00 -60.00 hrs, dt =0.01 hrs, 6001 points Runoff by SCS TR -20 method, UH =SCS, Weighted -CN Reach routing by Dyn -Stor -Ind method - Pond routing by Dyn -Stor -Ind method SubcatchmentE1: Runoff Area =1.419 ac 40.52% Impervious Runoff Depth = 0.68" Flow Length =542' Tc =14.7 min CN =76 Runoff =1.18 cfs 0.081 of SubcatchmentE1.5: Runoff Area =2.424 ac 31.35% Impervious Runoff Depth = 0.56" Flow Length =411' Tc =10.1 min CN =73 Runoff =1.88 cfs 0.112 of SubcatchmentE2: Runoff Area =3.518 ac 41.76% Impervious Runoff Depth = 0.68" Flow Length =832' Tc =25.0 min CN =76 Runoff =2.19 cfs 0.200 of SubcatchmentE3: Runoff Area =0.456 ac 51.75% Impervious Runoff Depth = 0.88" Tc =10.0 min CN =80 Runoff =0.61 cfs 0.033 of SubcatchmentE4: Runoff Area =0.318 ac 60.69% Impervious Runoff Depth= 1.04" Tc =10.0 min CN =83 Runoff =0.51 cfs 0.028 of SubcatchmentE5: Runoff Area =1.832 ac 19.27% Impervious Runoff Depth = 0.38" Flow Length =615' Tc =14.5 min CN =68 Runoff =0.68 cfs 0.058 of SubcatchmentE6: Runoff Area =0.681 ac 12.04% Impervious Runoff Depth= 0.24" Tc =10.0 min CN =63 Runoff =0.13 cfs 0.013 of SubcatchmentEOFFE -N: Runoff Area= 1.710 ac 47.78% Impervious Runoff Depth = 0.82" Flow Length =320' Tc =8.0 min CN =79 Runoff =2.35 cfs 0.117 of SubcatchmentEOFFE -S: Runoff Area= 1.865 ac 26.81% Impervious Runoff Depth = 0.48" Flow Length =490' Tc =17.5 min CN =71 Runoff =0.89 cfs 0.075 of SubcatchmentEOffW: Runoff Area= 19.973 ac 29.71% Imperious Runoff Depth = 0.52" Flow Length= 1,890' Tc =36.2 min CN =72 Runoff =7.01 cfs 0.863 of Reach 1 R: Cleared Channel Avg. Flow Depth =0.62' Max Vet =1.00 fps Inflow =3.49 cfs 0.493 of n =0.100 L= 100.0' S= 0.0125 T Capacity =81.91 cfs Outflow =3.44 cfs 0.493 of Pond E1.5P: Peak Elev= 965.21' Storage =0.018 of Inflow =1.88 cfs 0.112 of Outflow =1.66 cfs 0.099 of Pond E1 P: Peak Elev= 964.93' Storage =0.000 of Inflow =1.18 cfs 0.081 of Primary=1.18 cfs 0.081 of Secondary=0.00 cfs 0.000 of Outflow =1.18 cfs 0.081 of Pond E21P: Peak Elev= 963.57' Storage =0.093 of Inflow =3.30 cfs 0.299 of Primary=0.00 cfs 0.000 of Secondary=0.92 cfs 0.294 of Tertiary=0.00 cfs 0.000 of Outflow =0.92 cfs 0.294 of Pond E2Pipe: Peak Elev= 961.88' Storage =0.001 of Inflow =1.90 cfs 0.375 of Primary=1.90 cfs 0.375 of Secondary=0.00 cfs 0.000 of Outflow =1.90 cfs 0.375 of Pond E4P: Peak Elev= 964.60' Storage =0.001 of Inflow =0.51 cfs 0.028 of Primary=0.51 cfs 0.028 of Secondary=0.00 cfs 0.000 of Outflow =0.51 cfs 0.028 of Pre- Watermain_ClearedChannel_2Node MSE 24 -hr 3 1 -Year Rainfall= 2.48" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 3 Pond EOFFE -NP: Frontier Electric- N Peak Elev= 947.12' Storage =0.012 of Inflow =8.96 cfs 1.496 of Primary=8.95 cfs 1.496 of Secondary=0.00 cfs 0.000 of Outflow =8.95 cfs 1.496 of Pond EOFFE -SP: Frontier Electric- S Peak Elev= 949.99' Storage =0.040 of Inflow =8.78 cfs 1.380 of Primary=7.65 cfs 1.358 of Secondary=1.01 cfs 0.021 of Outflow =8.65 cfs 1.379 of Pond EOFFWP: MN -7 Ditch Peak Elev= 952.42' Storage =0.173 of Inflow =9.05 cfs 1.369 of Outflow =8.41 cfs 1.306 of Rii1n w[r•wiIi1exid: eavyI Inflow =3.57 cfs 0.507 of Primary=3.57 cfs 0.507 of Total Runoff Area = 34.196 ac Runoff Volume = 1.580 of Average Runoff Depth = 0.55" 68.07% Pervious = 23.277 ac 31.93% Impervious = 10.919 ac Pre- Watermain_ClearedChannel_2Node MSE 24 -hr 3 2 -Year Rainfall= 2.86" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 4 Time span =0.00 -60.00 hrs, dt =0.01 hrs, 6001 points Runoff by SCS TR -20 method, UH =SCS, Weighted -CN Reach routing by Dyn -Stor -Ind method - Pond routing by Dyn -Stor -Ind method SubcatchmentE1: Runoff Area =1.419 ac 40.52% Impervious Runoff Depth = 0.92" Flow Length =542' Tc =14.7 min CN =76 Runoff =1.64 cfs 0.109 of SubcatchmentE1.5: Runoff Area =2.424 ac 31.35% Impervious Runoff Depth = 0.77" Flow Length =411' Tc =10.1 min CN =73 Runoff =2.74 cfs 0.156 of SubcatchmentE2: Runoff Area =3.518 ac 41.76% Impervious Runoff Depth = 0.92" Flow Length =832' Tc =25.0 min CN =76 Runoff =3.06 cfs 0.270 of SubcatchmentE3: Runoff Area =0.456 ac 51.75% Impervious Runoff Depth= 1.15" Tc =10.0 min CN =80 Runoff =0.81 cfs 0.044 of SubcatchmentE4: Runoff Area =0.318 ac 60.69% Impervious Runoff Depth= 1.33" Tc =10.0 min CN =83 Runoff =0.66 cfs 0.035 of SubcatchmentE5: Runoff Area= 1.832 ac 19.27% Impervious Runoff Depth = 0.56" Flow Length =615' Tc =14.5 min CN =68 Runoff =1.12 cfs 0.085 of SubcatchmentE6: Runoff Area =0.681 ac 12.04% Impervious Runoff Depth= 0.38" Tc =10.0 min CN =63 Runoff =0.27 cfs 0.021 of SubcatchmentEOFFE -N: Runoff Area= 1.710 ac 47.78% Impervious Runoff Depth= 1.09" Flow Length =320' Tc =8.0 min CN =79 Runoff =3.14 cfs 0.155 of SubcatchmentEOFFE -S: Runoff Area= 1.865 ac 26.81% Impervious Runoff Depth = 0.68" Flow Length =490' Tc =17.5 min CN =71 Runoff =1.35 cfs 0.106 of SubcatchmentEOffW: Runoff Area= 19.973 ac 29.71% Imperious Runoff Depth = 0.73" Flow Length= 1,890' Tc =36.2 min CN =72 Runoff =10.39 cfs 1.209 of Reach 1 R: Cleared Channel Avg. Flow Depth =0.73' Max Vet =1.10 fps Inflow =4.74 cfs 0.680 of n =0.100 L= 100.0' S=0.0125'/' Capacity =81.91 cfs Outflow =4.69 cfs 0.680 of Pond E1.5P: Peak Elev= 965.24' Storage =0.019 of Inflow =2.74 cfs 0.156 of Outflow =2.62 cfs 0.143 of Pond E1 P: Peak Elev= 964.96' Storage =0.000 of Inflow =1.64 cfs 0.109 of Primary=1.64 cfs 0.109 of Secondary=0.00 cfs 0.000 of Outflow =1.64 cfs 0.109 of Pond E21P: Peak Elev= 963.81' Storage =0.159 of Inflow =4.72 cfs 0.413 of Primary=0.00 cfs 0.000 of Secondary=0.98 cfs 0.408 of Tertiary=0.00 cfs 0.000 of Outflow =0.98 cfs 0.408 of Pond E2Pipe: Peak EIev= 962.00' Storage =0.001 of Inflow =2.38 cfs 0.517 of Primary=2.38 cfs 0.517 of Secondary=0.00 cfs 0.000 of Outflow =2.38 cfs 0.517 of Pond E4P: Peak EIev= 964.65' Storage =0.001 of Inflow =0.66 cfs 0.035 of Primary=0.65 cfs 0.035 of Secondary=0.00 cfs 0.000 of Outflow =0.65 cfs 0.035 of Pre- Watermain_ClearedChannel_2Node MSE 24 -hr 3 2 -Year Rainfall= 2.86" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 5 Pond EOFFE -NP: Frontier Electric- N Peak Elev= 947.58' Storage =0.017 of Inflow =13.38 cfs 2.106 of Primary= 13.37 cfs 2.105 of Secondary=0.00 cfs 0.000 of Outflow= 13.37 cfs 2.105 of Pond EOFFE -SP: Frontier Electric- S Peak EIev= 950.24' Storage =0.054 of Inflow =13.08 cfs 1.953 of Primary=8.47 cfs 1.795 of Secondary=4.49 cfs 0.156 of Outflow =12.95 cfs 1.951 of Pond EOFFWP: MN -7 Ditch Peak EIev= 952.54' Storage =0.200 of Inflow =13.02 cfs 1.910 of Outflow =12.47 cfs 1.847 of Rii1mlnr•wiIi1exid: eavyI Inflow =4.94 cfs 0.702 of Primary=4.94 cfs 0.702 of Total Runoff Area = 34.196 ac Runoff Volume = 2.190 of Average Runoff Depth = 0.77" 68.07% Pervious = 23.277 ac 31.93% Impervious = 10.919 ac 609S -> so9 GL GL E1.5 E2 1.5 E5 E6 Channel\ \ YYYJJJ 1 L Is\ EOflW toto M� I 301S 302S COL 1 -EDIT /COL 2 01 606 60625 p I GL6 / G 60615 604 GL 6B V-�� 603S 603 o-� EoFFE -n Frontier ectnc - N eorre -s 605 �— 605S GL GI-5 MN -7 Ditch Subcat Reach on Link Electric - S 611S 604S CHAN GI-4 1 3 GL3 612S CHAN 1 Pre- Watermain_ClearedChannel MSE 24 -hr 3 10 -Year Rainfall= 4.26" Prepared by WSB & Associates, Inc. Printed 1/9/2019 HydroCAD® 10.00 -19 s/n 00883 @2016 HydroCAD Software Solutions LLC Page 2 Time span =0.00 -60.00 hrs, dt =0.01 hrs, 6001 points Runoff by SCS TR -20 method, UH =SCS, Weighted -CN Reach routing by Dyn -Stor -Ind method - Pond routing by Dyn -Stor -Ind method Subcatchment301S: COL 1 -EDITED RunoffArea= 24.783 ac 0.00% Impervious Runoff Depth= 2.18" Tc =30.0 min CN =79 Runoff =48.41 cfs 4.495 of Subcatchment302S: COL 2 Runoff Area =1.989 ac 0.00% Impervious Runoff Depth= 2.78" Tc =20.0 min CN =86 Runoff =6.17 cfs 0.461 of Subcatchment603S: GL 3 RunoffArea= 36.364 ac 0.00% Impervious Runoff Depth= 1.51" Tc =21.0 min CN =70 Runoff =57.72 cfs 4.564 of Subcatchment604S: GL 4 RunoffArea= 27.582 ac 0.00% Impervious Runoff Depth= 1.57" Tc =18.0 min CN =71 Runoff =50.10 cfs 3.620 of Subcatchment605S: GL 5 Runoff Area =5.097 ac 0.00% Impervious Runoff Depth= 1.79" Tc =20.0 min CN =74 Runoff =10.08 cfs 0.760 of Subcatchment609S: GL 9 RunoffArea =8.595 ac 0.00% Impervious Runoff Depth= 1.31" Tc =15.0 min CN =67 Runoff= 13.94 cfs 0.937 of Subcatchment611S: CHAN RunoffArea= 49.667 ac 0.00% Impervious Runoff Depth= 2.10" Tc =40.0 min CN =78 Runoff =78.40 cfs 8.676 of Subcatchment612S: CHAN 1 RunoffArea= 34.133 ac 0.00% Impervious Runoff Depth= 1.72" Tc =40.0 min CN =73 Runoff =43.33 cfs 4.883 of Subcatchment6061S: GL 6B RunoffArea= 27.178 ac 0.00% Impervious Runoff Depth= 2.10" Tc =42.0 min CN =78 Runoff =41.39 cfs 4.748 of Subcatchment6062S: GL 6A Runoff Area =1.181 ac 0.00% Impervious Runoff Depth= 2.51" Tc =20.0 min CN =83 Runoff =3.33 cfs 0.247 of SubcatchmentE1: RunoffArea =1.419 ac 40.52% Impervious Runoff Depth= 1.94" Flow Length =542' Tc =14.7 min CN =76 Runoff =3.58 cfs 0.229 of SubcatchmentE1.5: RunoffArea =2.424 ac 31.35% Impervious Runoff Depth= 1.72" Flow Length =411' Tc =10.1 min CN =73 Runoff =6.43 cfs 0.347 of SubcatchmentE2: RunoffArea =3.518 ac 41.76% Impervious Runoff Depth= 1.94" Flow Length =832' Tc =25.0 min CN =76 Runoff =6.75 cfs 0.569 of SubcatchmentE3: RunoffArea =0.456 ac 51.75% Impervious Runoff Depth= 2.26" Tc =10.0 min CN =80 Runoff =1.60 cfs 0.086 of SubcatchmentE4: RunoffArea =0.318 ac 60.69% Impervious Runoff Depth= 2.51" Tc =10.0 min CN =83 Runoff= 1.24 cfs 0.067 of SubcatchmentES: Runoff Area= 1.832 ac 19.27% Impervious Runoff Depth= 1.37" Flow Length =615' Tc =14.5 min CN =68 Runoff =3.17 cfs 0.210 of