City of Shorewood, MN Smithtown Stormwater Runoff Management Facilities Feasibility Report City Project No. 19-09 January 2021

Submitted by: Bolton & Menk, Inc. 2638 Shadow Lane Suite 200 Chaska, MN 55318 P: 952-448-8838 F: 952-488-8805

Certification

Feasibility Report

For

Smithtown Pond

City of Shorewood Hennepin County City Project No. 19-09 BMI Project No. C16.121587

January 19, 2021

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.

By: Andrew Budde, P.E. License No. 46585

Date: 1/19/2021

Prepared by: Bolton & Menk, Inc. Certification Smithtown Stormwater Management Improvements C16.121587

Table of Contents I. EXECUTIVE SUMMARY ...... 1 Background and Introduction...... 1 Proposed Improvements ...... 1 Permitting Requirements ...... 3 Potential Funding Opportunities ...... 3 II. BACKGROUND AND INTRODUCTION ...... 3 III. PROPOSED IMPROVEMENTS ...... 5 Smithtown Road Wet Retention Pond(s) and Freeman Park Channel Stabilization ...... 5 Freeman Park Outlet ...... 8 Other Potential Improvement Options ...... 8 Potential Improvements Comparison ...... 10 Landscape Impacts ...... 11 IV. PERMITTING REQUIREMENTS ...... 11 Minnehaha Creek Watershed District ...... 11 MPCA ...... 12 Army Corps of Engineers (ACOE) ...... 12 V. POTENTIAL FUNDING OPPORTUNITIES ...... 12 Hennepin County Opportunity Grant ...... 12 Minnesota Board of Water and Soil Resources (BWSR) Clean Water Fund Competitive Grant – Project and Practices ...... 12 Met Council ...... 12 Minnehaha Creek Watershed District (MCWD) ...... 12 VI. RECOMMENDATION ...... 12

Appendix Appendix A: Figures Appendix B: Preliminary Cost Estimates Appendix C: Hydrographs Appendix D: WQ Calculations and Drainage Area Maps Appendix E: BMI Neighborhood Drainage Evaluation

Prepared by: Bolton & Menk, Inc. Table of Contents Smithtown Stormwater Management Improvements C16.121587

I. EXECUTIVE SUMMARY Background and Introduction. As requested by the City of Shorewood, Bolton & Menk, Inc. has evaluated the feasibility of constructing new stormwater runoff detention and water quality treatment facilities between Smithtown Road and Freeman Park (Parcel No. 3211723420004) to improve or resolve multiple drainage issues in the area. The ultimate goal of the City is to construct stormwater runoff management facilities at this location that will reduce flows downstream, lower flooding potential upstream, improve water quality, meet governmental requirements for Strawberry Lane improvements, and provide aesthetic and recreational value (see Appendix A for Figures). Proposed Improvements Proposed improvements include maintenance activities in the existing Freeman Park wetland, including grading of a small basin on the north side of Freeman Park abutting the south side of the HCRRA Trail, replacement of the outlet control structure under the trail, stabilization of the channel north of the trail, and installation of wet retention pond(s) on the property at 26245 Smithtown Road (Parcel No. 3211723420004). 1. Smithtown Road Wet Retention Pond(s) and Freeman Park Channel Stabilization Under existing conditions, runoff from the north Strawberry Lane neighborhood drains to a channel east of the road, identified as Pebble Creek. Pebble Creek conveys flow to the culvert crossings at Smithtown Road and the Grant Lorenz Channel downstream of the crossings. Immediately upstream of the crossing, Pebble Creek merges with the drainage way conveying flow from Freeman Park, identified as the Freeman Park Channel for purposes of this report. Pebble Creek, Freeman Park Channel, and the Grant Lorenz Channel experience erosive flows during larger rainfall events resulting in severe gully erosion in the drainage ways. Strawberry Lane has a rural section with minimal storm sewer resulting in extended durations of inundation in low areas during wet periods. In addition, a large portion of existing impervious surface does not receive treatment to remove pollutants prior to discharge downstream. As part of the Smithtown Stormwater Runoff Management Facilities improvements, construction of a wet retention pond(s) at 26245 Smithtown Road connected to the Strawberry Lane storm sewer system is proposed to reduce flows in the Pebble Creek and Grant Lorenz Channel and provide additional water quality treatment of runoff prior to discharge. Additional improvements to minimize flooding potential on Strawberry Lane (i.e. urban street section, storm sewer, catchbasins, ditch cleaning, etc.) are to be addressed as part of the Strawberry Lane Street and Utility improvements. However, facilities at the 26245 Smithtown Road site are proposed to provide sufficient storage and treatment to meet needs upstream as well as reduce flows downstream. Bolton & Menk analyzed three options for these stormwater runoff management facilities as follows: Option A: Single Cell with Overflow Pipe from Freeman Park This option utilizes a single wet retention pond on the southwest side of the parcel. Flow from Freeman Park would bypass the pond to the east in the existing Freeman Park Channel. The Freeman Park Channel would be cleaned and stabilized at current elevations and a new culvert installed under the proposed trail (proposed

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in location of current driveway) prior to connection to Pebble Creek. An overflow pipe from Freeman Park to the Smithtown Pond Basin, installed at the 10-year high water elevation of the Freeman Park Basin, would allow for reduction of flows in the Freeman Park Channel and lowering of the high water level in Freeman Park. The Smithtown Basin would be connected to new storm sewer from Strawberry Lane, routing flow that would have drained to Pebble Creek through the pond prior to discharge back to Pebble Creek directly upstream of Smithtown Road. Option B: Single Cell with Connection to Freeman Park This option utilizes a single wet retention pond connected to the Freeman Park Channel. The profile of the Freeman Park Channel would be lowered with riprap grade drops to connect with the proposed Smithtown Basin normal water level, and the channel side slopes would be stabilized. Lowering and stabilization of the Freeman Park Channel would allow for higher flows from the Freeman Park Basin, thus eliminating the need for an overflow pipe while still limiting high water level in the Shorewood Oaks neighborhood. The Smithtown Basin would be connected to new storm sewer from Strawberry Lane, routing flow that would have drained to Pebble Creek through the pond prior to discharge back to Pebble Creek directly upstream of Smithtown Road. Option C: Two Cell with Connection to Freeman Park This option utilizes two wet retention ponds, with the lower cell connected to the Freeman Park Channel. The profile of the Freeman Park Channel would be lowered with riprap grade drops to connect with the proposed normal water level of the lower cell, and the channel side slopes would be stabilized. Lowering and stabilization of the Freeman Park Channel would allow for higher flows from the Freeman Park Basin, thus eliminating the need for an overflow pipe while still limiting high water level in the Shorewood Oaks neighborhood. The upper cell would be connected to new storm sewer from Strawberry Lane, routing flow that would have drained to Pebble Creek through the ponds prior to discharge back to Pebble Creek directly upstream of Smithtown Road. 2. Freeman Park Wet Retention Pond and Outlet Control Structure Under existing conditions, runoff from the south Strawberry Lane, Shorewood Oaks, Shorewood Ponds, Hendrickson Acres, and Freeman Park neighborhoods drain to the outlet control structure on the northwest side of Freeman Park controlling flow under the HCRRA trail. The downstream Freeman Park Channel connects with Pebble Creek immediately south of Smithtown Road prior to discharge under the street. The Freeman Park outlet control structure experiences frequent clogging due to vegetation and sedimentation, and the design contributes to erosive flows in the Freeman Park Channel. In addition, this structure controls high water elevations upstream, with potential inundation impacts to Freeman Park’s interior trails and the Shorewood Oaks neighborhood. As part of the Smithtown Stormwater Runoff Management Facilities improvements, construction of a wet retention pond adjacent to the south side of the HCRRA Trail and replacement of the outlet control structure to the Freeman Park Channel are proposed to reduce clogging potential while maintaining the high water level below existing conditions and releasing non-erosive flows downstream.

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3. Other Potential Improvements Although the proposed Smithtown Pond(s) and Freeman Park outlet structure improvements will greatly improve flow conditions and water quality in the watershed, a couple additional improvements that would increase benefits or improve flow conditions more have been evaluated. An Iron Enhanced Sand Filter installed on the Smithtown Pond would greatly improve pollutant load reductions, especially dissolved phosphorus. Disconnection of the Shorewood Oaks footing drain system from the adjacent storm sewer system and installation of a new connection directly to the Smithtown Pond(s) would greatly reduce the potential for surcharging of the footing drain system. 4. Landscape Impacts During the design and review of the pond options included in this study a significant effort was made to reduce the impact to existing trees whenever possible. Each option was also reviewed for potential landscaping improvements to provide the appearance of a natural ecosystem suited to this location. Permitting Requirements Permits will be required from Minnehaha Creek Watershed District (MCWD), the Minnesota Pollution Control Agency, and the Army Corps of Engineers (ACOE). The project will need to comply with erosion control, stormwater runoff management, waterbody crossings and structures, and wetland requirements of the listed agencies. Potential Funding Opportunities Hennepin County, Board of Soil and Water Resources, Metropolitan Council, and Minnehaha Creek Watershed District may offer opportunities for collaboration and cost sharing.

II. BACKGROUND AND INTRODUCTION To improve or resolve multiple drainage issues in western Shorewood, the City has requested Bolton & Menk, Inc. evaluate the feasibility of constructing new stormwater runoff detention and water quality treatment facilities at 26245 Smithtown Road (Parcel No. 3211723420004). The Western Shorewood Stormwater Management Plan (dated June 22, 2020) identified several historic and ongoing problem drainage issues in this area, including the Grant Lorenz Channel downstream of Smithtown Road and the Shorewood Oaks, Strawberry Lane, Alexander Lane, and Freeman Park neighborhoods upstream. In addition, Bolton & Menk completed a field review of these areas as part of this evaluation to further detail issues previously outlined and identify any other drainage issues present within the watershed (see Appendix E). Specifically, the following major drainage issues were identified: 1. Grant Lorenz Channel, Pebble Creek, and Freeman Park Channel Erosion The Grant Lorenz Channel conveys runoff along Grant Lorenz Road from Smithtown Road north to Noble Road. Pebble Creek conveys runoff from the Strawberry Lane storm sewer outfall on the northeast corner of 5915 Strawberry Lane to the culvert crossings at Smithtown Road. The Freeman Park Channel conveys runoff along the northeast property line of 26245 Smithtown Road from Freeman Park to Pebble Creek, connecting directly downstream of the Smithtown Road culverts. The total watershed area upstream of the Smithtown Road culvert crossings is approximately 262 acres. Poorly vegetated banks in combination with erosive flows have resulted in ongoing erosion of side slopes, downcutting of

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channel beds, sedimentation of the downstream wetland, and overtopping of the banks. 2. Shorewood Oaks footing drain collection system Flooding Approximately 50 residences in the Shorewood Oaks neighborhood are served by a footing drain collection system connected to the storm sewer in Shorewood Oaks Drive and ultimately routed north to the existing Freeman Park outlet control structure. Due to the low elevation of the footing drain system connection to the storm sewer, large or intense rainfall events can result in the storm sewer surcharging the footing drain system, resulting in flooding of private property. 3. Extended Inundation in Low Areas Adjacent to Strawberry Lane Strawberry Lane consists of a rural section with minimal storm sewer and inlets. Due to extremely flat topography or lack of a positive outlet, several low areas adjacent to the road and in rear yards experience prolonged inundation during wet periods. During field evaluation of current drainage conditions, pond outlets for the Strawberry Gardens and Shorewood Suburban Estates (Strawberry Court) were observed to be partially clogged, and due to their age, sediment may be reducing their treatment effectiveness. These ponds are currently being assessed as part of the City’s overall stormwater treatment ponds assessment. Strawberry Court floods frequently during larger rainfall events or spring melt, resulting in premature degradation of the street section. Potential tile blockages or breaks northeast of Strawberry Circle may be contributing to prolonged and increased inundation in the rear yards between Strawberry Lane and Cathcart Drive north of the HCRRA Trail. A large portion of the south Strawberry Lane watershed is connected to the Shorewood Oaks storm sewer, contributing to that neighborhood’s footing drain collection system issues. The rear yards north of Maple Avenue are extremely flat with no positive outlet. 4. Freeman Park Outlet Control Structure Repair and Maintenance The Freeman Park outlet control structure causes significant and ongoing maintenance issues for the City. Sediment has filled the low area adjacent to the structure and vegetation and debris collects against the outlet thus blocking flow. Reduced capacity of this outlet impacts water levels in Shorewood Oaks storm sewer, exacerbating flooding conditions in the footing drain collection system, as well as resulting in inundation of Freeman Park trails. When operating at full capacity, the Freeman Park channel downstream experiences erosive flows. 5. Drainage Ways Clogged with Vegetation Drainage ways in the entire neighborhood are clogged with vegetation, especially ditches adjacent to the HCRRA Trail. Trail ditches have become overgrown with vegetation and are littered with deadfall, which is inhibiting flow and creating areas of standing water. The Western Shorewood Stormwater Management Plan also reviewed several drainage improvement alternatives and recommended preferred solutions for each major issue. One solution, construction of a wet retention pond at 26245 Smithtown Road, was determined to improve or resolve multiple drainage issues identified. Construction of stormwater runoff management facilities at this location would reduce erosive flows in Pebble Creek and the Grant Lorenz Channel, lower flooding potential in upstream neighborhoods, improve water quality, meet governmental requirements for Strawberry Lane improvements, and

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provide aesthetic and recreational value. Additional improvements to minimize flooding potential on Strawberry Lane and the adjacent neighborhood (i.e. urban street section, storm sewer, catchbasins, ditch cleaning, etc.) are to be addressed as part of the Strawberry Lane Street and Utility improvements. All improvements addressed within this report are feasible from a technical standpoint. All proposed design options are constructed based on existing utility, topography, and parcel information. The improvements are necessary to provide adequate storm water runoff management and treatment for the adjacent properties and represent cost effective solutions for doing so.

III. PROPOSED IMPROVEMENTS The City of Shorewood purchased the approximately 5-acre parcel at 26245 Smithtown Road to allow for construction of regional stormwater management facilities to improve or resolve multiple drainage issues in the Western Shorewood area, as outlined in Section II . Proposed improvements include grading of a small basin on the north side of Freeman Park abutting the south side of the HCRRA Trail, replacement of the outlet control structure under the HCRRA trail, stabilization of the channel north of the HCRRA trail, and installation of a wet retention pond(s) on the property at 26245 Smithtown Road (Parcel No. 3211723420004). Watershed modeling completed for the Western Shorewood Stormwater Management Plan by Barr Engineering Co. was used as the basis for this project analysis. The modeling was then refined utilizing survey information obtained in the summer of 2020 to accurately define drainage way elevations and topography for potential pond options. The 2, 10, and 100-year 24-hour rainfall events were modeled to evaluate options listed (see Appendix C for hydrographs). Smithtown Road Wet Retention Pond(s) and Freeman Park Channel Stabilization Under existing conditions, 71 acres from the north Strawberry Lane neighborhood drain to a channel east of the road, identified as Pebble Creek. Pebble Creek conveys flow to the culvert crossings at Smithtown Road and the Grant Lorenz Channel downstream of the crossings. Immediately upstream of the crossing, Pebble Creek merges with the drainage way conveying flow from Freeman Park, identified as the Freeman Park Channel for purposes of this report. The culvert under the HCRRA Trail from Freeman park conveys runoff from 170 acres south of the trail to the Freeman Park Channel. An additional 21 acres from the Smithtown Lane neighborhood also drains to the Smithtown Road culvert crossings, making the total watershed upstream of crossings 262 acres. Pebble Creek, Freeman Park Channel, and the Grant Lorenz Channel experience erosive flows during larger rainfall events resulting in severe gully erosion in the drainage ways. Strawberry Lane has a rural section with minimal storm sewer resulting in extended durations of inundation in low areas during wet periods. In addition, only 37% of existing impervious surface (24.7 acres) and 29% of the total watershed (76.6 acres) receives treatment to remove pollutants prior to discharge downstream. As part of the Smithtown Stormwater Runoff Management Facilities improvements, construction of a wet retention pond(s) at 26245 Smithtown Road connected to the Strawberry Lane storm sewer system is proposed to reduce flows in the Pebble Creek and Grant Lorenz Channel and provide additional water quality treatment of runoff prior to discharge. Additional improvements to minimize flooding potential on Strawberry Lane (i.e. urban street section, storm sewer, catchbasins, ditch cleaning, etc.) are to be addressed as part of the Strawberry Lane Street and Utility improvements. However, facilities at the 26245 Smithtown Road site are proposed to provide sufficient storage and treatment to meet needs upstream as well as reduce flows downstream. Bolton & Menk analyzed three options for these stormwater runoff management facilities. By directing runoff from the Strawberry Lane storm sewer system to a

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pond(s) at this location, a large reduction in runoff volume to Pebble Creek (approximately 70%) is achieved for all options, eliminating the need to restore or stabilize Pebble Creek and prevent further erosion. In addition, the three options are further outlined as follows: Option A: Single Cell with Overflow Pipe from Freeman Park This option utilizes a single wet retention pond on the southwest side of the parcel. Flow from Freeman Park would bypass the pond to the east in the existing Freeman Park Channel. Proposed improvements would include construction of the pond, installation of an outlet control structure connecting the pond to Pebble Creek, cleaning and stabilization of the Freeman Park Channel at current elevations, installation of a new culvert connecting the Freeman Park Channel to Pebble Creek under the proposed trail (at current driveway location), and installation of a new pipe installed under the HCRRA Trail to the pond at the estimated 10- year highwater elevation of the Freeman Park Basin. Installation of these improvements (and the Freeman Park Basin improvements) would result in a 43% reduction of the Freeman Park Channel estimated 100-year flow rate and a 32% reduction in the Grant Lorenz Channel for the same event. The estimated 100-yr highwater level on the south side of the HCRRA Trail would be maintained just below existing conditions. Refer to Table 1 for a flow characteristic comparison for the various options. Refer to Appendix C for hydrographs for the 2, 10, and 100-year 24-hour rainfall events. By installing the overflow pipe to the pond, only cleaning and minimal stabilization of the existing channel at current elevations would be necessary to accommodate future reduced flows, resulting in minimal impact along the east property line. By increasing the treatment of impervious area to 49% (32.6 acres) and total area to 39% (101.8 acres), a 9% reduction in the Total Suspended Solids (TSS) load and 5% in Total Phosphorus would be achieved, improving overall water quality and meeting future needs for Strawberry Lane improvements. Refer to Table 2 for a water quality comparison for the various options. Refer to Appendix D for water quality figures and calculations. The estimated cost to construct these proposed improvements is $1,225,000 (see Appendix B for itemized breakdowns). The pond layout for this option utilizes the majority of the area west of the Freeman Park Channel, but the storage volume could be increased and the flow rate downstream further reduced at the expense of further excavation, land clearing, and contouring. Since the south side of the basin has a maximum depth of 3’, emergent vegetation will fill in this area. Option B: Single Cell with Connection to Freeman Park This option utilizes a single wet retention pond on the northwest side of the parcel connected to the Freeman Park Channel. Proposed improvements would include construction of the pond, installation of an outlet control structure connecting the pond to Pebble Creek, lowering of the Freeman Park Channel profile with riprap grade drops and stabilization of the channel bottom and side slopes, Installation of these improvements (and the Freeman Park Basin improvements) would result in a 15% reduction of the Freeman Park Channel estimated 100-year flow rate and a 16% reduction in the Grant Lorenz Channel for the same event. The estimated 100-yr highwater level on the south side of the HCRRA Trail would be maintained just below existing conditions. Refer to Table 1 for a flow characteristic comparison for the various options. Refer to Appendix C for hydrographs for the 2, 10, and 100-year 24-hour rainfall events. Lowering of the Freeman Park Channel profile and channel stabilization would require less flow reduction from the Freeman Park Basin to limit erosion and accommodate adjacent low openings. This eliminates the need for an overflow pipe while still limiting the highwater level in the Shorewood Oaks neighborhood. Installation of riprap grade drops would allow the profile

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lowering to be achieved while still maintaining channel integrity. A 30’ buffer of existing trees could be maintained on the east property line adjacent to the pond to provide screening from Smithtown Road. The Smithtown Basin would be connected to new storm sewer from Strawberry Lane, routing flow that would have drained to Pebble Creek through the pond prior to discharge back to Pebble Creek directly upstream of Smithtown Road. By connecting the pond to both the Strawberry Lane and Freeman Park watersheds, the treated impervious area is increased to 92% (61.6 acres, and the total area treated is increased to 94% (244.7 acres). This results in a 41% reduction in the Total Suspended Solids (TSS) load and 23% in Total Phosphorus, greatly improving overall water quality and meeting future needs for Strawberry Lane improvements. Refer to Table 2 for a water quality comparison for the various options. Refer to Appendix D for water quality figures and calculations. The estimated cost to construct these proposed improvements is $1,638,000 (see Appendix B for itemized breakdowns). The pond layout for this option utilizes the majority of the area west of the Freeman Park Channel, but the storage volume could be increased and the flow rate downstream further reduced at the expense of further excavation, land clearing, and contouring. This option also combines areas of open water to the north and a large area for emergent vegetation on the south. Option C: Two Cell with Connection to Freeman Park This option utilizes two wet retention ponds, with the lower cell connected to the Freeman Park Channel. Proposed improvements would include construction of the ponds, installation of outlet control structures connecting the upper cell to the lower cell and the lower cell to Pebble Creek, lowering of the Freeman Park Channel profile with riprap grade drops and stabilization of the channel bottom and side slopes. Installation of these improvements (and the Freeman Park Basin improvements) would result in a 15% reduction of the Freeman Park Channel estimated 100-year flow rate and a 23% reduction in the Grant Lorenz Channel for the same event. The estimated 100-yr highwater level on the south side of the HCRRA Trail would be maintained just below existing conditions. Refer to Table 1 for a flow characteristic comparison for the various options. Refer to Appendix C for hydrographs for the 2, 10, and 100-year 24-hour rainfall events. Lowering of the Freeman Park Channel profile and channel stabilization would require less flow reduction from the Freeman Park Basin to limit erosion and accommodate adjacent low openings. This eliminates the need for an overflow pipe while still limiting the highwater level in the Shorewood Oaks neighborhood. Installation of riprap grade drops would allow the profile lowering to be achieved while still maintaining channel integrity. A 30’ buffer of existing trees would be maintained on the east property line adjacent to the lower cell to provide screening from Smithtown Road. The Smithtown Basin would be connected to new storm sewer from Strawberry Lane, routing flow that would have drained to Pebble Creek through the pond prior to discharge back to Pebble Creek directly upstream of Smithtown Road. By connecting the ponds to both the Strawberry Lane and Freeman Park watersheds, the treated impervious area is increased to 92% (61.6 acres, and the total area treated is increased to 94% (244.7 acres). This results in a 45% reduction in the Total Suspended Solids (TSS) load and 25% in Total Phosphorus, improving overall water quality and meeting future needs for Strawberry Lane improvements. Refer to Table 2 for a water quality comparison for the various options. Refer to Appendix D for water quality figures and calculations. The estimated cost to construct these proposed improvements is $1,657,000 (see Appendix B for itemized breakdowns). The pond layout for this option utilizes most of the parcel, but the storage volume could be increased, and the flow rate downstream further reduced at the expense of further excavation, land clearing, and contouring. This option combines areas of open water with shallow areas along the sides for emergent vegetation.

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Freeman Park Outlet Under existing conditions, approximately 170 acres from the south Strawberry Lane, Shorewood Oaks, Shorewood Ponds, Hendrickson Acres, and Freeman Park neighborhoods drain to the outlet control structure on the northwest side of Freeman Park controlling flow under the HCRRA trail. The downstream Freeman Park Channel connects with Pebble Creek immediately south of Smithtown Road prior to discharge under the street. The Freeman Park outlet control structure experiences frequent clogging due to vegetation and sedimentation, and the design contributes to erosive flows in the Freeman Park Channel. This structure also controls high water elevations upstream, with potential inundation impacts to Freeman Park’s interior trails and the Shorewood Oaks neighborhood. In addition, easy access is not available making maintenance of the structure difficult. Proposed improvements would include excavation to create a pond permanent pool, removal of the existing outlet control structure, and installation of a new outlet control structure. By installing a wet retention pond, a submerged pipe to the outlet structure can be utilized to greatly reduce the potential for clogging. A re-configuration of the outlet structure itself will reduce peak runoff rates downstream in the Freeman Park Channel while maintaining highwater elevations upstream at just below current levels. In addition, construction of the basin provides an opportunity to reconfigure the system to include access for easy maintenance and removal of accumulated vegetation. The estimated cost to construct these proposed improvements is $325,000 (see Appendix B for itemized breakdowns). In addition to the Freeman Park Outlet improvements, installation of new storm sewer on south Strawberry Lane directing runoff directly to the Smithtown Pond(s) will reduce the total volume directed to Freeman Park, reducing the impact on highwater levels and potential surcharge of the Shorewood Oaks footing drain system. Other Potential Improvement Options Although the proposed Smithtown Pond(s) and Freeman Park outlet structure improvements will greatly improve flow conditions and water quality in the watershed, a couple additional improvements that would increase benefits or improve flow conditions more have been evaluated as follows: Iron Enhanced Sand Filter An Iron Enhanced Sand Filter (IESF) installed on the Smithtown Pond would greatly improve pollutant load reductions, especially dissolved phosphorus. Proposed improvements include installation of an IESF bench approximately 80’ long on the west of the pond. The bench would be lined with an EPDM liner to prevent inflow from the pond below the normal water level. Two feet of sand with iron filings (5% volume by weight) over one foot of 1” to 1-1/2” clear aggregate and a 6” perforated draintile pipe would comprise the filter. The draintile would be connected downstream of the weir in the outlet control structure. For all options, installation of an IESF would increase the TSS Load reduction by approximately 50% and the TP Load reduction by over 100%. Refer to Table 2 for a water quality comparison for the various options. Refer to Appendix D for water quality figures and calculations. The estimated cost to construct these proposed improvements is $28,000 (see Appendix B for itemized breakdowns). Shorewood Oaks Footing Drain System Connection Disconnection of the Shorewood Oaks footing drain system from the adjacent storm sewer system and installation of a new connection directly to the Smithtown Pond(s) would greatly reduce the potential for surcharging of the footing drain system. Proposed improvements include directionally drilling 1,350’ of 6” pipe from Shorewood Oaks Drive to the Smithtown Pond(s) and connecting the new pipe to the footing drain system. The estimated cost to

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construct these proposed improvements is $200,000 . HCRRA Culvert Replacement Replacement of the existing culvert between the Freeman Park wetland and Smithtown Pond improvements under the HCRRA trail. HCRRA will reimburse the City for costs and scope is currently being determined. Table 1: 100-year Peak Flow Characteristic Comparison Grant Lorenz Grant Lorenz Freeman Freeman Freeman Channel 100- Channel 100- Channel 100- Channel 100- Park Basin yr Flow Rate yr Flow yr Flow Rate yr Flow 100-yr HWL (cfs) Reduction (cfs) Reduction

Existing Condition 105.1 na 24.7 na 969.30 Option A (Single Cell w Bypass) 71.5 32% 14.2 43% 969.00 Option B (Single Cell) 88.1 16% 21.0 15% 969.00 Option C Two Cell 81.4 23% 21.0 15% 969.00

Table 2: Water Quality Comparison TSS PP DP Annual Annual Annual Removed Removed Removed TSS TP TSS Load PP Load DP Load by BMPs by BMPs by BMPs REDUCT. REDUCT. (lb/yr) (lb/yr) (lb/yr) (lb/yr) (lb/yr) (lb/yr)

Existing 34904 8561 105.672 26.488 86.458 0 na Na BMPs Option A (Single 35035 11628 106.068 35.877 86.783 0 9% 5% Cell w Bypass) Option A w/IESF (Single 35035 13419 106.068 40.918 86.783 11.421 14% 13% Cell w Bypass) Option B (Single 35035 22896 106.068 70.988 86.783 0 41% 23% Cell) Option B w/IESF 35035 31071 106.068 94.320 86.783 32.216 64% 52% (Single Cell) Option C 35035 24166 106.068 74.683 86.783 0 45% 25% Two Cell Option C w/IESF 35035 31262 106.068 94.874 86.783 32.216 65% 52% Two Cell

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Potential Improvements Comparison Following is a table comparing potential improvement options: Improvement Cost Pros Cons Option A $1,250,000 • Reduce 100-yr peak flow rate in • Bypass 30 ac untreated Grant Lorenz Channel 32% impervious (143 ac total) +$ 325,000 • Maintain existing vegetation • Erosion of Freeman Park =$1,550,000 buffer along east property line Channel only stabilized to limit • Reduce 100-yr peak flow rate in disturbance Freeman Park Channel 43% • Shorewood Oaks outlet to • Reduce TSS Load 9% extend to Smithtown Road at elev +/- 950 • Reduce TP Load 5%

Option B $1,638,000 • Reduce 100-yr peak flow rate in • Lowest reduction in peak flow Grant Lorenz Channel 16% rates to the Grant Lorenz +$ 325,000 • Maintain 30’ existing Channel =$1,963,000 vegetation buffer along east • Must disturb adjacent properties property line north of Freeman to east to repair Freeman Park Park Channel connection Channel / temporary easements • Repair erosion in Freeman Park would be necessary Channel and install riprap grade drops to provide energy dissipation • Reduce TSS Load 41% • Reduce TP Load 23% • Provides closest connection to Shorewood Oaks Option C $1,657,000 • Reduce 100-yr peak flow rate in • Must disturb adjacent properties Grant Lorenz Channel 23% to east to repair Freeman Park +$ 325,000 • Maintain 30’ existing Channel / temporary easements =$1,982,000 vegetation buffer along east would be necessary • property line north of Freeman Additional outlet structure to Park Channel connection operate and maintain • Repair erosion in Freeman Park • Shorewood Oaks outlet to Channel and install riprap grade extend to lower basin at elev +/- drops to provide energy 952 dissipation • Berm between ponds provides opportunities for additional landscape features/communal park area • Reduce TSS Load 45% • Reduce TP Load 25% IESF (Optional) $28,000 • Greatly enhances TSS and TP • Requires routine maintenance to removal keep surface free of leaves, debris, and algae

Prepared by: Bolton & Menk, Inc. PROPOSED IMPROVEMENTS Smithtown Stormwater Management Improvements C16.121587 Page 10

Landscape Impacts 1. Tree Impacts During the design and review of the pond options included in this study a significant effort was made to reduce the impact to existing trees whenever possible. The grading limits of each pond option were designed to meet the primary objectives of reducing peak flow rates in the Grant Lorenz channel and potential flooding upstream. Limits were then modified as available to leave existing areas of healthy and prominent trees in place to the maximum extent practical. In general, all pond options will result in a similar amount of tree removals on the Smithtown Pond parcel and the Freeman Park outlet area. Option A will maintain the existing buffer along the east property line, but the buffer adjacent to the HCRRA Trail would be minimized. Options B and C maintain a 30’ buffer along the east property line adjacent to the northeast side of the parcel and a large buffer adjacent to the HCRRA Trail. However, all options would require removal of some vegetation along Freeman Park Channel to either stabilize in current condition or lower the profile and re-shape the banks. 2. Landscaping Each option was reviewed for potential landscaping improvements to provide the appearance of a natural ecosystem suited to this location. Option A is a roughly triangular shaped basin with a deeper channel flowing in an arc from the inlet to outlet. Although the banks of the basin do not have much undulation, the shallow areas of the basin adjacent to the channel would fill with emergent vegetation providing shape to the basin surface. Option B is tear drop shaped with a deeper pool on the north end and shallow area on the south. The shallow area would fill with emergent vegetation providing additional relief to the south side of the basin. Option C utilizes two basins with a berm between to provide excellent undulation to the banks and a greenway for pedestrians and wildlife. Shallow areas on the sides of the upper cell would provide habitat for emergent vegetation and provide additional relief. Planting of new trees along proposed trails, basins, and the Freeman Park Channel would add to the natural look. Trails would provide a connection for pedestrians from Smithtown Road to the HCRRA Trail, as well as access to the new stormwater management facilities. Landscaping costs are included as a $30,000 lump sum for each option. This dollar amount is based on preliminary assumptions regarding the amount of tree and planting replacement. Additional coordination can be completed during the final design process to refine this dollar amount based on input from City staff.

IV. PERMITTING REQUIREMENTS Minnehaha Creek Watershed District As part of initial review of potential options to improve drainage in the Grant Lorenz Channel watershed, the City requested Minnehaha Creek Watershed District (MCWD) review solutions alternatives developed by WSB & Associates in July 2018. Selected options for this report were then discussed again with MCWD in August 2020. MCWD will require a Water Resource Permit for this project. The MCWD permit will address the districts rules including: Erosion Control, Waterbody Crossings & Structures, Wetland, and Stormwater Management for Strawberry Lane improvements. All alternatives meet District requirements so no variances to their rules are necessary.

Prepared by: Bolton & Menk, Inc. PERMITTING REQUIREMENTS Smithtown Stormwater Management Improvements C16.121587 Page 11

As part of the permitting process, a public notice will be required for all properties within 600 feet of the project. The timeframe for obtaining a MCWD permit is 21 days from submittal of a complete application. MPCA A construction stormwater permit will be required for this project prior to initiation of construction activities. The timeframe for obtaining a NPDES Permit is 7 days from submittal of a complete application. Army Corps of Engineers (ACOE) The Wetland Delineation application has been submitted to the American Corps of Engineers, and they have acknowledged receipt. A ruling for non-jurisdictional wetlands is expected back soon, so no additional permitting should be required from the ACOE.

V. POTENTIAL FUNDING OPPORTUNITIES Hennepin County Opportunity Grant This grant program accepts year-round applications and withholds review for “batch” periods. Typical grant amounts are between $25,000 and $50,000, with a maximum of $100,000. Shorewood staff applied for this grant prior to the December 2, 2020 deadline and are awaiting response for potential funds to be distributed in 2021. Minnesota Board of Water and Soil Resources (BWSR) Clean Water Fund Competitive Grant – Project and Practices The application period for this grant ends in September. If the project is phased or delayed, this could be an option. Typical grants can exceed $500,000, but there is a 25% match requirement. The City plans to apply for this grant in the future for other phases of Western Shorewood Drainage Area improvements (i.e. Strawberry Lane improvements, Grant Lorenz Channel stabilization, and additional Smithtown Pond improvements). Met Council Currently, Met Council does not have any funds planned for 2020-2022; however, funds could potentially be allocated to stormwater management in 2023 and on. Minnehaha Creek Watershed District (MCWD) Currently, Minnehaha Creek Watershed District does not have any dedicated funds for this area in their budget. However, the District has indicated they will consider a request from the City to provide funding. Therefore, Shorewood staff intends to submit a written request to the District for funding, with the amount yet to be determined.

VI. RECOMMENDATION All options provide a positive outlet for low areas upstream and will help reduce flooding potential and duration in the neighborhood as well as provide treatment of runoff from the Strawberry Lane neighborhood. Although Option A provides the greatest reduction in flow in the Grant-Lorenz Channel downstream, it does not completely restore the Freeman Park Channel or provide treatment for the runoff upstream of Freeman Park. Option B and C completely restore the Freeman Park Channel and provide treatment for the entire watershed. However, Option C provides a greater reduction in flow downstream than Option B. In addition, Option C’s two cell layout provides the greatest opportunity for landscaping features and communal areas while preserving the most existing

Prepared by: Bolton & Menk, Inc. POTENTIAL FUNDING OPPORTUNITIES Smithtown Stormwater Management Improvements C16.121587 Page 12

vegetation. The berm between ponds can be replanted with trees to maintain a more natural look and a trail /benches can provide unique viewing opportunities. Therefore, Option C is the recommend alternative. Due to the amount of maintenance required, the Iron Enhanced Sand Filter is not recommended. However, outside funds or future phasing may make the IESF more desirable and could be considered again at a future time.

Prepared by: Bolton & Menk, Inc. Smithtown Stormwater Management Improvements C16.121587 Page 13

Appendix A: Figures

Smithtown Road

8’ Trail

Property Line, Typ.

Freeman Park Channel, Cleaned & Stabilized

Property Line, Typ.

Pebble Creek Freeman Park Lake Minnetonka LRT Regional Trail

Smithtown Pond: Overflow Pipe • Pond Depth = 7’ • HWL = 963.9 • NWL = 957.0 • Bottom = 950.0

Freeman Pond: Emergent Marsh Area • Pond Depth = 4.3’ • HWL = 969.0 • NWL = 960.3 • Bottom = 956.0

Storm Sewer from Strawberry Lane

Notes: • Proposed Trees Shown After 10+ Peach Years Growth Circle

SMITHTOWN POND - OPTION A - SINGLE CELL FREEMAN PARK CONNECTION WITH OVERFLOW PIPE CITY OF SHOREWOOD Smithtown Road

Property Line, Typ. 30’

8’ Trail Utilizing Existing Driveway

Freeman Creek Channel Elevation Drop with Riprap, Typ.

Property Line, Typ.

Pebble Creek Lake Minnetonka LRT Regional Trail Freeman Park

Smithtown Pond: • Pond Depth = 6’ Freeman Pond: • HWL = 957.0 • Pond Depth = 4.3’ • NWL = 952.0 • HWL = 969.0 • Bottom = 946.0 • NWL = 960.3 • Bottom = 956.0 Emergent Marsh Area

Storm Sewer from Strawberry Lane

Notes: • Proposed Trees Shown After 10+ Peach Years Growth Circle

SMITHTOWN POND - OPTION B - SINGLE CELL FREEMAN PARK DIRECTLY CONNECTED CITY OF SHOREWOOD Smithtown Road

8’ Trail

30’ Property Line, Typ.

Smithtown Lower Pond: • Pond Depth = 5.8’ • HWL = 956.9 • NWL = 951.8 • Bottom = 946.0 Freeman Park Channel Elevation Drop with Riprap, Typ.

Overflow Pipe Property Line, Typ.

Pebble Creek Freeman Park Lake Minnetonka LRT Regional Trail

Emergent Marsh Area Overflow Pipe

Freeman Pond: Smithtown Upper Pond: • Pond Depth = 4.3’ • Pond Depth = 5’ • HWL = 969.0 • HWL = 959.1 • NWL = 960.3 • NWL = 954.0 • Bottom = 956.0 • Bottom = 949.0

Storm Sewer from Strawberry Lane

Notes: • Proposed Trees Shown After 10+ Peach Years Growth Circle

SMITHTOWN POND - OPTION C - TWO CELL CITY OF SHOREWOOD

Appendix B: Preliminary Cost Estimates

PRELIMINARY COST ESTIMATE SMITHTOWN POND - OPTION A CITY OF SHOREWOOD, MN NOVEMBER, 2020

UNIT ITEM NO. BID ITEM UNIT QUANTITY AMOUNT COST

DRAINAGE IMPROVEMENTS 1 MOBILIZATION LUMP SUM 1 $50,000.00 $50,000.00 2 TRAFFIC CONTROL LUMP SUM 1 $5,000.00 $5,000.00 3 BUILDING DEMOLITION LUMP SUM 1 $25,000.00 $25,000.00 4 CLEAR & GRUB ACRE 4.54 $10,000.00 $45,370.50 5 CONSTRUCTION ENTRANCE LUMP SUM 1 $2,000.00 $2,000.00 6 COMMON EXCAVATION CU YD 28,680 $20.00 $573,600.00 7 HYDROMULCH SEED MIX 33-261 SQYD 17,786 $1.00 $17,785.90 8 SILT FENCE LIN FT 3,851 $2.00 $7,702.56 9 RIP RAP CU YD 31 $80.00 $2,456.00 10 BITUMINOUS TRAIL 3" TON 116 $90.00 $10,400.40 11 AGGREGATE BASE 6" TON 232 $40.00 $9,288.00 12 MISCELLANEOUS LANDSCAPING LUMP SUM 1 $30,000.00 $30,000.00 13 24" RC PIPE SEWER DES 3006 CL III LIN FT 100 $35.00 $3,500.00 14 24" RC PIPE APRON EACH 4 $1,500.00 $6,000.00 15 30" RC PIPE SEWER DES 3006 CL III LIN FT 90 $50.00 $4,500.00 16 30" RC PIPE APRON EACH 1 $2,000.00 $2,000.00 17 36" RC PIPE SEWER DES 3006 CL III LIN FT 40 $75.00 $3,000.00 18 36" RC PIPE APRON EACH 1 $2,500.00 $2,500.00 19 OUTLET CONTROL STRUCTURE EACH 1 $12,000.00 $12,000.00 20 FREEMAN PARK CHANNEL CLEARING AND STABILIZATION LUMP SUM 1 $40,000.00 $40,000.00

SUBTOTAL $852,103.36 CONTINGENCIES (15%) $127,815.50 TOTAL CONSTRUCTION COST $979,918.86 SOFT COSTS (25%) $244,979.72 TOTAL DRAINAGE IMPROVEMENT PROJECT COST $1,224,898.58 PRELIMINARY COST ESTIMATE SMITHTOWN POND - OPTION B CITY OF SHOREWOOD, MN NOVEMBER, 2020

UNIT ITEM NO. BID ITEM UNIT QUANTITY AMOUNT COST

DRAINAGE IMPROVEMENTS 1 MOBILIZATION LUMP SUM 1 $50,000.00 $50,000.00 2 TRAFFIC CONTROL LUMP SUM 1 $5,000.00 $5,000.00 3 CLEAR & GRUB ACRE 4.53 $10,000.00 $45,307.50 4 BUILDING DEMOLITION LUMP SUM 1 $25,000.00 $25,000.00 5 CONSTRUCTION ENTRANCE LUMP SUM 1 $2,000.00 $2,000.00 6 COMMON EXCAVATION CUYD 43,767 $20.00 $875,340.00 7 HYDROMULCH SEED MIX 33-261 SQYD 14,301 $1.00 $14,301.40 8 SILT FENCE LIN FT 4,202 $2.00 $8,404.56 9 RIP RAP CU YD 70 $80.00 $5,600.00 10 BITUMINOUS TRAIL 3" TON 135 $90.00 $12,150.00 11 AGGREGATE BASE 6" TON 275 $40.00 $11,000.00 12 MISCELLANEOUS LANDSCAPING LUMP SUM 1 $30,000.00 $30,000.00 13 48" RC PIPE SEWER DES 3006 CL III LIN FT 90 $150.00 $13,500.00 14 48" RC PIPE APRON EACH 1 $4,000.00 $4,000.00 15 40"x65" ARCH RC PIPE SEWER DES 3006 CL III LIN FT 40 $200.00 $8,000.00 16 40"x65" ARCH RC PIPE APRON EACH 1 $5,000.00 $5,000.00 17 OUTLET CONTROL STRUCTURE EACH 1 $20,000.00 $20,000.00 18 TURF REINFORCEMENT MAT SQFT 2400 $1.00 $2,400.00 19 EROSION CONTROL BLANKET SQFT 4800 $0.50 $2,400.00

SUBTOTAL $1,139,403.46 CONTINGENCIES (15%) $170,910.52 TOTAL CONSTRUCTION COST $1,310,313.98 SOFT COSTS (25%) $327,578.49 TOTAL DRAINAGE IMPROVEMENT PROJECT COST $1,637,892.47 PRELIMINARY COST ESTIMATE SMITHTOWN POND - OPTION C CITY OF SHOREWOOD, MN NOVEMBER, 2020

UNIT ITEM NO. BID ITEM UNIT QUANTITY AMOUNT COST

DRAINAGE IMPROVEMENTS 1 MOBILIZATION LUMP SUM 1 $50,000.00 $50,000.00 2 TRAFFIC CONTROL LUMP SUM 1 $5,000.00 $5,000.00 3 CLEAR & GRUB ACRE 5.47 $10,000.00 $54,652.50 4 BUILDING DEMOLITION LUMP SUM 1 $25,000.00 $25,000.00 5 CONSTRUCTION ENTRANCE LUMP SUM 1 $2,000.00 $2,000.00 6 COMMON EXCAVATION CUYD 41,805 $20.00 $836,100.00 7 HYDROMULCH SEED MIX 33-261 SQYD 18,684 $1.00 $18,684.05 8 SILT FENCE LIN FT 4,083 $2.00 $8,166.96 9 RIP RAP CU YD 90 $80.00 $7,200.00 10 BITUMINOUS TRAIL 3" TON 146 $90.00 $13,122.00 11 AGGREGATE BASE 6" TON 292 $40.00 $11,664.00 12 MISCELLANEOUS LANDSCAPING LUMP SUM 1 $30,000.00 $30,000.00 13 42" RC PIPE SEWER DES 3006 CL III LIN FT 140 $100.00 $14,000.00 14 42" RC PIPE APRON EACH 2 $3,500.00 $7,000.00 15 48" RC PIPE SEWER DES 3006 CL III LIN FT 90 $150.00 $13,500.00 16 48" RC PIPE APRON EACH 1 $4,000.00 $4,000.00 17 40"x65" ARCH RC PIPE SEWER DES 3006 CL III LIN FT 40 $200.00 $8,000.00 18 40"x65" ARCH RC PIPE APRON EACH 1 $5,000.00 $5,000.00 19 OUTLET CONTROL STRUCTURE #1 EACH 1 $20,000.00 $20,000.00 20 OUTLET CONTROL STRUCTURE #2 EACH 1 $15,000.00 $15,000.00 21 TURF REINFORCEMENT MAT SQFT 2400 $1.00 $2,400.00 22 EROSION CONTROL BLANKET SQFT 4800 $0.50 $2,400.00

SUBTOTAL $1,152,889.51 CONTINGENCIES (15%) $172,933.43 TOTAL CONSTRUCTION COST $1,325,822.94 SOFT COSTS (25%) $331,455.73 TOTAL DRAINAGE IMPROVEMENT PROJECT COST $1,657,278.67 PRELIMINARY COST ESTIMATE SMITHTOWN POND - FREEMAN PARK CITY OF SHOREWOOD, MN NOVEMBER, 2020

UNIT ITEM NO. BID ITEM UNIT QUANTITY AMOUNT COST

DRAINAGE IMPROVEMENTS 1 MOBILIZATION LUMP SUM 1 $10,000.00 $10,000.00 2 TRAFFIC CONTROL LUMP SUM 1 $2,000.00 $2,000.00 3 CLEAR & GRUB ACRE 1.45 $10,000.00 $14,500.00 4 CONSTRUCTION ENTRANCE LUMP SUM 1 $2,000.00 $2,000.00 5 COMMON EXCAVATION CU YD 2,920 $20.00 $58,400.00 6 HYDROMULCH SEED MIX 33-261 SQYD 7,154 $1.00 $7,154.15 7 SILT FENCE LIN FT 1,863 $2.00 $3,726.00 8 36"x58" ARCH RC PIPE SEWER DES 3006 CL III LIN FT 40 $200.00 $8,000.00 9 36"x58" ARCH RC PIPE APRON EACH 1 $5,000.00 $5,000.00 10 OUTLET CONTROL STRUCTURE EACH 1 $15,000.00 $15,000.00 11 CONSTRUCTION ACCESS RESTORATION LUMP SUM 1 $100,000.00 $100,000.00

SUBTOTAL $225,780.15 CONTINGENCIES (15%) $33,867.02 TOTAL CONSTRUCTION COST $259,647.17 SOFT COSTS (25%) $64,911.79 TOTAL DRAINAGE IMPROVEMENT PROJECT COST $324,558.97 PRELIMINARY COST ESTIMATE SMITHTOWN POND - IRON ENHANCED SAND FILTER CITY OF SHOREWOOD, MN NOVEMEBER, 2020

UNIT ITEM NO. BID ITEM UNIT QUANTITY AMOUNT COST

IRON ENHANCED SAND FILTER 1 SITE GRADING LUMP SUM 1 $10,000.00 $10,000.00 2 45MIL RUBBER EPDM LINER SQYD 481 $5.00 $2,405.00 3 1" TO 1-1/2" CLEAR AGGREGATE CU YD 7 $100.00 $700.00 4 1/4" CLEAR AGGREGATE CU YD 3 $200.00 $600.00 5 CLEAN SAND WITH IRON FILINGS (5% BY WEIGHT) CU YD 18 $200.00 $3,600.00 6 6" PERFORATED DRAINTILE LIN FT 100 $20.00 $2,000.00

SUBTOTAL $19,305.00 CONTINGENCIES (15%) $2,895.75 TOTAL CONSTRUCTION COST $22,200.75 SOFT COSTS (25%) $5,550.19 TOTAL DRAINAGE IMPROVEMENT PROJECT COST $27,750.94

Appendix C: Hydrographs

FLOW RATE EVALUTION Smithtown Pond Watershed CITY OF SHOREWOOD, MN October, 2020

Freeman Channel - Discharge Comparison

30

Existing, 2-year Existing, 10-year

Existing, 100-year Option A, 2-year 25 Option A, 10-year Option A, 100-year

Option B, 2-year Option B, 10-year

Option B, 100-year Option C, 2-year 20 Option C, 10-year Option C, 100-year

15 Discharge (cfs)

10

5

0 6 12 18 24 30 36 42 48 54 60 Time (hours) FLOW RATE EVALUTION Smithtown Pond Watershed CITY OF SHOREWOOD, MN October, 2020

Grant Lorenz Channel - Discharge Comparison

120

Existing, 2-year Existing, 10-year Existing, 100-year Option A, 2-year Option A, 10-year Option A, 100-year Option B, 2-year Option B, 10-year 100 Option B, 100-year Option C, 2-year Option C, 10-year Option C, 100-year

80

60 Discharge (cfs)

40

20

0 6 12 18 24 30 36 42 48 Time (hours) HIGHWATER LEVEL EVALUTION Smithtown Pond Watershed CITY OF SHOREWOOD, MN October, 2020

Freeman Park - Ponding Elevation

970 Existing, 2-year Existing, 10-year 969 Existing, 100-year Option A, 2-year Option A, 10-year 968 Option A, 100-year Option B, 2-year Option B, 10-year 967 Option B, 100-year Option C, 2-year Option C, 10-year 966 Option C, 100-year

965

Elevation (feet) Elevation 964

963

962

961

960 6 12 18 24 30 36 42 48 Time (hours)

Appendix D: WQ Calculations and Drainage Area Maps

Drainage Map Figure 1: Existing Conditions City of Shorewood, MN November 2020

F Legend I! Legend I! !.

Storm Structure F !. F Existing Drainage (Impervious/ Total) Peach Cir. Pond (1.5/3.9) Storm Sewer !. Alexander Ln Basin (1.6/6.2) !. Pebble Creek (3.1/11.6)

F !. Drain Tile !. !. !. Church Basin (5.5/11.8) Strawberry Ct. No. (0.6/5.3) F Flow_Arrow

Smithtown Lane (3.5/20.3)

Strawberry Ct. So. (1.9/7.8) F F Freeman Park Basin (35.2/153.1) !.!. F Strawberry Gardens (4.9/30.8) F Shorewood Ponds Basin (8.6/10.7) F TOTAL AREA (66.4/261.6) !.!. 0 350 !. Feet !. !. !. !.!. Source: City of Shorewood, Hennepin County, MnDOT !. !. F !. !.!. !. !. !.

F F

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W F H F S \ F : F !. H

: t n e m u c o D p a M Drainage Map Figure 2: Option A City of Shorewood, MN November 2020

Legend F Legend "/ Storm Structure I! Proposed Drainage (Impervious/Total)

Storm Sewer Peach Cir. Pond (1.5/3.9) "/ F F Alexander Ln Basin (1.6/6.2) Ex Storm Sewer Pebble Creek (2.8/10.9) "/ "/ F Church Basin (5.5/11.8) Ex Draintile "/ "/ "/ Smithtown Pond A (8.3/25.8) Smithtown Lane (3.1/14.2)

F Flow_Arrow Strawberry Ct. No. (0.5/5.1)

F F Freeman Park Basin (28.5/134.7) Strawberry Ct. So. (1.9/7.8) F Shorewood Ponds Basin (8.6/10.7) F Strawberry Gardens (4.7/30.5) F 0 350 "/ "/ "/ TOTAL AREA (67.0/261.6) "/ Feet "/"/ "/ "/ "/ "/ Source: City of Shorewood, Hennepin County, MnDOT "/ "/ "/ "/"/ "/ "/ F "/ "/"/ "/ "/ "/

F F F "/ F "/ "/ "/ "/ "/ F "/ M "/ "/ P

3 "/ 1 : "/ "/ 2

3 "/ : 1

0 2 0 2 / F 3 2 /

1 "/

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: F d F e

v F "/ a "/ F S e t F "/ "/ a "/ D

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t "/ F n F "/ e m u c o D p a M Drainage Map Figure 3: Option B City of Shorewood, MN November 2020

!. !.

Legend Legend I! F I! !. Storm Structure Proposed Drainage (Impervious/Total) Peach Cir. Pond (1.5/3.9)

Storm Sewer F Alexander Ln Basin (1.6/6.2) !. Pebble Creek (2.8/10.9) Ex Storm Sewer F !. Church Basin (5.5/11.8) !. Smithtown Pond B (8.8/34.0) Ex Draintile F !.!. !. !. Smithtown Lane (2.6/6.0) Strawberry Ct. No. (0.5/5.1) Flow_Arrow !.

F !.

Freeman Park Basin (28.5/134.7)

F Strawberry Ct. So. (1.9/7.8) F !. !.!. Shorewood Ponds Basin (8.6/10.7) F F Strawberry Gardens (4.7/30.5) F TOTAL AREA (67.0/261.6) !.!. !. !.!. !.!.!. !. 0 350 !. !. !. !.!. Feet !. !. F !. !.!.!.!. !. Source: City of Shorewood, Hennepin County, MnDOT !.

F F

M F P

8 4

: !. 0 !. F 3 :

3 !. !. !.

0 F !. !.

2 !. 0 !. !. 2 /

3 !.

2 !. / !. 1

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m !. F u F !. c o D p a M Drainage Map Figure 4: Option C City of Shorewood, MN November 2020

Legend I! F Legend I! !. Storm Structures

Proposed Drainage (Impervious/Total) Pebble Creek (2.8/10.9) Storm Sewer !. F F Alexander Ln Basin (1.6/6.2) !. Smithtown Pond C Upper (8.4/25.8) Ex Draintile !.

F !. !. Church Basin (5.5/11.8) !. !. Smithtown Pond C Lower (0.4/8.2) Ex Storm Sewer !. Smithtown Lane (2.6/6.0)

F Flow_Arrow !. Strawberry Ct. No. (0.5/5.1) F F Freeman Park Basin (28.5/134.7) !. Strawberry Ct. So. (1.9/7.8) !.!. F Shorewood Ponds Basin (8.6/10.7) F Strawberry Gardens (4.7/30.5) F !.!. !. Peach Cir. Pond (1.5/3.9) !.!. TOTAL AREA (67.0/261.6) !.!.!. !. !. !. !. !.!. !. !. F !. !.!.!.!. !. 0 350 !. Feet

F

SouF rce: City of Shorewood, Hennepin County, MnDOT F !. !. F !. !. !. M F !. !. A

!.

1 !. !. 5 : !. 9

5 !. : !. 9

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: !. F t F n !. e m u c o D p a M Project Information

Calculator Version: Version 3: January 2017 Project Name: Smithtown Pond - Existing User Name / Company Name: Date: Project Description: Existing Condition Construction Permit?: No

Site Information

Retention Requirement (inches): 1.1 Site's Zip Code: 55331 Annual Rainfall (inches): 29.6 Phosphorus EMC (mg/l): 0.3 TSS EMC (mg/l): 54.5

Total Site Area

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 195.144 195.144 other turf to be mowed/managed

Impervious Area (acres) 66.451

Total Area (acres) 261.595

Site Areas Routed to BMPs

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 51.883 51.883 other turf to be mowed/managed Impervious Area (acres) 24.673

Total Area (acres) 76.556 Summary Information

Performance Goal Requirement

Performance goal volume retention requirement: 265338 ft3 Volume removed by BMPs towards performance goal: ft³ Percent volume removed towards performance goal %

Annual Volume and Pollutant Load Reductions

Post development annual runoff volume 235.4535 acre -ft Annual runoff volume removed by BMPs: 0 acre-ft Percent annual runoff volume removed: 0 %

Post development annual particulate P load: 105.672 lbs Annual particulate P removed by BMPs: 26.488 lbs Post development annual dissolved P load: 86.458 lbs Annual dissolved P removed by BMPs: 0 lbs Percent annual total phosphorus removed: 14 %

Post development annual TSS load: 34903.6 lbs Annual TSS removed by BMPs: 8560.6 lbs Percent annual TSS removed: 25 %

BMP Summary Performance Goal Summary

BMP Volume Volume Volume Volume Percent BMP Name Capacity Recieved Retained Outflow Retained (%) (ft3) (ft3) (ft3) (ft3)

Church Pond 0 22001 0 22001 0 Strawberry Gardens 0 41651 0 41651 0 Strawberry Court North 0 2424 0 2424 0 Strawberry Court South 0 51577 0 51577 0 Peach Circle 0 6125 0 6125 0 Alexander Lane 0 6409 0 6409 0 Shorewood Ponds 0 34408 0 34408 0

Annual Volume Summary Volume Volume From Volume Volume Percent From Direct BMP Name Upstream Retained outflow Retained Watershed BMPs (acre-ft) (acre-ft) (%) (acre-ft) (acre-ft) Church Pond 14.7097 0 0 14.7097 0 Strawberry Gardens 23.0299 14.7097 0 37.7396 0 Strawberry Court North 3.5556 0 0 3.5556 0 Strawberry Court South 6.8747 41.2952 0 48.1699 0 Peach Circle 4.3702 0 0 4.3702 0 Alexander Lane 5.6399 0 0 5.6399 0 Shorewood Ponds 19.195 0 0 19.195 0

Particulate Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 6.6017 0 4.0931 2.5086 62 Strawberry Gardens 10.3358 2.5086 7.9635 4.8809 62 Strawberry Court North 1.5958 0 0.9894 0.6064 62 Strawberry Court South 3.0853 5.4873 5.315 3.2576 62 Peach Circle 1.9614 0 1.2161 0.7453 62 Alexander Lane 2.5312 0 1.5693 0.9619 62 Shorewood Ponds 8.6147 0 5.3411 3.2736 62

Dissolved Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 5.4014 0 0 5.4014 0 Strawberry Gardens 8.4566 5.4014 0 13.858 0 Strawberry Court North 1.3056 0 0 1.3056 0 Strawberry Court South 2.5244 15.1636 0 17.688 0 Peach Circle 1.6048 0 0 1.6048 0 Alexander Lane 2.071 0 0 2.071 0 Shorewood Ponds 7.0484 0 0 7.0484 0

TSS Summary Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 2180.57 0 1308.34 872.23 60 Strawberry Gardens 3413.95 872.23 2571.71 1714.47 60 Strawberry Court North 527.08 0 316.25 210.83 60 Strawberry Court South 1019.1 1925.3 1766.64 1177.76 60 Peach Circle 647.85 0 388.71 259.14 60 Alexander Lane 836.06 0 501.64 334.42 60 Shorewood Ponds 2845.46 0 1707.28 1138.18 60

BMP Schematic Project Information

Calculator Version: Version 3: January 2017 Project Name: Smithtown Pond - Option A User Name / Company Name: Date: Project Description: Option A - One Cell Pond with Overflow Connection to Freeman Park Construction Permit?: No

Site Information

Retention Requirement (inches): 1.1 Site's Zip Code: 55331 Annual Rainfall (inches): 29.6 Phosphorus EMC (mg/l): 0.3 TSS EMC (mg/l): 54.5

Total Site Area

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 194.599 194.599 other turf to be mowed/managed

Impervious Area (acres) 66.996

Total Area (acres) 261.595

Site Areas Routed to BMPs

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 69.217 69.217 other turf to be mowed/managed Impervious Area (acres) 32.615

Total Area (acres) 101.832 Summary Information

Performance Goal Requirement

Performance goal volume retention requirement: 267514 ft3 Volume removed by BMPs towards performance goal: ft³ Percent volume removed towards performance goal %

Annual Volume and Pollutant Load Reductions

Post development annual runoff volume 236.3367 acre -ft Annual runoff volume removed by BMPs: 0 acre-ft Percent annual runoff volume removed: 0 %

Post development annual particulate P load: 106.068 lbs Annual particulate P removed by BMPs: 35.877 lbs Post development annual dissolved P load: 86.783 lbs Annual dissolved P removed by BMPs: 0 lbs Percent annual total phosphorus removed: 19 %

Post development annual TSS load: 35034.6 lbs Annual TSS removed by BMPs: 11628.4 lbs Percent annual TSS removed: 33 %

BMP Summary Performance Goal Summary

BMP Volume Volume Volume Volume Percent BMP Name Capacity Recieved Retained Outflow Retained (%) (ft3) (ft3) (ft3) (ft3)

Church Pond 0 22001 0 22001 0 Strawberry Gardens 0 40836 0 40836 0 Strawberry Court North 0 2100 0 2100 0 Strawberry Court South 0 50324 0 50324 0 Peach Circle 0 6125 0 6125 0 Alexander Lane 0 6409 0 6409 0 Shorewood Ponds 0 34408 0 34408 0 Smithtown Pond - Option A 0 89415 0 89415 0

Annual Volume Summary Volume Volume From Volume Volume Percent From Direct BMP Name Upstream Retained outflow Retained Watershed BMPs (acre-ft) (acre-ft) (%) (acre-ft) (acre-ft) Church Pond 14.7097 0 0 14.7097 0 Strawberry Gardens 22.5635 14.7097 0 37.2732 0 Strawberry Court North 3.3413 0 0 3.3413 0 Strawberry Court South 6.7857 40.6146 0 47.4003 0 Peach Circle 4.3702 0 0 4.3702 0 Alexander Lane 5.6399 0 0 5.6399 0 Shorewood Ponds 19.195 0 0 19.195 0 Smithtown Pond - Option A 25.9853 51.7705 0 77.7558 0

Particulate Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 6.6017 0 4.0931 2.5086 62 Strawberry Gardens 10.1265 2.5086 7.8338 4.8013 62 Strawberry Court North 1.4996 0 0.9298 0.5698 62 Strawberry Court South 3.0454 5.3711 5.2182 3.1983 62 Peach Circle 1.9614 0 1.2161 0.7453 62 Alexander Lane 2.5312 0 1.5693 0.9619 62 Shorewood Ponds 8.6147 0 5.3411 3.2736 62 Smithtown Pond - Option A 11.6622 3.9436 9.6756 5.9302 62

Dissolved Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 5.4014 0 0 5.4014 0 Strawberry Gardens 8.2853 5.4014 0 13.6867 0 Strawberry Court North 1.2269 0 0 1.2269 0 Strawberry Court South 2.4917 14.9136 0 17.4053 0 Peach Circle 1.6048 0 0 1.6048 0 Alexander Lane 2.071 0 0 2.071 0 Shorewood Ponds 7.0484 0 0 7.0484 0 Smithtown Pond - Option A 9.5418 19.0101 0 28.5519 0

TSS Summary Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 2180.57 0 1308.34 872.23 60 Strawberry Gardens 3344.82 872.23 2530.23 1686.82 60 Strawberry Court North 495.32 0 297.19 198.13 60 Strawberry Court South 1005.91 1884.95 1734.52 1156.34 60 Peach Circle 647.85 0 388.71 259.14 60 Alexander Lane 836.06 0 501.64 334.42 60 Shorewood Ponds 2845.46 0 1707.28 1138.18 60 Smithtown Pond - Option A 3852.06 1415.48 3160.52 2107.02 60

BMP Schematic Project Information

Calculator Version: Version 3: January 2017 Project Name: Smithtown Pond - Option A - IESF User Name / Company Name: Date: Project Description: Option A - One Cell Pond with Overflow Connection to Freeman Park and IESF Construction Permit?: No

Site Information

Retention Requirement (inches): 1.1 Site's Zip Code: 55331 Annual Rainfall (inches): 29.6 Phosphorus EMC (mg/l): 0.3 TSS EMC (mg/l): 54.5

Total Site Area

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 194.599 194.599 other turf to be mowed/managed

Impervious Area (acres) 66.996

Total Area (acres) 261.595

Site Areas Routed to BMPs

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 69.217 69.217 other turf to be mowed/managed Impervious Area (acres) 32.615

Total Area (acres) 101.832 Summary Information

Performance Goal Requirement

Performance goal volume retention requirement: 267514 ft3 Volume removed by BMPs towards performance goal: ft³ Percent volume removed towards performance goal %

Annual Volume and Pollutant Load Reductions

Post development annual runoff volume 236.3367 acre -ft Annual runoff volume removed by BMPs: 0 acre-ft Percent annual runoff volume removed: 0 %

Post development annual particulate P load: 106.068 lbs Annual particulate P removed by BMPs: 40.918 lbs Post development annual dissolved P load: 86.783 lbs Annual dissolved P removed by BMPs: 11.421 lbs Percent annual total phosphorus removed: 27 %

Post development annual TSS load: 35034.6 lbs Annual TSS removed by BMPs: 13419.4 lbs Percent annual TSS removed: 38 %

BMP Summary Performance Goal Summary

BMP Volume Volume Volume Volume Percent BMP Name Capacity Recieved Retained Outflow Retained (%) (ft3) (ft3) (ft3) (ft3)

IESF 0 89415 0 89415 0 Church Pond 0 22001 0 22001 0 Strawberry Gardens 0 40836 0 40836 0 Strawberry Court North 0 2100 0 2100 0 Strawberry Court South 0 50324 0 50324 0 Peach Circle 0 6125 0 6125 0 Alexander Lane 0 6409 0 6409 0 Shorewood Ponds 0 34408 0 34408 0 Smithtown Pond - Option A 0 89415 0 89415 0

Annual Volume Summary Volume Volume From Volume Volume Percent From Direct BMP Name Upstream Retained outflow Retained Watershed BMPs (acre-ft) (acre-ft) (%) (acre-ft) (acre-ft) IESF 0 77.7557 0 77.7557 0 Church Pond 14.7097 0 0 14.7097 0 Strawberry Gardens 22.5635 14.7097 0 37.2732 0 Strawberry Court North 3.3413 0 0 3.3413 0 Strawberry Court South 6.7857 40.6146 0 47.4003 0 Peach Circle 4.3702 0 0 4.3702 0 Alexander Lane 5.6399 0 0 5.6399 0 Shorewood Ponds 19.195 0 0 19.195 0 Smithtown Pond - Option A 25.9853 51.7705 0 77.7558 0

Particulate Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

IESF 0 5.9302 5.0407 0.8895 85 Church Pond 6.6017 0 4.0931 2.5086 62 Strawberry Gardens 10.1265 2.5086 7.8338 4.8013 62 Strawberry Court North 1.4996 0 0.9298 0.5698 62 Strawberry Court South 3.0454 5.3711 5.2182 3.1983 62 Peach Circle 1.9614 0 1.2161 0.7453 62 Alexander Lane 2.5312 0 1.5693 0.9619 62 Shorewood Ponds 8.6147 0 5.3411 3.2736 62 Smithtown Pond - Option A 11.6622 3.9436 9.6756 5.9302 62

Dissolved Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

IESF 0 28.5519 11.4208 17.1311 40 Church Pond 5.4014 0 0 5.4014 0 Strawberry Gardens 8.2853 5.4014 0 13.6867 0 Strawberry Court North 1.2269 0 0 1.2269 0 Strawberry Court South 2.4917 14.9136 0 17.4053 0 Peach Circle 1.6048 0 0 1.6048 0 Alexander Lane 2.071 0 0 2.071 0 Shorewood Ponds 7.0484 0 0 7.0484 0 Smithtown Pond - Option A 9.5418 19.0101 0 28.5519 0

TSS Summary Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

IESF 0 2107.02 1790.97 316.05 85 Church Pond 2180.57 0 1308.34 872.23 60 Strawberry Gardens 3344.82 872.23 2530.23 1686.82 60 Strawberry Court North 495.32 0 297.19 198.13 60 Strawberry Court South 1005.91 1884.95 1734.52 1156.34 60 Peach Circle 647.85 0 388.71 259.14 60 Alexander Lane 836.06 0 501.64 334.42 60 Shorewood Ponds 2845.46 0 1707.28 1138.18 60 Smithtown Pond - Option A 3852.06 1415.48 3160.52 2107.02 60

BMP Schematic Project Information

Calculator Version: Version 3: January 2017 Project Name: Smithtown Pond - Option B User Name / Company Name: Date: Project Description: Option B - One Cell Pond with Direct Connection to Freeman Park Construction Permit?: No

Site Information

Retention Requirement (inches): 1.1 Site's Zip Code: 55331 Annual Rainfall (inches): 29.6 Phosphorus EMC (mg/l): 0.3 TSS EMC (mg/l): 54.5

Total Site Area

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 194.599 194.599 other turf to be mowed/managed

Impervious Area (acres) 66.996

Total Area (acres) 261.595

Site Areas Routed to BMPs

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 183.16 183.16 other turf to be mowed/managed Impervious Area (acres) 61.583

Total Area (acres) 244.743 Summary Information

Performance Goal Requirement

Performance goal volume retention requirement: 267514 ft3 Volume removed by BMPs towards performance goal: ft³ Percent volume removed towards performance goal %

Annual Volume and Pollutant Load Reductions

Post development annual runoff volume 236.3367 acre -ft Annual runoff volume removed by BMPs: 0 acre-ft Percent annual runoff volume removed: 0 %

Post development annual particulate P load: 106.068 lbs Annual particulate P removed by BMPs: 70.988 lbs Post development annual dissolved P load: 86.783 lbs Annual dissolved P removed by BMPs: 0 lbs Percent annual total phosphorus removed: 37 %

Post development annual TSS load: 35034.6 lbs Annual TSS removed by BMPs: 22895.6 lbs Percent annual TSS removed: 65 %

BMP Summary Performance Goal Summary

BMP Volume Volume Volume Volume Percent BMP Name Capacity Recieved Retained Outflow Retained (%) (ft3) (ft3) (ft3) (ft3)

Church Pond 0 22001 0 22001 0 Strawberry Gardens 0 40836 0 40836 0 Strawberry Court North 0 2100 0 2100 0 Strawberry Court South 0 50324 0 50324 0 Peach Circle 0 6125 0 6125 0 Alexander Lane 0 6409 0 6409 0 Shorewood Ponds 0 34408 0 34408 0 Smithtown Pond - Option B 0 245900 0 245900 0

Annual Volume Summary Volume Volume From Volume Volume Percent From Direct BMP Name Upstream Retained outflow Retained Watershed BMPs (acre-ft) (acre-ft) (%) (acre-ft) (acre-ft) Church Pond 14.7097 0 0 14.7097 0 Strawberry Gardens 22.5635 14.7097 0 37.2732 0 Strawberry Court North 3.3413 0 0 3.3413 0 Strawberry Court South 6.7857 40.6146 0 47.4003 0 Peach Circle 4.3702 0 0 4.3702 0 Alexander Lane 5.6399 0 0 5.6399 0 Shorewood Ponds 19.195 0 0 19.195 0 Smithtown Pond - Option B 142.7286 76.6053 0 219.3339 0

Particulate Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 6.6017 0 4.0931 2.5086 62 Strawberry Gardens 10.1265 2.5086 7.8338 4.8013 62 Strawberry Court North 1.4996 0 0.9298 0.5698 62 Strawberry Court South 3.0454 5.3711 5.2182 3.1983 62 Peach Circle 1.9614 0 1.2161 0.7453 62 Alexander Lane 2.5312 0 1.5693 0.9619 62 Shorewood Ponds 8.6147 0 5.3411 3.2736 62 Smithtown Pond - Option B 64.0566 8.1791 44.7861 27.4496 62

Dissolved Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 5.4014 0 0 5.4014 0 Strawberry Gardens 8.2853 5.4014 0 13.6867 0 Strawberry Court North 1.2269 0 0 1.2269 0 Strawberry Court South 2.4917 14.9136 0 17.4053 0 Peach Circle 1.6048 0 0 1.6048 0 Alexander Lane 2.071 0 0 2.071 0 Shorewood Ponds 7.0484 0 0 7.0484 0 Smithtown Pond - Option B 52.4099 28.1295 0 80.5394 0

TSS Summary Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 2180.57 0 1308.34 872.23 60 Strawberry Gardens 3344.82 872.23 2530.23 1686.82 60 Strawberry Court North 495.32 0 297.19 198.13 60 Strawberry Court South 1005.91 1884.95 1734.52 1156.34 60 Peach Circle 647.85 0 388.71 259.14 60 Alexander Lane 836.06 0 501.64 334.42 60 Shorewood Ponds 2845.46 0 1707.28 1138.18 60 Smithtown Pond - Option B 21158.08 2888.08 14427.7 9618.46 60

BMP Schematic Project Information

Calculator Version: Version 3: January 2017 Project Name: Smithtown Pond - Option B - IESF User Name / Company Name: Date: Project Description: Option B - One Cell Pond with Direct Connection to Freeman Park and IESF Construction Permit?: No

Site Information

Retention Requirement (inches): 1.1 Site's Zip Code: 55331 Annual Rainfall (inches): 29.6 Phosphorus EMC (mg/l): 0.3 TSS EMC (mg/l): 54.5

Total Site Area

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 194.599 194.599 other turf to be mowed/managed

Impervious Area (acres) 66.996

Total Area (acres) 261.595

Site Areas Routed to BMPs

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 183.16 183.16 other turf to be mowed/managed Impervious Area (acres) 61.583

Total Area (acres) 244.743 Summary Information

Performance Goal Requirement

Performance goal volume retention requirement: 267514 ft3 Volume removed by BMPs towards performance goal: ft³ Percent volume removed towards performance goal %

Annual Volume and Pollutant Load Reductions

Post development annual runoff volume 236.3367 acre -ft Annual runoff volume removed by BMPs: 0 acre-ft Percent annual runoff volume removed: 0 %

Post development annual particulate P load: 106.068 lbs Annual particulate P removed by BMPs: 94.32 lbs Post development annual dissolved P load: 86.783 lbs Annual dissolved P removed by BMPs: 32.216 lbs Percent annual total phosphorus removed: 66 %

Post development annual TSS load: 35034.6 lbs Annual TSS removed by BMPs: 31071.3 lbs Percent annual TSS removed: 89 %

BMP Summary Performance Goal Summary

BMP Volume Volume Volume Volume Percent BMP Name Capacity Recieved Retained Outflow Retained (%) (ft3) (ft3) (ft3) (ft3)

IESF 0 245900 0 245900 0 Church Pond 0 22001 0 22001 0 Strawberry Gardens 0 40836 0 40836 0 Strawberry Court North 0 2100 0 2100 0 Strawberry Court South 0 50324 0 50324 0 Peach Circle 0 6125 0 6125 0 Alexander Lane 0 6409 0 6409 0 Shorewood Ponds 0 34408 0 34408 0 Smithtown Pond - Option B 0 245900 0 245900 0

Annual Volume Summary Volume Volume From Volume Volume Percent From Direct BMP Name Upstream Retained outflow Retained Watershed BMPs (acre-ft) (acre-ft) (%) (acre-ft) (acre-ft) IESF 0 219.3339 0 219.3339 0 Church Pond 14.7097 0 0 14.7097 0 Strawberry Gardens 22.5635 14.7097 0 37.2732 0 Strawberry Court North 3.3413 0 0 3.3413 0 Strawberry Court South 6.7857 40.6146 0 47.4003 0 Peach Circle 4.3702 0 0 4.3702 0 Alexander Lane 5.6399 0 0 5.6399 0 Shorewood Ponds 19.195 0 0 19.195 0 Smithtown Pond - Option B 142.7286 76.6053 0 219.3339 0

Particulate Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

IESF 0 27.4496 23.3322 4.1174 85 Church Pond 6.6017 0 4.0931 2.5086 62 Strawberry Gardens 10.1265 2.5086 7.8338 4.8013 62 Strawberry Court North 1.4996 0 0.9298 0.5698 62 Strawberry Court South 3.0454 5.3711 5.2182 3.1983 62 Peach Circle 1.9614 0 1.2161 0.7453 62 Alexander Lane 2.5312 0 1.5693 0.9619 62 Shorewood Ponds 8.6147 0 5.3411 3.2736 62 Smithtown Pond - Option B 64.0566 8.1791 44.7861 27.4496 62

Dissolved Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

IESF 0 80.5394 32.2158 48.3236 40 Church Pond 5.4014 0 0 5.4014 0 Strawberry Gardens 8.2853 5.4014 0 13.6867 0 Strawberry Court North 1.2269 0 0 1.2269 0 Strawberry Court South 2.4917 14.9136 0 17.4053 0 Peach Circle 1.6048 0 0 1.6048 0 Alexander Lane 2.071 0 0 2.071 0 Shorewood Ponds 7.0484 0 0 7.0484 0 Smithtown Pond - Option B 52.4099 28.1295 0 80.5394 0

TSS Summary Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

IESF 0 9618.46 8175.69 1442.77 85 Church Pond 2180.57 0 1308.34 872.23 60 Strawberry Gardens 3344.82 872.23 2530.23 1686.82 60 Strawberry Court North 495.32 0 297.19 198.13 60 Strawberry Court South 1005.91 1884.95 1734.52 1156.34 60 Peach Circle 647.85 0 388.71 259.14 60 Alexander Lane 836.06 0 501.64 334.42 60 Shorewood Ponds 2845.46 0 1707.28 1138.18 60 Smithtown Pond - Option B 21158.08 2888.08 14427.7 9618.46 60

BMP Schematic Project Information

Calculator Version: Version 3: January 2017 Project Name: Smithtown Pond - Option C User Name / Company Name: Date: Project Description: Option C - Two Pond Cells with Direct Connection to Freeman Park Construction Permit?: No

Site Information

Retention Requirement (inches): 1.1 Site's Zip Code: 55331 Annual Rainfall (inches): 29.6 Phosphorus EMC (mg/l): 0.3 TSS EMC (mg/l): 54.5

Total Site Area

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 194.599 194.599 other turf to be mowed/managed

Impervious Area (acres) 66.996

Total Area (acres) 261.595

Site Areas Routed to BMPs

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 183.16 183.16 other turf to be mowed/managed Impervious Area (acres) 61.583

Total Area (acres) 244.743 Summary Information

Performance Goal Requirement

Performance goal volume retention requirement: 267514 ft3 Volume removed by BMPs towards performance goal: ft³ Percent volume removed towards performance goal %

Annual Volume and Pollutant Load Reductions

Post development annual runoff volume 236.3367 acre -ft Annual runoff volume removed by BMPs: 0 acre-ft Percent annual runoff volume removed: 0 %

Post development annual particulate P load: 106.068 lbs Annual particulate P removed by BMPs: 74.683 lbs Post development annual dissolved P load: 86.783 lbs Annual dissolved P removed by BMPs: 0 lbs Percent annual total phosphorus removed: 39 %

Post development annual TSS load: 35034.6 lbs Annual TSS removed by BMPs: 24166 lbs Percent annual TSS removed: 69 %

BMP Summary Performance Goal Summary

BMP Volume Volume Volume Volume Percent BMP Name Capacity Recieved Retained Outflow Retained (%) (ft3) (ft3) (ft3) (ft3)

Church Pond 0 22001 0 22001 0 Strawberry Gardens 0 40836 0 40836 0 Strawberry Court North 0 2100 0 2100 0 Strawberry Court South 0 50324 0 50324 0 Peach Circle 0 6125 0 6125 0 Alexander Lane 0 6409 0 6409 0 Shorewood Ponds 0 34408 0 34408 0 Smithtown Pond - Option C Upper 0 89842 0 89842 0 Smithtown Pond - Option C Lower 0 245900 0 245900 0

Annual Volume Summary Volume Volume From Volume Volume Percent From Direct BMP Name Upstream Retained outflow Retained Watershed BMPs (acre-ft) (acre-ft) (%) (acre-ft) (acre-ft) Church Pond 14.7097 0 0 14.7097 0 Strawberry Gardens 22.5635 14.7097 0 37.2732 0 Strawberry Court North 3.3413 0 0 3.3413 0 Strawberry Court South 6.7857 40.6146 0 47.4003 0 Peach Circle 4.3702 0 0 4.3702 0 Alexander Lane 5.6399 0 0 5.6399 0 Shorewood Ponds 19.195 0 0 19.195 0 Smithtown Pond - Option C Upper 26.1587 51.7705 0 77.9292 0 Smithtown Pond - Option C Lower 116.5699 102.764 0 219.3339 0

Particulate Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 6.6017 0 4.0931 2.5086 62 Strawberry Gardens 10.1265 2.5086 7.8338 4.8013 62 Strawberry Court North 1.4996 0 0.9298 0.5698 62 Strawberry Court South 3.0454 5.3711 5.2182 3.1983 62 Peach Circle 1.9614 0 1.2161 0.7453 62 Alexander Lane 2.5312 0 1.5693 0.9619 62 Shorewood Ponds 8.6147 0 5.3411 3.2736 62 Smithtown Pond - Option C Upper 11.74 3.9436 9.7238 5.9598 62 Smithtown Pond - Option C Lower 52.3166 10.1953 38.7574 23.7545 62

Dissolved Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 5.4014 0 0 5.4014 0 Strawberry Gardens 8.2853 5.4014 0 13.6867 0 Strawberry Court North 1.2269 0 0 1.2269 0 Strawberry Court South 2.4917 14.9136 0 17.4053 0 Peach Circle 1.6048 0 0 1.6048 0 Alexander Lane 2.071 0 0 2.071 0 Shorewood Ponds 7.0484 0 0 7.0484 0 Smithtown Pond - Option C Upper 9.6055 19.0101 0 28.6156 0 Smithtown Pond - Option C Lower 42.8045 37.735 0 80.5395 0

TSS Summary Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

Church Pond 2180.57 0 1308.34 872.23 60 Strawberry Gardens 3344.82 872.23 2530.23 1686.82 60 Strawberry Court North 495.32 0 297.19 198.13 60 Strawberry Court South 1005.91 1884.95 1734.52 1156.34 60 Peach Circle 647.85 0 388.71 259.14 60 Alexander Lane 836.06 0 501.64 334.42 60 Shorewood Ponds 2845.46 0 1707.28 1138.18 60 Smithtown Pond - Option C Upper 3877.76 1415.48 3175.94 2117.3 60 Smithtown Pond - Option C Lower 17280.32 3589.9 12522.13 8348.09 60

BMP Schematic Project Information

Calculator Version: Version 3: January 2017 Project Name: Smithtown Pond - Option C - IESF User Name / Company Name: Date: Project Description: Option C - Two Pond Cells with Direct Connection to Freeman Park and IESF Construction Permit?: No

Site Information

Retention Requirement (inches): 1.1 Site's Zip Code: 55331 Annual Rainfall (inches): 29.6 Phosphorus EMC (mg/l): 0.3 TSS EMC (mg/l): 54.5

Total Site Area

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 194.599 194.599 other turf to be mowed/managed

Impervious Area (acres) 66.996

Total Area (acres) 261.595

Site Areas Routed to BMPs

Land Cover A Soils B Soils C Soils D Soils Total (acres) (acres) (acres) (acres) (acres) Forest/Open Space - Undisturbed, protected 0 forest/open space or reforested land Managed Turf - disturbed, graded for yards or 183.16 183.16 other turf to be mowed/managed Impervious Area (acres) 61.583

Total Area (acres) 244.743 Summary Information

Performance Goal Requirement

Performance goal volume retention requirement: 267514 ft3 Volume removed by BMPs towards performance goal: ft³ Percent volume removed towards performance goal %

Annual Volume and Pollutant Load Reductions

Post development annual runoff volume 236.3367 acre -ft Annual runoff volume removed by BMPs: 0 acre-ft Percent annual runoff volume removed: 0 %

Post development annual particulate P load: 106.068 lbs Annual particulate P removed by BMPs: 94.874 lbs Post development annual dissolved P load: 86.783 lbs Annual dissolved P removed by BMPs: 32.216 lbs Percent annual total phosphorus removed: 66 %

Post development annual TSS load: 35034.6 lbs Annual TSS removed by BMPs: 31261.9 lbs Percent annual TSS removed: 89 %

BMP Summary Performance Goal Summary

BMP Volume Volume Volume Volume Percent BMP Name Capacity Recieved Retained Outflow Retained (%) (ft3) (ft3) (ft3) (ft3)

IESF 0 245900 0 245900 0 Church Pond 0 22001 0 22001 0 Strawberry Gardens 0 40836 0 40836 0 Strawberry Court North 0 2100 0 2100 0 Strawberry Court South 0 50324 0 50324 0 Peach Circle 0 6125 0 6125 0 Alexander Lane 0 6409 0 6409 0 Shorewood Ponds 0 34408 0 34408 0 Smithtown Pond - Option C Upper 0 89842 0 89842 0 Smithtown Pond - Option C Lower 0 245900 0 245900 0

Annual Volume Summary Volume Volume From Volume Volume Percent From Direct BMP Name Upstream Retained outflow Retained Watershed BMPs (acre-ft) (acre-ft) (%) (acre-ft) (acre-ft) IESF 0 219.3339 0 219.3339 0 Church Pond 14.7097 0 0 14.7097 0 Strawberry Gardens 22.5635 14.7097 0 37.2732 0 Strawberry Court North 3.3413 0 0 3.3413 0 Strawberry Court South 6.7857 40.6146 0 47.4003 0 Peach Circle 4.3702 0 0 4.3702 0 Alexander Lane 5.6399 0 0 5.6399 0 Shorewood Ponds 19.195 0 0 19.195 0 Smithtown Pond - Option C Upper 26.1587 51.7705 0 77.9292 0 Smithtown Pond - Option C Lower 116.5699 102.764 0 219.3339 0

Particulate Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

IESF 0 23.7545 20.1913 3.5632 85 Church Pond 6.6017 0 4.0931 2.5086 62 Strawberry Gardens 10.1265 2.5086 7.8338 4.8013 62 Strawberry Court North 1.4996 0 0.9298 0.5698 62 Strawberry Court South 3.0454 5.3711 5.2182 3.1983 62 Peach Circle 1.9614 0 1.2161 0.7453 62 Alexander Lane 2.5312 0 1.5693 0.9619 62 Shorewood Ponds 8.6147 0 5.3411 3.2736 62 Smithtown Pond - Option C Upper 11.74 3.9436 9.7238 5.9598 62 Smithtown Pond - Option C Lower 52.3166 10.1953 38.7574 23.7545 62

Dissolved Phosphorus Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

IESF 0 80.5395 32.2158 48.3237 40 Church Pond 5.4014 0 0 5.4014 0 Strawberry Gardens 8.2853 5.4014 0 13.6867 0 Strawberry Court North 1.2269 0 0 1.2269 0 Strawberry Court South 2.4917 14.9136 0 17.4053 0 Peach Circle 1.6048 0 0 1.6048 0 Alexander Lane 2.071 0 0 2.071 0 Shorewood Ponds 7.0484 0 0 7.0484 0 Smithtown Pond - Option C Upper 9.6055 19.0101 0 28.6156 0 Smithtown Pond - Option C Lower 42.8045 37.735 0 80.5395 0 TSS Summary

Load From Load From Load Outflow Direct Upstream Percent BMP Name Retained Load Watershed BMPs Retained (%) (lbs) (lbs) (lbs) (lbs)

IESF 0 8348.09 7095.88 1252.21 85 Church Pond 2180.57 0 1308.34 872.23 60 Strawberry Gardens 3344.82 872.23 2530.23 1686.82 60 Strawberry Court North 495.32 0 297.19 198.13 60 Strawberry Court South 1005.91 1884.95 1734.52 1156.34 60 Peach Circle 647.85 0 388.71 259.14 60 Alexander Lane 836.06 0 501.64 334.42 60 Shorewood Ponds 2845.46 0 1707.28 1138.18 60 Smithtown Pond - Option C Upper 3877.76 1415.48 3175.94 2117.3 60 Smithtown Pond - Option C Lower 17280.32 3589.9 12522.13 8348.09 60

BMP Schematic

Appendix E: BMI Neighborhood Drainage Evaluation

Smithtown Pond Feasibility Report/ Neighborhood Drainage Evaluation Overview Map City of Shorewood October 2020

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: 0 300 t n e Feet m u c o Source: Hennepin County, MnDOT D p a M NEIGHBORHOOD DRAINAGE EVALUTION Smithtown Pond Watershed CITY OF SHOREWOOD, MN October, 2020

ITEM NO. ITEM/ISSUE POTENTIAL ACTION TIMING PRIORITY

1 Ditch clogged with vegetation on south side of trail. Clean and regrade ditch to promote positive drainage. Future Improvements Low

2 Ditch clogged with vegetation on north side of trail. Clean and regrade ditch to promote positive drainage. Future Improvements Low

3 Low area on west side of Cathcart Drive in right-of-way Clean and regrade drainage way to promote positive Future Improvements Low holds runoff and remains wet for extended periods. drainage and replace 12" CMP crossing street.

4 Church pond No work proposed None NA 5 Street outlet to south trail ditch is clogged with Clean and regrade ditch to promote positive drainage. Future Improvements Low vegetation 6 Trail crossing - 44" arch RC pipe No work proposed None NA 7 Area north of trail is experiencing more frequent, longer, No work proposed None NA and higher inundation. However, City determined through O&E reports no documentation exists of public drainage improvements and therefore considers it to be a private system.

8 Culverts clogged with debris and vegetation Clean culverts to promote positive drainage. Potentially Future Improvements Low replace culverts if conditon warrants. 9 Low areas between driveways on the north side of 62nd Install draintile and connect to new storm sewer on Strawberry Ln Med Street do not adequately drain Strawberry Lane. 10 Resident sumps run frequently Install draintile and connect to new storm sewer on Strawberry Ln Med Strawberry Lane. 11 Bituminous spillway drains to rear yard area with Eliminate spillway and connect curb to new storm sewer on Strawberry Ln HI treatment. Rear yard area is low and does not have a Strawberry Lane. positive outlet. 12 Low areas between driveways and houses on east side of Replace existing draintile system with new area drains and Strawberry Ln HI street do not adequately drain. Existing draintile system draintile and connect to new storm sewer on Strawberry was installed in 1998 and is connected to Shorewood Lane. Oaks storm sewer. 13 Low areas between driveways and houses on west side Replace existing draintile system with new area drains and Strawberry Ln HI of street do not adequately drain. Existing draintile draintile and connect to new storm sewer on Strawberry system was installed in 1998 and is connected to Lane. Shorewood Oaks storm sewer. 14 Low area in rear yards between Strawberry Lane and Oak Install area drain and connect to new storm sewer on Strawberry Ln HI Leaf Trail does not have a positive outlet and Strawberry Lane. experiences prolonged inundation during wet periods.

15 Ditch on west side of road is clogged with vegetation and Clean and regrade ditch to promote positive drainage. Strawberry Ln HI sediment. 16 Low area in rear yards between Strawberry Lane and Install area drain and connect to new storm sewer on Strawberry Ln HI Church Road does not have a positive outlet and Strawberry Lane. experiences prolonged inundation during wet periods.

17 Existing storm sewer is connected to the Shorewood Replace storm sewer in the intersection and connect to new Strawberry Ln HI Oaks system, contributing to flooding in the Shorewood storm sewer on Strawberry Lane. Oaks development and Freeman Park.

18 Low areas between driveways and houses on west side Replace existing draintile system with new area drains and Strawberry Ln HI of street do not adequately drain. Existing draintile draintile and connect to new storm sewer on Strawberry system was installed in 1998 and is connected to Lane. Shorewood Oaks storm sewer. 19 Low areas between driveways and houses on east side of Replace existing draintile system with new area drains and Strawberry Ln HI street do not adequately drain. Existing draintile system draintile and connect to new storm sewer on Strawberry was installed in 1998 and is connected to Shorewood Lane. Oaks storm sewer. 20 Curb cuts on both sides of the Alexancer Lane lead to Remove curb cuts, install new curb, catchbasins, and area Strawberry Ln HI low spots in the right-of-way with no positive outlets. drains as necessary to connect to storm sewer on Strawberry Lane. 21 Low area in rear yards on south side of Alexander Lane No work proposed None NA does not appear to drain adequately. An area drain is present but may not be adequate. 22 The Alexander Lane wet retention pond appears to be No work proposed None NA holding more runoff than designed, resulting in saturated rear yards adjacent to the basin. ITEM NO. ITEM/ISSUE POTENTIAL ACTION TIMING PRIORITY

23 The outlet control structure for the Alexander Lane wet No work proposed None NA retention pond appears to have settled and erosion is present around the structure where higher flows are bypassing the structure. However, the City considers this a private system, and maintenance must be provided by the HOA. 24 Ditch clogged with vegetation on south side of trail. Clean and regrade ditch to promote positive drainage. Strawberry Ln Med

25 Ditch clogged with vegetation on north side of trail. Clean and regrade ditch to promote positive drainage. Strawberry Ln Med

26 Culvert clogged with debris and vegetation. Remove existing culvert and connect to new storm sewer on Strawberry Ln HI Strawberry Lane. 27 Rear yard of 6600 Strawberry Lane is experiencing more No work proposed None HI frequent, longer, and higher inundation. Resident indicated that tile was present but may be broken or clogged. However, City determined through O&E reports no documentation exists of public drainage improvements and therefore considers it to be a private system. 28 Pipe inlet from south to the Strawberry Garden Pond is Repair erosion and install new riprap to dissipate energy. Strawberry Ln Med eroding the bank of the basin. 29 Strawberry Garden Pond was constructed in the late Dredge pond to design elevations. Expand basin flood Future Improvements Low 1970s. The current outlet control structure and piping storage area to lower high water level and reduce flow rates to Strawberry Lane was installed in the 1990s. Due to downstream. the age of the pond, dredging is likely necessary to restore design treatment effectiveness. Due to higher precipitation and land changes, the adjacent low openings do not meet ordinance requirements for separation from the estimated high water level.

30 Strawberry Garden Pond's outlet control structure does Install skimmer outlet control structure Future Improvements Low not provide skimming to prevent discharge of floatables.

31 Strawberry Court South Pond was constructed in the Dredge pond to design elevations. Strawberry Ln HI early 1990s. Due to the age of the pond, dredging is likely necessary to restore design treatment effectivenes.

32 A low area on the northwest corner of the trail Install area drain or apron and connect to new storm sewer Strawberry Ln HI intersection with Strawberry Lane holds runoff due to no on Strawberry Lane. positive outlet. 33 Strawberry Garden Pond outlet piping is connected to Connect outlet piping to new storm sewer on Strawberry Strawberry Ln HI existing storm manhole adjacent to Strawberry Court Lane. South Pond 34 The outlet control structure for Strawberry Court South Install new skimmer outlet control structure and connect to Strawberry Ln HI Pond provides skimming, but a flap gate has been new storm sewer on Strawberry Lane. installed on the pond pipe due to draintile connections installed after original construction.

35 An area drain on the east side of the road and located on Remove connection to Strawberry Court South Pond. Install Strawberry Ln HI the current Strawberry Court South Pond outlet provides new area drain connected to new storm sewer on a positive outlet for the low area present. Strawberry Lane or leave existing piping and manhole in place. 36 Existing storm sewer connection between Strawberry Replace catchbasins and pipe connections between ponds to Strawberry Ln HI Court South and North Ponds is clogged with vegetation improve flow dynamics and reduce potential for street and may be under sized. According to adjacent flooding. residents, the street frequently floods during rain events and spring snow melt.

37 Strawberry Court North Pond was constructed in the Dredge pond to design elevations. Strawberry Ln HI early 1990s. Due to the age of the pond, dredging is likely necessary to restore design treatment effectivenes.

38 The rear yards west of Strawberry Lane and between Grade / re-grade swale as necessary from backyards to the Future Improvements Low Strawberry Court and Smithtown Road is extremely flat Strawberry Court North Pond. and experiences prolonged inundation during wet periods due to lack of an adequate positive outlet.

39 Yards on the south side of Smithtown Road are lower No work proposed None NA than the road. However, area drains and piping adequately drain the area west in storm sewer on Smithtown Road. 40 A pipe outlet is present on the south side of the road, No work proposed None NA but the upstream location of the pipe is uncertain. The area appears to adequately drain. 41 A low area on the southwest corner of the Smithtown Re-grade the boulevard to adequately drain to the existing Strawberry Ln HI Road and Strawberry Lane intersection holds runoff due catchbasin. to inadequate slope toward an existing catchbasin. ITEM NO. ITEM/ISSUE POTENTIAL ACTION TIMING PRIORITY

42 Ditch clogged with vegetation on south side of trail. Clean and regrade ditch to promote positive drainage. Future Improvements Low

43 Swale draining from the Alexander Pond to the south Clean and regrade swale to provide positive drainage to the Future Improvements Low ditch of the trail is extremely flat and clogged with south ditch of the HCRRA trail. Install culverts for interior vegetation. Interior Freeman Park trails intersect the trails as necessary. swale and block low flows resulting in inundation of the upstream forested area.

44 Trail from Shorewood Oaks through Freeman Park Re-grade the trail and install additional inlets to provide Future Improvements Low experiences extended periods of inundation during wet adequate positive drainage. periods. 45 The energy dissipator on the outlet from the Shorewood Remove sediment and restore banks around energy Future Improvements Low Oaks neighborhood appears to be in adequate working dissipator. Install riprap to stabilize banks. condition. However, sediment deposits adjacent to the dissapator has resulted in the channel cutting into the southeast bank. 46 The basin and channel upstream of the outlet control Remove sediment, debris, and vegetation. Re-grade basin to Smithtown Pond HI structure controlling flow under the HCRRA trail from provide a permanent pool capable of providing sediment Freeman Park is full of sediment, debris, and vegetation storage and a skimmer outlet structure. resulting in blockage of the outlet pipe and extended inundation during prolonged wet periods.

47 The existing outlet control structure design results in Replace outlet control structure with skimmer structure that Smithtown Pond HI frequent clogging and may be undersized to is adequately sized to accommodate the upstream area. accommodate the upstream area. 48 Pebble Creek, from the storm sewer outfall on the Re-route flows to new stormwater management facilities to None NA northeast corner of 5915 Strawberry Lane to the south be installed at 26245 Smithtown Road. The reduction in side of Smithtown Road, is experiencing severe erosion. flows will greatly reduce the potential for continued erosion. The property owner of 5865 Strawberry Lane informed the City they are fine with changes in flow but do not want any grading or trees removed on their property.

49 The Peach Circle cul-de-sac is extremely flat and sumps Install curb and gutter or provide draintile connections to Future Improvements Low draining to the street result in extend inundation the adjacent pond. duration during wet periods. 50 The ditch draining from Freeman Park to Smithtown Stabilize channel and connect to new stormwater Smithtown Pond HI Road is experiencing severe erosion. The centerline of management facilities to be installed at 26245 Smithtown the ditch crosses several property lines on the east side Road. of 26245 Smithtown Road.

51 The existing culverts under the driveway to 26245 Remove existing culverts and restore with new stormwater Smithtown Pond HI Smithtown Road are partially blocked and potentiall management facilities to be installed at 26245 Smithtown undersized. Erosion is occurring upstream and Road. downstream of the culverts.