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CC Staff Report 07-28-2014CITY OF CllANHASSEN 7700 Market Boulevard PO Box 147 Chanhassen, MN 55317 Administration Phone: 952.2271100 Fax 952.227.1110 Building Inspections Phone: 952.227.1180 Fax: 952.227.1190 Engineering Phone: 952.227.1160 Fax: 952.227.1170 Finance Phone: 952.2271140 Fax 952.227.1110 Park & Recreation Phone: 952.227.1120 Fax: 952.227.1110 Recreation Center 2310 Coulter Boulevard Phone: 952.227.1400 Fax: 952.227.1404 Planning & Natural Resources Phone: 952.227.1130 Fax: 952.227.1110 Public Works 7901 Park Place Phone: 952.227.1300 Fax: 952.227.1310 Senior Center Phone, 952.227.1125 Fax 952.2271110 Well MEMORANDUM TO: Todd Gerhardt, City Manager FROM: Sharmeen Al -Jaff, Senior Planner DATE: July 28, 2014 6� SUBJ: Preserve at Rice Lake Final Plat Approval — Planning Case 2013 -12 PROPOSED MOTION "The Chanhassen City Council grants approval of the final plat for Preserve at Rice Lake as shown in plans dated received June 13, 2014 and subject to the conditions of approval in the staff report." Approval requires a simple majority vote of City Council present. PROPOSAL SUMMARY Final Plat with Variances to Subdivide 13.22 Acres into 16 lots and 2 outlots, Preserve at Rice Lake, located southeast of the intersection of Tigua Lane and West 86w Street, and north of Highway 212. BACKGROUND On August 12, 2013, the Chanhassen City Council approved multiple applications that included: • COMPREHENSIVE PLAN AMENDMENT from Residential — Low Density to Residential — Low and Medium Density. • REZONING from Residential — Low Density (R4) and Mixed Low Density Residential (R8) to Planned Unit Development — Residential (PUD -R). • VARIANCES to allow a reduced setback from Highway 212 and a cul -de -sac that exceeds 800 feet in length. • SITE PLAN REVIEW for a medium density development. • WETLAND ALTERATION PERMIT to allow wetland alteration. • PRELIMINARY PLAT: www ci.chanhassemmmus The City Council approves the preliminary plat to subdivide 13.22 acres into 16 lots and 2 outlots as shown in plans dated received August 5, 2013with the following conditions, and adoption of the attached Findings of Fact and Recommendation: Chanhassen is a Community for Life - Providing for Today and Planning for Tomorrow Todd Gerhardt Preserve at Rice Lake - Planning Case 2013 -12 July 28, 2014 Page 2 of 21 All lots must comply with the following table: COMPLIANCE TABLE Wetland setback: 20 -foot buffer, 30 -foot principal structure, 15 -foot accessory structure. Front: 25 feet. Rear: 30 feet, accessory structure 15 feet. Side: 10 -foot house, 5 -foot garage. Area Width Depth Maximum (square feet) (feet) (feet) Hardcover Notes (s uare feet 60 at PUD 10,000 building 100 30 percent setback Ll BI 10,085 126 122 3,025 Wetland L2 BI 10,001 90 108 1 3,000 Wetland L3 BI 11,324 148 109 3,397 Wetland L4 Bl 10,281 76 143 3,084 Wetland L5 Bl 10,103 70 146 3,031 L6 BI 10,301 63 134 3,090 L7 Bl 10,017 62 128 3,005 L8 Bl 10,000 62 128 3,000 Wetland L9 Bl 10,187 62 129 3,056 Wetland L10 Bl 10,024 63 123 3,007 Wetland Lll Bl 12,083 65 (building 116 3,625 Wetland setback) L12 B1 65 (building Wetland 10,017 setback) 118 3,005 Ll B2 108 Wetland, *area of neck 14,085* (building 132 4,225 (4,961 sq. ft.) excluded setback) from lot area calculations L2 B2 10,781 91 106 3,234 Comer lot L3 B2 10,000 106 127 3,000 L4 B2 10,003 91 148 3,001 Outlot A 24 6.47 acres open 282,005 space /wetlands Outlot B 47,560 1.09 acres open space/wetlands ROW 7,309 1.66 acres 72,332 TOTAL 576,299 13.23 acres Wetland setback: 20 -foot buffer, 30 -foot principal structure, 15 -foot accessory structure. Front: 25 feet. Rear: 30 feet, accessory structure 15 feet. Side: 10 -foot house, 5 -foot garage. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 3 of 21 2. All relocated trees shall be warranted for two seasons and replaced by developer if dead or dying within that time period. Finding: This condition has been modified by adding the following language "All relocated trees shall be warranted for two seasons and replaced by developer if dead or dying within that time period. All overstory trees must be a minimum of 2.5" diameter and all understory trees must be a minimum of 1.5" diameter or 6' height." 3. Advanced warning and speed advisory signs are required where the design speed is less than 30 mph. Finding: This condition still applies. 4. The site plan and HydroCAD model must be revised to address the following comments: a. Peak discharge rates are proposed to increase at the following locations: i. Runoff leaving the overall site for the snowmelt events. Finding: This condition still applies. ii. Runoff leaving the western portion of Wetland A for the 2, 10 and 100 year design events. Finding: This condition still applies. iii. Runoff leaving the site to the north of the eastern portion of Wetland A for the snowmelt event. Finding: This condition still applies. iv. Runoff leaving the site to the north of the western portion of Wetland A for all events. Finding: This condition still applies. b. The drainage areas and/or curve number in the HydroCAD model must correspond to the Drainage Area and Curve Number Table. Finding: This condition no longer applies. c. Directly connected impervious areas must be modeled separately rather than included in the composite Curve Number computation. Finding: This condition no longer applies. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 4 of 21 d. The applicant must provide calculations (or submit a model) demonstrating that the city's requirements for water quality are satisfied. Finding: This condition still applies. i. If the event -based NURP standard cannot be achieved by dead pool storage, then (P8 or other) calculations should be based on equivalent annual removal efficiencies. Finding: This condition no longer applies. ii. If an iron - enhanced filtration system is included in the design, calculations should be provided demonstrating the water quality treatment benefits of the BMP. Detailed plans of the system should be submitted for review with the calculations. Finding: This condition no longer applies. iii. The report notes that the east pond is able to remove 87.8% of the phosphorus load. This removal efficiency appears excessively high. It is anticipated that there is either an error with the model inputs or the calculation was performed for a particular rainfall event rather than annualized removal efficiency. Finding: This condition no longer applies. 5. The developer shall obtain off -site easements over the existing swale and 18" culvert. Finding: This condition no longer applies. 6. The developer agreed to replace the 18" culvert north of the site with a new pipe that provides the same capacity. Finding: This condition still applies. 7. The HydroCAD model must be revised so that the impervious surface of the lots is 30 %. Finding: This condition no longer applies. 8. If groundwater is encountered during site construction the lowest floor elevations must be adjusted so that there is a minimum three -foot separation. Finding: This condition still applies. 9. The grading plan must be revised to address the following comments: a. The developer must obtain a MnDOT permit for the proposed grading within the MnDOT right -of -way. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 5 of 21 Finding: this condition has been modified to read "The developer must acquire any necessary permits from MnDOT for grading or drainage." b. It is difficult to discern between the proposed contours, lot lines and setback lines. The developer's engineer is requested to change the drawing line weights. Finding: This condition still applies. 10. Some homes may choose to install a privately -owned and maintained booster to provide a higher water pressure. Finding: This condition still applies. 11. The watermain shall be 8 -inch PVC (C -900). Finding: This condition has been met. 12. Prior to final submittal the developer must obtain all necessary easements to install the sanitary sewer off -site, to the north. Finding: This condition has been modified to read "Final Plat approval is contingent upon filing the drainage and utility easement on the property to the north, 8591 Tigua Lane." 13. A portion of the trunk sewer and water hookup fees must be paid in cash with the final plat in the rate in effect at that time. Finding: This condition has been modified to read "A portion of the trunk sewer and water hookup fees must be paid in cash with the final plat and is calculated as follows: WAC: 16 Units x $1,886 = $30,176 SAC: 16 Units x $664 = $10,624 The remainder of the WAC and SAC fees and the MCES SAC fee shall be paid with the building permit application at the rate in effect at that time." 14. The proposed location of the catch basin on the east side of the cul de sac must be shifted so that it will not conflict with the pedestrian ramp to the trail between Lots 11 and 12, Block 1. Finding: This condition still applies. 15. Street and utility plan and profile construction plans must be submitted with the final plat. Finding: This condition has been met. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 6 of 21 16. Outfalls into the easterly pond must be minimized to the greatest extent practicable. Finding: This condition no longer applies. 17. Plan shall show proposed pond maintenance access and landscaping must not interfere with pond maintenance access. Finding: This condition has been modified to read "An easement for trail and pond maintenance access between Lots 11 and 12, Block 1, must be filed with the final plat." 18. The applicant must apply for and receive an NPDES permit from the Minnesota Pollution Control Agency and provide evidence to the city prior to grading the site. Finding: This condition still applies. 19. The Surface Water Pollution Prevention Plan ( SWPPP) must be prepared as a standalone document and submitted to engineering for review and comment prior to final plat approval. This SWPPP shall include a narrative, plan set and applicable details. Finding: This condition has been met. 20. The SWPPP must include the required elements as listed in Part III of the National Pollution Discharge Elimination System General Permit Authorization to Discharge Stormwater Associated with Construction Activity ( NPDES Construction Permit) and in the MPCA SWPPP checklist. Finding: This condition has been met. 21. A detailed erosion prevention and sediment control plan must be submitted for review and approval per the requirements of Section 19 -145 of Chanhassen City Code and the NPDES Construction Permit. This should include, among the other listed requirements, all temporary and permanent best management practices. Finding: This condition has been met. 22. There is significant evidence of gully erosion at both off -site discharge locations.. Rates must be reduced below existing discharge rates or efforts must be taken to stabilize these discharge points to prevent further channel incision and head cutting. Finding: This condition still applies. 23. Wetland buffers are required around all wetlands on site. Extend buffer around wetland E. Finding: This condition still applies. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 7 of 21 24. Wetland buffer must be extended through all disturbed areas. A detailed vegetation management plan must be developed showing how these areas will be permanently stabilized. Finding: This condition has been met. 25. A vegetation establishment and management plan must be developed and submitted for review for all areas preserved as open space including those areas graded for the construction of stormwater management practices and the installation of utilities that are above the normal water level prior to final plat approval. Finding: This condition has been met. 26. Minnesota Department of Transportation right -of -way is outside of the City of Chanhassen's WCA jurisdiction as MnDOT is their own LGU. Chanhassen's review of wetland boundaries ended at the property limits. The applicant must get all appropriate approvals from MnDOT for work on the sound wall. Finding: This condition still applies. 27. The development must comply with the MN Rules Chapter 6120 and the DNR must issue their concurrence to this effect. Finding: This condition still applies. 28. Estimated Surface Water Management Connection charges due at the time of final plat are $69,983.50. Provide area of wetland buffer and preservation/volume reduction area after development to accurately calculate credit. Finding: This condition still applies. 29. Fifty - percent (50 %) of park fees shall be collected in consideration for the dedication of Outlots A and B. The park fees shall be collected in full at the rate in force upon final plat submission and approval. At today's rate these fees would total $46,400 (16 lots X $5,800 per lot/2). Finding: This condition still applies. 30. Wetland nomenclature on plan set shall be amended to correspond with HydroCAD drainage report and wetland replacement application. Finding: This condition has been met. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 8 of 21 31. The land owner and the selected contractor must provide a Landowner Statement and Contractor Responsibility for Work in Wetlands or Public Waters form to the City prior to working on the road crossing into the site. This form is available on the Board of Soil and Water Resources website. Finding: This condition still applies. 32. A detailed planting schedule and maintenance plan must be provided for the preservation/volume reduction area. Finding: This condition has been met. 33. Preservation/volume reduction area shall be protected from construction traffic, material stockpiling and other construction related activities during site development. These protection measures shall be shown in plans. Finding: This condition has been met. 34. Signs shall be placed along the preservation/volume reduction area to protect the area from encroachment after build out. Finding: This condition has been modified to read "Signs shall be placed along the preservation area to protect the area from encroachment after build out, as shown on sheet L -1, prior to any permits being issued for any lot." 35. Seeded areas within the outlots shall be established and managed according to guidelines and policies developed by the Minnesota Board of Soil and Water Resources as are available on their website. Finding: This condition still applies. 36. Construction of the 8 -foot wide neighborhood trail connection from the public street to the southeast corner of the property. Finding: This condition has been modified to read "Construction of the 8 -foot wide neighborhood trail connection from the public street to the southeast corner of the property at connection point to existing trail." 37. The applicant shall comply with all MnDOT requirements for any work within their right -of- way, i.e. noise wall, landscaping, etc. Finding: This condition still applies. The final plat contained 16 lots and 2 outlots which is consistent with the preliminary plat. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 9 of 21 FINAL PLAT The applicant is requesting final plat approval to subdivide 13.22 acres into 16 lots and 2 outlots. The site is zoned PUD, Planned Unit Development and is southeast of the intersection of Tigua Lane and West 86a' Street, and north of Highway 212. The density is 1.2 units per acre gross and 4 units per acre net after removing the roads, storm ponds, wetlands and park. The applicant is proposing to develop the site in one phase. The outlots contain wetlands, storm ponds and open space. The applicant intends to dedicate the outlots to the city. All lots meet the minimum area, width and depth of the zoning ordinance requirements. All lots are proposed to contain single - family homes. The applicant submitted several home designs they intend to build. Access is gained off of an internal road. There is a variance attached to the application that deals with the length of the cul -de -sac serving this development. This variance was approved with the preliminary plat. All of the proposed lots meet the minimum width and depth requirements of the Zoning Ordinance. Staff notes that the proposal is consistent with the Comprehensive Plan and consistent with the Zoning Ordinance, with the recommended conditions. IZ•7\ 1]' I \1 1 The property lies north of Highway 212, east of County Road 101 and south of 86th Street. The proposed access on 86th Street is located so as to minimize wetland impacts. To further reduce wetland impacts staff supports a reduced right -of -way width (50 feet, with a 15 -foot front yard drainage and utility easement) and a reduced street width (28 feet) for the portion of the road that does not have any lots adjacent to it (approximately 400 feet). The remainder of the street and Block 1 8 9 10 - • • • 7 11 6 12 �: 5 2 4 0' to 2 _ The density is 1.2 units per acre gross and 4 units per acre net after removing the roads, storm ponds, wetlands and park. The applicant is proposing to develop the site in one phase. The outlots contain wetlands, storm ponds and open space. The applicant intends to dedicate the outlots to the city. All lots meet the minimum area, width and depth of the zoning ordinance requirements. All lots are proposed to contain single - family homes. The applicant submitted several home designs they intend to build. Access is gained off of an internal road. There is a variance attached to the application that deals with the length of the cul -de -sac serving this development. This variance was approved with the preliminary plat. All of the proposed lots meet the minimum width and depth requirements of the Zoning Ordinance. Staff notes that the proposal is consistent with the Comprehensive Plan and consistent with the Zoning Ordinance, with the recommended conditions. IZ•7\ 1]' I \1 1 The property lies north of Highway 212, east of County Road 101 and south of 86th Street. The proposed access on 86th Street is located so as to minimize wetland impacts. To further reduce wetland impacts staff supports a reduced right -of -way width (50 feet, with a 15 -foot front yard drainage and utility easement) and a reduced street width (28 feet) for the portion of the road that does not have any lots adjacent to it (approximately 400 feet). The remainder of the street and Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 10 of 21 right of way shall meet the City's minimum requirements. The proposed street curves do not meet a 30 mph design speed; advanced warning and speed advisory signs would be required. The proposed cul de sac is approximately 1,400 feet long, which exceeds the 800 -foot maximum length stipulated in the City Code. Based on the lot configuration and wetland conditions on the site, staff supports the proposed variance. DRAINAGE AND GRADING The developer hired Kallio Engineering to perform a hydrology analysis of the site. The study includes the off -site drainage from the west and north. Runoff from the eastern half of the street and the eastern lots is proposed to be treated in the proposed pond east of Lot 11, Block 1. A portion of the street is proposed to drain to the proposed pond in the southwest corner of the property. Runoff from the first 230 feet of the proposed street south of the intersection with Tigua Lane is not proposed to be treated on site. The developer's engineer that prepared the hydrology report has included this runoff in the analysis. The following comments pertain to the hydrology analysis provided by the developer: 1. Peak discharge rates are proposed to increase at the following locations: a. Runoff leaving the overall site for the snowmelt event. b. Runoff leaving the western portion of Wetland A for the 2 -, 10- and 100 -year design events. c. Runoff leaving the site to the north of the eastern portion of Wetland A for the snowmelt event. 2. The applicant must provide calculations (or submit a model) demonstrating that the city's requirements for water quality are satisfied. The impervious surface of some lots may be at or near the maximum impervious coverage allowed once the home, driveway and required landings to exterior doors are constructed. Future home owners of these lots would have limited or no opportunities to construct other site amenities such as patios based on the plans provided. During pre - submittal meetings with the developer, city staff expressed concern of potential high groundwater elevations within the development. The developer responded by installing six piezometers on the site that allow for the measurement of static water pressures. Though groundwater was not encountered when soil borings were taken, groundwater is present in all piezometers. The developer's soils engineer took seven readings between May 1 and Julyl6, 2013. Readings were also taken on May 5 and June 24, 2014. Based on the readings from Boring #7 on May 5, 2014 the lowest floor elevation of Lots 1 and 2, Block 1 need to be adjusted to maintain three feet of separation from the groundwater. If groundwater is encountered during site construction the lowest floor elevations of adjacent lots must be adjusted to maintain minimum three feet of separation. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 11 of 21 The developer proposes to mass grade the site. The developer must acquire any necessary permits from MnDOT for grading or drainage. It is difficult to discern between the proposed contours, lot lines and setback lines on the grading plan. The developer's engineer is requested to change the drawing line weights. A 12 -inch trunk watermain extends from the townhome development to the west to the Reflections development south of Highway 212. The property was assessed for this improvement. According to city records this assessment has been paid. The developer proposes to extend lateral watermain from this trunk line to service the development. Based on the proposed elevations of the homes, the operating water pressures within the homes will meet the minimum required per 10 States Standards; however, some homes may choose to install a privately -owned and maintained booster to provide a higher water pressure. The plan includes a water service to the property to the north of the plat located at 8591 Tigua Lane. This service will extend from the watermain within the cul de sac, through Lot 11, Block 1 and Outlot A. This service is not a public utility or a small utility (eg. gas, electric, phone); therefore, the platted side yard drainage and utility easement on Lot 11 is not the appropriate measure to allow for this water service. Upon consultation with the city attorney's office, an easement from the owner of Lot 11, Block 1, Preserve at Rice Lake must be recorded in favor of 8591 Tigua Lane to allow for the water service installation. This easement shall be recorded with the final plat. Additionally, an encroachment agreement is required for this water service as it will lie within the drainage and utility easement within Lot 11, Block 1 and Outlot A. The encroachment agreement shall be recorded against Lot 11, Block 1, and Outlot A, Preserve at Rice Lake with the final plat. The developer proposes to extend lateral sanitary sewer from the existing 8 -inch lateral sanitary sewer north of the site. Final plat approval shall be contingent upon filing the drainage and utility easement on the property to the north, 8591 Tigua Lane. A portion of the trunk water and sewer hookup fees (WAC and SAC, respectively) must be paid in cash with the final plat and are calculated as follows: WAC 16 units x $1,886 /unit = $30,176 SAC 16 units x $664 /unit = $10,624 The remainder of the WAC and SAC fees, along with the Met Council SAC fee shall be paid with the building permit application at the rate in effect at that time. The proposed location of the catch basin on the east side of the cul de sac must be shifted so that it will not conflict with the pedestrian ramp to the trail between Lots 11 and 12, Block 1. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 12 of 21 NOISE WALL The developer proposes to construct a noise wall within MnDOT right of way. MnDOT requires that the City enter into a cooperative agreement in order to allow the wall within the right of way. After completing a wetland delineation as required by MnDOT, the noise wall plans were revised to reflect the wetland conditions and avoid impact. The revised noise wall plans have been submitted to MnDOT for review. To date, the city has not received the revised plans. MnDOT will not release the required noise wall agreement to the city for review and execution until their review is complete and all comments have been implemented. The deadline for MnDOT's review is July 22, 2014. At the time of writing this report, an update on MnDOT's review status and decision was not available. Approval of the noise wall plans and agreement with MnDOT will be on a future City Council agenda. This agreement must be executed before the final plat is recorded. The noise wall will be over the city's 12 -inch trunk water main that extends under Highway 212. The water main within the MnDOT right of way is within a 24 -inch steel casing; therefore, there would not be any impact to the wall should the water main ever need to be replaced. Owns FEE woaxsHIEET DATE AuSW9,3013 FLENO. 1313 PROJECT P`acveetNi[e MaM Lake Ste A.m Ame 13 ]00 We ft 3600 Ammbbuer 9A00 ZONING CLASS@TCATION Me um D®vtylb -a il -pUD FEES ReRpttAae Aan ToW RATES QUALITY WATER QUAMI3Y S 3,930 00 9.60 S 37.168.00 R Il WAa, A— TmW S 5.590.00 9.60 $ 53b0,00 CREDITS ITEM UNR QUANTMY UNIT TOTAL PRICE PLAICE E..Pma 59 f 1,415.00 f 018.50 O fld u meh 1.00 f 3,IIO.R f 3390.00 SWMP RE SWMP CREDRS TMALB PFEE S ITSO 50 S 80,833.00 f 10,818.50 Fs: wllFemmmal6uNC avice Weuma eueee ermaere wmebF ®au®1mmeEOO � :P.awemm we ary A Surface Water Management Connection Fee will be assessed to this project. This fee is broken into water quality and water quantity and is based upon net developable acreage and a multiplier intended to reflect the anticipated burden the land use will place upon the storm sewer system relative to other land uses. Credit is then given for storm water management best management practices at a rate of 50% the water quality rate per acre treated. The table to the left shows the calculations. Buffer areas with proper demarcation, protection and vegetative management are deducted from the calculated area. Not only is the protection and enhancement of open space a necessary component of the PUD process, it serves as a financial reward for proper protection and management. Before permits are issued for any lot adjacent to a wetland, the developer shall install wetland buffer signs at each lot corner and major angle point as shown on sheet Ll Landscape Plan / Planting Plan. A $750.00 security will be required at time of final plat to assure this is completed. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 13 of 21 Before the final plat is recorded the DNR must approve the wetland vegetation management plan. Outlots A and B shall be deeded to the city. EROSION PREVENTION AND SEDIMENT CONTROL �t r Er ♦�s� .r: .��. n y y r�'•; y � Peak discharge rates are increased at both places where drainage will leave the site. In both instances the outlet channel has become incised and head cuts are forming within the channel. At the outfall downstream of the driveway, a surge basin was installed at some point in the past. The channel has since worked around either side of the surge basin as illustrated in the photograph to the left. The other channel is incised. The depth of this incision will increase and will almost certainly accelerate as the discharge rate and, therefore, the scour force within the channel increases. In both instances, these channels discharge to Rice Marsh Lake and the resulting erosion will lead to increased sediment deposition into the lake. The shoreland PUD standards requires that erosion control and storm water management facilities "be designed, and their construction managed, to minimize the likelihood of serious erosion occurring either during or after construction..." Efforts must be taken to reduce the rate of runoff or assure that the channels are stabilized to prevent further degradation. The total disturbed area is approximately 8.5 acres which exceeds the one -acre threshold. Given the total disturbance it must be compliant with the National Pollution Discharge Elimination System General Permit Authorization to Discharge Stormwater Associated with Construction Activity ( NPDES Construction Permit). As part of this permit, the applicant is required to develop a Surface Water Pollution Prevention Plan (SWPPP) with three elements: a narrative, plan sheets and standard detail plates. Each of these elements requires specific content. Section 19 -145 of Chanhassen City Code requires that the construction is compliant with the NPDES Construction Permit and the SWPPP is provided to the City for review and comment. A draft Surface Water Pollution Prevention Plan (SWPPP) has been prepared and submitted. This plan shall be edited and updated throughout all phases of development including home construction. The primary contractor responsible for day -to -day operations of the site shall be identified and the SWPPP updated to reflect this prior to any disturbance on the site. This updated SWPPP shall be made available to the City at the pre - construction meeting. The following changes need to be incorporated into the SWPPP before any site grading can occur. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 14 of 21 • The sheet labeled Appendix C -1: Erosion and Sediment Control Plan shall show erosion control blanket covering the disturbed areas adjacent to the road crossing the wetland and above the 894' contour for the most southwesterly pond. • All erosion control blanket except in the overland emergency overflow areas shall either be netting -free or use jute netting or another biodegradable material approved by the City. • Topsoil shall be stripped and stockpiled in a berm on the up- gradient side of the silt fence. This shall be indicated on Appendix C -1: Erosion and Sediment Control Plan. • Sheets L -1 and L -2 shall be added to the SWPPP after Appendix C -2 as these are part of the Final Stabilization Plan for the site. An escrow in the amount of $62,815 will be due with the final plat for erosion and sediment control. This amount was calculated based upon the estimated SWPPP quantities provided by the applicant. Clearing and grubbing and common excavation were deducted from this figure. Select granular topsoil was added to this based upon 70% of the lot area to a depth of 6 inches. WETLAND PROTECTION Graham Environmental Services, Inc. (GES) performed an on -site wetland determination and boundary delineation on April 28 and May 4, 2011. This was reviewed by city staff as the local government unit (LGU) responsible for administration of the Wetland Conservation Act and submitted to the technical evaluation panel for comment. Based upon review of the delineation, the boundaries were approved excepting that Wetland C and Wetland D were determined to be part of the same basin and Wetland B was expanded to the north. The current plan submittal appears to accurately reflect these modified boundaries. The plan set was provided by Probe Engineering Company, Inc. on behalf of J &S Ventures. The plan shows the required buffer around wetlands A through D but does not show a buffer around wetland E. All wetlands, including Wetland E, require the establishment of buffer areas and setbacks per Section 20 -411 of Chanhassen City Code. Any wetland buffer areas that are disturbed, do not meet the requirement for native vegetation as stated in §20 -411, or which contains noxious weeds must have a detailed vegetation management plan and that plan must be followed. These areas must be identified as buffer on the plan. SHORELAND MANAGEMENT This property lies within the Shoreland Management District and is subject to the Planned Unit Development (PUD) requirements. The applicant must demonstrate that by granting the flexibility that comes with a PUD, enhancements are made that would not be seen with a straight single - family residential development plan. A detailed management plan, with scheduled maintenance activities, has been prepared as required with the preliminary plat approval conditions. This plan should be adequate to manage these disturbed areas to provide the aesthetic, ecological and water quality benefits for which the Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 15 of 21 open space is intended to provide. However, the Department of Natural Resources shall need to make such a determination. PARK DEDICATION Comprehensive Park Plan The city's comprehensive park plan calls for a neighborhood park to be located within one -half mile of every residence in the city. The proposed Preserve at Rice Lake development would not meet this guideline. The nearest park is Rice Marsh Lake Park which is located approximately one mile away if utilizing the city's pedestrian trail network. Comprehensive Trail Plan The city's comprehensive trail plan calls for the future completion of the Rice Marsh Lake Trail to be constructed around the perimeter of the lake. This proposed subdivision should provide for and construct a trail connection to this future trail starting at the public street and extending to the southeast corner of the property. This trail connection should be situated in a public outlot or trail easement. TREE PRESERVATION/LANDSCAPING The applicant has provided a tree inventory and removal plan for the subdivision. Bufferyard plantings are required for this development along Highway 212. Tree preservation calculations for the development are shown below. Total upland area (excluding wetlands) 413,111 SF or 9.48 acres Total canopy area (excluding wetlands) 66,600 SF or 1.52 acres Baseline canopy coverage 16% Minimum canopy coverage allowed 25% or 103,277 SF Proposed tree preservation 4% or 16,820 SF The developer does not meet minimum canopy coverage allowed. Additional plantings will be required to bring the baseline canopy coverage up to the minimum required. Required plantings 87 trees (66600 - 16820)x1.2 54 trees required (103277- 66600) 33 trees required The applicant has proposed a total of 48 new trees and 50 transplanted evergreens in the landscape plan. The applicant is required to provide bufferyards along Highway 212. The minimum plantings required and the applicant's proposed quantities are shown in the table below. Mr. Todd Gerhardt Preserve at Rice Lake - Planning Case 2013 -12 July 28, 2014 Page 16 of 21 The applicant does not meet minimum requirements for bufferyard plantings along the south property line. All but a handful of trees are located offsite on MnDOT property. Staff recommends the landscaping be located on the applicant's property unless proof of MnDOT approval is given to the city. COMPLIANCE TABLE Required Proposed South property line - 15 overstory trees 7 overstory trees Hwy 212, bufferyard B, 31 understory trees 4 understory trees 956' 46 shrubs 50 transplant evergreens 36 shrubs The applicant does not meet minimum requirements for bufferyard plantings along the south property line. All but a handful of trees are located offsite on MnDOT property. Staff recommends the landscaping be located on the applicant's property unless proof of MnDOT approval is given to the city. COMPLIANCE TABLE Area Width Depth Maximum (square feet) (feet) (feet) Hardcover Notes (square feet) 60 at PUD 10,000 building 100 30 percent setback Ll BI 1 10,085 129 122 3,025 Wetland L2 B1 10,001 90 108 3,000 Wetland L3 BI 11,324 152 109 3,397 Wetland L4 Bl 10,281 76 143 3,084 Wetland L5 Bl 10,103 70 146 3,031 L6 Bl 10,301 63 134 3,090 L7 Bl 10,017 62 128 3,005 L8 B1 10,000 62 128 3,000 Wetland L9 Bl 10,187 62 129 3,056 Wetland L10 B1 10,024 63 123 3,007 Wetland Lll Bl 65 (building Wetland 12,083 setback) 116 3,625 L12 B1 65 (building Wetland 10,017 setback) 118 3,005 Ll B2 108 Wetland, * area of neck 14,085* (building 132 4,225 (4,961 sq. ft.) excluded setback) from lot area calculations L2 B2 10,781 91 106 3,234 Comer lot L3 B2 10,000 106 127 3,000 L4 B2 10,003 90 148 3,001 Outlot A 282,005 6.47 acres open space/wetlands Outlot B 1.09 acres open 47,560 space/wetlands ROW 72,332 1.66 acres TOTAL 576,299 13.23 acres Mr. Todd Gerhardt Preserve at Rice Lake - Planning Case 2013 -12 July 28, 2014 Page 17 of 21 Wetland setback: 20 -foot buffer, 30 -foot principal structure, 15 -foot accessory structure. Front: 25 feet Rear: 30 feet, accessory structure 15 feet Side: 10 -foot house, 5-foot garage Staff recommends that the City Council adopt the following motion: "The City Council grants final plat approval of Planning Case #2013 -12 for Preserve at Rice Lake to subdivide 13.22 Acres into 16 lots and 2 outlots as shown in plans dated received June 13, 2014, subject to the following conditions: Planning Department Conditions 1. All lots must comply with the following table: COMPLIANCE TABLE Area Width Depth Maximum (square feet) (feet) (feet) Hardcover Notes (square feet) 60 at PUD 10,000 building 100 30 percent setback Ll BI 10,085 129 122 3,025 Wetland L2 Bl 10,001 90 108 3,000 Wetland L3 Bl 11,324 152 109 3,397 Wetland L4 Bl 10,281 76 143 3,084 Wetland L5 BI 10,103 70 146 3,031 L6 BI 1 10,301 63 134 3,090 L7 Bl 10,017 62 128 3,005 L8 Bl 10,000 62 128 3,000 Wetland L9 Bl 10,187 62 129 3,056 Wetland L10 BI 10,024 63 123 3,007 Wetland 65 (building Lll BI 12,083 setback) 116 3,625 Wetland L12 B1 10,017 65 (building 118 3,005 Wetland setback) 108 Wetland, * area of neck Ll B2 14,085* (building 132 4,225 (4,961 sq. ft.) excluded setback) from lot area calculations L2 B2 10,781 91 106 3,234 Corner lot L3 B2 10,000 106 127 3,000 L4 B2 10,003 90 148 3,001 Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 18 of 21 Wetland setback: 20 -foot buffer, 30 -foot principal structure, 15 -foot accessory structure. Front: 25 feet Rear: 30 feet, accessory structure 15 feet Side: 10 -foot house, 5 -foot garage Environmental Resources Conditions 1. All relocated trees shall be warranted for two seasons and replaced by developer if dead or dying within that time period. All overstory trees must be a minimum of 2.5" diameter and all understory trees must be a minimum of 1.5" diameter or 6' height. Building Official Conditions 1. Provide a 1:200 "clean" plat drawing (for addressing). 2. Proposed street -name "PRESERVE COURT" is acceptable. 3. Buildings may be required to be designed by an architect and/or engineer as determined by the Building Official. 4. A final grading plan and soils report must be submitted to the Inspections Division before permits can be issued. 5. Retaining walls over four feet high require a permit and must be designed by a professional engineer. 6. Each lot must be provided with separate sewer and water services. 7. The applicant and or their agent shall meet with the Inspections Division as early as possible to discuss plan review and permit procedures. Fire Marshal Conditions 1. An additional fire hydrant will be required at the southwest comer of Lot 1. 2. A three -foot clear space must be maintained around fire hydrants. 3. Prior to combustible construction, fire apparatus access roads capable of supporting the weight of fire apparatus shall be made serviceable. 4. Temporary street signs shall be installed prior to and during time of construction. 5. Prior to combustible construction fire hydrants must be made serviceable. Area Width Depth Maximum (square feet) (feet) (feet) Hardcover Notes (s ware feet Outlot A 282,005 6.47 acres open space /wetlands Outlot B 47,560 1.09 acres open space /wetlands ROW 72,332 1.66 acres TOTAL 576,299 13.23 acres Wetland setback: 20 -foot buffer, 30 -foot principal structure, 15 -foot accessory structure. Front: 25 feet Rear: 30 feet, accessory structure 15 feet Side: 10 -foot house, 5 -foot garage Environmental Resources Conditions 1. All relocated trees shall be warranted for two seasons and replaced by developer if dead or dying within that time period. All overstory trees must be a minimum of 2.5" diameter and all understory trees must be a minimum of 1.5" diameter or 6' height. Building Official Conditions 1. Provide a 1:200 "clean" plat drawing (for addressing). 2. Proposed street -name "PRESERVE COURT" is acceptable. 3. Buildings may be required to be designed by an architect and/or engineer as determined by the Building Official. 4. A final grading plan and soils report must be submitted to the Inspections Division before permits can be issued. 5. Retaining walls over four feet high require a permit and must be designed by a professional engineer. 6. Each lot must be provided with separate sewer and water services. 7. The applicant and or their agent shall meet with the Inspections Division as early as possible to discuss plan review and permit procedures. Fire Marshal Conditions 1. An additional fire hydrant will be required at the southwest comer of Lot 1. 2. A three -foot clear space must be maintained around fire hydrants. 3. Prior to combustible construction, fire apparatus access roads capable of supporting the weight of fire apparatus shall be made serviceable. 4. Temporary street signs shall be installed prior to and during time of construction. 5. Prior to combustible construction fire hydrants must be made serviceable. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 19 of 21 Engineering Department Conditions 1. Advanced warning and speed advisory signs are required where the design speed is less than 30 mph. 2. The site plan and HydroCAD model must be revised to address the following comments: a. Peak discharge rates are proposed to increase at the following locations: i. Runoff leaving the western portion of Wetland A for the 2, 10 and 100 year design events. ii. Runoff leaving the site to the north of the eastern portion of Wetland A for the snowmelt event. iii. Runoff leaving the site to the north of the western portion of Wetland A for all events. b. The applicant must provide calculations (or submit a model) demonstrating that the city's requirements for water quality are satisfied. 3. The developer shall replace the 18" culvert north of the site with a new pipe that provides the same capacity. 4. The lowest floor elevation of Lots 1 and 2, Block 1 need to be adjusted to maintain three feet of separation from the groundwater. 5. If groundwater is encountered during site construction the lowest floor elevations must be adjusted so that there is a minimum three -foot separation. 6. The developer must acquire any necessary permits from MnDOT for grading or drainage. 7. It is difficult to discern between the proposed contours, lot lines and setback lines. The developer's engineer is requested to change the drawing line weights. 8. Some homes may choose to install a privately -owned and maintained booster to provide a higher water pressure. 9. The owner of Lot 11, Block 1, Preserve at Rice Lake must be recorded in favor of 8591 Tigua Lane to allow for the water service installation. This easement shall be recorded with the final plat. 10. An Encroachment Agreement shall be recorded against Lot 11, Block 1, and Outlot A, Preserve at Rice Lake with the final plat to allow for the private water service to 8591 Tigua Lane. 11. Final Plat approval is contingent upon filing the drainage and utility easement on the property to the north, 8591 Tigua Lane. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 20 of 21 12. A portion of the trunk sewer and water hookup fees (WAC and SAC, respectively) must be paid in cash with the final plat: WAC 16 units x $1,886 /unit = $30,176 SAC 16 units x $664 /unit = $10,624 The remainder of the WAC and SAC fees and the MCES SAC fee shall be paid with the building permit application at the rate in effect at that rime. 13. The proposed location of the catch basin on the east side of the cul de sac must be shifted so that it will not conflict with the pedestrian ramp to the trail between Lots 11 and 12, Block 1. 14. The Agreement between the City and MnDOT to allow for the construction of the noise wall within MnDOT right of way must be executed before the final plat is recorded. 15. A trail easement between Lots 11 and 12, Block 1, must be filed with the final plat. 16. The applicant must apply for and receive an NPDES permit from the Minnesota Pollution Control Agency and provide evidence to the city prior to grading the site. 17. The following changes need to be incorporated into the SWPPP before any site grading can occur: a. The sheet labeled Appendix C -1: Erosion and Sediment Control Plan shall show erosion control blanket covering the disturbed areas adjacent to the road crossing the wetland and above the 894' contour for the most southwesterly pond. b. All erosion control blanket except in the overland emergency overflow areas shall either be netting free or use jute netting or another biodegradable material approved by the City. c. Topsoil shall be stripped and stockpiled in a berm on the up- gradient side of the silt fence. This shall be indicated on Appendix C -1: Erosion and Sediment Control Plan. d. Sheets L -1 and L -2 shall be added to the SWPPP after Appendix C -2 as these are part of the Final Stabilization Plan for the site. Water Resources Coordinator Conditions 1. An escrow in the amount of $62,815 will be due with the final plat for erosion and sediment control. 2. There is significant evidence of gully erosion at both off -site discharge locations. Rates must be reduced below existing discharge rates or efforts must be taken to stabilize these discharge points to prevent further channel incision and head cutting. 3. Wetland buffers are required around all wetlands on site. Extend buffer around wetland E. 4. Before permits are issued for any lot adjacent to a wetland, the developer shall install wetland buffer signs as shown on sheet Ll Landscape Plan / Planting Plan. A $750.00 security will be required at time of final plat. Mr. Todd Gerhardt Preserve at Rice Lake — Planning Case 2013 -12 July 28, 2014 Page 21 of 21 5. Minnesota Department of Transportation right -of -way is outside of the City of Chanhassen's WCA jurisdiction as MnDOT is their own LGU. Chanhassen's review of wetland boundaries ended at the property limits. The applicant must get all appropriate approvals from MnDOT for work on the sound wall. 6. The development must comply with the MN Rules Chapter 6120 and the DNR must issue their concurrence to this effect. 7. Estimated Surface Water Management Connection charges due at the time of final plat are $69,983.50. Provide area of wetland buffer and preservation/volume reduction area after development to accurately calculate credit. The land owner and the selected contractor must provide a Landowner Statement and Contractor Responsibility for Work in Wetlands or Public Waters form to the City prior to working on the road crossing into the site. This form is available on the Board of Soil and Water Resources website. 9. Signs shall be placed along the preservation area to protect the area from encroachment after build out, as shown on sheet L -1, prior to any permits being issued for any lot. 10. Seeded areas within the outlots shall be established and managed according to guidelines and policies developed by the Minnesota Board of Soil and Water Resources as are available on their website. 11. The applicant shall comply with all MnDOT requirements for any work within their right -of- way, i.e. noise wall, landscaping, etc. 12. Before the final plat is recorded the DNR must approve the wetland vegetation management plan. 13.Outlots A and B shall be deeded to the city. Park and Recreation Conditions 1. Fifty - percent (50 %) of park fees shall be collected in consideration for the dedication of Outlots A and B. The park fees shall be collected in full at the rate in force upon final plat submission and approval. At today's rate these fees would total $46,400 (16 lots X $5,800 per lot/2). 2. Construction of the 8 -foot wide neighborhood trail connection from the public street to the southeast corner of the property at connection point to existing trail. ATTACHMENTS 1. Final Plat. gAplan\2013 planning cases\2013 -12 preserve at rice IakeVinal plat submittal 061314\final plat.doc ICI z c; ra Of ,to C14 1 zo lr—L:: jig lt'N, Jv Li 14 11A �3 i-liti, 0 it ff, `'ll