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HomeMy WebLinkAbout09(B) - Consider Adoption of Resolution 21- 084 to Approve the Springview Meadows Preliminary Plat and Ordinance 121-09 for a Planned Unit Development (PUD) Report88.36 88.00 97.55 71. 8 499.2770. 5 2 72. 0 0 72. 0 0 86.00 88.1701270.39 86.5070. 0 0 70. 0 0 70.984 5 6 7 8 9 90 91 92 93 94 95 96 97 98 99 100 101 12,728 sf 14,787 sf 90,046 sf 11,615 sf 22,542 sf 10,549 sf 10,738 sf 12,393 sf 12,829 sf 12,148 sf 12,317 sf 13,315 sf 99320523 5994086110 15788 101 37 64495127 80161 78644 71 72 12 5 12 4 10288 132132328876 31 10 0 71 72 22 58 768641266 363 70 70 12 1 115 157134133134 152817052155133 11,605 sf 9,437 sf 9,609 sf 12,375 sf 11 3 . 1 0 105.00 F:\Projects\_Design_Misc_Projects\CH 12-CH 17 Int Skew\CH12-CH17_LAY.dwg (4/20/2021 10:44 AM) 00 50'100' CSAH 17 & 170TH ST. E INTERSECTION IMPROVEMENTS PRELIMINARY LAYOUT SCOTT COUNTY 17 SCOTT COUNTY 12 L:\21 FILES\21 SUBDIVISIONS\PRELIMINARY PLAT\Springview Meadows PDEV21-000004\Referrals and Correspondence\05 21 2021 Springview Meadows PrePlat Eng Memo.docx 701 XENIA AVENUE S | SUITE 300 | MINNEAPOLIS, MN | 55416 | 763.541.4800 | WSBENG.COM Memorandum To: Nick Monserud, Assistant City Engineer Pete Young, Water Resources Engineer From: Kris Keller, Tom Hoffman - WSB Date: May 21, 2021 Re: Springview Meadows WSB Project No. 10704-000 We have completed our secondary plat review of the civil and stormwater plans submitted for Springview Meadows on May 14, 2021 as prepared by Westwood Professional Services, Inc. The following documents were received: · Preliminary Plans (0020057.00 Springview Meadows Prelim Plans Rev 1pdf) · Preliminary Stormwater Summary (21-04-30 Springview Meadow- Stormwater Report.pdf) · Storm sewer Design (21-04-30 Storm Sewer Design - Springview Meadows.pdf) · Developer Response (21-04-30 WPS Response Springview Meadows Prelim Plat Review Memo 031721.pdf) · Geotechnical Report (B2010179_MARSCHALL PROPERTY_GEOTECHNICAL EVALUATION REPORT DRAFT.pdf) Comments are provided within this Memorandum and in the corresponding redlined plan set. Please note that not all comments within the plan set are in the Memorandum. We have the following comments with regards to stormwater management and engineering. General 1. Submit for and provide copies to the City of all required permits from regulatory agencies (MCES, Minnesota Pollution Control Agency, Minnesota Department of Health, NPDES, County, etc.) Noted. Copies all permits will be provided as approved. Plat 1. Provide drainage and utility easements for all public utilities running across private property. a. The width of the easement should be at least two times the greatest depth of the utility with a minimum of 20' centered on the utility Noted easements have been adjusted to reflect comment 2. Provide drainage and utility easements for all drainage swales that convey water from one lot across another a. The width of the easement should be a minimum of 10’ with at least 5' on either side of the center of the swale Noted. Easements have been adjusted to reflect comment Springview Meadows May 21, 2021 Page 2 Streets/Trails 1. Based on the proposed site plan the anticipated traffic generation would be 406 vehicle per day (vpd), 32 AM peak hour trips and 43 PM peak hour trips, assuming 43 single family lots on the site. Applicant noted 2. 170th Street is a local City street that is identified as a future transfer to Scott County (CSAH 12) as a Major Collector in the County’s 2040 Comprehensive Plan. CSAH 12 east of CSAH 17 has and existing ADT of 1600vpd and a projected 2040 ADT of 5800vpd. CSAH 17 north of CSAH 12 has an existing ADT of 6800vpd and a projected 2040 ADT of 11,900vpd. a. Applicant noted – any changes to be addressed with final plans 3. A sight line analysis shall be completed for all intersections including the intersection of Street 1 at 170th Street. 4. The final plans shall include a signing and pavement marking plan, including at a minimum, locations of stop signs, street signs, pedestrian crossing signs, street striping and pedestrian crossing striping. Applicant noted 5. Add sidewalks to: a. The east and west sides of Street 1 b. The north side of Street 2 c. The north side of Street 3 d. Label new sidewalks and trails e. Extend trail along CSAH 17 from Street 3 cul de sac to 170th Street intersection 6. Move the driveway access for Lot 1 Block 2 from Street 1 to Street 2 7. Provide locations for all proposed cluster mailboxes. a. Mailboxes to be included with Final Plans 8. The cul de sac at the southeast end of Street 3 should be designed per City Detail Plate #605. 9. Provide a temporary cul de sac at the west end of Street 3 a. Provide barricades and a future through street sign b. Applicant indicated that, following discussion with City staff, temporary cul de sac was not necessary 10. Street Profiles a. Identify centerlines of connecting streets at intersections in profile views. b. Several vertical curves do not meet the minimum required K value (30 for crest curves, 36 for sag curves) for 30 mph. 11. Provide horizontal curve/alignment information for all roads. a. Curves must meet a 30 MPH design speed and shall have a minimum 250’ centerline radius i. There are two curves on Street 2 that do not meet the 250’ minimum requirement (50’) Springview Meadows May 21, 2021 Page 3 ii. Applicant indicated Horizontal curves proposed match previous projects in the area (Summit Preserve) and that the design is intended to encourage slower speeds in the residential development. 12. Provide typical sections for all roads a. Include proposed curb types b. Include supporting geotechnical information 13. Revise 170th Street per Scott County alignment provided to Developer. 14. At this time grading of trail and sidewalk only will be allowed. A deposit for the sidewalk construction will be collected for future construction. The trail will be constructed when the property to the north is constructed. This will detour residents from trying to cross CSAH 17 until pedestrian facilities are able to be installed at the intersection. Stormwater Management (Updated Design) 1. Rate Control a. Provide the HydroCAD calculations for the 2- and 10-year events in addition to the 100-year event. b. Portions of the site drain to wetlands. Please verify the rate control requirements for wetland 1W. The wetland does not appear to meet the discharge requirements of 0.05 cfs per tributary acre for the 2-year event based on the Wetland Bounce and Inundation Table. i. Applicant indicated that per City Staff discussions, the project will not be required to meet the 0.05 cfs per tributary acre requirement. Wetland bounce and inundation will still apply. 2. Volume Control a. Preliminarily met via filtration. 3. Water Quality a. This requirement has been met. A pretreatment forebay has been adequately sized to 25% of the water quality volume. 4. Freeboard a. Label the emergency overflow elevations (EOF) for the wetlands. i. Ensure there is 2 feet of freeboard from the EOF to the low opening of the adjacent homes. b. Adjust the grading in several locations to allow for 2 feet of freeboard between the low openings and the EOF from the rear yard or street low point. c. The EOF of the basin should be at least 1 foot higher than the HWL. i. Applicant indicated that per discussions with City Staff, EOF of basin can be less than 1.0’ above the HWL. 5. General Stormwater a. Modify the pond skimmer outlet detail to show the weir wall and orifice. i. Modified detail to show weir wall and orfice Springview Meadows May 21, 2021 Page 4 b. Include pond cross section details. i. Added pond cross section detail c. Include the HydroCAD storage tables in the stormwater management report. i. Stage storage tables hae been added to report d. Define a maintenance access route to filtration basin 1P that is a maximum of 8% grade, 2% cross slope, and a minimum of 10 feet wide. i. Added maintenance access route to filtration basin 1P 6. Filtration Basin a. Ensure the velocities from the inlet pipes into the basins are non-erosive. i. Inlet velocities are designed to be less than 5 fps b. The invert elevations of the pond flared end sections shall match the outlet elevation of the pond. i. Adjusted per comment c. Call out the underdrain specifics. i. Include at least 2 observation/cleanout ports on each underdrain. ii. Include size of underdrain iii. Set at a minimum 0.5% slope. Added notes for underdrain 7. Wet Basin/Forebay a. A 10-foot wide aquatic bench is required below the NWL of the forebay. A 10 ft wide aquatic bench at 10:1 (H:V) has been provided for both forebays. Added slope labels for clarity 8. Drainage Areas a. Provide consistent labels between the proposed drainage area map and HydroCAD model. Updated labels for consistency 9. HydroCAD Model a. Filtration Basin 1P i. Modify the EOF elevation in HydroCAD to match the plans. Adjusted EOF elevation per HyrdoCAD b. Filtration Basin 2P i. Show pipe spacing/bedding detail to verify spacing to no meet dnr bridge requirements. See Requirements below: ii. Modify the primary outlet size to match the plans. Adjusted per HydroCAD iii. Modify the weir elevation in the plans and HydroCAD to match one another. Springview Meadows May 21, 2021 Page 5 Adjusted per HydroCAD c. Model the emergency overflow routes as secondary outlets. Pond EOF’s updated to secondary routing d. Use an infiltration rate in inches per hour and show the appropriate soil amendments to achieve that infiltration rate on a pond detail. A design filtration rate of 0.80 in/hr has been used to model the basins. An effective filtration flow has been calculated and applied to the HydroCAD model to accurately model the filtration based on the filtration area and basin live storage without including filtration over the wet cell (forebay). Refer to stormwater report for more details. e. Calculate the proposed time of concentration values in lieu of using a generic value. Calculated time of concentration values per comment Grading 1. Modify the grading and erosion control notes to state: a. Perimeter and downstream sediment control BMPs shall be installed by the contractor and inspected by the City prior to any site work. b. Slopes greater than or equal to 3:1 shall have approved erosion control BMPs installed immediately after grading has finished. Added notes 2. Show the wetland buffer on the grading plan. Added label for wetland buffer Utilities 1. Storm Sewer a. Label the storm sewer. Labeled storm sewer as requested b. Provide rational calculations for the storm sewer, designed for the 10-year 24- hour event. Refer to storm sewer design included with submittal c. Ensure the minimum storm sewer pipe diameter is 15 inches and the minimum slope is 0.5%. Noted. Pond inlets will have flatter slopes to maintain inlet velocities of less than 5 fps. d. Locate the catch basins to collect drainage on the upstream side of the intersection. Modified storm sewer layout per comment e. Include City of Prior Lake standard storm sewer details. Springview Meadows May 21, 2021 Page 6 Added storm sewer details f. Ensure that the last structure which is road accessible prior to discharge to any waterbody is an environmental manhole with a 3 foot sump. Noted sumps will be provided per city detail g. Label the existing culvert inverts near the project area on the plan sheets. Added labels for existing culverts h. Shift the structure on the north side of Lot 4 Block 1 to the right of way/ property line. Structure moved per comment i. Extend the storm sewer on the north side of 170th Street west to the western development limits. Storm sewer extended as requested. 2. Sanitary Sewer a. Include City of Prior Lake standard sanitary sewer details. b. Note the following pipe types and class are identified in general with respect to depths with soil type verification and design criteria required to substantiate size and type of pipe used: i. Depth 8’ to 16’ PVC, SDR 35 ii. Depth 16’ to 26’ PVC, SDR 26 iii. Depth 26’ to 40’ DIP, Class 52 iv. Over 40’ DIP, Class 53 c. When the sanitary sewer mainline is constructed with ductile iron pipe, the sanitary sewer services shall be constructed with Class 52 ductile iron pipe from main line sewer to the 45 degree bend. Applicant noted d. The size, type, and class of all sanitary sewer services shall be noted on the plans. i. Utility services to be included with Final Plans e. The maximum depth of the sanitary sewer service at the ROW line shall be 10’ unless documented by a proposed house or building elevation that justifies a deeper service. Applicant noted f. Install service risers where cover over the top of the sanitary main is greater than 12’ or as directed by the engineer. i. Service risers to be included with Final Plans g. Provide 10 gauge tracer wires for the sanitary sewer services for locating purposes. The tracer wire should connect to a tracer wire access box at the easement (see Plate #401). h. Show the existing and proposed sanitary sewer in plan and profile view, along with other existing and proposed utilities in the construction zone. i. Utility services to be included with Final Plans Springview Meadows May 21, 2021 Page 7 i. The construction plans for water main and sanitary sewer shall include the lowest elevation of all houses or buildings to be served. i. Service elevation details to be included with Final Plans j. Discuss the sanitary sewer, storm sewer and watermain locations within 170th Street with Scott County in case the road should become CSAH 12 at some point in the future. i. Applicant referenced meeting on 4/12/21 k. Stub sanitary sewer and water to the north on the west side of CSAH 17 at the intersection with 170th for future development. l. Do not construct manholes within CSAH 17. m. Connect the existing sanitary forcemain that runs along the west side of CSAH 17 into one of the new proposed sanitary manholes near the intersection of CSAH 17 and 170th Street. i. Existing/proposed forcemain is shown connecting into MH-13 in the Street 3 cul de sac per 4/12/21 meeting 1. Verify downstream pipe capacity/sizing for additional existing forcemain flows 2. Connect to structure with psx direct drive boot or approved equal 3. See city stanadard detail plate #404 (clean-out manhole) for extending tracer wire within structure 4. Use a radial turn instead of bends to go from the forcemain connection to MH-13 5. Provide the approximate elevation/depth to the forcemain connection 6. Verify/label the existing/proposed forcemain pipe material 7. Verify the existing grade (positive/negative) of the forcemain to maintain to structure MH-13 n. Utility crossings in CSAH 17 must be perpendicular to the highway. i. Scott County requires casing pipe for utilities under all highways. ii. All bends shall be outside the county row. o. Label sanitary sewer between MH-4 and MH-5 in 170th Street 3. Watermain a. Include City of Prior Lake standard water details. b. Remove the pipe past the existing hydroguard unit on the east side of CSAH 17 and connect to the existing watermain with a gate valve. c. Maintain the watermain on the outside of the Street 2 loop to minimize utility crossings. Storm sewer would shift to the inside of the loop. d. Shift the gate valve at the intersection of Street 1 with Street 2 from the north leg to the west leg to minimize affected lots during maintenance or an outage. e. Add a hydrogurad unit to the watermain at the west end of 170th Street. Springview Meadows May 21, 2021 Page 8 f. All water fittings should be labeled as to size and type such as bends, tees, plugs, etc. i. Water fitting labels to be included with Final Plans g. The size, type, and class of all water services shall be noted on the plans. i. Utility services to be included with Final Plans h. Developers are responsible for constructing the services to the easement line which is approximately 10’ beyond the right of way line. Applicant noted i. Provide a minimum of 18” vertical separation for all watermain crossings with sanitary and storm sewer. Also, other utilities that cross the watermain shall cross at a 90 degree angle, if possible, with the minimum requirement of a 45 degree angle for the crossing. Provide insulation for all storm sewer crossings. i. Utility crossings to be included with Final Plans j. Show on plans the existing and proposed watermain in plan and profile view along with other existing and proposed utilities in the construction zone. i. Utility profiles to be included with final plans k. Identify and address potential utility conflicts where the storm sewer is deeper (greater than 6’) or the sanitary sewer is shallower (less than 10’) with the watermain. i. Utility crossings to be included with Final Plans l. Fire official to verify fire protection. Applicant noted Miscellaneous 1. Utilize current City of Prior Lake Design Manual and Standard Detail Plates Added details 2. Add the MnDOT standard rip rap detail. Added MNDOT rip rap detail. SWPPP 1. Submit a SWPPP that meets all NPDES permit requirements. a. SWPPP documentation and NPDES permitting will be provided by DR Horton at time of final plans 2. Drainage areas over 5 acres must have a temporary sediment basin. Indicate on the erosion control plan. Added note Wetland 1. The development has an approved wetland delineation but not an approved wetland impact permit. Wetland impacts will need to be approved under WCA. Applicant noted Phone 952.447.9800 / Fax 952.447.4245 / www.cityofpriorlake.com Memo The Community Development Department has reviewed the Preliminary Plat and PUD plans for the subject project with a plan date of 5-14-21 and we have the following comments. General 1. Development Fees – The following development fees are to be collected prior to recording of any approved 2021 final plat application: Park Dedication of 43 lots at $3,750 per lot, Trunk Water ($3,840/net acre), Trunk Sanitary Sewer ($4,700/net acre), Trunk Storm Sewer ($4,160/net acre), and a 6% administrative fee and 8% construction observation fee based on the total estimated construction costs (which include landscaping, streets, public trails, and public utilities). 2. The City Council will need to weight the number of modifications (lot size and setbacks) requested verses the amount of PUD Benefits proposed above standard development requirements. PUD benefits proposed include: · County Right of Way (Hwy 17) – 25-foot width above 75 feet · City Right of Way (170th Street) – 10 ft width above 50 ft 3. Warranty Deeds – Submit draft warranty deeds for any future public ownership Outlots with Final Plat application. Preliminary Plat/Site Plan 4. PUD Zoning Modifications – In addition to other proposed public improvement modifications, the developer requests modifications to the typical R-1 zoning requirements in the following areas: a. Lot size – Min. proposed – 9,494 sq. ft. Min. required (R-1) – 12,000 sq. ft. b. Lot width - Min. proposed – 11 lots at 70 feet, 30 lots at 86+ feet Min. required – 86 ft. 5. Setback Exceptions - Are any decks, eves, cantilevers, or window well pits proposed within the 10-foot side setbacks, 25-foot front setbacks, or 25-foot rear setbacks? If so, they need to be identified as a note on the preliminary plat plan. 6. Impervious Surface – all lots within the Shoreland Overlay district (northwest part of development) will be required to maintain maximum 30% impervious surface coverage. Date: May 24, 2021 To: Mike Suel, DR Horton From: Jeff Matzke, Planner Subject: Springview Meadows Preliminary Plat and PUD City Project #DEV21-000004 Grading Plan 7. Retaining walls – Any walls exceeding 4 feet in height will require a building permit application. Tree Preservation/Landscape Plan 8. Tree placement – On landscape plan/details plan, indicate note that placement of all trees shall be a minimum of 5 feet from front property lines within front yards. 9. Tree replacement – No tree replacement as a result of tree removals is required for this development. 2 front yard trees and 4 corner trees are required per lot and are indicated on the proposed landscape plan. 10. Final tree locations – Tree locations may be subject to change depending on field construction of public/private utilities and maintenance access locations for ponding and utilities. Springview Meadows Prior Lake, MN R-1 Sketch Plan Phone (952) 937-5150 Fax (952) 937-5822 Toll Free (888) 937-5150 12701 Whitewater Drive Minnetonka, MN 55343 westwoodps.com Westwood Professional Services, Inc. R-1 Single Family PONDING PONDING DELINEATED WETLAND DELINEATED WETLAND Wetland BUFFER (TYP.) Wetland Buer (TYP.) CONCEPT DATA Gross Site Area: 23.7 ac Estimated Wetlands: ~2.6 ac Addtl CR R/W: ~2.1 ac Net Developable Area: 19.0 ac Other Open Space: 3.5 ac (includes wetland buers and ponding) Proposed R-1 Lots: 38 lots 86’ wide x 140’ deep typical R-1 Standards: Min Lot Width: 86‘ at front sbk Min Lot Area: 12,000 Front & Rear Setback: 25’ Side Setbacks: 10’/10‘ (20’ total) Overall Gross Density: 1.6 un/ac (38 un / 23.7 gross acres) Overall Net Density: 2.0 un/ac (38 un / 19.0 net developable )