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06.a Engineer Comments_Rolling Acres 61 Preliminary Plat Review 11-30-202214727 209 th St. N. PO Box 128, Scandia, Minnesota 55073 Phone (651) 433-2274 Fax (651) 433-5112 http://www.ci.scandia.mn.us November 30, 2022 Brenda Eklund City Clerk 14727 209th Street N Scandia, MN 55073 RE: Rolling Acres 61 Preliminary Plat Review Dear Ms. Eklund, We have completed our review of the submittal for Rolling Acres 61 Preliminary Plat received November 14, 2022, from the representatives of Grandemoore Homes, Inc. The following submitted documents were reviewed: · Preliminary Plat – Rolling Acres 61, dated November 15, 2022, by Loucks Inc. · Preliminary Plan Set – Rolling Acres 61, dated November 14, 2022, by Loucks, Inc. containing 10 plan sheets including: Existing Conditions, Site Plan, Grading Plan, SWPPP Plan, Details, and Landscape Plan. · Preliminary Stormwater Management Plan – Rolling Acres 61, dated November 14, 2022, by Loucks, Inc. We provide the following comments for the proposed improvements: Preliminary Plat 1. Street connection, right of way, and any associated turn lanes at Keystone Avenue N (Co Rd 50) will need to be coordinated with, approved, and permitted by Washington County (refer to attached County preliminary comment letter for details). a. It is highly recommended to initiate coordination with Washington County early in design. b. County will be requiring 60’ right of way from centerline of Keystone Ave N (Co Rd 50), see grading plan comments related to Pond 1 grading. 2. Proposed street names shall be reviewed and approved by Washington County. 3. Verify drainage and utility easements are shown for all low areas, ponds, and wetlands up to the 100-yr High Water Level. 4. Drainage and utility easements shall be shown over any drainage swales crossing multiple lots. 5. All non-typical drainage and utility easements shall be labeled on the plat. 14727 209 th St. N. PO Box 128, Scandia, Minnesota 55073 Phone (651) 433-2274 Fax (651) 433-5112 http://www.ci.scandia.mn.us Preliminary Plan Set Sheet C2-1: Site Plan 6. Coordinate street connection details for 198th St N at Keystone Avenue N (Co Rd 50) with Washington County. 7. Update the “Septic Areas…” note in the lower right corner of the sheet to include the name and date of the review/report. Provide a copy of the report to the City. a. Soil and perc tests will need to be conducted to ensure proposed building sites are able to accommodate on-site septic systems that will allow for a primary and secondary drainfield location approved by Washington County Environmental. Sheet C3-1: Grading Plan 8. The project is located within the Comfort Lake-Forest Lake Watershed District and will require a permit. Plans shall be submitted to the watershed district for review and approval. a. It is highly recommended to initiate coordination with CLFLWD early in design. 9. Lots shall be graded to drain to adjacent drainage and utility easements. Drainage shall not flow directly onto an adjacent lot, unless an appropriate drainage and utility easement is provided. 10. Ensure ditch drainage is contained within the right of way and does not flow onto adjacent property, particularly along the south side of Lot 1, Block 1. 11. As noted in the preliminary plat comments, the County will be requiring a 60’ right of way on Keystone Ave N (Co Rd 50), revise grading of Pond 1, including maintenance bench, so it is located entirely within the revised Outlot B. Also revise grading as noted in the Stormwater Management Plan comments. 12. Stormwater management facilities shall be located outside of public property and right of way. Site grading shall be revised for the eastern low area to include an access path with culvert to Outlot A and additional grading of the eastern low area north and south of the Outlot A access as necessary to provide adequate treatment of stormwater. 13. Provide soil borings for Infiltration Pond 2 to verify MPCA required separation to groundwater table of 3’ is achieved. If it is not, basin shall be redesigned/moved to achieve the required separation or replaced with a filtration feature. 14. A concrete outlet control structure shall be provided for Pond 1. 15. The outlet pipe for Pond 1 shall be Reinforced Concrete Pipe (RCP). 16. Rip rap shall be provided at all culvert outlets. 17. Proposed driveway grades shall be shown on the plan. 18. All emergency overflow elevations shall be noted on the plan. 19. Label 100-yr High Water Level (HWL) for the southwest and east low areas and ensure drainage and utility easements encompass this elevation. 20. Plans shall include both plan and profile views of the storm sewer and street. 21. The septic field for Lot 3, Block 1 is proposed in an area with clayey fill down to approximately 4’ depth per Boring B-01, verify design of septic system can meet the requirements of Mn Rule Chapter 7080. 14727 209 th St. N. PO Box 128, Scandia, Minnesota 55073 Phone (651) 433-2274 Fax (651) 433-5112 http://www.ci.scandia.mn.us 22. The proposed septic field for Lot 1, Block 2 is partially located within the 100-yr HWL of the eastern low area basin. It is recommended to revise grading to eliminate this or relocate the septic system outside of the 100-yr HWL area. Sheets C3-2 and C3-3: SWPPP Plan and Notes 23. Show proposed turf establishment methods, i.e. seed/disc anchored mulch, seed/EC blanket, etc. and culvert inlet protection. 24. Erosion control measures shall be implemented downslope from the disturbed areas for the proposed septic fields. 25. Note 29 on sheet C3-3 shall be updated to reflect “infiltration” basins. Sheet C8-1: Civil Details 26. The detail for typical rural street section shall be revised to show the 12” Select Granular Sub- base extending across the entire roadway and a note added to extend the sand sub-base (or provide draintile) to the ditch at all low points. 27. Add a detail for a proposed concrete outlet control structure for Pond 1. Sheets L1-1 and L2-1: Landscape Plan and Details 28. Landscape plan shall meet the requirements of the Development Code and as determined by the City. Stormwater Management Plan Southwest Low Area (SWLA) 29. The project is proposing an increase in the 100-yr HWL of the SWLA. Proposed Pond 1 grading and fill in the existing low area shall be revised to match or reduce the existing 100-yr HWL elevation for this basin. 30. The SWLA is a closed basin with no outlet pipe. It is recommended to model the back-to-back 100-yr storm events. a. If roadway overtopping occurs, then expand the model to incorporate all areas that contribute to the closed basin. b. Report the back-to-back 100-yr HWL elevations in relation to the lowest existing and proposed structures within the closed basin. 31. Provide infiltrometer testing or additional soil borings for Pond 1 to ensure the NURP basin will be able to maintain a permanent pool. A liner may be required. Eastern Low Area (SWLA) 32. As noted in the grading plan comments, additional grading of the eastern low area north and south of the Outlot A access shall be completed to provide adequate treatment of stormwater outside of public property and right of way. 33. This basin should be designated as a stormwater basin, as it is contributing towards the water quality volume requirements and is being modelled as such. 34. A drainage and utility easement shall be provided which encompasses the 100-yr HWL of the basin. 14727 209 th St. N. PO Box 128, Scandia, Minnesota 55073 Phone (651) 433-2274 Fax (651) 433-5112 http://www.ci.scandia.mn.us General Comments 35. This project will be responsible for development fees/permits as required by the City, Washington County, and Watershed District (CLFLWD). 36. Well systems will be permitted by the Minnesota Department of Health. 37. Septic systems will be permitted by Washington County Environmental and shall fulfill all other state and local permit requirements. 38. All stormwater management facilities outside of the right of way shall be owned and maintained by the development Homeowners Association. 39. Developer shall anticipate having to execute a maintenance agreement as part of the Watershed’s permit requirements to fulfill the maintenance requirements for the stormwater management features. 40. The plans shall clearly identify removals necessary, specifically at the exiting road connection. Full depth saw cut will be required the connection. 41. Street lighting plan shall meet the requirements of the Development Code and as determined by the City. 42. The specifications for construction shall be submitted for review with final plans. 43. Site improvements shall be coordinated with the private utility owners. Conduit crossings for private utilities shall be shown on the construction plans. 44. A fully executed developer’s agreement must be in place prior to commencing work. 45. Developer shall provide proof of MPCA NPDES/SDS construction stormwater permit approval prior to construction. 46. A preconstruction meeting is required to be held prior to any construction activity starting on site. The developer shall invite representatives from the City, Watershed and the private utility owners. 47. Monuments. All lot corner pipes or iron rods must be a minimum of one half (1/2) inch in diameter, 18 inches in length, and shall be inscribed with the registration number of the land surveyor performing the survey. 48. After final restoration and turf establishment reaches 70% coverage applicant shall request final inspection through the City of Scandia. 49. Revised documents shall be submitted for review and acceptance prior to any construction activity starting. 50. Please respond in writing as to how the above comments will be addressed. Please do not hesitate to contact me at 612-597-7140 with any questions or comments you may have regarding this memo. Sincerely, Ryan J. Goodman, P.E. City Engineer Enclosures PUBLIC WORKS Wayne Sandberg, P.E., Director, County Engineer Frank D. Ticknor, P.E., Deputy Director October 25, 2022 Evan Monson City Planner City of Scandia 14727 209th St N, Scandia, MN 55073 Comments on Rolling Acres 61 Concept Plan Thank you for the opportunity to review and provide comments for the Rolling Acres 61 concept plan along County Road 50 (CR 50/199th St N) in the City of Scandia. Our development review team has reviewed the plans and offers the following comments. As this is a concept plan, the County understands that the plan will go through revisions with City, and the plan will change through the process. As such, the County development review team would suggest the City and the developer provide updated plans as the project proceeds. This will allow the County to give the developer and City appropriate comments to ensure the project remains on track and incorporates feedback. The Washington County 2040 Comprehensive Plan, along this segment of County Road 50, has identified the need to preserve 120 feet of right-of-way. The concept plan should specify that a total of 60 feet of right-of-way from the centerline will be dedicated by the project to meet this requirement prescribed by the comprehensive plan. County Road 50 is currently classified as a “Major Collector” roadway. The Washington County 2040 Comprehensive Plan contains access criteria for county roads related to spacing, sight lines, and availability of local road connections. With respect to spacing, collector roads are guided for full-access intersections at a minimum spacing of 1/8 mile (660 feet). Therefore, Washington County does not support the proposed additional access onto County Road 50 at the proposed location because of its proximity to 199th Street N. The County suggests that the developer consider aligning the entrance with 199th Street North. This would be the preferred access point for the County. The County understands the difficulty of this due to the developer not owning the property to the north. The County, however, does recommend that the developer study the possibility of connecting to 199th. If the access alignment with 199th St N is not feasible, the County suggests the developer locate the access as far south on the property as possible. This will ensure maximum distance between the accesses and allow for appropriate safety measures should turn lanes need to be installed at this location or at 199th. A great place to live, work and play…today and tomorrow Government Center | 14949 62nd Street North | P. O. Box 6 | Stillwater, MN 55082-0006 P: 651-430-6001 | F: 651-430-6017 | TTY: 651-430-6246 www.co.washington.mn.us Washington County is an equal opportunity organization and employer Additionally, every driveway for the lots in the proposed developments need to come off the new city street. The County is interested in how the city plans to provide access to the parcels to the south and east of this property in the event they develop. Any access that is ultimately approved for this proposed development should be compatible with any future access to the south and east. The County suggests the City work with the developer to develop high-level ghost plats for future development to see how they align with this development. Thank you again for the opportunity to provide comments on the concept plan for Rolling Acres 61. We look forward to continuing to work with the City of Scandia to ensure that development in this area is successful and well-served by the transportation network. If you have any questions, please contact me at 651-430-4307 or daniel.elder@co.washington.mn.us Sincerely, Daniel Elder Planner II Wayne Sandberg, Public Works Director/County Engineer Frank Ticknor, Deputy Director Public Works Lyssa Leitner, Public Works Planning Director Joe Gustafson, Traffic Engineer Kevin Peterson, Design Engineer See County Comment Letter:60' ROW required from CL of Co Rd 50Concerns with location of proposedstreet versus 199th St NStreet Names to bereviewed and approvedby Washington CountyShow additional drainage andutility easements as noted onsheet C3-1: Grading Plan. Coordinate streetconnection details withWashington CountyUpdate Note Label EOF ElevationLabel NWL Elevationapprox 956?Verify 3' separation togroundwater table isacheivedShow 100-yr HWLElevation and adjustD&UE to encompass Outlot A Access pathwith culvert shall beconstructed andproposed infiltrationbasin expanded tonorth and south toprovide treatmentvolumeAdd DUE for pondHWL and swaleacross lotsAdd DUE for pondHWL and outlet swaleacross lotsSeptic Field in 100-yrHWL of pond,consider gradingrevisions or relocateoutside of DUEGrade to drain alongDUE so Lot 3 doesn'tdrain onto Lot 2Add DUE for swaleacross lots.Relocate septic out ofDUEProvide profile views ofstreet and storm sewerpipes.Add Rip Rap at culvertoutletsShow driveway gradesEnsure drainage fromROW is contained inthe ditch and doesnot flow onto adjacentproperty Add 982 contour byFES-101?Label 100-yrHWL elevationGrade to drainalong DUERevise Pond Gradingper SWMP commentsAll pipe should beRCPProvide concreteoutlet controlstructureRevise PondGrading soaccess is outside60' ROW Add Erosion Controlmeasures downslope ofareas disturbed by septicfields Infiltration?Typo Sub-base shallextend the entirewidth of the roadwayand shall daylight tothe ditch at low points(or provide draintileoutlet to ditch at lowpoints)Overlapping TextAdd Pond 1 OutletControl StructureDetail Landscape plan shall meet therequirements of theDevelopment Code and asdetermined by the City. Landscape plan shall meet therequirements of theDevelopment Code and asdetermined by the City.