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ITEM 2.2_attachmentReview No. 1 �Ha[canson � )11Anderson ENGINEERING REVIEW Residential Subdivision for the City of Otsego by Hakanson Anderson Submitted to: Honorable Mayor and City Council cc: Lori Johnson, Administrator Tami Loff, City Clerk Dan Licht, City Planner Andy MacArthur, City Attorney Rick Murray, Meridian Land Company Paul Cherne, P.E., Pioneer Engineering Reviewed by: Ronald J. Wagner, P.E. Brent M. Larson, P.E. Date: April 14, 2015 Proposed Development: Wildflower Meadows 4th Addition Street Location A portion of the NW 1/a of the SW 1/a of S26, T121, R23. of Property: SW of CSAH 42, east of Hwy 101 and north of CSAH 37. Applicant: Meridian Land Company 3600 American Blvd, Suite 750 Bloomington, MN 55431 Developer: Meridian Land Company Owners of Record: Meridian Land Holdings, LLC Purpose: Wildflower Meadows 4th Addition is a proposed 2.55± acre, 9 lot single-family residential development within the original 82± acres of Wildflower Meadows development in the City of Otsego, Wright County, Minnesota. The proposed development will be served with municipal water, sanitary sewer, storm sewer, and public streets typical of an urban setting. Jurisdictional Agencies: City of Otsego, Wright County, Minnesota Department of (but not limited to) Health, Minnesota Department of Natural Resources, Minnesota Pollution Control Agency, Wright Soil and Water Conservation District. Permits Required: NPDES, Minnesota Department of Health (water), and (but not limited to) Minnesota Pollution Control Agency (sanitary sewer) TABLE OF CONTENTS INFORMATION AVAILABLE PRELIMINARY PLAT, UTILTIY AND STREET CONSTRUCTION PLANS COVER SHEET EXISTING CONDITIONS PRELIMINARY PLAT SITE AND DEVELOPMENT PLAN DEMOLITION AND GRADING PLAN SANITARY SEWER AND WATERMAIN OTSEGO STANDARD PLATES GRADING DETAILS FINAL PLAT STORM SEWER MANAGMENT OTHER CONSIDERATIONS SUMMARY AND/OR RECOMMENDATION PAGE 2 S:\Municipai\Aotsego23xx\2324.04kot2324.04RVVVI.doc INFORMATION AVAILABLE Final Plat for Wildflower Meadows 4th Addition, 3/5/15 submittal, by Pioneer Engineering Preliminary Plat, Construction and Grading Plans for Wildflower Meadows 0 Addition, 3/5/15 revision, by Pioneer Engineering Wildflower Meadows Construction Plans for Wildflower Meadows, 4/10/07 revision, by Pioneer Engineering Final Grading Plans for Wildflower Meadows, 4/10/07 revision, by Pioneer Engineering Storm Sewer Design for Wildflower Meadows, 4/10/07 revision, by Pioneer Engineering Inlet Spread Calculations for Pinnacle Crossing, 1/17/06 revision, by Pioneer Engineering Hydrology Report for Pinnacle Crossing, 10/30/06 revision, by Pioneer Engineering Existing Conditions of Pinnacle Crossing, 1/13/06 revision, by Pioneer Engineering Preliminary Plat of Pinnacle Crossing, 1/13/06 revision, by Pioneer Engineering Preliminary Utility Plan for Pinnacle Crossing, 1/13/06 revision, by Pioneer Engineering Preliminary Grading, Drainage & Erosion Control Plan for Pinnacle Crossing, 1/13/06 revision, by Pioneer Engineering Phase 1 Environmental Site Assessment, 2/4/04 revision, by Braun Intertec Corp. Geotechnical Report for Pinnacle Crossing, 1/29/04 revision, by Braun Intertec Corp. Wetland Delineation Report for Pinnacle Crossing, 11/6/03 revision, by Pioneer Engineering City of Otsego Engineering Manual Trunk Stormwater Facilities Study for Portions of Lefebvre Watershed, March 1999 City of Otsego Zoning and Subdivision Ordinances National Wetland Inventory Map, 1991 PAGE 3 S:\Municipal\Aotsego23xx\2324.04\ot2324.04RVW1.doc PRELIMINARY PLAT, UTILTIY AND STREET CONSTRUCTION COVER SHEET No comments EXISTING CONDITIONS (SHEET 3) Existing zoning classifications for land in and abutting the subdivision. 2. Show location, names, widths of existing streets, buildings, etc within 150' of boundary 3. Show location, size, and elevations of existing sewers, watermain, culverts, and other underground facilities within 150'. 4. Boundary lines of adjoining unsubdivided or subdivided land, identified by name and ownership within 150'. Label 100 year flood elevations for pond to the NW and wetland to the SW. PRELIMINARY PLAT (SHEET 4) 1. Show and label setback lines. SITE AND DEVELOPMENT PLANS (SHEET 5) A temporary cul-de-sac is required at the west end of 72nd Street. The temporary cul-de- sac shall have a minimum radius of 40' and shall have bituminous curb. If the development to the west, which is proposed to be developed soon, is final platted and receives final approval the construction of the temporary cul-de-sac may not be required. 2. The bituminous street shall be saw cut and patched the full width of the street near the manhole used to connect to the sanitary sewer. Where curb and gutter is to be removed, the existing bituminous shall be milled 18" wide x 1 %" deep along the entire length and patched. DEMOLITION AND GRADING PLAN (SHEET 6) The existing water and sewer lines stubs being abandoned shall be capped or plugged and the gate valves shall be removed. 2. The storm sewer pipe being abandoned in front of Lot 1 shall be plugged. This shall be called out in the plans. The grading of the rear yards directs nearly all the runoff over the retaining wall at the edge of the gas easement. There is some concern that this might cause erosion or even failure of the retaining wall. PAGE 4 S:\Municipal Aotsego23xa\2324.04\ot2324.04RVW1.doc SANITARY SEWER AND WATERMAEN (SHEET 7) 1. The angle of the proposed sanitary sewer connection to the existing manhole in front of Lot 8, Block 1 is unacceptable as it will potentially hinder flow and cause built up of debris at the bend in the manhole. This issue has been discussed with the developer's engineer and they propose to reverse the flow of the lateral sewer line and connect at the existing manhole in front of Lot 1, Block 1 instead. 2. Relocate or salvage the existing hydrant at the connection near the NE corner of Outlot A. The 90° bend between Lots 7 and 8 shall be made with two 45° bends. 4. The connection to the existing 4" water service stub needs a 6"x 4" reducer called out. DETAILS (SHEETS 8-9) 1. The following Otsego Standard Plates do not apply to this job and should be removed; 308, 500, 707, 408, 409, & 308. 2. Otsego Standard Plate 704 (surmountable curb) is needed. FINAL PLAT 1. A temporary cul-de-sac is required at the west end of 72nd Street. The cul-de-sac shall be covered by an easement. 2. Outlot A is missing the drainage and utility easement coverage shown on the preliminary plat and in the construction plans. STORMWATER MANAGEMENT 1. The hydrology report and storm sewer design calculations submitted with the original Wildflower Meadows submittal cover this area and were found acceptable. 2. The new NPDES permit requires that the water quality volume of 1" over the new impervious area shall be infiltrated. At the time of construction of the first addition of Wildflower Meadows City Ordinances were more strict and required that %2" of runoff be infiltrated which was achieved. The remaining %2" volume must be infiltrated. Per developer's engineer's response to this comment with Wildflower Meadows 3rd Addition, the project is covered by a previously permitted ongoing project. Per the NPDES permit, for Previously Permitted Ongoing Projects "additional permanent treatment required in this reissued permit (which requires the additional infiltration) is not required for previously permitted projects". I am unable to find an Active NDPES Permit for this site or any previous additions. If documentation is provided to verify that this site is covered by a current open NDPES permit the requirement of additional infiltration is not necessary. PAGE 5 S:\Municipal\Aotsego23xx\2324.04\ot2324.04RVW1.doc OTHER CONSIDERATIONS New laws require all new developments to install locking cluster mailboxes or cluster box units (CBU). The developer shall coordinate the location and model of CBU is with the Postmaster. SUMMARY AND/OR RECOMMENDATION We recommend approval contingent upon the above comments being addressed. PAGE 6 SAMunicipalWotsego23xa\2324.041ot2324.04 RWV1.d oc