04-13-26 Planning Commission Meeting Packet

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Page: 3 8. Streetlights are shown on the Preliminary Plans as required. Streetlight fixtures and poles are installed, owned and maintained by Xcel Energy using city specified fixtures and poles in accordance with the city engineering design standards. Plan revisions may be needed as the construction plans are finalized. STORMWATER MANAGEMENT, GRADING AND STORM SEWER 1. The proposed subdivision improvements are subject to a Stormwater Management Plan (SWMP) meeting State, Valley Branch Watershed District (VBWD) and city rules. A VBWD permit is required. Storm water facilities proposed as part of the subdivision to meet State and watershed permitting requirements must be constructed in accordance with the City Engineering Design Standards. 2. All storm water BMPs, including 3 wet ponds and 2 filtration basins, have been placed in Outlots to be dedicated to the city as required. Each Outlot must fully incorporate the 100-year HWL, 10- foot maintenance bench and all BMP maintenance access roads. Maintenance access roads meeting city standards must be provided for all storm water facilities and structures. All adjacent lot corners must be +.2 ft above the 100-year HWL to meet construction tolerance and maintain 100-year HWL on each Outlot.  Basin 1E. Plan revisions are required to fully contain Basin 1E 100-year HWL within Outlot E. Revisions are also required to eliminate the encroachment of the proposed pond maintenance bench to the small/dry utility corridor along the proposed public right-of-way.  Pond 2 and Pond 3. Plan revisions are required to provide a feasible pond maintenance access road meeting city standards. If maintenance access is from the County right-of-way, a field access roadway must be constructed and permitted by the County. In addition, plan revisions are necessary to fully mitigate the overhead power line interference and to provide clearing, grubbing and grading over the full extent of the access routes.  Pond 3 and 5. Grading revisions are needed to provide for a 10:1 maintenance bench to be located just above the NWL, and a 10-ft aquatic bench to be located just below the NWL. The grading currently shows both benches above the NWL. 3. Minimum floor elevations must be at least 2 feet higher than the adjacent stormwater basin or wetland 100-year HWL elevation. In addition, all low opening elevations for all buildings must be at least 1-ft higher than any adjacent emergency overflow elevation (EOF). Plan revisions may be required as the construction plans are finalized  Pond 3 and Pond 5. The low floor and low opening elevations for the existing homes adjacent to these ponds are not 2-feet above the proposed 100-year HWL as required by the City Engineering Design Standards. Flood mitigation and protection measures have been proposed at Pond 5, including a berm and pond liner. The VBWD has provided a preliminary indication that a permit will be issued for the proposed design. At a minimum, pond lining will be required for Pond 3 and Pond 5 in accordance with minimum requirements of the Minnesota Stormwater Manual (Level 2 liner).  Low floor and low opening elevations must be obtained and shown on the existing condition, site and grading plans, including the FFE for the city water booster station. 4. All wetlands and wetland buffers must be protected by easement. It is standard Lake Elmo practice to require wetlands and wetland buffers to be placed in Outlots dedicated to the city, however, the city is amenable to allowing them to remain on private lots protected by easements for Rural Estate Residential Lots. Wetland, wetland buffers and wetland HWL areas are shown on the preliminary plans and are protected by easements as required. 5. When wetlands are present on private lots, each lot must have a minimum of 1.25 acres of land above the wetland HWL elevation and free of any drainage easements.