04/13/2016 P&Z Packet - Laserfiche WebLink

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stormwater management. In many cases agricultural ditch and tile networks have significantly altered drainage basins and changed sub -watershed divides. The drainage capacity of these existing tile networks is insufficient to convey stormwater runoff. The site consists mostly of B/D hydrologic soils which are a combination of drained and un- drained soils. Wetlands and high ground water table also contribute to the challenge. Watermark will create a natural greenway corridor and regional stormwater conveyance system through the construction 40+ acres of lakes and storm ponds and 20+ acres of restored and created wetlands. Ultimate discharge of the site is to Peltier Lake. Storm water management is not only a challenge for the Watermark development but also for the entire I-35E corridor. The City is analyzing the concept of a more regional approach to mitigate stormwater for the entire area through the preparation of the Northeast Drainage System Study. The site will be mass graded in 2 phases. The first phase includes the townhome neighborhood, southwest quadrant section including the public park and the northeast 55' wide lot neighborhood. The second phase will be the remainder of the site. Stormwater reuse is proposed to improve efficient use of groundwater resources. Stormwater instead of groundwater irrigation wells or treated municipal water will be used for irrigation of the public places and townhome area. Utilities Public water, sanitary and storm sewer utilities will be installed within the development. Sanitary Sewer An 18-inch trunk sanitary sewer main extends from Main Street along 21st Avenue North to the southern boundary of the property. A combination of 8", 10", 15" and 18" PVC sanitary sewer pipe will serve the site. Sanitary sewer will also be stubbed under CSAH 54 to the west to accommodate future development. Watermain A 16-inch trunk water main extends from Main Street along 21st Avenue project North. The site is served by an 8" and 16" watermain. The system will be interconnected to an 8" watermain in Centerville to provide improved fire flow and system redundancy. Watermain will be stubbed to the west and east property boundaries for future development. Public Land Dedication The City will require a combination of land dedication and cash in lieu of land dedication. The development will dedicate 5.38 acres of public parkland to the City and 19