5.2. SR 08-08-2011 - Laserfiche WebLink

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D2. A 16-inch diameter watermain should be extended south from the existing 16- t inch diameter watermain within the TH 10 right-of-way at 171St Avenue. The 16-inch diameter watermain should be extended through the west portion of the ' development ideally within aCity-owned right-of--way. It could then be downsized to a i2-inch diameter on the east side of TH 10 within the 16Sth Avenue right-of-way. The 12-inch diameter watermain should then be looped ' within the eastern portion of the development as shown on Figure 13-2 for Scenario 1 or on Figure 13-3 for Scenarios 2 and 3. The 12-inch diameter watermain should then be connected to the existing 16-inch watermain within 171St Avenue. The remaining looping could be accomplished with 8-inch diameter watermain as shown on the attached Figures 13-2 and 13-3. As the ' City does not have a Comprehensive Water System Plan, the trunk watermain was sized in accordance with typical development recommendations . ' D3. Any abandoned wells found within the study area will be sealed in accordance with Minnesota De artment of Health (MDH) uidelines p g . D4. As the City currently does not have a Wellhead Protection Plan (wHPP), a 1 Drinking Water Supply Management Area (DWSMA) has not been established. A DWSMA will be detailed for future wells as they are constructed and when the ' City is called into the WHPP program by the MDH. E. Water Quality and Quantity Mitigation Plan ' E1. Infiltration best management practices will be required to meet volume control goals as listed in Table 17-2. Group A soils within the Study Area will likely provide sufficient infiltration capacity to achieve these goals. ' E2. Design considerations for comprehensive storm water management should include regional ponding, individual site underground infiltration systems and a perforated trunk storm sewer conveyance system. E3. Approved Total Maximum Daily Loads (TMDL) load reductions and implementation plans for the Mississippi River and the Rum River shall be addressed by the development's storm water management plan. ' E4. The storm water management plan(s) for the future developments will provide an in depth analysis of existing and proposed drainage patterns and pollutant loads. The plan(s) will demonstrate compliance with nondegradation, City and ' other local storm water management requirements. ' E5. It will be required that post-development discharge rates will be no greater than pre-development discharge rates for the critical duration event to reduce erosion impacts downstream of the site. E6. The developer will be responsible for grading the site appropriately to provide adequate storm water management to the extent necessary and will be required t to obtain the necessary permits for storm water management and grading, to City of Elk River Draft Alternative Urban Areawide Review July 2011 Page 11 of 84