07/15/2004 Env Bd Packet - Laserfiche WebLink

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• similar to stormwater wetlands and rainwater gardens, which rely primarily on settling of suspended solids, adsorption, and microbial breakdown of pollutants. Swales reduce the flow velocity of storm water runoff. The swale essentially acts as a very long and linear shallow wetland treatment system. • A wet/infiltration pond (NURP) will be provided. The pond will be over excavated by 2- 3 feet and granular material will be placed to allow infiltration. A wet pond is a constructed stormwater pond that retains a permanent pool of water. Wet ponds have a moderate to high capacity for removing most urban pollutants. Accumulated trash and debris will be removed from the side slopes, embankment, emergency spillway and weir trash gates as often as needed. Sediment will be removed from the pond as necessary. Treated stormwater will discharge to the surrounding wetlands /lake. 13. Water use. Will the project involve installation or abandonment of any water wells, connection to or changes in any public water supply or appropriation of any ground or surface water (including dewatering)? ElYes ❑No The project will be served by municipal water. The addition of eight lots will not significantly effect the public water supply. The Metro average is 274 gallons per day per household: 2192 gallons per day for eight households. Dewatering will be necessary to create a dry area to construct the center pier of the bridge, and possibly the abutments. The MnDNR requires a dewatering permit for any dewatering greater than 50 million gallons. The DNR bridge permit includes special provisions authorizing dewatering within specified parameters. A plan for the dewatering must be submitted to the DNR for approval. The City will examine this and ensure all DNR requirements are met prior to allowing bridge construction to commence. 14. Water - related land use management district. Does any part of the project involve a shoreland zoning district, a delineated 100 -year flood plain, or a state or federally designated wild or scenic river land use district? Q Yes ❑ No If yes, identify the district and discuss project compatibility with district land use restrictions. Both a shoreland management overlay district and a 100 -year floodplain affect the design of the proposed project. Shoreland: The project is located within a shoreland management overlay district that includes land within 1000 feet of the ordinary high water level (OHWL) of Wards Lake. In fact the project would be exempt from the EAW process because of its small size if it were not in a shoreland overlay district or a floodplain. Wards Lake is a DNR protected waterbody #10P. The Minnesota Dept. of Natural Resources (DNR) establishes the OHWL for water bodies designated as protected waters. The OHWL Environmental Assessment Worksheet Page 10 Pheasant Hills 12'" Addition