09/10/2007 Council Packet - Laserfiche WebLink

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Memo Di sfr %tad et t Co,vtc'r( (3 61—(3.2007 Environmental To: Jeff Smyser From: Marty Asleson Date: June 28, 2007 Re: Environmental Board Recommendations of the June 27, 2007 Environmental Board Meeting The Environmental Board made the following recommendations conceming the Moon Marsh application at the June 27, 2007 Environmental Board Meeting: 1. This development , although not called a "conservation development ", should employ the guidelines of the AUAR. 2. A conservation easement containing no-mow , dumping, cubing, building in, or filling in , and naming the City as the easement holder with the right to perform restoration work in the easement This easement should be written from the wetland edge and cover as much as possible of the area shown in Attachment 10. Signs should be posted on the easement line , describing the easement , every 50 feet 3. SMA's within the AUAR and therefore in Moon Marsh must have: • No more than 20% of their surface as permanent open water, the remaining surface area of each SMA shall contain mesic prairie or wet prairie communities to maximize the infiltration and water quality treatment capacities of the system • Design high water levels (100 -year) less than or equal to 2.5 feet above the normal water level or lowest outlet invert • Side slopes that are less than or equal to 6:1. horizontal to vertical and 10:1 safety bench at the normal water level per RCWD requirements. • Post development runoff release volumes should be no less than 80% and no greater than 150% of existing conditions runoff volumes. These standards must be verified by our City Engineer 4. RCWD CAPROC Items are addressed including and particularily: Geotechnical soil borings at proposed BMP location in order to determine depth to the water table. This is important in that the designer is calling these infiltration ponds. Infiltration ponds designed into the groundwater are not infiltrating anything other than possible contaminants to the ground water. Adequate separation (3 ") must be shown between the pond bottom and the ordinary high ground water. A number of Wetland, Erosion and sediment control, Administrative, findings and stipulations as outlined in the CAPROC Attachment • Page 1