6.2. - 6.4. SR 07-19-2004 - Laserfiche WebLink

Home Browse Search

WCA Replacement Plan Application Trout Brook Estates June 28, 2004 Page 3 Sequencing Avoidance and Minimization The "no-build" alternative would avoid wetland impacts. However, needed housing would not be provided within the rapidly growing northwestern metropolitan market. A "no-impact" alternative would not provide public right-of-way access to much of the site. The existing width of upland corridors that could be used for streets are sometimes too narrow to provide adequate room for the right-of-way. The City of Elk River limits cul-de-sac length to 700 feet as a fire access and safety concern. By not filling within Wetland 8, road access could not be provided to much of the southeastern portion of the site due to the maximum cul-de-sac length. In addition, the two impacts in Basin 3, totaling 54,175 square feet, occur within shallow excavated channels. These basins are disturbed as a result of their excavated nature. Not impacting these basins would leave these channels that have reduced functions and values. We believe that Sequencing Flexibility should apply to these channel areas. Other proposed impact areas are also typically vegetated in reed canarygrass. By avoiding impacts, these basins will remain in spite of the fact that their values are also reduced. Proposed replacement wetlands not only will provide wetlands with improved function and values, but will tie directly into existing medium-quality sedge meadows. These replacement wetlands will convert reed canarygrass-filled upland areas into wetlands vegetated by native species. A no-impact scenario would most likely not provide the opportunity to restore wetland and upland areas that could potentially act as refugia for invasive species to infest these nearby sedge meadows. Typically, impacts to wetlands from house construction are quite narrow. These lots will have no upland backyard between the decks/patios and the slope dropping into the wetland. Therefore, impacts have been minimized. These fills are typically less than 15 feet in width, and individual fills are less than 1,000 square feet. The site has approximately 36.4 acres of wetland. If the 1.3 acres of disturbed channels that are proposed to be filled are deducted, approximately 0.67 acres of wetland fill is proposed in the remaining wetlands. This represents less than 3 percent of the wetlands on the subject site. Roadway alignments were typically located along the midline of upland ridges between wetlands to reduce fill impacts. Street widths were kept to minimum safe widths, as are yard depths that are kept to minimum setback distances. Side slopes were maximized at 3:1 slopes. Some lots have narrower building pads to avoid or reduce the amount of encroachment into wetlands.