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Environmental Assessment Worksheet Nature's Refuge Conservation Development Lino Lakes, Anoka County, Minnesota Draft Document — September 25, 2006 Page 13 4_ Water - related land use management district. Does any part of the project involve a shorelan d zoning district, a delineated 100 -year flood plaint or a state or federally designated wild or scenic river land use district? X Yes No If yes, identify the district and discuss project compatibility with district land use restrictions. A portion of the property includes an area with a surface flood hazard area (SFHA) identified as an approximate study area (Unnumbered A Zone) that does not have a previously determined base flood elevation (BFE). The Rice Creek Watershed District has done a study of the regional drainage system, but the basin within the property was not included in that study. The City has not performed a detailed hydrologic study of the basin. The property is not part of a wild or scenic land use district and not within a shoreland overlay district. According to the FEMA Flood Insurance Rate Map, a portion of the site surrounding the main drainage ditch and Wetland 7 is within the 100 -year flood plain surrounding the main east -west drainage ditch. The project is designed to minimize impacts within the floodplain. The only proposed construction within the floodplain are: 1) one street and two pedestrian trails will cross the floodplain and ditch, and 2) the rear portions of 8 lots will lie within the floodplain boundary. The project will necessitate changes to the flood plain boundary. Flood elevation will be established based on the final grading plan for the project. Any floodplain fill proposed will be compensated for. Building and temporary equipment - storage elevations will be determined based on the new floodplain contour. It is probable that the FEMA map will need to revised (Letter of Map Revision or LOMR) or amended (Letter of Map Amendment or LOMA). 15. Water surface use. Will the project change the number or type of watercraft on any water br If yes, indicate the current and projected watercraft usage and discuss any potential overcrow with other uses. There are no navigable water bodies on the project site, and none will be created by the project. 16. Erosion and sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to be moved. Describe any steep slopes or highly erodible soils and identify them on the site map. Describe any erosion and sedimentation control measures to be used during and after project construction. The estimated area to be graded is approximately 100 acres. Because of the high water table in the upland portions of the site, grade in the build area will be raised 4 to 6 feet to ensure that building elevations are high enough to avoid water - table- related problems. Thus, an estimated 392,000 cubic yards of imported fill material and an estimated 97,000 cubic yards of on -site excavation and fill will be needed. The majority of the material will not be excavated on -site because most non -build portions of the site will be designated as conservation areas and placed under a conservation easement. Excavation of such areas would be counterproductive in view of the long -term restoration goals for the site. Thus, most fill material will be trucked in from off -site sources. There are no existing steep slopes or highly erodible soils on the site. With the exception of street embankments at the proposed wetland impacts and storm water pond banks, no steep slopes will be constructed on the site. Erosion and sedimentation control measures will follow the Storm Water Pollution Prevention Plan (SWPPP) to be developed for the site. The SWPPP will include the incorporation of Best Management Practices (BMPs) as prescribed by the MPCA and required by the City of Lino Lakes and Rice Creek Watershed District. The granular nature of the soils in the Anoka County area has created issues with wind erosion from construction sites. These problems generally occur when there is a combination of unfavorable conditions that include large areas of exposed soil, hot, dry, windy weather, and improper construction practices such as insufficient silt fence, insufficient dust