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Environmental Assessment Worksheet Nature's Refuge Conservation Development Lino Lakes, Anoka County, Minnesota Draft Document — September 25, 2006 14. Water- related land use management district. Does any p district, a delineated [100 -year flood piir or estate of tederaly de dis X Yes No yes,:identii+.tlte- district and projec ignated wild Page 13 lve a shoreland zoning nic river land'' use Er s project compatibility with district land use 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. 1 ater surfaee u yes, indicate t th other uses.'' e project change the nu and projected watercra or type of ge and di afl on any aterbody? ''Yes X' No' iy potential overcrowding or conflicts' There are no navigable water bodies on the project site, and none will be created by the project. sedim ribe any si . Give the acreage to be slopes or highly erodible control measures to be used d sd the cubic yards of soil to be It the site map. Describe any xon. 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