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• • • Environmental Assessment Worksheet Nature's Refuge Conservation Development Lino Lakes, Anoka County, Minnesota Draft Document — September 25, 2006 Page 4 Construction Actions Because of the high water table on the site, grade will be raised over much of the build area, requiring imported fill of 392,000 cubic yards and excavation of 97,000 cubic yards. Other excavation will be required for other earthwork, utility installation, and street grading. Equipment to be used will consist of conventional earthwork equipment, including on- and off -road trucks, backhoes, scrapers, compactors, track dozers, and graders typical of activities such as timber removal, transport of fill material, grading, utility installations, and street improvements. Connections to City sewer and water will be made at Main Street and will be extended into the property to serve it up to Pine Street. A lift station will be required in the area north of Phase I. Erosion Control A SWPPP (Storm Water Pollution Prevention Plan) will be prepared to clearly state all required erosion control practices. As noted above, silt fences will be placed before any earthwork begins. Proper grading techniques will be used in the construction of the site. Best Management Practices will be employed during the construction of the lots, roadways, and sedimentation ponds. Prompt seeding and mulching of completed areas will restore protective turf as soon as possible. These protective measures will be monitored and maintained until final completion of all construction activities. Easements and Outlots Drainage and utility easements will be provided along all lot lines. Outlots will be created for sedimentation ponds and the majority of wetlands. Conservation easements will cover the conservation areas described below. Right -of -Way and Streets Public street rights -of -way will be 50 feet wide and will create approximately 18.5 acres of right -of -way area. Approximately 16,300 lineal feet of curbed, paved streets will be constructed. The street pavements will be constructed 28 feet wide (face -of -curb to face -of- curb), using ribbon curb in many places to reduce stormwater runoff and increase infiltration. The pavement section will be built to City of Lino Lakes standards and will lie within the right -of -way. Drainage The project will be built to handle all stormwater on -site using rain gardens, swales, and storm drains to retention ponds, preventing excess discharge to wetlands. The goal will be to cause no net change to existing drainage patterns in remaining wetlands. Wetland Impacts Out of 28 delineated wetlands on the site covering 93.3 acres, seventeen jurisdictional wetlands will be impacted either partially or entirely, resulting in the fill of 7.5 acres of jurisdictional wetland. Impacts will include complete fill of entire wetlands, small areas of fill at the edges of wetlands, and footings for constructed boardwalk crossings for pedestrian trails. Mitigation will be part of the restoration and management plan in the conservation area. Conservation development phases: Approximately 1550 acres (including the —17.6 -acre public parcel) will be set aside as a conservation area (CA). No construction activity will occur in these areas, except trail and boardwalk construction where the planned trails will cross the CA. The entire CA acreage will be placed under a conservation easement at the beginning of the project. Following that, it will be subject to an active restoration and management regime. The restoration tasks and timelines will be designed to correspond with the ecological requirements of the proposed conservation area, and the natural communities, flora, fauna, and rare species existing within. The systems to be restored are diverse fire - dependent herbaceous systems, and restoration and management approaches will be designed to re- establish a more natural disturbance regime (i.e. prescribed fire), reduce encroachment of woody species, manage exotic and invasive species, and promote the proliferation of diverse herbaceous systems and rare native plant species. The plan will be designed to: adequately document existing pre - restoration conditions, monitor improvements to the natural systems as a result of restoration and management implementation, and justify the allocation of wetland mitigation credits with sufficient monitoring data upon successful implementation of the restoration and management plan.