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Willow Bay Sanctuary Conservation Design Application <br /> Topographic Survey and Existing Drainage Patterns <br /> Gronberg&Associates completed a topographic survey of the property. The site generally <br /> drains to overland and through the narrow watercourse (other water resource)to Long Lake <br /> (Figure 3). The property is not known to include any existing storm sewers or water quality <br /> treatment basins. Much of the site falls within the Shoreland Overlay District of Long Lake. <br /> Detailed review of the existing topography indicates the site does not include any bluffs as <br /> defined in the City of Orono Shoreland Management Ordinance. Compliance with shoreland <br /> requirements is discussed further under the section of this narrative titled Maintain and Protect <br /> Positive Views. Appendix C shows the topographic survey and existing drainage patterns. <br /> Orono Natural Resources Inventory Recommendations <br /> The property includes few areas that are the subject of recommendations set forth in the Orono <br /> Natural Resources Inventory (Figure 5). The site does not include: <br /> 1. MLCCS Regional Ecological Corridors, <br /> 2. Priority Natural Resource Corridors, <br /> 3. Regionally Significant Ecological Areas, <br /> 4. plant communities mapped by the Minnesota DNR Biological Survey, or <br /> 5. natural areas with identified potential for rare species. <br /> However, the site does include part of a conceptual greenway corridor and part of a floodplain <br /> identified in the Orono Natural Resources Inventory (Appendix B). This conceptual corridor <br /> extends northwest from Long Lake along the watercourse in the northern part of the site <br /> (Appendix B,Figure 3). Preservation of woodland, wetland, and the watercourse is expected to <br /> minimize potential effects on the conceptual greenway. <br /> 3. CONSERVATION DESIGN MASTER PLAN <br /> Consider Existing Drainage Systems <br /> Existing drainage includes overland flow toward wetlands, the narrow watercourse, and Long <br /> Lake. The site has no known surface drain inlets or storm sewers. Lake Minnetonka and limited <br /> areas that drain to surface storm sewer inlets. After project construction, runoff will generally <br /> follow existing drainage patterns, but runoff from Willow Bay Court will drain through grassed <br /> ditches and then to a stormwater basin prior to discharge to wetlands and Long Lake. Rain <br /> gardens are planned to treat backyard runoff in four locations (Figure 6). The existing drainage <br /> system is shown in Appendix C. The proposed drainage system is shown in Appendix E. <br /> Establish Stormwater Management System <br /> Stormwater will be managed in compliance with local, state, and federal regulations to provide <br /> rate, volume, and sediment control as shown on the Proposed Grading Plan (Appendix E). The <br /> project includes design elements that minimize stormwater runoff effects on water quality and <br /> quantity, including grassed ditches, rain gardens, a stormwater pond, limiting soil disturbance <br /> 4 <br />