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r <br />42 ” RCP (NURP Basin 3)57 cfs 28 cfs 3 cfs 29 cfs 6.5 cfs 0.9 cfs <br />The roadway culvert crossings on County Road 6 and Spring Hill Road were also included in <br />the storm water flow rate modeling. Based on the results of the flow rating, these culverts are <br />capable of handling up to 100-year design storms without overtopping the roads. The <br />proposed golf course construction did not increase the flow rates to these culverts. <br />A nutrient budget was performed to evaluate the impact of the pollutant loadings to Long Lake <br />from the construction of the golf course. The procedures used in the analysis are from the <br />MPCA's “Protecting Water Quality in Urban Areas, ” Best Management Practices Manual. The <br />pollutant concentrations used in determining the loadings for both undeveloped and developed <br />conditions were those representing open/non-urban land use. Although there will be a change <br />in the land use. A 1995 study by Mr. John Barten, of Suburban Hennepin County Park District, <br />on the quantity and quality of golf course runoff found that the nutrient export from golf courses <br />is very similar to undeveloped land.' A copy of the entire report is located in appendix H. <br />The removal efficiencies of the proposed NURP basins are based on “Walkeris ” long term <br />NURP basin pond performance criteria. The results of nutrient budget analyses indicate an <br />( 'erall reduction in the pollutant loadings to Long Lake. The nutrient budget data is tabulated <br />bb.ow. <br />TABLE 2 <br />LONG LAKE NUTRIENT LOADING BUDGET <br />Total Existing * <br />Loading <br />,:: (lbs.) ■ <br />Total Proposed <br />Loading to NURP <br />Basins <br />(lbs.)* <br />Removal <br />Efficiency Range <br />w <br />Total Proposed <br />Loading to Long <br />Lake ■ <br />(lbs.) <br />Total Suspended <br />Solids (TSS) <br />28,602 38.409 89-98 <br />5.700 - 770 <br />Total <br />Phosphorous (TP) <br />30.46 40.89 40-70 28.6-12.3 <br />TotalKjeldahl <br />Nitrogen (TKN) <br />180.08 241.83 20-40 192-145 <br />Lead (Pb)7.13 9.6 80-95 1 9-0.5 <br />Zinc (Zn)30.46 40 89 40-80 24.5-8.2 <br />•The proposed pollutant loadings are based on the additional runoff volumes generated by the proposed greens, <br />fairways and tees <br />’ Barter), John M.. Quantity and Quality of Runoff from Four Golf Courses in the <br />Twin Cities Metropolitan Area . September 1995, Suburban Hennepin Regional Park <br />District. <br />11