The Seven Mile Creek Watershed Project application is based on three years of intensive monitoring, assessment, modeling, evaluation, and coalition building. The work was undertaken through funding by a MPCA Resource Investigation Grant with contributions from several other local and state agencies from 1999-2001. The 23,551-acre study watershed is located in the Minnesota River Basin, within the Middle MN Major Watershed in South Central Minnesota. The watershed is located between the communities of Nicollet and St. Peter. 86% of the watershed land use is under a corn/soybean cultivation. Seven Mile Creek is Nicollet County's most visible natural resource with a 640-acre county park located at the mouth of the watershed. Since 1985, the creek has been designated as a class 1-D marginal trout stream by the MN DNR.

Cooperators
The coalition interested in improving this watershed includes normal water resource players (SWCD, Environmental Services, etc), as well as an extraordinary roster, which includes two branches of the University of Minnesota (Soils/Ag & Public Health), the MN DNR, the national Center for Agricultural Partnerships, USDA paired watershed study, and the McKnight Foundation. In addition, the watershed's biggest business, 3,000-head proposed Northern Plains Dairy operation, and Red Top Farms, southern Minnesota's longest-running demonstration farm, are both interested in being part of any Phase II project. The Brown-Nicollet-Cottonwood Water Quality Board is the project sponsor; a total of 15 agencies, citizens groups, and private enterprises are involved in this watershed project.

Diagnostic Study Results
Throughout the 2000 and 2001 study period, flow-weighted mean concentrations (FWMC) for sediment at the mouth of the watershed were 5 times higher than the expected values for minimally impacted streams of the same eco-region (western corn-belt plains). Nitrates were 3 times higher and average phosphorus concentrations were 1.2 times higher. Fecal coliform levels were above the 200-col./100ml limit 45% of the tested time. Average FWMC during the two-year study was 227 mg/l, 13.7 mg/l, .340 mg/l and .234 mg/l for total suspended solids, nitrate-nitrogen, total phosphorus and ortho-phosphorus respectively. The watershed yielded an average of 6,712 tons of suspended sediment or 570 lbs./acre or 52 lbs./acre/inch of runoff during the growing season (April-September). The watershed loads approximately 10.7 tons of phosphorus, .912 lbs./acre or .156 lbs./acre/inch of runoff. About 60% of the total phosphorus was found to be in the dissolved reactive form. Considering the size of the drainage area, the watershed contributes high levels of nitrate-nitrogen to the MN River. The two-year average nitrate load measured from the watershed amounts to 320 tons or about 27 lbs./acre or about 3.2 lbs./acre/inch of runoff. Most of the nitrate-nitrogen leaching within the watershed is derived from an over application of commercially applied fertilizers, tile drainage network, soil mineralization, and climatic factors. About 50-70% of the pollutant loads came during the months of April, May, and June. Sediment modeling results indicate that about 42% of the sediment is derived from bank erosion sources, 37% upland, 13% riparian corridor, and 8% from open tile intakes. Phosphorus delivery modeling indicates that 52% of the phosphorus load is from upland sources, 14% bank erosion, 12% non-complying septics and 11% riparian and open tile intakes. Main stem water quality goals will require pollutant reductions of 25% for TSS and 25% for phosphorus and 40% reduction for nitrate-nitrogen. Along with numeric goals, watershed surveys documenting behavioral changes before and after the Clean Water Partnership (CWP) will track project success. Overall, water storage and nutrient management will be the most important BMPs in the watershed restoration effort. The diagnostic study has enabled the watershed technical committee to make informed responses to TMDL recommendations and to target remediative strategies during implementation phases for watersheds like Seven Mile located in the eastern half of the Middle MN Major Watershed.

Implementation Funding
The Water Quality Board is seeking $ 196,432 cash and $ 550,000 in septic improvement loan funds from the CWP program. This will be added to $21,000 local cash (from county agencies and a DNR Environmental Partners grant) and over $ 650,000 in in-kind contributions from the coalition described above to carry out the proposed implementation plan.