The water quality of the proposed LaFarge Lake, Wisconsin, was investigated using a version of the reservoir portion of the Water Quality for River-Reservoir Systems (WQRRS) ecological model. Although other water-quality constituents were simulated, the study concentrated on temperature, dissolved oxygen, and algae concentrations. Daily field measurements of phosphorus and nitrogen on the Kickapoo River were used in the simulations. Algal bioassays were also conducted on the Kickapoo River and surrounding impoundments. These assays indicated that essentially all of the soluble nitrogen and phosphorus in the river were in forms available for algal growth and that phosphorus was most likely to be the limiting nutrient in the proposed impoundment. The simulations indicated that LaFarge Lake probably will be thermally stratified from May through September.

The water quality of the proposed LaFarge Lake, Wisconsin, was investigated for a lower pool elevation (250.5 m MSL) using a version of the reservoir portion of the Water Quality for River-Reservoir Systems (WQRRS) ecological model. As in a previous study at a higher elevation (256 m MSL), the effort concentrated on temperature, dissolved oxygen, and algae. All model coefficients from the previous study were retained with the exception of Secchi disk depth, which was reduced from 3 to 2 m to account for probable increased turbidity at the lower pool elevation. The simulations indicated that LaFarge Lake would be a dynamic impoundment at the lower pool elevation. Temperature stratification was weak and intermittent. Dissolved oxygen was distributed throughout the pool during periods of complete mixing and was rapidly depleted in the hypolimnion during periods of stratification. A bloom of diatoms and green algae during the spring and at least two major blooms of blue-green algae during summer and fall were predicted. The phasing of these blooms was similar to that found at the higher elevation, but the two blue-green algae blooms increased in magnitude at the lower pool level. Coliforms were found to persist longer and to be distributed throughout more of the pool at the lower elevation. The phosphorus loadings at the lower pool elevation were approximately twice as large, but since the flushing rate was increased approximately three times, the eutrophication potentials of the two pool levels, based on Vollenweider's loading curves, were similar. It was not possible to meet downstream temperature objectives for a cold-water fishery. (Author).

The plan consists of a multiple-purpose lake for flood control, fish and wildlife production, and recreation. The dam-site would be located on the Kickapoo River about 1 mile north of La Farge, in Vernon County, southwestern Wisconsin. The dam would be an earth-fill structure with an overall length of 3,960 feet and a maximum height of 103 feet. The conservation or recreation pool at elevation 840 is designed to impound 33,000 acre-feet of water with a surface area of about 1,780 acres extending about 12 miles upstream. Local flood protection measures for the downstream communities of Gays Mills and Soldiers Grove have been approved; however these are separate projects which will be treated in separate environmental impact statements.