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 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 proposed Trexler Lake, Pennsylvania, was evaluated with respect to its eutrophication potential and water quality criteria and standards appropriate for project purposes. Study approaches included review of existing water quality data taken on the four tributaries to the proposed project; review of existing data on surrounding impoundments; algal bioassay analyses on water samples taken in the proposed tributaries and in one surrounding lake; mathematical simulation; and nutrient loading analyses. Algal bioassays were conducted on water samples taken in Mill, Lyon, Switzer, and Jordan creeks and in Beltzville Lake. All samples were phosphorus limited, and all of the orthophosphate was available for algal growth. The proposed Trexler Lake is expected to be in the mesotrophic or early eutrophic stage and exhibit strong thermal stratification during the summer months with a 1-month period of hypolimnetic anoxia during the fall. The project purposes are not expected to be vitiated by water quality although the lake is expected to be anoxic for a short time during late summer. Appendix A describes the algal assay procedures. Appendix B discusses the Hydrocomp simulation of Jordan Creek drainage basin. Appendix C presents the initial conditions, coefficients, and updates for mathematical ecological simulations. Appendix D lists the coefficient references.