Evaluation of alternative reservoir-management practices in the Rock River basin, Wisconsin
Simulation of the operation of upstream impoundments in the Rock River basin to reduce spring floods showed that such operation would reduce flood peaks by 0.11 foot on the average, and would increase flood peaks some years. The most significant reductions would occur during the average- size floods, whereas little or no reductions would occur for larger and smaller floods. Modifying the simulation of impoundment operations to reduce larger floods produced only minor reductions in flood peaks for the larger floods, and slightly increased flood peaks for average-size floods. Alternative operating procedures for Indianford Dam which controls Lake Koshkonong were simulated with estimated power generation and the use of flashboards during the summer, neither of which are currently used. The simulation showed that, for most periods without significant runoff, the stage of Lake Koshkonong would tend toward the stage at which power generation was prohibited. It also showed that use of flashboards to raise the minimum lake stage during the summer would not raise the peak stage of the lake measurably if the flashboards were removed when the stage rose above its normal level. Simulation showed that winter drawdown of Lake Koshkonong would not lower spring flood peaks significantly downstream.