Model for River Regulation

Flow modification of the 450 mile Wisconsin River, which drains 12,000 sq miles as it traverses the state, is accomplished by the average annual release of 465,000 acre-ft of water from a system of 21 reservoirs on the River's headwaters that are owned by a private corporation and have a capacity of 401,000 acre-ft. Twenty-six hydro-plants, which develop an aggregate head of 650 ft, are benefited directly by the reservoir operation which reduces flood flows by as much as 50% and frequently doubles low flows. Data from 38 rain gages (twelve recorders), twelve ground-water wells, six stream gages, five snow courses, four lake evaporation pans, and the hydro-stations permit close control of the annual runoff of 12.5 in. which results from 31 in. of rainfall. Ground-water Index correlations indicate that an Index range of 5.75 ft represents a change of 1,300 cfs in base flow of the River. The Wisconsin Valley Improvement Company, whose stockholders are eight paper companies and four utilities, hopes to provide reservoirs to control flashy runoff from five other tributary streams.