Mississippi River Ice Cover Between Dam No. 3 And Lake Pepin

The suppression of ice covers on the Mississippi River between Lock and Dam No.3 (near Red Wing, Minnesota) and Lake Pepin by the cooling water effluent from the Prairie Island Nuclear Power Generating Plant was investigated. The winter river temperature regime below Dam No. 3 was analyzed by.equi1ibrium temperature and non-equilibrium temperature methods with very similar results. The length of-the open water reach below Dam No. 3 was predicted. The total river reach from Dam No. 3 to Lake Pepin is 11 miles long. River ice covers during past winters (1972/73 through 1979/80) were documented by interpretation of LANDSAT imagery and by two aerial surveys. Predictions were made for the hypothetical case that the Prairie Island Plant would operated in a once-through cooling mode resulting in a maximum heat rejection of 8.34*109 BTU's per hour.Northern States Power Compan