US Army Corps of Engineers

McNary Dam & Lake Wallula

January 2026

Day of MonthTotal Generation MWhAverage Generation MWStation Use MWhInflow kcfsTotal Outflow kcfsGeneration Flow kcfsSpill kcfsMidnight Reservoir ElevationAverage Forebay ElevationAverage Tailwater ElevationAverage Head feet
1 22891 954 120 178.50 189.30 185.30 0.00 338.63 338.91 267.16 71.75
2 22424 934 120 172.20 188.50 184.50 0.00 337.80 338.02 267.29 70.73
3 22010 917 120 188.20 185.50 181.50 0.00 337.94 337.79 267.23 70.56
4 21995 916 81 182.60 185.50 181.60 0.00 337.77 337.82 267.36 70.46
5 21516 896 24 181.90 180.10 176.70 0.00 337.93 337.96 267.17 70.79
6 21083 878 24 175.80 177.80 175.00 0.00 337.76 337.46 267.15 70.31
7 20872 870 24 192.80 172.60 169.80 0.00 338.83 338.18 266.69 71.49
8 21703 904 24 198.50 187.30 173.60 10.90 339.52 339.29 266.86 72.43
9 22806 950 24 203.20 210.90 184.40 23.70 339.08 339.37 267.57 71.80
10 22790 950 24 189.60 194.10 185.70 5.60 338.83 339.02 267.60 71.42
11 22749 948 24 176.00 189.90 187.10 0.00 338.04 338.35 267.51 70.84
12 22676 945 24 190.00 190.40 187.60 0.00 338.07 337.99 267.50 70.49
13 21965 915 24 202.80 181.20 178.40 0.00 339.23 338.64 267.10 71.54
14 22561 940 24 195.30 187.70 180.10 4.70 339.57 339.54 267.07 72.47
15 22329 930 24 199.80 199.20 179.10 17.30 339.62 339.54 267.31 72.23
16 22851 952 24 214.50 214.80 185.00 26.90 339.64 339.61 267.88 71.73
17 22769 949 24 197.90 196.20 184.60 8.70 339.63 339.47 267.82 71.65
18 22784 949 24 197.70 200.70 183.70 14.20 339.56 339.69 267.74 71.95
19 22810 950 24 201.80 201.30 184.70 13.70 339.61 339.58 267.86 71.72
20 22831 951 24 204.70 198.20 185.10 10.40 339.76 339.64 267.94 71.70
21 22815 951 24 194.00 194.80 184.00 7.90 339.75 339.73 267.80 71.93
22 22819 951 24 191.40 198.90 184.40 11.80 339.33 339.65 267.81 71.84
23 22823 951 24 185.40 194.10 186.40 4.90 338.87 338.94 267.69 71.25
24 22593 941 24 176.70 187.40 184.60 0.00 338.26 338.52 267.35 71.17
25 21154 881 24 182.70 172.50 169.70 0.00 338.97 338.48 266.72 71.76
26 22430 935 24 191.30 181.90 179.10 0.00 339.36 339.02 266.61 72.41
27 22818 951 24 184.70 186.30 183.50 0.00 339.33 339.33 267.21 72.12
28 19951 831 24 174.70 167.80 159.80 5.10 339.59 339.36 266.99 72.37
29 18997 792 24 155.10 166.60 151.70 12.20 338.95 339.38 266.89 72.49
30 160.10 166.00 153.50 9.70 338.67 338.71 266.87 71.84
31 169.10 160.80 152.90 5.00 339.09 338.78 266.69 72.09
TOT642814  1041        
AVG 22166 924 36 187.39 187.36 178.16 6.22 338.94 338.90 267.30 71.59
MAX 22891   214.50 214.80 187.60 26.90 339.76 339.73 267.94 72.49
MIN 18997   155.10 160.80 151.70 0.00 337.76 337.46 266.61 70.31
BUILDING STRONG®