US Army Corps of Engineers

McNary Dam & Lake Wallula

April 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 22640 943 120 225.10 224.10 186.80 34.60 339.40 339.25 268.56 70.69
2 21994 916 120 201.60 206.60 179.20 24.70 339.13 339.39 268.36 71.03
3 22653 944 120 193.80 202.40 184.90 14.80 338.72 338.80 268.26 70.54
4 22625 943 120 201.00 197.50 184.70 10.10 338.91 338.76 268.24 70.52
5 22620 943 120 191.30 196.70 184.50 9.50 338.53 338.79 268.20 70.59
6 21247 885 102 181.60 184.80 172.90 9.20 338.40 338.44 267.75 70.69
7 20136 839 104 167.30 173.80 161.90 9.10 338.07 338.40 267.42 70.98
8 19920 830 120 167.80 174.10 162.80 8.60 337.64 337.87 267.22 70.65
9 19672 820 120 184.90 171.50 160.20 8.50 338.43 337.83 267.28 70.55
10 6721 280 120 187.80 175.50 52.30 120.50 339.08 338.63 266.20 72.43
11 6653 277 120 194.00 195.70 51.60 141.40 339.03 339.26 266.53 72.73
12 200.70 204.10 52.10 149.30 338.77 338.86 266.58 72.28
13 210.50 207.50 52.20 152.50 339.02 338.94 266.89 72.05
14 207.00 207.00 52.60 150.90 339.04 339.01 266.74 72.27
15 204.60 209.60 53.30 151.60 338.75 338.85 267.08 71.77
16 214.90 210.00 53.50 151.80 338.99 338.80 267.16 71.64
17 219.70 223.30 52.80 165.70 338.78 338.79 267.29 71.50
18 220.90 227.10 52.90 169.50 338.45 338.61 267.17 71.44
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TOT206881  1286        
AVG 18807 784 117 198.58 199.52 113.96 82.35 338.73 338.74 267.38 71.35
MAX 22653   225.10 227.10 186.80 169.50 339.40 339.39 268.56 72.73
MIN 6653   167.30 171.50 51.60 8.50 337.64 337.83 266.20 70.52