US Army Corps of Engineers

John Day & Lake Umatilla

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 40526 1689 50 231.70 232.10 221.10 9.80 265.52 265.52 162.87 102.65
2 36634 1526 53 214.40 209.10 198.30 9.80 265.72 265.46 161.88 103.58
3 36952 1540 52 213.80 211.20 200.10 9.80 265.82 265.86 162.37 103.49
4 35992 1500 49 209.10 206.50 195.20 9.80 265.92 265.95 162.57 103.38
5 36790 1533 48 208.60 211.20 200.00 9.80 265.82 265.91 162.84 103.07
6 193.70 204.10 193.10 9.80 265.42 265.67 162.09 103.58
7 186.40 194.20 183.50 9.70 265.12 265.08 161.46 103.62
8 181.50 176.30 165.20 9.70 265.32 265.25 160.94 104.31
9 178.20 178.20 166.60 10.50 265.32 265.48 161.43 104.05
10 184.20 184.20 64.90 118.00 265.32 265.40 160.35 105.05
11 199.30 199.30 60.20 137.70 265.32 265.28 160.95 104.33
12 205.70 216.20 60.60 154.30 264.92 265.16 161.19 103.97
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TOT186894  252        
AVG 37379 1557 50 200.55 201.88 159.07 41.56 265.46 265.50 161.75 103.76
MAX 40526   231.70 232.10 221.10 154.30 265.92 265.95 162.87 105.05
MIN 35992   178.20 176.30 60.20 9.70 264.92 265.08 160.35 102.65