US Army Corps of Engineers

Wanapum Dam & Lake

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 18646 777 17 133.80 142.40 135.40 6.10 569.46 570.22 492.33 77.89
2 14029 585 17 120.20 115.50 98.80 15.70 570.11 569.87 490.07 79.80
3 17784 741 18 128.80 135.50 128.50 6.00 569.20 569.70 491.47 78.23
4 16571 690 17 127.20 134.10 122.60 10.50 568.23 568.83 491.04 77.79
5 16020 668 17 125.70 123.40 117.20 4.20 568.56 568.62 490.65 77.97
6 16853 702 17 127.60 125.70 123.70 0.00 568.82 568.57 491.27 77.30
7 13110 546 17 105.10 100.90 92.10 6.80 569.40 569.87 489.41 80.46
8 15018 626 18 118.80 121.00 105.70 13.30 569.11 570.04 490.65 79.39
9 14093 587 18 111.40 122.10 101.30 18.70 567.62 568.29 490.62 77.67
10 15452 644 17 134.90 133.50 112.90 18.60 567.82 568.16 491.36 76.80
11 14553 606 17 127.10 125.70 105.00 18.70 568.02 568.43 490.77 77.66
12 17225 718 17 152.90 145.40 123.90 19.50 569.05 569.61 491.88 77.73
13 13639 568 16 139.50 130.40 96.60 31.80 570.30 570.13 490.91 79.22
14 15177 632 18 139.30 135.30 107.20 26.10 570.85 570.87 491.39 79.48
15 13448 560 17 126.90 132.70 95.30 35.40 570.06 570.79 491.34 79.45
16 12971 540 18 124.60 128.20 92.20 34.00 569.57 570.34 491.19 79.15
17 15776 657 16 130.00 146.80 115.30 29.50 567.23 568.95 491.81 77.14
18 15743 656 16 146.00 135.10 114.50 18.60 568.76 568.32 490.80 77.52
19 15838 660 16 133.40 134.60 113.30 19.30 568.59 569.34 491.02 78.32
20 17866 744 17 160.20 149.90 128.40 19.40 570.01 569.57 491.59 77.98
21 17959 748 17 154.90 154.00 127.60 24.40 570.13 570.46 491.75 78.71
22 119.10 136.90 107.50 27.40 567.66 568.93 490.66 78.27
23 151.60 139.80 87.10 50.60 569.30 568.97 490.62 78.35
24 164.50 154.10 123.20 29.00 570.72 570.53 492.11 78.42
25 150.80 154.70 132.60 20.00 570.19 570.39 492.43 77.96
26 139.30 144.80 122.90 19.90 569.44 570.17 491.68 78.49
27 142.70 138.50 116.90 19.60 570.02 569.74 491.38 78.36
28 131.20 139.10 111.50 25.70 568.93 570.14 491.12 79.02
29
30
TOT327771  358        
AVG 15608 650 17 134.55 135.00 112.83 20.31 569.18 569.57 491.19 78.38
MAX 18646   164.50 154.70 135.40 50.60 570.85 570.87 492.43 80.46
MIN 12971   105.10 100.90 87.10 0.00 567.23 568.16 489.41 76.80