US Army Corps of Engineers

Wanapum Dam & Lake

February 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 17513 730 25 116.60 129.30 127.90 0.00 569.03 569.66 491.68 77.98
2 18083 753 24 133.70 131.60 130.20 0.00 569.32 569.70 491.55 78.15
3 18464 769 24 149.10 135.10 132.60 1.20 571.23 570.41 491.87 78.54
4 19728 822 24 130.50 147.90 145.20 1.40 568.82 569.87 492.82 77.05
5 18069 753 26 126.80 137.30 135.90 0.00 567.36 567.57 492.19 75.38
6 17207 717 24 123.90 131.10 129.70 0.00 566.35 566.37 491.54 74.83
7 16462 686 25 135.30 120.60 119.20 0.00 568.40 568.29 490.76 77.53
8 15483 645 25 115.80 111.90 110.50 0.00 568.94 568.64 490.14 78.50
9 18014 751 25 131.70 131.50 130.10 0.00 568.97 569.84 491.85 77.99
10 18975 791 25 151.20 141.90 140.50 0.00 570.25 569.10 492.39 76.71
11 20065 836 24 146.40 147.80 146.40 0.00 570.05 569.95 492.50 77.45
12 19603 817 25 126.20 146.30 144.90 0.00 567.26 569.07 492.51 76.56
13 18375 766 24 149.70 136.40 135.00 0.00 569.12 568.76 491.84 76.92
14 18464 769 24 122.80 137.70 136.30 0.00 567.03 568.37 491.93 76.44
15 17402 725 24 129.70 132.10 130.70 0.00 566.70 567.24 491.61 75.63
16 18033 751 24 152.50 135.80 134.40 0.00 569.02 567.76 491.88 75.88
17 20753 865 24 155.40 158.30 156.90 0.00 568.62 568.67 493.09 75.58
18 19661 819 26 143.80 149.00 147.60 0.00 567.89 568.06 492.74 75.32
19 19390 808 23 139.20 151.30 149.90 0.00 566.20 566.91 492.59 74.32
20 18523 772 26 154.80 143.80 142.40 0.00 567.74 566.81 492.33 74.48
21 18064 753 25 157.10 134.80 133.20 0.20 570.83 569.51 492.17 77.34
22 17899 746 24 155.80 155.20 143.70 10.10 570.92 570.74 493.04 77.70
23 21857 911 24 161.60 162.60 161.20 0.00 570.78 570.88 493.50 77.38
24 22000 917 26 158.60 166.80 165.40 0.00 569.65 570.01 493.79 76.22
25 18024 751 21 153.10 143.60 142.20 0.00 570.96 570.48 492.51 77.97
26 18157 757 19 146.20 146.80 130.80 14.50 570.88 571.04 492.42 78.62
27 17892 746 18 128.30 134.90 129.00 4.50 569.98 570.62 492.13 78.49
28 18447 769 18 140.40 140.20 138.80 0.00 570.00 569.93 492.03 77.90
TOT520607  666        
AVG 18593 775 24 140.58 140.77 138.24 1.14 569.01 569.08 492.19 76.89
MAX 22000   161.60 166.80 165.40 14.50 571.23 571.04 493.79 78.62
MIN 15483   115.80 111.90 110.50 0.00 566.20 566.37 490.14 74.32