US Army Corps of Engineers

Wanapum Dam & Lake

June 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 19045 794 16 169.40 168.20 138.00 28.20 571.08 570.69 493.41 77.28
2 20174 841 16 196.30 196.10 149.60 44.60 571.11 570.86 494.63 76.23
3 18846 785 16 202.00 204.10 138.60 63.50 570.82 570.94 494.86 76.08
4 18120 755 16 193.40 198.20 134.30 61.90 570.16 570.28 494.45 75.83
5 18735 781 15 171.90 170.80 137.90 30.90 570.32 569.71 493.33 76.38
6 17885 745 15 171.30 168.80 129.30 37.50 570.66 570.77 493.25 77.52
7 16743 698 16 168.00 174.10 121.90 50.20 569.82 570.31 493.34 76.97
8 19946 831 15 183.90 175.50 147.10 26.40 570.97 570.15 493.66 76.49
9 17927 747 15 157.60 166.50 129.80 34.70 569.75 570.46 493.17 77.29
10 16628 693 15 118.70 142.60 121.90 18.70 566.43 568.32 491.69 76.63
11 16591 691 16 146.30 143.20 123.80 17.40 566.86 566.50 491.59 74.91
12 16659 694 16 146.70 144.00 124.50 17.50 567.24 566.70 491.83 74.87
13 16566 690 16 158.20 141.90 121.40 18.50 569.51 568.19 491.83 76.36
14 18181 758 16 162.90 153.00 131.10 19.90 570.86 570.23 492.46 77.77
15 19628 818 17 169.40 166.20 142.10 22.10 571.30 570.74 493.38 77.36
16 18630 776 18 159.10 160.20 134.00 24.20 571.15 570.78 492.95 77.83
17 18000 750 19 120.40 153.30 131.40 19.90 566.59 568.76 492.38 76.38
18 15987 666 19 136.10 137.80 118.30 17.50 566.34 566.72 491.35 75.37
19 15964 665 20 154.40 138.30 118.70 17.50 568.59 566.81 491.45 75.36
20 15462 644 19 111.40 133.20 113.00 18.20 565.54 567.60 491.24 76.36
21 104.20 101.50 83.10 16.50 565.91 565.17 489.60 75.57
22 128.00 122.50 103.80 16.70 566.68 565.57 490.75 74.82
23 150.30 150.10 130.80 17.40 566.71 566.49 492.19 74.30
24 139.50 148.30 129.60 16.70 565.47 565.52 492.16 73.36
25 143.80 139.70 121.40 16.30 566.05 564.99 491.74 73.25
26 161.00 142.30 122.50 17.80 568.66 567.14 491.85 75.29
27 95.90 104.90 84.40 18.50 567.41 568.12 489.62 78.50
28
29
30
TOT355717  331        
AVG 17786 741 17 152.60 153.53 125.27 26.27 568.59 568.46 492.38 76.09
MAX 20174   202.00 204.10 149.60 63.50 571.30 570.94 494.86 78.50
MIN 15462   95.90 101.50 83.10 16.30 565.47 564.99 489.60 73.25
BUILDING STRONG®