US Army Corps of Engineers

Wanapum Dam & Lake

August 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 11805 492 19 98.80 104.10 83.30 18.80 567.90 568.63 489.42 79.21
2 9676 403 18 89.40 88.20 68.20 18.00 568.07 567.45 488.39 79.06
3 9524 397 20 102.40 87.30 66.80 18.50 570.15 568.25 488.49 79.76
4 11343 473 21 84.90 101.10 80.50 18.60 567.92 568.23 489.50 78.73
5 11082 462 20 103.80 99.30 79.20 18.10 568.54 567.55 489.27 78.28
6 11154 465 21 86.90 101.10 81.60 17.50 566.56 566.65 489.95 76.70
7 12363 515 21 119.00 110.50 90.80 17.60 567.75 566.92 490.41 76.51
8 10266 428 21 91.20 94.00 75.00 17.10 567.35 566.03 489.26 76.77
9 9228 384 20 96.00 85.90 66.20 17.70 568.76 567.02 488.95 78.07
10 9612 400 20 88.30 89.10 69.10 18.10 568.64 567.52 489.46 78.06
11 9064 378 20 94.40 84.10 63.40 18.70 570.07 568.47 488.34 80.13
12 12510 521 20 104.00 99.00 87.70 9.30 570.76 569.75 489.77 79.98
13 13497 562 20 95.20 97.40 93.70 1.70 570.45 570.10 489.59 80.51
14 13679 570 20 98.20 99.50 95.60 1.90 570.28 569.58 490.05 79.53
15 12902 538 20 96.10 94.10 90.10 2.00 570.56 569.90 489.87 80.03
16 14098 587 20 93.40 105.80 99.90 3.90 568.85 569.22 490.31 78.91
17 13020 542 21 100.00 96.70 93.20 1.50 569.31 568.27 489.60 78.67
18 11774 491 21 85.90 86.40 83.20 1.20 569.24 568.58 489.02 79.56
19 12598 525 21 101.40 94.40 88.90 3.50 570.21 569.88 489.60 80.28
20 101.10 101.10 97.60 1.50 570.21 569.67 489.96 79.71
21 102.60 105.10 101.50 1.60 569.86 568.67 490.16 78.51
22 73.10 73.40 69.60 1.80 569.82 569.37 488.56 80.81
23 70.50 77.70 73.90 1.80 568.81 569.40 488.84 80.56
24 92.30 95.40 92.00 1.40 568.38 568.06 489.36 78.70
25 104.20 105.70 102.20 1.50 568.16 567.91 489.98 77.93
26 102.50 98.80 95.40 1.40 568.67 567.91 489.64 78.27
27
28
29
30
31
TOT219195  384        
AVG 11537 481 20 95.22 95.20 84.18 9.03 569.05 568.42 489.45 78.97
MAX 14098   119.00 110.50 102.20 18.80 570.76 570.10 490.41 80.81
MIN 9064   70.50 73.40 63.40 1.20 566.56 566.03 488.34 76.51
BUILDING STRONG®