US Army Corps of Engineers

Wanapum Dam & Lake

October 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 7726 322 17 67.60 57.10 54.00 1.10 567.85 567.14 487.37 79.77
2 8032 335 18 53.60 59.70 56.50 1.20 566.99 567.16 487.91 79.25
3 8156 340 19 59.80 60.90 57.90 1.10 566.83 566.89 487.64 79.25
4 7063 294 19 54.60 52.50 49.50 1.00 567.12 566.55 486.78 79.77
5 7921 330 19 69.10 57.60 54.10 1.40 568.73 568.10 487.33 80.77
6 11077 462 19 80.60 81.30 77.80 1.50 568.64 568.27 488.81 79.46
7 12044 502 18 88.10 88.10 84.50 1.60 568.63 568.51 488.80 79.71
8 12053 502 18 86.10 88.30 85.20 1.10 568.34 567.62 488.60 79.02
9 8499 354 17 47.60 61.90 58.80 1.20 566.34 567.12 487.07 80.05
10 8222 343 17 69.90 60.60 57.70 0.90 567.64 566.42 486.97 79.45
11 7761 323 17 50.20 57.00 53.90 1.10 566.69 567.03 487.11 79.92
12 10340 431 17 89.00 75.60 72.30 1.20 568.58 567.37 488.16 79.21
13 9799 408 17 57.80 72.80 69.80 1.10 566.47 566.79 488.26 78.53
14 7833 326 17 54.50 58.10 55.30 0.90 565.96 566.09 487.33 78.76
15 6016 251 17 58.70 47.90 41.60 4.30 567.48 566.85 485.89 80.96
16 6514 271 17 48.50 47.90 44.80 1.10 567.55 567.02 486.27 80.75
17 4670 195 17 34.70 39.60 31.80 5.80 566.86 567.09 485.47 81.62
18 6161 257 17 48.50 45.30 42.30 1.00 567.30 566.65 486.11 80.54
19 8076 336 17 69.70 59.00 55.80 1.30 568.79 567.57 487.19 80.38
20 9154 381 17 52.90 67.40 64.20 1.30 566.75 567.38 487.60 79.78
21 8556 356 17 75.40 62.70 59.70 1.00 568.52 566.75 487.34 79.41
22 8059 336 17 57.80 58.60 55.30 1.40 568.41 567.91 487.22 80.69
23 6353 265 17 37.20 47.90 43.50 2.40 566.91 567.44 485.89 81.55
24 6238 260 17 53.80 45.80 42.60 1.10 568.03 567.08 485.98 81.10
25 6102 254 17 44.20 44.70 41.40 1.30 567.96 567.79 486.22 81.57
26 8217 342 18 57.70 60.60 57.30 1.30 567.55 567.76 487.05 80.71
27 6721 280 17 44.50 49.80 46.70 1.10 566.82 566.87 486.50 80.37
28 7169 299 18 62.40 52.80 49.70 1.10 568.16 566.98 485.86 81.12
29 9371 390 18 73.90 67.70 64.20 1.50 569.02 568.40 487.43 80.97
30 66.10 77.40 74.00 1.50 567.45 568.21 488.04 80.17
31 73.90 68.30 65.00 1.40 568.22 567.96 487.33 80.63
1 64.90 76.20 72.70 1.50 567.00 568.42 487.53 80.89
TOT233903  507        
AVG 8066 336 17 61.04 60.97 57.50 1.49 567.61 567.35 487.16 80.19
MAX 12053   89.00 88.30 85.20 5.80 569.02 568.51 488.81 81.62
MIN 4670   34.70 39.60 31.80 0.90 565.96 566.09 485.47 78.53
BUILDING STRONG®