US Army Corps of Engineers

McNary Dam & Lake Wallula

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 19030 793 24 160.30 153.60 150.80 0.00 339.49 339.30 266.26 73.04
2 19038 793 24 151.30 152.60 149.80 0.00 339.36 339.39 265.97 73.42
3 18984 791 24 149.10 151.50 148.70 0.00 339.15 339.42 265.78 73.64
4 19058 794 24 167.10 158.90 149.10 7.00 339.79 339.55 265.77 73.78
5 19071 795 24 167.30 168.00 150.00 15.30 339.61 339.56 266.12 73.44
6 19071 795 24 155.70 163.10 150.00 10.30 339.20 339.54 266.10 73.44
7 19064 794 24 147.10 153.40 150.60 0.00 338.94 339.10 265.94 73.16
8 19047 794 24 139.80 154.20 151.40 0.00 338.04 338.70 265.89 72.81
9 18530 772 24 137.90 152.80 150.00 0.00 337.39 337.61 266.05 71.56
10 17667 736 24 174.10 144.90 142.10 0.00 338.93 338.00 265.78 72.22
11 18005 750 24 166.90 154.90 141.10 11.00 339.50 339.47 265.83 73.64
12 19063 794 24 176.50 181.10 152.10 26.30 339.28 339.40 266.80 72.60
13 19070 795 24 161.80 158.60 151.70 4.10 339.53 339.51 266.73 72.78
14 19074 795 24 157.10 153.80 151.00 0.00 339.58 339.63 266.58 73.05
15 19081 795 24 159.60 164.20 151.80 9.60 339.35 339.63 266.84 72.79
16 19072 795 24 161.10 158.90 151.30 4.80 339.56 339.53 266.59 72.94
17 19069 795 24 181.50 181.20 151.40 27.10 339.66 339.63 266.75 72.88
18 19070 795 24 169.30 170.60 152.70 15.10 339.54 339.34 266.97 72.37
19 19003 792 24 177.90 173.60 150.70 20.10 339.73 339.61 266.70 72.91
20 18979 791 24 167.10 172.80 150.90 19.10 339.50 339.57 266.80 72.77
21 19011 792 24 156.80 152.70 149.90 0.00 339.57 339.51 266.25 73.26
22 19010 792 24 163.90 170.10 149.80 17.80 339.21 339.42 266.12 73.30
23 19000 792 24 191.30 188.40 150.90 35.00 339.38 339.26 266.43 72.83
24 19009 792 24 183.30 189.80 152.30 35.00 339.14 339.23 266.90 72.33
25 18994 791 24 189.00 189.50 153.10 33.90 339.06 339.24 267.25 71.99
26 18993 791 24 171.30 171.50 153.40 15.30 339.08 339.07 267.19 71.88
27 18989 791 64 176.00 174.60 152.60 18.40 339.14 339.34 267.17 72.17
28 19047 794 120 181.00 175.20 153.90 17.60 339.43 339.24 267.36 71.88
TOT530098  808        
AVG 18932 789 29 165.75 165.52 150.47 12.24 339.25 339.28 266.46 72.82
MAX 19081   191.30 189.80 153.90 35.00 339.79 339.63 267.36 73.78
MIN 17667   137.90 144.90 141.10 0.00 337.39 337.61 265.77 71.56
BUILDING STRONG®