US Army Corps of Engineers

McNary Dam & Lake Wallula

March 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 19053 794 120 167.70 167.20 153.30 10.30 339.49 339.52 267.37 72.15
2 18967 790 120 164.70 165.90 152.10 10.30 339.45 339.53 267.19 72.34
3 19060 794 120 163.10 165.40 153.30 10.10 339.33 339.32 267.16 72.16
4 19031 793 120 158.70 159.00 153.00 4.20 339.28 339.31 267.17 72.14
5 19039 793 120 148.00 155.20 153.50 0.00 338.89 339.07 267.08 71.99
6 19045 794 120 154.80 157.20 153.70 1.80 338.88 338.73 266.81 71.92
7 19051 794 120 177.20 162.40 152.30 8.40 339.55 339.39 266.93 72.46
8 18244 760 115 182.40 185.80 153.50 30.60 339.30 339.57 267.60 71.97
9 19044 794 120 162.50 171.70 154.60 15.40 338.90 338.98 267.39 71.59
10 19048 794 120 157.50 165.70 154.60 9.40 338.47 338.71 267.10 71.61
11 19030 793 120 172.30 171.10 155.10 14.30 338.39 338.36 266.98 71.38
12 19018 792 120 191.40 182.30 155.50 25.10 338.91 338.50 267.27 71.23
13 19067 794 120 204.60 201.90 154.00 46.30 339.07 339.16 267.27 71.89
14 19003 792 120 234.10 232.30 155.60 74.90 339.26 339.30 268.20 71.10
15 249.60 244.10 155.70 86.70 339.55 339.55 268.57 70.98
16 209.50 217.10 154.50 60.90 339.13 339.47 267.99 71.48
17 167.70 181.40 155.20 24.40 338.40 338.68 267.44 71.24
18 191.20 176.60 155.30 19.60 339.27 338.60 267.37 71.23
19 198.90 187.40 153.20 32.50 339.69 339.55 267.38 72.17
20 213.20 215.50 155.00 58.80 339.70 339.50 268.03 71.47
21 236.60 240.70 155.60 83.30 339.40 339.68 268.58 71.10
22 339.60
23
24
25
26
27
28
29
30
31
TOT265698  1675        
AVG 18978 791 120 185.99 186.00 154.22 29.87 339.18 339.17 267.47 71.70
MAX 19067   249.60 244.10 155.70 86.70 339.70 339.68 268.58 72.46
MIN 18244   148.00 155.20 152.10 0.00 338.39 338.36 266.81 70.98
BUILDING STRONG®