US Army Corps of Engineers

Lower Granite Dam & Lake

July 2026

Day of MonthTotal Generation MWhAverage Generation MWStation Use MWhInflow kcfsTotal Outflow kcfsGeneration Flow kcfsSpill kcfsMidnight Reservoir ElevationAverage Forebay ElevationAverage Tailwater ElevationAverage Head feetMidnight Lewiston Gage ft
1 4778 199 52 47.20 44.80 26.70 17.60 736.11 735.95 634.36 101.59 736.62
2 4687 195 52 43.40 44.10 26.20 17.30 735.97 736.01 634.53 101.48 736.43
3 3876 162 52 39.90 40.70 21.70 18.40 735.80 735.83 634.49 101.34 736.16
4 2936 122 52 36.20 35.20 16.50 18.30 736.02 735.97 634.41 101.56 736.42
5 2921 122 53 35.50 34.80 16.30 18.00 736.18 736.16 634.14 102.02 736.59
6 3095 129 53 34.90 35.50 17.30 17.70 736.04 736.10 634.18 101.92 736.42
7 3361 140 51 36.80 37.10 18.80 17.50 735.92 736.02 634.20 101.82 736.29
8 3422 143 53 36.60 37.10 19.20 17.40 735.81 735.87 634.33 101.54 736.22
9 3095 129 52 34.00 35.20 17.40 17.40 735.53 735.73 634.35 101.38 735.86
10 2538 106 52 32.70 32.90 14.20 18.10 735.49 735.59 634.16 101.43 735.90
11 2187 91 53 29.90 30.40 12.20 17.60 735.37 735.45 633.99 101.46 735.83
12 2188 91 52 27.40 27.40 12.30 14.80 735.35 735.40 634.17 101.23 735.78
13 2184 91 53 27.00 26.80 12.30 14.00 735.39 735.35 634.15 101.20 735.81
14 2185 91 53 31.20 29.90 12.20 17.20 735.70 735.62 634.21 101.41 736.10
15 2514 105 53 34.70 33.30 14.00 18.80 736.01 735.90 634.25 101.65 736.38
16 3386 141 52 34.40 37.10 19.00 17.60 735.36 735.85 634.41 101.44 735.91
17 2726 114 53 34.00 33.50 15.20 17.80 735.52 735.71 634.05 101.66 736.02
18 2493 104 53 32.00 32.40 13.90 17.90 735.39 735.51 633.71 101.80 735.79
19 2187 91 53 30.40 30.80 12.20 17.90 735.29 735.33 633.80 101.53 735.73
20 2183 91 53 30.10 29.00 12.20 16.30 735.58 735.43 633.71 101.72 735.96
21 2240 93 53 30.90 29.90 12.50 16.90 735.84 735.74 633.92 101.82 736.22
22 2234 93 54 30.30 30.90 12.50 18.00 735.68 735.79 633.95 101.84 736.10
23 2181 91 54 29.10 29.10 12.20 16.30 735.68 735.72 634.05 101.67 736.13
24 2190 91 54 28.80 29.10 12.20 16.30 735.61 735.64 633.92 101.72 736.00
25 2191 91 53 27.70 28.10 12.30 15.30 735.52 735.55 634.12 101.43 736.06
26 2189 91 53 28.00 27.40 12.20 14.60 735.67 735.59 633.91 101.68 736.09
27 2180 91 53 26.70 27.30 12.20 14.60 735.52 735.59 633.98 101.61 735.91
28 2182 91 53 26.50 25.90 12.20 13.10 735.65 735.56 634.19 101.37 736.09
29 2187 91 53 25.60 25.80 12.30 13.10 735.60 735.62 634.09 101.53 736.04
30 2167 90 54 26.00 25.30 12.10 12.80 735.77 735.63 633.91 101.72 736.19
31 26.70 26.50 12.50 13.60 735.80 735.83 633.83 102.00 736.22
TOT 80884  1586         
AVG 2696 112 53 32.08 32.04 15.00 16.52 735.68 735.71 634.11 101.60 736.11
MAX 4778   47.20 44.80 26.70 18.80 736.18 736.16 634.53 102.02 736.62
MIN 2167   25.60 25.30 12.10 12.80 735.29 735.33 633.71 101.20 735.73
BUILDING STRONG®