US Army Corps of Engineers

Lower Granite Dam & Lake

February 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 4752 198 16 28.50 26.80 26.80 0.00 736.45 736.53 635.92 100.61 736.35
2 5063 211 17 27.70 28.60 28.60 0.00 736.22 736.31 636.59 99.72 736.90
3 5043 210 16 27.20 28.60 28.50 0.00 735.87 736.49 636.67 99.82 736.09
4 4250 177 16 27.10 24.10 24.10 0.00 736.63 736.28 636.88 99.40 736.66
5 4651 194 16 26.00 26.50 26.40 0.00 736.48 736.72 636.91 99.81 736.64
6 4249 177 16 25.20 24.30 24.20 0.00 736.72 736.60 636.80 99.80 736.85
7 4939 206 16 25.10 28.10 28.00 0.00 735.92 736.46 636.76 99.70 735.95
8 4565 190 16 24.30 26.30 26.20 0.00 735.46 735.75 636.76 98.99
9 4572 190 16 25.70 26.30 26.20 0.00 735.29 735.49 636.67 98.82 736.10
10 4997 208 16 31.70 28.50 28.30 0.00 736.06 735.78 636.63 99.15 736.30
11 4900 204 16 29.40 28.50 28.10 0.00 736.27 736.05 637.26 98.79 736.25
12 5384 224 17 29.50 30.50 30.40 0.00 736.03 735.87 636.26 99.61 736.18
13 4579 191 17 28.40 26.10 25.90 0.00 736.65 736.42 635.79 100.63 736.92
14 4945 206 16 30.20 30.00 29.90 0.00 736.69 737.05 636.19 100.86 736.80
15 4855 202 16 27.10 27.80 27.70 0.00 736.48 736.83 636.58 100.25 736.56
16 4776 199 16 28.30 27.10 26.90 0.00 736.85 736.68 636.30 100.38 737.04
17 6066 253 34 30.10 35.00 34.60 0.00 735.57 736.28 635.52 100.76 735.56
18 4431 185 49 29.80 25.50 25.30 0.00 736.68 735.95 636.41 99.54 736.76
19 5487 229 49 30.00 31.30 31.00 0.00 736.30 736.49 636.87 99.62 736.54
20 5076 211 49 28.40 28.70 28.60 0.00 736.19 736.13 635.94 100.19 736.40
21 4723 197 54 27.60 26.60 26.50 0.00 736.49 736.36 635.99 100.37 736.65
22 4280 178 49 24.00 24.30 24.20 0.00 736.43 736.41 635.83 100.58 736.45
23 4977 207 30 25.40 28.00 27.90 0.00 735.78 736.06 635.65 100.41 735.85
24 5654 236 22 31.90 31.90 31.80 0.00 735.77 735.95 635.65 100.30 736.01
25 5973 249 37 38.50 35.10 35.00 0.00 736.61 736.12 635.63 100.49 736.85
26 6819 284 50 41.40 40.00 39.90 0.00 737.20 736.98 636.47 100.51 737.21
27 6578 274 49 40.60 40.40 40.30 0.00 737.21 737.21 636.63 100.58 737.25
28 6769 282 49 37.60 39.70 39.60 0.00 736.45 737.03 636.33 100.70 736.73
TOT143352  781         
AVG 5120 213 28 29.52 29.45 29.32 0.00 736.31 736.37 636.35 100.01 736.51
MAX 6819   41.40 40.40 40.30 0.00 737.21 737.21 637.26 100.86 737.25
MIN 4249   24.00 24.10 24.10 0.00 735.29 735.49 635.52 98.79 735.56
BUILDING STRONG®