US Army Corps of Engineers

Lower Granite Dam & Lake

December 2025

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 4045 169 48 20.40 24.30 23.80 0.00 735.90 736.55 636.57 99.98 736.15
2 2755 115 48 17.70 16.10 15.70 0.00 736.38 736.33 636.30 100.03 736.49
3 3071 128 48 17.70 18.10 17.50 0.00 736.28 736.32 636.30 100.02 736.40
4 3434 143 48 18.70 20.10 19.70 0.00 735.92 736.00 636.01 99.99 735.95
5 3650 152 48 18.00 21.40 20.90 0.00 735.07 735.41 635.53 99.88 735.47
6 3095 129 47 18.60 18.10 17.70 0.00 735.19 735.20 635.63 99.57 735.49
7 3187 133 47 21.20 18.60 18.20 0.00 735.85 735.49 635.37 100.12 736.00
8 4843 202 47 21.10 28.30 27.70 0.00 734.07 735.42 635.17 100.25 735.16
9 4279 178 47 23.20 25.10 24.60 0.00 733.60 733.79 634.16 99.63 733.95
10 6757 282 46 38.50 39.40 39.00 0.00 733.38 733.67 634.29 99.38 733.83
11 7260 302 46 43.00 42.30 41.70 0.00 733.56 733.83 634.14 99.69 734.10
12 7898 329 46 48.00 45.80 45.30 0.00 734.11 733.63 633.69 99.94 734.08
13 8309 346 47 49.40 47.60 47.20 0.00 734.57 734.65 633.67 100.98 734.79
14 7470 311 47 39.40 43.40 42.90 0.00 733.57 734.42 633.69 100.73 734.43
15 5383 224 47 36.90 31.00 30.50 0.00 735.04 734.43 633.53 100.90 735.16
16 6285 262 47 34.70 36.20 35.70 0.00 734.67 734.96 633.82 101.14 735.11
17 5173 216 48 35.50 32.40 29.50 2.50 735.44 735.53 634.20 101.33 735.83
18 8013 334 48 40.20 46.00 45.60 0.00 734.00 735.30 634.25 101.05 735.12
19 7015 292 48 45.00 40.10 39.60 0.00 735.20 734.64 634.48 100.16 735.40
20 8247 344 47 50.60 46.70 46.30 0.00 736.17 735.92 635.95 99.97 735.40
21 7961 332 47 41.60 44.80 44.40 0.00 735.38 736.09 635.89 100.20 735.40
22 7454 311 47 39.80 42.60 42.20 0.00 734.68 735.46 636.37 99.09 735.40
23 6832 285 47 39.60 39.70 39.20 0.00 734.65 734.78 636.21 98.57 735.40
24 5193 216 47 38.70 29.90 29.50 0.00 736.82 736.51 636.08 100.43 737.10
25 6746 281 47 37.50 38.50 38.10 0.00 736.58 735.80 636.49 99.31 737.00
26 7334 306 47 44.00 41.70 41.30 0.00 737.14 736.42 636.66 99.76 737.48
27 9302 388 48 53.30 53.00 52.60 0.00 737.20 737.36 637.15 100.21 737.70
28 9797 408 49 52.00 55.60 55.20 0.00 736.32 736.68 637.35 99.33 737.10
29 7659 319 49 44.00 43.50 43.10 0.00 736.46 736.34 636.96 99.38 736.82
30 6860 286 49 37.80 39.10 38.70 0.00 736.12 736.09 636.57 99.52 736.08
31 6652 277 50 36.70 38.40 38.00 0.00 735.69 735.83 636.40 99.43 736.21
TOT191959  1473         
AVG 6192 258 48 35.57 35.74 35.21 0.08 735.32 735.45 635.45 100.00 735.68
MAX 9797   53.30 55.60 55.20 2.50 737.20 737.36 637.35 101.33 737.70
MIN 2755   17.70 16.10 15.70 0.00 733.38 733.63 633.53 98.57 733.83
BUILDING STRONG®