US Army Corps of Engineers

Lower Granite Dam & Lake

March 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 5559 232 48 33.50 32.80 31.10 1.60 736.61 736.55 636.79 99.76 736.89
2 5852 244 49 32.70 32.90 32.80 0.00 736.54 736.68 636.81 99.87 736.61
3 5515 230 49 32.10 32.60 31.00 1.50 736.38 736.37 636.91 99.46 736.62
4 5871 245 48 32.80 33.10 33.00 0.00 736.27 736.36 636.86 99.50 736.42
5 6962 290 48 40.10 41.00 39.40 1.40 736.05 736.02 637.18 98.84 736.22
6 6706 279 47 39.90 37.90 37.80 0.00 736.62 736.44 637.19 99.25 736.76
7 6563 273 46 36.80 36.90 36.80 0.00 736.56 736.61 637.14 99.47 736.80
8 5834 243 44 35.70 36.00 34.30 1.60 736.50 736.37 637.05 99.32 736.71
9 7019 292 48 35.10 39.90 39.80 0.00 735.48 735.85 637.03 98.82 735.54
10 5891 245 49 37.20 34.70 33.20 1.50 736.11 735.71 636.30 99.41 736.05
11 6857 286 48 39.30 38.70 38.50 0.00 736.27 735.95 636.34 99.61 736.34
12 7549 315 48 42.00 43.80 41.80 1.60 735.55 736.31 635.39 100.92 735.84
13 11054 461 49 59.90 62.30 61.90 0.00 735.03 735.08 635.24 99.84 735.47
14 15670 653 49 93.40 88.80 88.40 0.00 736.21 735.45 636.42 99.03 736.70
15 15764 657 48 85.50 91.80 89.90 1.50 734.62 735.52 637.28 98.24 735.19
16 72.80 65.70 65.30 0.00 736.43 735.31 637.12 98.19 736.67
17 62.80 63.50 61.40 1.60 736.03 736.62 637.18 99.44 736.42
18 58.70 60.40 60.00 0.00 735.85 735.84 636.65 99.19 736.12
19 60.90 62.90 61.10 1.40 735.21 735.63 635.44 100.19 735.63
20 62.80 61.40 60.90 0.00 735.63 735.24 635.39 99.85 736.02
21 65.40 61.20 51.70 9.10 736.65 736.24 634.28 101.96 737.08
22 72.40 75.70 66.00 9.20 735.75 736.30 634.98 101.32 736.17
23 736.24 736.60
24
25
26
27
28
29
30
31
TOT118665  721         
AVG 7911 330 48 51.45 51.55 49.82 1.45 736.03 736.02 636.41 99.61 736.30
MAX 15764   93.40 91.80 89.90 9.20 736.65 736.68 637.28 101.96 737.08
MIN 5515   32.10 32.60 31.00 0.00 734.62 735.08 634.28 98.19 735.19
BUILDING STRONG®