US Army Corps of Engineers

Bonneville Dam & Lake on Columbia River

September 2021

Day of MonthTotal Generation MWhAverage Generation MWStation Use MWhInflow kcfsTotal Outflow kcfsGeneration Flow kcfsSpill kcfsMidnight Reservoir ElevationAverage Forebay ElevationAverage Tailwater ElevationAverage Head feetProject Average Tailwater2nd Powerhouse Total MWh2nd Powerhouse Flow kcfs
1 10639 443 96 108.00 101.00 91.40 2.00 75.00 74.80 8.90 65.90 9.00 8693 75.30
2 10840 452 96 101.90 100.90 92.20 1.30 75.10 75.00 8.90 66.10 9.00 8730 74.80
3 10165 424 96 100.30 93.30 85.30 0.60 75.90 75.30 8.30 67.00 8.50 8142 68.80
4 9738 406 96 87.60 90.60 81.80 1.40 75.60 75.30 8.30 67.00 8.40 7663 64.90
5 9338 389 96 84.20 87.20 78.40 1.40 75.10 75.40 8.20 67.20 8.40 7323 62.00
6 8570 357 96 86.40 80.40 71.60 1.40 75.70 75.20 7.80 67.40 8.00 6334 53.50
7 9142 381 96 83.80 84.80 76.00 1.40 75.70 75.50 7.90 67.60 8.20 6943 57.90
8 9672 403 96 94.10 90.10 81.30 1.40 76.10 75.40 8.50 66.90 8.70 7661 64.90
9 10938 456 96 98.40 101.40 92.60 1.40 75.80 75.90 9.40 66.50 9.50 8815 75.30
10 8622 359 96 84.70 80.70 71.90 1.40 76.30 76.00 8.10 67.90 8.40 6568 55.30
11 8086 337 96 75.70 75.70 66.90 1.40 76.20 76.10 7.50 68.60 7.60 7262 60.10
12 8103 338 96 69.20 76.20 67.40 1.40 75.50 75.90 7.60 68.30 7.50 8039 66.60
13 9322 388 96 92.60 88.60 78.80 1.40 75.90 75.60 8.20 67.40 8.20 9260 78.00
14 9695 404 96 93.10 91.10 82.30 1.40 76.10 75.90 8.50 67.40 8.50 9632 81.50
15 7920 330 96 73.80 74.80 66.00 1.40 76.00 75.70 7.40 68.30 7.30 7857 65.20
16 8711 363 96 80.20 81.20 72.50 1.40 75.90 76.00 7.50 68.50 7.40 8646 71.70
17 9300 388 96 85.50 87.50 78.70 1.30 75.80 75.60 8.20 67.40 8.10 9238 77.90
18 9061 378 96 86.00 86.00 77.30 1.30 75.80 75.60 8.50 67.10 8.50 8999 76.50
19 8125 339 96 74.10 77.10 68.40 1.30 75.50 75.60 8.10 67.50 8.00 8062 67.70
20 96.40 94.40 85.60 1.30 75.70 75.50 9.00 66.50 9.00 84.80
21 91.50 93.50 84.80 1.30 75.50 75.40 8.80 66.60 8.80 84.00
22 87.80 83.80 75.10 1.30 75.80 75.30 8.30 67.00 8.30 74.30
23 92.30 92.30 83.60 1.30 75.80 75.70 8.70 67.00 8.70 82.80
24 104.00 105.00 96.30 1.30 75.70 75.20 9.50 65.70 9.50 95.50
25 98.60 103.60 94.90 1.30 75.20 75.20 9.60 65.60 9.60 94.10
26 82.10 80.10 71.40 1.30 75.50 74.90 7.90 67.00 7.90 70.60
27
28
29
30
TOT175987  1824           
AVG 9262 386 96 88.93 88.51 79.71 1.35 75.70 75.50 8.37 67.13 8.42 8098 72.46
MAX 10938   108.00 105.00 96.30 2.00 76.30 76.10 9.60 68.60 9.60 9632 95.50
MIN 7920   69.20 74.80 66.00 0.60 75.00 74.80 7.40 65.60 7.30 6334 53.50