US Army Corps of Engineers

John Day & Lake Umatilla

August 2026

Day of MonthTotal Generation MWhAverage Generation MWStation Use MWhInflow kcfsTotal Outflow kcfsGeneration Flow kcfsSpill kcfsMidnight Reservoir ElevationAverage Forebay ElevationAverage Tailwater ElevationAverage Head feet
1 15302 638 38 131.50 126.50 83.10 42.10 263.62 263.47 160.34 103.13
2 14581 608 37 134.20 124.40 78.90 44.10 264.02 263.85 160.35 103.50
3 14338 597 39 117.10 122.00 77.60 42.90 263.52 263.91 160.39 103.52
4 14247 594 39 118.60 121.10 77.00 42.90 263.72 263.67 159.91 103.76
5 15563 648 38 133.70 128.80 84.30 43.00 263.91 263.76 160.18 103.58
6 16010 667 42 130.50 132.90 86.70 45.10 263.82 263.90 160.40 103.50
7 15144 631 39 125.20 130.10 81.90 47.10 263.62 263.74 160.16 103.58
8 14871 620 38 129.60 127.20 80.00 46.00 263.71 263.71 159.51 104.20
9 14872 620 38 116.40 126.30 80.10 45.00 263.32 263.62 159.57 104.05
10 13980 583 40 123.30 118.50 75.40 41.90 263.32 263.44 159.57 103.87
11 6576 274 15 123.30 137.90 94.90 41.90 263.32 263.31 159.94 103.37
12 14483 603 39 118.20 120.70 78.30 40.90 263.21 263.41 159.74 103.67
13 13858 577 39 123.10 118.10 75.10 41.90 263.41 263.43 160.00 103.43
14 13032 543 39 122.40 112.50 70.00 41.10 263.82 263.71 159.76 103.95
15 15303 638 38 119.90 122.50 82.10 39.00 263.71 263.93 159.76 104.17
16 13742 573 38 118.40 118.40 74.00 43.00 263.71 263.86 159.75 104.11
17 13437 560 38 117.40 114.80 72.60 41.00 263.82 263.90 160.23 103.67
18 13357 557 41 113.10 113.10 71.90 40.00 263.82 263.96 160.05 103.91
19 13571 565 41 115.10 115.10 73.50 40.00 263.82 263.89 160.54 103.35
20 14078 587 42 117.30 117.30 75.80 40.10 263.82 263.97 159.88 104.09
21 13823 576 42 114.10 116.60 74.30 41.00 263.71 263.96 159.81 104.15
22 13908 579 42 114.40 116.80 74.70 40.90 263.62 263.88 159.57 104.31
23 10685 445 40 105.10 100.10 57.90 40.90 263.82 263.70 160.03 103.67
24 13023 543 41 111.40 106.40 70.10 35.00 264.02 264.04 160.12 103.92
25 15535 647 42 117.10 122.10 83.80 37.00 263.82 263.94 160.18 103.76
26 15451 644 41 128.60 128.60 84.00 43.10 263.82 263.88 160.52 103.36
27 12198 508 41 122.60 112.40 66.20 45.00 264.21 263.92 160.13 103.79
28 17271 720 41 119.20 134.30 94.00 38.90 263.62 264.02 160.92 103.10
29 9531 397 40 101.60 96.70 51.60 43.80 263.82 263.67 159.86 103.81
30 11239 468 40 91.30 96.20 61.00 33.90 263.62 263.61 159.91 103.70
31 11365 474 40 86.90 96.90 61.90 33.90 263.21 263.54 160.14 103.40
TOT424374  1210        
AVG 13689 570 39 118.08 118.56 75.89 41.37 263.69 263.76 160.04 103.72
MAX 17271   134.20 137.90 94.90 47.10 264.21 264.04 160.92 104.31
MIN 6576   86.90 96.20 51.60 33.90 263.21 263.31 159.51 103.10
BUILDING STRONG®