US Army Corps of Engineers

John Day & Lake Umatilla

December 2025

Day of MonthTotal Generation MWhAverage Generation MWStation Use MWhInflow kcfsTotal Outflow kcfsGeneration Flow kcfsSpill kcfsMidnight Reservoir ElevationAverage Forebay ElevationAverage Tailwater ElevationAverage Head feet
1 21871 911 46 130.90 118.00 116.90 0.00 264.62 264.33 159.91 104.42
2 22488 937 48 128.50 120.70 119.60 0.00 264.92 264.66 159.62 105.04
3 22928 955 47 127.90 122.70 121.30 0.00 265.12 265.05 159.53 105.52
4 24099 1004 46 124.70 130.20 129.00 0.00 264.82 264.89 160.60 104.29
5 25005 1042 47 112.40 135.60 134.60 0.00 264.02 264.56 160.91 103.65
6 26254 1094 46 152.90 142.80 141.70 0.00 264.39 264.20 160.89 103.31
7 25781 1074 45 132.90 140.40 139.30 0.00 264.12 264.09 160.85 103.24
8 24605 1025 48 139.50 134.30 133.10 0.00 264.32 264.05 160.83 103.22
9 23705 988 47 128.60 128.60 127.60 0.00 264.32 264.23 160.50 103.73
10 27219 1134 45 158.70 148.30 147.10 0.00 264.72 264.48 161.17 103.31
11 27895 1162 44 156.60 151.50 150.40 0.00 264.92 264.69 161.15 103.54
12 30777 1282 45 174.50 166.60 165.60 0.00 265.22 265.08 161.43 103.65
13 31511 1313 46 186.00 178.20 167.70 9.30 265.50 265.36 160.64 104.72
14 31701 1321 47 187.30 179.50 168.40 10.00 265.82 265.64 160.68 104.96
15 31936 1331 46 158.90 174.50 170.50 2.90 265.22 265.53 161.15 104.38
16 32716 1363 46 166.30 179.30 176.20 1.90 264.72 264.95 161.41 103.54
17 32967 1374 49 173.50 182.20 178.50 2.70 264.32 264.42 161.84 102.58
18 37240 1552 49 197.80 225.50 204.10 20.20 263.21 263.74 161.92 101.82
19 36924 1539 49 212.30 212.30 204.60 6.70 263.21 263.18 162.61 100.57
20 37169 1549 49 197.20 207.10 205.90 0.00 262.81 263.02 162.47 100.55
21 36029 1501 49 198.50 200.90 199.60 0.00 262.71 262.76 162.25 100.51
22 35420 1476 49 211.00 196.10 195.10 0.00 263.32 263.07 162.01 101.06
23 33927 1414 49 201.00 186.10 185.20 0.00 263.91 263.44 161.65 101.79
24 34146 1423 47 190.60 185.40 184.50 0.00 264.12 264.02 161.29 102.73
25 35095 1462 49 196.00 190.80 189.70 0.00 264.32 264.26 161.57 102.69
26 35415 1476 48 189.90 192.50 191.70 0.00 264.21 264.27 161.71 102.56
27 35432 1476 49 202.60 192.10 191.10 0.00 264.62 264.57 161.61 102.96
28 37628 1568 49 207.70 205.10 204.00 0.00 264.72 264.55 162.08 102.47
29 37967 1582 49 207.70 207.70 206.60 0.00 264.72 264.76 162.41 102.35
30 34952 1456 51 191.80 191.10 189.90 0.00 264.74 264.73 162.36 102.37
31 35439 1477 51 200.20 193.00 192.00 0.00 265.02 265.00 162.21 102.79
TOT966243  1473        
AVG 31169 1299 48 172.40 171.58 168.76 1.73 264.41 264.37 161.33 103.04
MAX 37967   212.30 225.50 206.60 20.20 265.82 265.64 162.61 105.52
MIN 21871   112.40 118.00 116.90 0.00 262.71 262.76 159.53 100.51
BUILDING STRONG®