Platte River Ecosystem Resources and Management, with Emphasis on the Big Bend Reach in Nebraska
Tables
Table 17. Instream flow shortages (thousands acre-feet (kaf)) at Grand Island sorted from highest to lowest and based upon the comparison of each monthly volume with monthly weighted USFWS instream flow recommendations (IFR) (M. Butler, USFWS, personal communication). The wet and normal years are included together because the target flows during February/March and May/June are desired 75 percent of the time and therfore includes all years except dry years. For May and June, the shortage is relative to a 3,000 cfs flow with a 30-day duration. Because the pulse flow recommendation includes a mean annual peak flow of 8,300 cfs to 10,800 cfs, the May/June shortage is based upon the mean annual pulse flow target and monthly volume.
| Oct | Nov | Dec | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Mean CFS | |
| Wet IFR, cfs | 2400 | 1700 | 1000 | 1000 | 2575 | 2724 | 2400 | 2284 | 2400 | 1200 | 1200 | 1100 | 1825 |
| Avg IFR, cfs | 1800 | 1400 | 1000 | 1000 | 2575 | 2724 | 2400 | 2284 | 2400 | 1200 | 1200 | 1100 | 1749 |
| Wet IFR, kaf | 147.0 | 101.2 | 61.5 | 61.5 | 143.0 | 167.5 | 142.8 | 140.4 | 142.8 | 73.8 | 65.5 | 147.8 | 1321.3 |
| Avg IFR, kaf | 110.7 | 83.3 | 61.5 | 61.5 | 143.0 | 167.5 | 142.8 | 140.8 | 142.8 | 73.8 | 65.5 | 147.6 | 1266.5 |
| Average Years | |||||||||||||
| Year | Oct | Nov | Dec | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Mean CFS |
| 1978 | 55.8 | 29.0 | 2.2 | 14.6 | 86.4 | 0.0 | 35.7 | 83.9 | 123.4 | 67.3 | 63.7 | 51.9 | 613.9 |
| 1976 | 66.4 | 24.3 | 0.0 | 0.0 | 37.0 | 60.8 | 44.1 | 74.1 | 123.3 | 64.5 | 72.5 | 47.0 | 613.9 |
| 1982 | 61.6 | 21.4 | 0.0 | 0.0 | 39.6 | 50.0 | 83.9 | 78.0 | 102.7 | 52.3 | 49.6 | 28.6 | 587.6 |
| 1968 | 38.1 | 3.0 | 0.0 | 0.0 | 53.6 | 75.5 | 72.7 | 88.9 | 104.1 | 57.4 | 47.6 | 22.8 | 563.7 |
| 1943 | 87.1 | 48.7 | 0.0 | 0.0 | 19.0 | 83.4 | 29.0 | 54.3 | 63.5 | 35.8 | 72.8 | 64.9 | 558.4 |
| 1944 | 99.9 | 34.6 | 12.5 | 0.0 | 60.0 | 53.6 | 5.2 | 0.0 | 102.7 | 61.1 | 70.8 | 54.8 | 555.2 |
| 1967 | 56.0 | 21.4 | 6.2 | 0.0 | 67.0 | 98.3 | 110.4 | 110.9 | 0.0 | 0.0 | 48.1 | 29.2 | 547.5 |
| 1990 | 55.0 | 28.7 | 16.9 | 0.0 | 50.4 | 43.1 | 30.6 | 34.5 | 102.0 | 64.9 | 38.4 | 49.1 | 513.6 |
| 1977 | 65.0 | 36.9 | 0.9 | 5.8 | 71.1 | 74.9 | 5.4 | 28.7 | 85.1 | 63.1 | 57.3 | 18.3 | 512.5 |
| 1989 | 48.5 | 29.3 | 0.0 | 0.0 | 49.0 | 43.7 | 98.2 | 115.3 | 85.1 | 0.0 | 39.0 | 0.0 | 508.2 |
| 1945 | 69.7 | 24.2 | 0.0 | 0.0 | 38.0 | 81.3 | 77.5 | 81.1 | 0.0 | 43.9 | 59.2 | 27.3 | 502.1 |
| 1948 | 60.4 | 18.2 | 0.0 | 0.0 | 32.0 | 0.0 | 42.1 | 92.6 | 106.3 | 54.7 | 33.1 | 55.4 | 494.6 |
| 1975 | 55.1 | 34.5 | 2.7 | 0.0 | 69.9 | 64.7 | 51.5 | 81.3 | 34.3 | 35.6 | 51.7 | 12.0 | 493.1 |
| 1965 | 69.9 | 40.5 | 14.7 | 6.9 | 83.2 | 74.5 | 74.2 | 64.1 | 0.0 | 0.0 | 68.2 | 0.0 | 486.2 |
| 1966 | 0.0 | 0.0 | 0.0 | 0.0 | 26.9 | 16.1 | 17.4 | 102.6 | 117.4 | 68.4 | 62.3 | 53.2 | 464.3 |
| 1979 | 74.3 | 35.5 | 1.7 | 10.6 | 93.3 | 2.1 | 40.1 | 66.1 | 20.5 | 0.0 | 48.6 | 45.2 | 437.9 |
| 1960 | 52.7 | 15.2 | 0.6 | 4.5 | 48.6 | 0.0 | 14.2 | 54.4 | 61.1 | 46.3 | 73.7 | 65.5 | 436.7 |
| 1950 | 42.9 | 0.0 | 0.0 | 0.0 | 34.1 | 55.5 | 36.3 | 37.4 | 98.4 | 39.6 | 55.0 | 28.8 | 428.0 |
| 1969 | 37.0 | 4.4 | 9.0 | 0.0 | 52.4 | 0.0 | 54.5 | 69.8 | 68.0 | 0.0 | 57.0 | 1.6 | 353.8 |
| 1958 | 56.5 | 18.5 | 0.0 | 0.0 | 647.0 | 37.5 | 0.0 | 1.4 | 28.5 | 9.8 | 59.1 | 60.9 | 339.1 |
| 1947 | 0.0 | 0.0 | 0.0 | 0.0 | 65.0 | 46.2 | 35.6 | 84.7 | 0.0 | 0.0 | 52.8 | 34.5 | 318.9 |
| 1962 | 48.9 | 0.0 | 0.0 | 0.0 | 24.2 | 0.0 | 64.4 | 89.9 | 5.7 | 0.0 | 43.0 | 38.7 | 314.8 |
| 1990 | 85.3 | 40.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 50.4 | 53.8 | 36.8 | 266.8 |
| 1972 | 17.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 26.2 | 0.0 | 104.9 | 56.7 | 24.4 | 32.5 | 262.2 |
| 1974 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.5 | 82.6 | 70.7 | 62.6 | 39.5 | 255.9 |
| 1949 | 76.3 | 11.8 | 0.0 | 13.4 | 52.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 58.0 | 23.8 | 235.7 |
| 1952 | 11.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 7.1 | 68.1 | 27.2 | 62.9 | 55.8 | 233.0 |
| 1988 | 7.0 | 0.0 | 0.0 | 0.0 | 0.0 | 14.0 | 28.1 | 12.8 | 112.2 | 5.4 | 25.8 | 14.8 | 220.1 |
| 1951 | 34.9 | 5.7 | 0.0 | 0.0 | 34.9 | 46.9 | 34.7 | 18..5 | 0.0 | 0.0 | 34.0 | 0.0 | 209.6 |
| 1970 | 17.4 | 0.0 | 0.0 | 0.0 | 1.0 | 25.1 | 0.0 | 27.2 | 15.9 | 0.0 | 65.0 | 20.9 | 172.4 |
| 1971 | 19.7 | 0.0 | 0.0 | 0.0 | 24.1 | 3.7 | 9.7 | 0.0 | 0.0 | 0.0 | 59.0 | 34.9 | 151.1 |
| 1985 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 4.9 | 0.0 | 61.4 | 30.5 | 23.7 | 0.0 | 120.5 |
| 1983 | 48.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 48.7 |
| 1984 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 435 | 0.0 | 43.5 |
| 1987 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 29.2 | 0.0 | 29.2 |
| 1973 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 6.2 | 0.0 | 6.2 |
| 1986 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
|
Mean shortage kaf |
41.1 |
14.2 |
1.8 |
1.5 |
34.6 |
28.4 |
30.5 |
42.2 |
50.7 |
27.2 |
47.6 |
28.3 |
348.1 |
| Dry Years | |||||||||||||
| Oct | Nov | Dec | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Mean CFS | |
|
Dry IFR, cfs |
1300 | 950 | 600 | 600 | 1725 | 1863 | 1700 | 1090 | 800 | 800 | 800 | 700 | 1072 |
|
Dry IFR, kaf |
79.9 | 56.5 | 36.9 | 36.9 | 95.8 | 114.0 | 101.2 | 67.0 | 49.6 | 49.2 | 49.2 | 41.7 | 775.8 |
| Year | Oct | Nov | Dec | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Mean CFS |
| 1956 | 74.3 | 26.8 | 0.2 | 0.0 | 40.3 | 49.5 | 57.3 | 56.6 | 46.4 | 49.1 | 49.2 | 41.7 | 491.4 |
| 1957 | 79.9 | 48.3 | 20.5 | 24.6 | 56.5 | 66.6 | 44.1 | 0.0 | 0.0 | 30.3 | 48.8 | 19.7 | 439.4 |
| 1963 | 14.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 21.8 | 410.1 | 21.7 | 48.7 | 49.2 | 8.7 | 409.3 |
| 1955 | 63.6 | 10.3 | 0.0 | 0.0 | 35.1 | 13.8 | 51.0 | 57.9 | 14.7 | 47.1 | 49.2 | 41.7 | 384.4 |
| 1954 | 72.7 | 0.0 | 0.0 | 0.0 | 0.0 | 34.5 | 49.0 | 9.9 | 31.6 | 49.2 | 43.6 | 41.2 | 331.6 |
| 1964 | 33.6 | 5.9 | 0.0 | 0.0 | 37.2 | 36.4 | 18.8 | 32.6 | 27.4 | 40.7 | 39.8 | 28.8 | 301.3 |
| 1961 | 51.6 | 10.3 | 0.0 | 0.0 | 26.3 | 38.9 | 44.1 | 0.0 | 0.0 | 43.8 | 40.7 | 33.9 | 289.6 |
| 1991 | 49.9 | 8.4 | 0.0 | 0.0 | 10.3 | 38.8 | 59.0 | 0.0 | 0.0 | 41.1 | 38.9 | 26.6 | 272.9 |
| 1981 | 43.7 | 16.8 | 0.0 | 0.0 | 30.7 | 31.2 | 52.5 | 21.9 | 31.0 | 12.1 | 0.0 | 15.8 | 255.8 |
| 1959 | 49.9 | 0.0 | 0.0 | 0.0 | 22.6 | 0.0 | 0.0 | 0.0 | 38.2 | 36.2 | 48.7 | 35.3 | 230.9 |
| 1953 | 39.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.1 | 0.0 | 15.9 | 49.2 | 49.2 | 41.7 | 212.2 |
| 1946 | 15.6 | 0.0 | 0.0 | 0.0 | 7.9 | 7.8 | 59.4 | 20.1 | 7.8 | 40.2 | 47.2 | 10.0 | 206.0 |
| 1992 | 59.7 | 4.9 | 0.0 | 0.0 | 9.6 | 0.0 | 25.7 | 43.8 | 13.2 | 1.2 | 20.9 | 19.9 | 198.9 |
|
Mean Shortage kaf |
49.9 |
10.1 |
1.6 |
1.9 |
21.3 |
24.4 |
38.5 |
21.8 |
19.1 |
37.6 |
40.4 |
27.3 |
293.8 |
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