Header for Water Supply Period Rankings Page

Select Period:

COLUMBIA - GRAND COULEE DAM   (GCDW1)
Period Rankings - 1960 to 2017
APR-SEP Normal -- 60110 (KAF)
Rank Year Period Volume
(KAF)
Percent of Normal Exceedance
Probability*
1 1974 88474.10 147 1.724 %
2 1997 88294.97 147 3.448 %
3 1972 85404.26 142 5.172 %
4 2012 82810.00 138 6.897 %
5 1976 81920.80 136 8.621 %
6 2011 78743.00 131 10.345 %
7 1971 77954.04 130 12.069 %
8 1996 75486.72 126 13.793 %
9 1969 74722.00 124 15.517 %
10 1999 74534.72 124 17.241 %
11 1982 74356.03 124 18.966 %
12 1967 74009.00 123 20.690 %
13 1991 73375.53 122 22.414 %
14 1961 72214.00 120 24.138 %
15 1964 70846.00 118 25.862 %
16 1965 69973.00 116 27.586 %
17 1990 69101.64 115 29.310 %
18 1981 68588.25 114 31.034 %
19 2002 68483.23 114 32.759 %
20 1975 68089.58 113 34.483 %
21 1978 67771.78 113 36.207 %
22 2014 66104.00 110 37.931 %
23 2013 65121.00 108 39.655 %
24 1983 63879.35 106 41.379 %
25 1968 63755.00 106 43.103 %
26 2006 63719.94 106 44.828 %
27 1966 63228.00 105 46.552 %
28 1962 63098.00 105 48.276 %
29 2008 62764.56 104 50.000 %
30 2017 62276.20 104 51.724 %
31 1984 61660.49 103 53.448 %
32 2000 61539.89 102 55.172 %
33 1980 61149.47 102 56.897 %
34 2007 59675.67 99 58.621 %
35 1998 58686.29 98 60.345 %
36 1963 58517.00 97 62.069 %
37 1986 57679.84 96 63.793 %
38 1989 57565.64 96 65.517 %
39 1995 57341.10 95 67.241 %
40 1985 54722.55 91 68.966 %
41 1970 54718.00 91 70.690 %
42 2016 54651.43 91 72.414 %
43 2004 54259.75 90 74.138 %
44 1993 52691.82 88 75.862 %
45 1979 52482.46 87 77.586 %
46 2003 52407.76 87 79.310 %
47 1994 51883.03 86 81.034 %
48 2005 51724.41 86 82.759 %
49 2010 51372.41 85 84.483 %
50 2009 50989.86 85 86.207 %
51 1988 50917.33 85 87.931 %
52 1987 50128.10 83 89.655 %
53 1973 47144.63 78 91.379 %
54 2015 46129.00 77 93.103 %
55 1992 45644.81 76 94.828 %
56 1977 41230.32 69 96.552 %
57 2001 39832.82 66 98.276 %

*Exceedance Probability: The probability that a specific seasonal volume will be exceeded.