Table 4-14. Monthly tree water use1(ac-in) at WSU Tree Fruit Research Center, 1972-2002.
YEAR | APR | MAY | JUN | JUL | AUG | SEP | OCT2 | SEASON TOTAL |
1972 | 2.03 | 5.18 | 7.47 | 9.20 | 8.03 | 4.43 | 2.00 | 38.34 |
1973 | 2.28 | 5.40 | 9.22 | 11.48 | 9.80 | 4.60 | 2.00 | 44.78 |
1974 | 1.74 | 4.57 | 8.69 | 9.21 | 8.95 | 5.21 | 2.00 | 40.37 |
1975 | 1.72 | 5.26 | 8.33 | 10.49 | 8.88 | 4.66 | 2.00 | 41.34 |
1976 | 1.84 | 2.82 | 7.86 | 10.04 | 6.71 | 4.84 | 2.00 | 36.11 |
1977 | 1.69 | 4.49 | 6.67 | 8.32 | 5.43 | 4.32 | 2.00 | 32.92 |
1978 | 1.92 | 5.18 | 8.07 | 10.20 | 8.25 | 4.63 | 2.00 | 40.25 |
1979 | 2.10 | 3.78 | 8.11 | 9.45 | 8.31 | 3.28 | 2.00 | 37.03 |
1980 | 1.66 | 4.52 | 6.25 | 9.72 | 7.06 | 3.61 | 2.00 | 34.82 |
1981 | 1.61 | 4.26 | 6.19 | 8.53 | 7.63 | 3.76 | 2.00 | 33.98 |
1982 | 1.61 | 4.60 | 7.18 | 8.06 | 6.74 | 3.22 | 2.00 | 33.41 |
1983 | 1.44 | 5.20 | 6.66 | 7.18 | 6.53 | 3.89 | 2.00 | 32.90 |
1984 | 1.47 | 3.92 | 6.42 | 9.86 | 7.89 | 3.26 | 2.00 | 34.82 |
1985 | 1.72 | 5.18 | 8.34 | 10.71 | 7.93 | 3.13 | 2.00 | 39.01 |
1986 | 1.74 | 4.65 | 7.69 | 8.56 | 7.97 | 4.08 | 2.00 | 36.69 |
1987 | 1.88 | 4.75 | 7.30 | 8.28 | 8.09 | 4.46 | 2.00 | 36.76 |
1988 | 1.56 | 4.22 | 6.38 | 10.06 | 7.57 | 4.16 | 2.00 | 35.95 |
1989 | 1.79 | 4.47 | 7.65 | 9.40 | 7.13 | 4.43 | 2.00 | 36.87 |
1990 | 1.78 | 3.91 | 6.69 | 9.39 | 6.83 | 4.55 | 2.00 | 35.15 |
1991 | 1.87 | 4.21 | 6.41 | 10.00 | 7.42 | 4.48 | 2.00 | 36.39 |
1992 | 2.08 | 6.34 | 8.58 | 8.75 | 7.65 | 4.22 | 2.00 | 39.62 |
1993 | 1.10 | 4.75 | 6.36 | 7.46 | 7.20 | 3.90 | 2.00 | 32.77 |
1994 | 1.69 | 4.74 | 8.23 | 12.41 | 8.53 | 4.67 | 2.00 | 42.27 |
1995 | 1.47 | 5.28 | 7.90 | 10.52 | 7.90 | 4.66 | 2.00 | 39.73 |
1996 | 1.53 | 4.34 | 8.54 | 11.02 | 9.58 | 4.65 | 2.00 | 41.66 |
1997 | 1.14 | 4.27 | 7.22 | 9.16 | 7.30 | 3.48 | 2.00 | 34.57 |
1998 | 1.49 | 3.66 | 7.81 | 9.52 | 8.29 | 4.75 | 2.00 | 37.52 |
1999 | 1.60 | 4.57 | 8.03 | 9.31 | 7.26 | 4.00 | 2.00 | 36.77 |
2000 | 1.65 | 4.38 | 8.02 | 9.85 | 8.56 | 3.66 | 2.00 | 38.12 |
2001 | 1.39 | 4.98 | 7.06 | 10.23 | 7.65 | 4.35 | 2.00 | 37.66 |
2002 | 1.49 | 4.12 | 7.69 | 9.83 | 7.82 | 3.81 | 2.00 | 36.76 |
MO. AVG. SINCE 1972 | 1.68 | 4.58 | 7.52 | 9.55 | 7.77 | 4.17 | 2.00 | 37.27 ac-in |
1. | Data have already been adjusted using pan evaporation KC value to approximate orchard tree water use. |
2. | The October value of 2 acre-inches was estimated based on miscellaneous October measurements provided by the WSU Tree Fruit Research Center, and conversations with Tim Smith, WSU Cooperative Extension. April through September values are based on data collected by T. Smith. |
* | Note: Actual irrigation rates must be 10 to 40% higher than tree use, depending on irrigation efficiency |
(This table is from the watershed plan, based on the State of Washington Irrigation Guide and supplemented by Washington State Tree Fruit Research data collected in Wenatchee WA.)
Table 4-15. Average monthly tree and pasture/turf irrigation water use (ac-in) estimates.
Description of Value | Apr | May | Jun | Jul | Aug | Sep | Oct | Season (ac-in) |
Average tree fruit water use by month, based on 1972-2002 WSU data. | 1.68 | 4.58 | 7.52 | 9.55 | 7.77 | 4.17 | 2.00 | 37.27 |
Average tree water use by month, with 65% application efficiency. | 2.58 | 7.05 | 11.57 | 14.69 | 11.95 | 6.42 | 3.08 | 57.34 |
Average Pasture/Turf water use by month (85% of WSU tree fruit water use avg. value). | 1.43 | 3.89 | 6.39 | 8.12 | 6.60 | 3.54 | 1.70 | 31.68 |
Average Pasture/Turf water use by month, with 65% efficiency. | 2.20 | 5.99 | 9.83 | 12.49 | 10.16 | 5.45 | 2.62 | 48.74 |
(This table is from the watershed plan, based on the State of Washington Irrigation Guide and supplemented by Washington State Tree Fruit Research data collected in Wenatchee WA.)
Wash. Admin. Code § 173-546-070
Statutory Authority: Chapters 43.27A, 90.54, 90.22, and 90.82 RCW. 05-16-114 (Order 04-11), § 173-546-070, filed 8/3/05, effective 9/3/05.