Opinion ID: 1373013
Heading Depth: 1
Heading Rank: 4

Heading: water duty

Text: [8] [Water duty] that measure of water, which, by careful management and use, without wastage, is reasonably required to be applied to any given tract of land for such period of time as may be adequate to produce therefrom a maximum amount of such crops as ordinarily are grown thereon. It is not a hard and fast unit of measurement, but is variable according to conditions. [40] The referee based his determination of the volume of water necessary for irrigation in the Marshall Lake basin on a Washington State University Research Bulletin entitled Irrigation Requirements for Washington  Estimates and Methodology (Irrigation Report), and on the expert testimony of Jim Lyerla, the District Supervisor for seven Eastern Washington counties, including Pend Oreille County, in the Water Resources Program of the Department of Ecology. Mr. Lyerla testified that as a part of his work in assigning water quantities to new water permittees, he relied on the Irrigation Report to determine the water duty for a proposed use of water. The Irrigation Report provides information for water requirements for specific crops, given in inches per acre per irrigation season, in 40 locations around the state, including Newport, Washington, 5 miles south of Marshall Lake. Based on the testimony of Mr. Lyerla and the Irrigation Report, the referee determined that an irrigated alfalfa crop grown in the Marshall Lake area requires 21 inches or 1.75 acre feet of water per acre during the irrigation season. The referee then applied an efficiency factor and increased this water duty to 2.5 acre feet per acre per year. The referee found this water duty to be approximately commensurate with the duty utilized by the Department of Ecology in its quantity allocations in this geographic area under the water right permit system. [41] Because water rights are characterized in both total yearly allowance and instantaneous flow, the referee also established the maximum rate of diversion at 0.0166 c.f.s. per acre under irrigation. The referee first calculated a standard flow of 1 c.f.s. of water per 60 acres as a reasonable instantaneous flow for alfalfa irrigation in the Marshall Lake basin. [42] In considering the Grimeses' claim, he determined that the Grimeses were entitled to sufficient flow to irrigate 73 acres, or a minimum of 1.21 c.f.s. He then calculated in an efficiency factor to increase this flow by 25 percent and awarded the Grimeses an instantaneous flow of 1.5 c.f.s. The referee observed that a larger water duty could be awarded to any claimant with specific information proving a right to a larger amount. The 2.5 acre feet/0.0166 c.f.s. water duty was applied when quantitative evidence of the rate and volume of a right was neither submitted nor made clear during testimony. [43] The referee also observed that the use of water under all irrigation rights is, however, limited to the amount of water that can be beneficially applied to that number of acres identified in the water right. [44] The referee did not indiscriminately award this water duty to any claim for an irrigation right, but required claimants to prove the number of acres historically irrigated. [9] In water rights adjudications, the establishment of a water duty must not be disturbed in the absence of very conclusive evidence contrary to the ... adjudication, showing arbitrariness on [the] part [of the adjudicator].... [45] The referee's determination of a generic water duty for irrigation of alfalfa in the Marshall Lake basin is supported by a preponderance of the evidence and will not be disturbed by this court. [46]