Water Rights. Washington operates under a water right permit system. With certain exceptions, new rights to use surface or groundwater must be established according to the permit system. Exemptions include any withdrawal of public groundwater for stock watering purposes, for watering a lawn, or for a noncommercial garden less than one-half acre. Single or group domestic uses or industrial purposes not exceeding 5000 gallons a day are also exempt.
Ecology must consider a four-part test when deciding whether to issue a new water right, specifically whether:
If an application passes this test, Ecology issues a permit which establishes a timetable for constructing the infrastructure to access the water and for putting water to beneficial use. When the conditions of the permit are satisfied, Ecology issues a water right certificate.
Transfers and Changes. The water right may be transferred to other uses or places of use through a transfer or change of a surface water right or an amendment to a groundwater right. A substitute or supplementary well may also be provided at a new location under an amendment for a groundwater right. These transfers, changes, amendments, and substitute wells do not change the priority date of the original water right. However, they cannot be approved if they would interfere with existing rights, including junior rights.
Municipal Water Supply Purposes. The state water code provides a definition for the term municipal water supply purposes, and provides specific procedures relating to those water rights held for those purposes. The definition includes beneficial uses of water for residential purposes above a set number of service connections and for governmental or governmental proprietary purposes by local government. If a portion of the water in a water right is used beneficially for municipal water supply purposes, then any other beneficial use of the water that is generally associated with the municipal use is also considered a municipal water supply purpose. This includes any beneficial uses for commercial purposes, industrial purposes, irrigation of parks and open spaces, institutional purposes, landscaping, fire flow, water system maintenance and repair, or other purposes. A water right being used for municipal water supply purposes may also be considered to be beneficially used if it is used to benefit instream resources or is needed to implement an environmental obligation under a watershed plan, a habitat conservation plan, or a hydropower license.
Where an amendment to a permit or certificate of a groundwater right enables an alternate water right to be transferred in whole or in part and beneficially used by another water right holder, the amendment must preserve the terms of the alternate water right, including any aggregate limit on the amount of water withdrawn under the alternate water right and any related rights.
An alternate water right is a right that may be used either instead of or simultaneously with another identified water right or rights and where the aggregate amount of water used from all identified sources is not allowed to exceed a total authorized quantity.
Water rights for municipal supply purposes may be amended under the groundwater code to enable beneficial use within the original or another public water system.