Odessa subarea study evaluates water wells

SPOKANE VALLEY — The U.S. Dept. of Agriculture Natural Resources Conservation Service – Washington has adopted the 2012 Odessa Subarea Special Study Final Environmental Impact Statement produced by the Bureau of Reclamation in cooperation with the state Dept. of Ecology.

NRCS-WA issued a Record of Decision that selects Alternative 4A, the same alternative that was selected in the Reclamation 2013 decision for the impact statement. East Columbia Basin Irrigation District in partnership with Reclamation, Ecology, and NRCS-WA will base the development of a watershed plan under the Watershed Protection and Flood Prevention Program authorized by Public Law 83-566 on the existing impact statement.

With an Authorized Watershed Plan, the Irrigation District will be eligible to pursue NRCS 83-566 funding to support the phased implementation of the distribution systems needed to supply surface water to eligible lands currently irrigated with groundwater under the Odessa Groundwater Replacement Program.

Located in Central Washington, the district is the largest irrigation district in the state, with authorization to irrigate 472,000 acres. Currently, 169,000 acres are developed and managed by 4,500 landowners within the federal Columbia Basin Project.

The impact statement analyzed the potential to replace groundwater irrigation on up to 102,600 acres of land in the Odessa Subarea with surface water from the project. The alternatives put forward in the FEIS analyzed the potential to replace groundwater irrigation on a range of acreages (up to 102,600 acres) with varying diversion amounts of project surface water (up to 273,000 acre-feet).

The Odessa Subarea aquifer is experiencing significant declines in groundwater levels. Domestic, commercial, municipal and industrial uses, as well as water quality, are also affected. Many of the groundwater wells in the area are currently drilled to a depth of 800 to 1,000 feet, with some as deep as 2,100 feet.

Some wells in the area have been reported out of production. Drilling deeper wells is not feasible because deeper water may not be available, may be potentially unusable, or may be too expensive to access.

As a result of this decline, the ability of producers to irrigate their crops is at risk.

The Reclamation 2013 decision and the NRCS-WA 2024 decision identify Alternative 4A: Partial Modified-Replacement-Banks with Limited Spring Diversion Scenario as the selected alternative.

Alternative 4A seeks to replace acre-for-acre groundwater irrigation on 70,000 acres in the Odessa Subarea with 164,000 acre-feet of new Columbia River diversions. Since Reclamation published the FEIS in 2012, the Odessa Groundwater Replacement Program, a consortium of local, state and federal partners, has worked towards phased implementation of Alternative 4A.