Odessa Subarea Special Study

The Odessa Subarea Special Study is investigating the possibility of continued phased development of the Columbia Basin Project to deliver surface water from the Project to lands currently using groundwater in the Odessa Subarea. The aquifer in the Odessa Subarea is declining to such an extent that the ability of farmers to irrigate their crops is at risk. Domestic, commercial, municipal, and industrial uses and water quality are also affected. In response to the State of Washington’s and the public’s concern about the declining aquifer and associated socioeconomic effects, Congress has authorized funding for Reclamation to investigate the problem. The State of Washington, represented by the Department of Ecology, with the Bureau of Reclamation, are co-leads and cost-share partners in the Odessa Subarea Special Study. The co-leads jointly prepared and released to the public a Draft Environmental Impact Statement (EIS) on October 26, 2010, in compliance with both National Environmental Policy Act (NEPA) and State Environmental Policy Act (SEPA) requirements.

What alternatives will Reclamation investigate?
Reclamation and Ecology have identified alternatives through public scoping, appraisal study, and public hearing processes. In addition to the No Action Alternative, six action alternatives are evaluated in the Final EIS—two partial groundwater replacement alternatives, two full groundwater replacement alternatives, and two modified partial groundwater replacement alternatives. The alternatives utilize two water supply options and two diversion scenarios. The Final EIS addresses impacts of these alternatives on environmental, economic, and social resources in the Odessa Subarea. Resources likely to be impacted from the alternatives include agriculture, power production, fisheries, municipal water supply, industrial water supply, water quality, wildlife, and transportation.

The partial-replacement alternatives include an expanded East Low Canal (ELC) with a 2.5-mile extension that would provide surface water to approximately 57,000 acres south of Interstate-90 (I-90) and east of the ELC by a system of pipe laterals and pumping plants.

The full-replacement alternatives would provide surface water to approximately 102,600 acres currently irrigated with groundwater north of I-90 and east of the ELC. These alternatives include construction to expand and extend the ELC as described above, construction of the East High Canal from above Billy Clapp Lake to a point about 15 miles east of Moses Lake, construction of a Black Rock reregulation reservoir, and construction of the Black Rock Branch Canal from the proposed Black Rock reregulating reservoir to about 21 miles east of Moses Lake, Washington. Water would be delivered via a system of pumping plants and pressurized pipe laterals to irrigate land from Billy Clapp Lake to I-90.

The modified partial-replacement alternatives combine components of the partial- and full-replacement alternatives to fully utilize existing irrigation infrastructure. Water would be conveyed by the expanded East Low Canal only, without the 2.5-mile extension. Approximately 70,000 acres of land east of the ELC would be served both north (25,000 acres) and south (45,000 acres) of I-90 with Project water by a system of pressurized pipe laterals and pumping plants.

Water supply options include an additional drawdown of Banks Lake (up to 10 feet), use of additional water from Lake Roosevelt, or combinations of both reservoirs.

The two diversion scenarios include:

  • Spring Diversions Scenario—Diversions from the Columbia River of up to 2,700 cfs in October would be allowed. Additional diversions of up to 350 cfs could occur November-March to refill Banks Lake and/or Lake Roosevelt. Diversions occur when flows in the Columbia River exceed flow objectives.
  • Limited Spring Diversions Scenario—Diversions in October of up to 2,700 cfs would be allowed. Additional diversions could occur November-March to refill Banks Lake and/or Lake Roosevelt. Diversions in April-June may occur, but only less than 10 percent of the time.

The alternatives have been selected to:

  • Reduce groundwater pumping from the Odessa Subarea aquifer,
  • Maximize the use of existing infrastructure capabilities, and
  • Retain the possibility of full Columbia Basin Project development in the future.

What is the study area?
The study will focus on lands currently irrigated with groundwater in Adams and Grant Counties and small portions of Lincoln and Franklin Counties. The Study Area is within the Columbia Basin Project boundary and is generally defined by the area bounded on the west by the Project’s East Low Canal, on the east by the City of Lind, extending north to Wilson Creek and south to the Connell area. Previous Reclamation studies have determined that these lands have irrigation development potential. The Study Area is located within the Odessa Ground Water Subarea as designated by the Washington State Department of Ecology.

What documents will be prepared?
Reclamation has prepared several technical reports and other documents describing the decision making process. Final technical reports and a Final Special Study Report that descirbes the alternatives considered and displays a feasibility-level cost estimate and economic analysis required by Federal law and policy will be published in addition to the Final EIS. The economic portion of the Special Study Report consists of a benefit-cost analysis and a regional economic impact analysis. A fish and Wildlife Coordination Act Report is included in the Final EIS.

What is the timeframe for the study?
Reclamation and Ecology released the Final EIS August 21, 2012. The Final EIS includes a Volume 2, which consists of all comment letters received on the Draft EIS, and Reclamation and Ecology’s responses to those comments.

Reclamation’s Columbia Basin Project
The Columbia Basin Project, located in central Washington, was authorized for the irrigation of 1,029,000 acres. Currently, the Project serves about 671,000 acres in Lincoln, Adams, Grant, and Franklin Counties. The multipurpose project provides irrigation, power production, flood control, municipal water supply, recreation, and fish and wildlife benefits. Irrigated acreage was developed primarily in the 1950s and 1960s, with some acreage added until 1985.


Wendy Christensen
(509) 575-5848 x 203

Bureau of Reclamation
Pacific Northwest Region
Columbia-Cascades Area Office
1917 Marsh Road
Yakima, WA 98901-2058

Last Updated: 2/26/16