Odessa Subarea Special Study

What was the selected alternative?
Reclamation and Ecology identified alternatives through public scoping, an appraisal study, and a public hearing process. In addition to the No Action Alternative, six action alternatives were evaluated in the final environmental impact statement—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 FEIS analyzed impacts to environmental, economic, and social resources in the Odessa Subarea. Resources likely 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 with a 2.5-mile extension providing surface water to approximately 57,000 acres south of Interstate-90 and east of the ELC by a system of pipe laterals and pumping plants.

The full-replacement alternatives 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 above Billy Clapp Lake to about 15 miles east of Moses Lake, Washington; construction of a Black Rock re-regulation reservoir; and construction of the Black Rock Branch Canal from the proposed Black Rock re-regulating reservoir to about 21 miles east of Moses Lake. Water will 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 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 up to 2,700 cubic feet per second from the Columbia River in October will 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 in October of up to 2,700 cfs will 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 will:

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

What is the study area?
Lands currently irrigated with groundwater in Adams and Grant counties and small portions of Lincoln and Franklin counties is the focus of the study. 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. The canal is located east of Lind, Washington extending north to Wilson Creek and south to the Connell area. The study area is located within the Odessa Subarea.

What documents were prepared?
Reclamation completed several technical reports and other documents describing the decision-making process. The final technical reports and a final Special Study Report described the alternatives considered and displayed a feasibility-level cost estimate and economic analysis required by Federal law and policy. The economic portion of the Special Study Report consisted of a benefit-cost analysis and a regional economic impact analysis. The Fish and Wildlife Coordination Act report was included in the FEIS.

What is the Columbia Basin Project?
The Columbia Basin Project—located in central Washington—was authorized for the irrigation of 1,029,000 acres. The project currently 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.


Contact

Jennifer Hickenbottom
509-573-8043
jhickenbottom@usbr.gov

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


Last Updated: 1/6/23