GRANT COUNTY — The Lower Crab Creek basin is the best site to support large, off-channel water storage on the Columbia River, according to a study, federal and state officials reported Friday.

The study sought to identify where new water could be stored for irrigation, to improve flows for fish and set aside water for future municipal, domestic and industrial uses.

Construction and operational costs would be significantly less at the Crab Creek site than Hawk Creek in Lincoln County, or Sand Hollow, also in Grant County, according to the study.

The Lower Crab Creek site also posed the lowest risk and the best geology for construction of a dam and reservoir. Another site, Foster Creek, in Douglas County, was found early on to have geotechnical flaws and eliminated from consideration.

The study was conducted by the state Department of Ecology and U.S. Bureau of Reclamation.

"Long-term storage is an important component of a balanced water management program on the Columbia River," said Derek Sandison, central regional director for ecology.

Ecology, reclamation and Columbia Basin project irrigation districts are reviewing the study and plan to consult with Gov. Chris Gregoire, the state's congressional delegation, stakeholders, agencies and other entities, including the Columbia River Basin Policy Advisory Group, before deciding whether to seek federal authorization and funding for a feasibility study and environmental impact statement on any one of the sites.

"Based on cost and technical criteria, the Crab Creek site represents a potentially viable location for a reservoir," said Bill Gray, a manager with Reclamation. "However, construction of a facility at the Crab Creek site has significant environmental, socioeconomic and cultural impacts that would need to be thoroughly evaluated in an environmental impact statement."

U.S. Rep. Doc Hastings, R-Wash., whose district includes the Columbia River, said he's seeking the input of residents about the sites identified in the report.

"Water is the lifeblood ofcentral Washington and we need more storage," he said in a statement Friday. "This is an opportunity for us to work together on options to ensure our farmers and communities have the water they need to survive and prosper. I'm encouraged by the effort shown to date on moving forward on increased water storage, but a stronger resolve will be needed as anti-irrigation, pro-dam removal groups push their agendas."

The state, reclamation and the Columbia Basin project irrigation districts entered into an agreement in 2004 to promote improved water management on the Columbia River and to explore new storage opportunities.

Ecology and reclamation identified 11 sites along the entire Columbia River corridor, in December 2005, to study for storage. Based on a number of criteria — including potential storage capacity, location, known geologic integrity and other environmental and social issues — the four upper-basin sites were identified for more in-depth study.

Each of the potential storage sites has a predicted reservoir capacity of at least one million acre-feet, which is in line with future water needs in the basin. In addition, each is above Priest Rapids Dam, which allows it to be easily integrated into Reclamation's Columbia Basin Project.