Boise/Payette Water Storage Assessment Study Background

Increased demand for water in the Boise/Payette river basins is a trend evidenced by the increased competition among water users. This is especially true in the Boise and Payette River basins, where municipal and industrial water needs are projected to at least double over the next 50 years.

A Water Use Assessment and Forecast study, funded by Reclamation and accomplished mainly by Idaho Department of Water Resources in 2001, estimated that by the year 2025, annual Domestic, Commercial, Municipal and Industrial (DCM&I) water demand in the Boise Valley would grow by 74 percent. Drought, ESA, Fish and Wildlife needs, and Recreational pressures also contribute to the increasing burden on already scarce water resources.

In the fall of 2004, a Congressional delegation assembled a stakeholders group to discuss the potential need for additional storage in the Upper Snake area. These meetings resulted in a confirmed desire by the stakeholders group to pursue additional water supplies in the Boise and Payette River basins. This group has requested Reclamation conduct a study to determine potential opportunities for new storage projects.

Reclamation was requested by the State and Idaho Water Users Association to identify and conduct appraisal/feasibility studies on potential water storage sites in the Boise/Payette River basins. Reclamation has completed a Boise/Payette Water Storage Assessment Report as the first phase of this process. The assessment used the best available information to examine and prioritize water storage options at a reconnaissance level, and did not require the collection of new data. The Water Storage Assessment Report identified any options based on a specific set of screening criteria, which would warrant future appraisal and feasibility level analysis.

The first steps this study focused on (1) specifying the volume of additional water storage believed to be needed in the mid- to long-term, based on demand projections, and (2) create a reconnaissance-level water storage opportunities assessment to identify and assess a wide range of potential options for achieving this volume of storage. The storage options mainly considered were:

  • new or enhanced off-stream, on-stream, or pumped storage facilities;
  • modification of existing facilities (e.g., dredging, raising dams).

The goal is to develop a short list of several of the most promising sites; and which represent a starting point on which to move into more detailed appraisal and feasibility-level analysis.


John Tiedeman
Activity Manager
(208) 378-5034

Bureau of Reclamation
Pacific Northwest Regional Office
Attention: PN-6304 (Tiedeman)
1150 North Curtis Road, Suite 100
Boise, Idaho 83706-1234

Selena Moore
Study Manager
(208) 383-2207

Bureau of Reclamation
Snake River Area Office
230 Collins Road
Boise, ID 83702-4520

Last Updated: 7/8/16