Potholes Supplemental Feed Route

Reclamation designed the Columbia Basin Project (CBP) to collect return flows from irrigation of land in the north half of the CBP for delivery to the south half. This return flow is stored behind O'Sullivan Dam in Potholes Reservoir. Due to increased demand in the south half and increased efficiency in the north half, an increased amount of return flow is necessary to adequately supply Potholes Reservoir. Therefore, return flows are supplemented with "feed water" - water diversions in the canal system specifically made to add water supply to Potholes Reservoir. Historically, Reclamation feeds water to Potholes Reservoir mainly through the East Low Canal. A supplemental feed route to Potholes Reservoir has been established in the natural channel of Crab Creek. To allow for operational flexibility in Crab Creek, the Frenchman Hills Wasteway was also modified to convey flows to Potholes Reservoir. Area Map >>

Potholes Supplemental Feed Route Route Operations >>

Since 2005, Washington State Department of Ecology has partnered with Reclamation and invested $2.1 million in study and $10 million in capital cost for a supplemental feed route. In August 2007, Reclamation issued a final Environmental Assessment (EA) and Finding of No Significant Impact for the Potholes Reservoir Supplemental Feed Route (PSFR).

The PSFR project consists of modifying existing facilities to allow water to be routed from Pinto Dam to Potholes Reservoir.

This study is separate and distinct from the Yakima River Basin Water Storage Feasibility Study and the Odessa Subarea Special Study.

Update 10/11/2016:
Reclamation is aware there has been a change in groundwater levels and at this point, we are still unclear what factors are causing it. We will undertake some preliminary (analysis / investigations) to see if we can gain a better understanding of what those factors may be and their significance to the groundwater situation. If you have any information to share that may assist Reclamation with our investigations into this situation, please do not hesitate to contact Charity Davidson, Project Manager by phone at 509-754-0221 or by email at cndavidson@usbr.gov.

08/23/0216 Potholes Reservoir Supplemental Feed Route Conveyance Water Shut-Down

The Bureau of Reclamation has turned off the 100 cfs of irrigation water that was being delivered from Billy Clapp Reservoir via middle Crab Creek and Frenchman Hills Wasteway to the Potholes Reservoir. Reclamation is currently collecting hydrological data in middle Crab Creek to gain a better understanding of the water table within the project boundary, to allow Grant County to complete their Stratford Road project, as well as further assess hydrological modeling results used to develop the final Environmental Assessment (EA) and Finding of No Significant Impact for the Potholes Reservoir Supplemental Feed Route (PSFR).

Reclamation and Washington State Department of Ecology will continue as partners to ensure the demands in the south half of the Columbia Basin Project (CBP) are met while maintaining operational flexibility. Reclamation will be hosting several meetings in the near future to discuss hydrological data analyses, the 2017 irrigation season, habitat enhancement successes, and project updates.

While we are not sure what all the contributing factors are to the increased water levels in some areas near Crab Creek, Reclamation is committed to working with irrigation districts, private landowners, tribes, local, state, and federal resources agencies, and interested parties to increase the reliability of transporting water from Billy Clapp Reservoir to Potholes Reservoir.

04/2016 Fact Sheet PDF 217 kb
04/2016 Map of Area PDF 630 kb
04/2016 Notification of Increased Flow in the Frenchman Hills Wasteway PDF 27 kb
08/2007 Potholes Reservoir Supplemental Feed Route EA and FONSI HTML


Jennifer McConnell
Project Manager
(509) 754-0237

Bureau of Reclamation
Ephrata Field Office
P.O. Box 815
Ephrata, WA 98823-0815

Last Updated: 8/30/18