Assessing Groundwater/Surface Water Interaction and Stream Discharge Uncertainty in the Snake River Completed
The State of Idaho needs to determine stream discharge, adjusted to remove fluctuations resulting from the operation of hydropower facilities, in the Snake River below Swan Falls Dam near Murphy, Idaho. The State will use this information to distribute water to owners of water rights in the middle Snake River, particularly at thresholds of 3,900 and 5,600 ft3/s.
Water exchange between surface water and groundwater can play a role in the calculation of “adjusted” discharge and the availability of water for water rights owners, but that exchange is not easily quantified.
Additionally, all discharge data have some level of uncertainty, and that uncertainty should be considered for the State of Idaho to effectively monitor and manage water rights.
We quantified the amount of water exchanged between groundwater and surface water in the Snake River from King Hill to Murphy, Idaho, in November 2012 and July 2013.
We also estimated the uncertainty in measured and computed discharge at Idaho Power Company streamgages on the Snake River downstream of Lower Salmon Falls Dam to downstream of Swan Falls Dam.
The State of Idaho will use this information to develop a protocol to calculate and report an adjusted discharge needed to manage hydropower and minimum discharge water rights in the middle Snake River.
Below are publications associated with this project.
Evaluation of seepage and discharge uncertainty in the middle Snake River, southwestern Idaho
Below are partners associated with this project.
- Overview
The State of Idaho needs to determine stream discharge, adjusted to remove fluctuations resulting from the operation of hydropower facilities, in the Snake River below Swan Falls Dam near Murphy, Idaho. The State will use this information to distribute water to owners of water rights in the middle Snake River, particularly at thresholds of 3,900 and 5,600 ft3/s.
Water exchange between surface water and groundwater can play a role in the calculation of “adjusted” discharge and the availability of water for water rights owners, but that exchange is not easily quantified.
Additionally, all discharge data have some level of uncertainty, and that uncertainty should be considered for the State of Idaho to effectively monitor and manage water rights.
We quantified the amount of water exchanged between groundwater and surface water in the Snake River from King Hill to Murphy, Idaho, in November 2012 and July 2013.
We also estimated the uncertainty in measured and computed discharge at Idaho Power Company streamgages on the Snake River downstream of Lower Salmon Falls Dam to downstream of Swan Falls Dam.
The State of Idaho will use this information to develop a protocol to calculate and report an adjusted discharge needed to manage hydropower and minimum discharge water rights in the middle Snake River.
- Publications
Below are publications associated with this project.
Evaluation of seepage and discharge uncertainty in the middle Snake River, southwestern Idaho
The U.S. Geological Survey, in cooperation with the State of Idaho, Idaho Power Company, and the Idaho Department of Water Resources, evaluated seasonal seepage gains and losses in selected reaches of the middle Snake River, Idaho, during November 2012 and July 2013, and uncertainty in measured and computed discharge at four Idaho Power Company streamgages. Results from this investigation will beAuthorsMolly S. Wood, Marshall L. Williams, David M. Evetts, Peter J. Vidmar - Partners
Below are partners associated with this project.