Colorado River Basin Focus Area Study: Groundwater discharge to streams

Science Center Objects

Methods were developed in the CRB FAS to estimate groundwater discharge to streams in the upper Colorado River Basin (UCBR) using in-stream water-quality data. Results indicate groundwater discharge to streams contributes an average of 48 percent of total streamflow in the UCRB.

 

National Water Census  •  Colorado River Basin  •  Evapotranspiration  •  Snowpack  •  Water Use  •  Groundwater Discharge 

 

Historically, management of water resources in the Colorado River Basin has focused on surface-water supplies; however, groundwater and surface water are interconnected, and groundwater discharge to streams sustains surface-water flows in much of the Upper Colorado River Basin (UCRB). To better understand the link between groundwater and surface water in the basin, the USGS, as part of the Colorado River Basin FAS, has quantified groundwater discharge to streams across the UCRB.

To estimate groundwater discharge to streams in the UCRB, methods were developed to use in-stream water-quality data, specifically the electrical conductivity (specific conductance) of stream water, to quantify the fraction of streamflow that originates as groundwater. For sites where only occasional measurements of specific conductance (referred to as discrete data) have been made, an additional method was developed to estimate the percentage of streamflow that originates as groundwater.

Estimates of groundwater discharge to streams (baseflow) at 229 sites in the Upper Colorado River Basin.

Estimates of groundwater discharge to streams (baseflow) at 229 sites in the Upper Colorado River Basin. Groundwater discharge to streams contributes an average of 48 percent of total streamflow in the UCRB.

Key Findings and Results

  • Groundwater discharge to streams contributes an average of 48 percent of total streamflow in the Upper Colorado River Basin at 229 gaged sites in the basin.
  • Spatially, groundwater discharge to streams is greater in upland, mountainous areas that have greater precipitation.
  • Read the report

 

National Water Census  •  Colorado River Basin  •  Evapotranspiration  •  Snowpack  •  Water Use  •  Groundwater Discharge