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.
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
Below are related science components of the Colorado River Basin Focus Area Study.
Colorado River Basin Focus Area Study
Colorado River Basin Focus Area Study: Evapotranspiration
Colorado River Basin Focus Area Study: Snowpack Hydrodynamics
Colorado River Basin Focus Area Study: Water Use
Below are publications associated with the Colorado River Basin Focus Area Study.
Characterization of mean transit time at large springs in the Upper Colorado River Basin, USA: A tool for assessing groundwater discharge vulnerability
The importance of base flow in sustaining surface water flow in the Upper Colorado River Basin
Regional scale estimates of baseflow and factors influencing baseflow in the Upper Colorado River Basin
A new approach for continuous estimation of baseflow using discrete water quality data: Method description and comparison with baseflow estimates from two existing approaches
Continuous estimation of baseflow in snowmelt-dominated streams and rivers in the Upper Colorado River Basin: A chemical hydrograph separation approach
Geospatial database of estimates of groundwater discharge to streams in the Upper Colorado River Basin
- Overview
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. 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
- Science
Below are related science components of the Colorado River Basin Focus Area Study.
Colorado River Basin Focus Area Study
As one of several Focus Area Studies within the USGS National Water Census (NWC), the USGS has completed a 3-year study of water availability and use in the Colorado River Basin.Colorado River Basin Focus Area Study: Evapotranspiration
New USGS-developed, remote-sensing based approaches were used to quantify agricultural irrigation water consumption on a field-by-field scale. The work produced the first ever Colorado River Basin-wide, 100-m scale actual ET estimate (2010) using Landsat imagery.Colorado River Basin Focus Area Study: Snowpack Hydrodynamics
The Focus Area Study examined factors affecting snowpack distribution, snowmelt, and losses of snowpack water due to sublimation in the Upper Colorado River Basin. Also, as part of the FAS, the USGS has developed methods to make physical measurements of snowpack sublimation.Colorado River Basin Focus Area Study: Water Use
Water-use data were compiled as annual total withdrawals by source and aggregated to 8-digit Hydrologic Unit Code watersheds from 1985 to 2010 in five year intervals. The new compilation allows for an evaluation of water-use trends in the Colorado River Basin and the effect of use on the water budget. - Publications
Below are publications associated with the Colorado River Basin Focus Area Study.
Characterization of mean transit time at large springs in the Upper Colorado River Basin, USA: A tool for assessing groundwater discharge vulnerability
Environmental tracers (noble gases, tritium, industrial gases, stable isotopes, and radio-carbon) and hydrogeology were interpreted to determine groundwater transit-time distribution and calculate mean transit time (MTT) with lumped parameter modeling at 19 large springs distributed throughout the Upper Colorado River Basin (UCRB), USA. The predictive value of the MTT to evaluate the pattern and tAuthorsJohn E. Solder, Bernard J. Stolp, Victor M. Heilweil, David D. SusongThe importance of base flow in sustaining surface water flow in the Upper Colorado River Basin
The Colorado River has been identified as the most overallocated river in the world. Considering predicted future imbalances between water supply and demand and the growing recognition that base flow (a proxy for groundwater discharge to streams) is critical for sustaining flow in streams and rivers, there is a need to develop methods to better quantify present-day base flow across large regions.AuthorsMatthew P. Miller, Susan G. Buto, David D. Susong, Christine RumseyRegional scale estimates of baseflow and factors influencing baseflow in the Upper Colorado River Basin
Study region The study region encompasses the Upper Colorado River Basin (UCRB), which provides water for 40 million people and is a vital part of the water supply in the western U.S. Study focus Groundwater and surface water can be considered a single water resource and thus it is important to understand groundwater contributions to streamflow, or baseflow, within a region. Previously, quantificAuthorsChristine Rumsey, Matthew P. Miller, David D. Susong, Fred D. Tillman, David W. AnningA new approach for continuous estimation of baseflow using discrete water quality data: Method description and comparison with baseflow estimates from two existing approaches
Understanding how watershed characteristics and climate influence the baseflow component of stream discharge is a topic of interest to both the scientific and water management communities. Therefore, the development of baseflow estimation methods is a topic of active research. Previous studies have demonstrated that graphical hydrograph separation (GHS) and conductivity mass balance (CMB) methodsAuthorsMatthew P. Miller, Henry M. Johnson, David D. Susong, David M. WolockContinuous estimation of baseflow in snowmelt-dominated streams and rivers in the Upper Colorado River Basin: A chemical hydrograph separation approach
Effective science-based management of water resources in large basins requires a qualitative understanding of hydrologic conditions and quantitative measures of the various components of the water budget, including difficult to measure components such as baseflow discharge to streams. Using widely available discharge and continuously collected specific conductance (SC) data, we adapted and appliedAuthorsMatthew P. Miller, David D. Susong, Christopher L. Shope, Victor M. Heilweil, Bernard J. StolpGeospatial database of estimates of groundwater discharge to streams in the Upper Colorado River Basin
The U.S. Geological Survey, as part of the Department of the Interior’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) initiative, compiled published estimates of groundwater discharge to streams in the Upper Colorado River Basin as a geospatial database. For the purpose of this report, groundwater discharge to streams is the baseflow portion of streamflow that includes contributAuthorsAdriana Garcia, Melissa D. Masbruch, David D. Susong