A detailed annual water budget is invaluable for effective interrelated water management, particularly in river valleys where streamflow and crop demands are key components of the budget. Extraction of groundwater or diversion of surface water can affect flow to streams, wetlands, and other surface-water bodies. We are providing new insights into the water budget by estimating quantities of groundwater recharge and stream base flow and relating them to soil type, land use, and geology on a local scale for two small drainages, one in the Sand Hills and one in the Dissected Plains.
A detailed annual water budget is invaluable for effective interrelated water management, particularly in river valleys where streamflow and crop demands are key components of the budget. Extraction of groundwater or diversion of surface water can affect flow to streams, wetlands, and other surface-water bodies. This impact can be assessed and mitigated if all of the components of the water budget are quantified. However, two of the largest components of the groundwater budget, groundwater recharge and base flow to streams, are spatially variable, and are quantified using varying techniques.
We are constructing an annual water budget for two Elkhorn-Loup Model (ELM) area drainage basins, including quantitative analysis of the most important components of the water budget: groundwater recharge and stream base flow.
We focused on two distinct regions:
- Sand Hills: Upper reach of Holt Creek in Holt County
- Dissected plains: South Loup River near Arnold
Five piezometers and one lysimeter were installed in each region. For streamflow data, a temporary streamgage was installed at Holt Creek. In the Dissected Plains region, the USGS streamgage at Arnold was used. Data collected at these sites is being used to determine recharge, evapotranspiration, and baseflow. Data also will be used as calibration and observation points for each specific model.
Do small streams in the Nebraska Sand Hills and Dissected Plains receive their base flow from local recharge, from regional groundwater flow, or from a combination of both?
To answer this question, we have constructed water budgets that include several components:
- Inputs: precipitation, imported water for irrigation, groundwater inflow, and percolation from surface-water bodies.
- Outputs: runoff, plant consumption, evaporation, base flow to streams, and groundwater outflow.
Several components of the water budget (local precipitation, streamflow, irrigation pumping and surface-water deliveries, and vegetation demands) can be measured or calculated from existing data or data collected during the study. The amount and spatial distribution of groundwater recharge and base flow, however, is more difficult to assess.
Ground-Water Recharge Estimates
We are estimating groundwater recharge using
- Passive drainage lysimetry,
- chloride mass balance, and
- water-table fluctuations.
Using these methods together allows us to overcome common problems of spatial and temporal representativeness that often plague traditional water-balance investigations.
Base Flow
Streamflow is measured at the gaging station within each region. The daily flow time series at each gage will be analyzed using a hydrograph base-flow separation method.
Piezometers
Piezometers were installed at various locations within each region. Data from the piezometers is being used to map the water table and analyze the flow system.
Numerical Models
Recharge measurements are being used to calibrate a recharge analysis using the Soil Water Balance (SWB) code for the region. The SWB code uses land use, soil properties, and flow direction with daily weather data to track the soil-water budget and estimate the deep percolation that may become groundwater recharge. Components of the soil-water budget include precipitation infiltration, inflow from other cells, snow melt, potential and actual plant evapotranspiration (ET), and change in soil storage. Temperature and precipitation data collected at each site or downloaded from an existing weather station will provide climate data input for SWB. Point readings made using the chloride mass balance, lysimetry, and water-table fluctuation methods will be used to calibrate the SWB model and better estimate recharge in areas with no direct measurements. The SWB output includes recharge and evapotranspiration grids that will be used as recharge arrays in the groundwater model.
The SWB grids will be used with streamflow and base-flow estimates and piezometer readings to build a local, high-resolution MODFLOW simulation of groundwater flow for each site area. This model will include streams, recharge, lateral flow from the regional flow system, and any irrigation or domestic wells in the area. As much as possible, the model will use parameters from previous regional models such as the Elkhorn and Loup Model Phase I and Phase II.
Below are publications associated with this project.
Hydrostratigraphic interpretation of test-hole and surface geophysical data, Elkhorn and Loup River Basins, Nebraska, 2008 to 2011
Effects of linking a soil-water-balance model with a groundwater-flow model
Simulation of groundwater flow and effects of groundwater irrigation on stream base flow in the Elkhorn and Loup River basins, Nebraska, 1895-2055: Phase Two
Apparent Resistivity and Estimated Interaction Potential of Surface Water and Groundwater along Selected Canals and Streams in the Elkhorn-Loup Model Study Area, North-Central Nebraska, 2006-07
Streamflow Simulations and Percolation Estimates Using the Soil and Water Assessment Tool for Selected Basins in North-Central Nebraska, 1940-2005
Simulation of Ground-Water Flow and Effects of Ground-Water Irrigation on Base Flow in the Elkhorn and Loup River Basins, Nebraska
Streamflow Measurements in North-Central Nebraska, November 2006
Below are software products associated with this project.
Soil-Water-Balance (SWB) for estimating groundwater recharge
The Soil-Water-Balance (SWB) model has been developed to allow estimates of potential recharge to be made quickly and easily. The code calculates components of the water balance at a daily time-step by means of a modified version of the Thornthwaite-Mather soil-moisture-balance approach.
- Overview
A detailed annual water budget is invaluable for effective interrelated water management, particularly in river valleys where streamflow and crop demands are key components of the budget. Extraction of groundwater or diversion of surface water can affect flow to streams, wetlands, and other surface-water bodies. We are providing new insights into the water budget by estimating quantities of groundwater recharge and stream base flow and relating them to soil type, land use, and geology on a local scale for two small drainages, one in the Sand Hills and one in the Dissected Plains.
A detailed annual water budget is invaluable for effective interrelated water management, particularly in river valleys where streamflow and crop demands are key components of the budget. Extraction of groundwater or diversion of surface water can affect flow to streams, wetlands, and other surface-water bodies. This impact can be assessed and mitigated if all of the components of the water budget are quantified. However, two of the largest components of the groundwater budget, groundwater recharge and base flow to streams, are spatially variable, and are quantified using varying techniques.
Topographic regions of Nebraska. We are constructing an annual water budget for two Elkhorn-Loup Model (ELM) area drainage basins, including quantitative analysis of the most important components of the water budget: groundwater recharge and stream base flow.
We focused on two distinct regions:
- Sand Hills: Upper reach of Holt Creek in Holt County
- Dissected plains: South Loup River near Arnold
Five piezometers and one lysimeter were installed in each region. For streamflow data, a temporary streamgage was installed at Holt Creek. In the Dissected Plains region, the USGS streamgage at Arnold was used. Data collected at these sites is being used to determine recharge, evapotranspiration, and baseflow. Data also will be used as calibration and observation points for each specific model.
Do small streams in the Nebraska Sand Hills and Dissected Plains receive their base flow from local recharge, from regional groundwater flow, or from a combination of both?
Sand Hills region study area. To answer this question, we have constructed water budgets that include several components:
- Inputs: precipitation, imported water for irrigation, groundwater inflow, and percolation from surface-water bodies.
- Outputs: runoff, plant consumption, evaporation, base flow to streams, and groundwater outflow.
Several components of the water budget (local precipitation, streamflow, irrigation pumping and surface-water deliveries, and vegetation demands) can be measured or calculated from existing data or data collected during the study. The amount and spatial distribution of groundwater recharge and base flow, however, is more difficult to assess.
Ground-Water Recharge Estimates
We are estimating groundwater recharge using
- Passive drainage lysimetry,
- chloride mass balance, and
- water-table fluctuations.
Dissected Plains region study area. Using these methods together allows us to overcome common problems of spatial and temporal representativeness that often plague traditional water-balance investigations.
Base Flow
Streamflow is measured at the gaging station within each region. The daily flow time series at each gage will be analyzed using a hydrograph base-flow separation method.
Piezometers
Piezometers were installed at various locations within each region. Data from the piezometers is being used to map the water table and analyze the flow system.
Numerical Models
Recharge measurements are being used to calibrate a recharge analysis using the Soil Water Balance (SWB) code for the region. The SWB code uses land use, soil properties, and flow direction with daily weather data to track the soil-water budget and estimate the deep percolation that may become groundwater recharge. Components of the soil-water budget include precipitation infiltration, inflow from other cells, snow melt, potential and actual plant evapotranspiration (ET), and change in soil storage. Temperature and precipitation data collected at each site or downloaded from an existing weather station will provide climate data input for SWB. Point readings made using the chloride mass balance, lysimetry, and water-table fluctuation methods will be used to calibrate the SWB model and better estimate recharge in areas with no direct measurements. The SWB output includes recharge and evapotranspiration grids that will be used as recharge arrays in the groundwater model.
The SWB grids will be used with streamflow and base-flow estimates and piezometer readings to build a local, high-resolution MODFLOW simulation of groundwater flow for each site area. This model will include streams, recharge, lateral flow from the regional flow system, and any irrigation or domestic wells in the area. As much as possible, the model will use parameters from previous regional models such as the Elkhorn and Loup Model Phase I and Phase II.
- Publications
Below are publications associated with this project.
Hydrostratigraphic interpretation of test-hole and surface geophysical data, Elkhorn and Loup River Basins, Nebraska, 2008 to 2011
The Elkhorn-Loup Model (ELM) was begun in 2006 to understand the effect of various groundwater-management scenarios on surface-water resources. During phase one of the ELM study, a lack of subsurface geological information was identified as a data gap. Test holes drilled to the base of the aquifer in the ELM study area are spaced as much as 25 miles apart, especially in areas of the western Sand HAuthorsChristopher M. Hobza, Paul A. Bedrosian, Benjamin R. BlossEffects of linking a soil-water-balance model with a groundwater-flow model
A previously published regional groundwater-flow model in north-central Nebraska was sequentially linked with the recently developed soil-water-balance (SWB) model to analyze effects to groundwater-flow model parameters and calibration results. The linked models provided a more detailed spatial and temporal distribution of simulated recharge based on hydrologic processes, improvement of simulatedAuthorsJennifer S. Stanton, Derek W. Ryter, Steven M. PetersonSimulation of groundwater flow and effects of groundwater irrigation on stream base flow in the Elkhorn and Loup River basins, Nebraska, 1895-2055: Phase Two
Regional groundwater-flow simulations for a 30,000-square-mile area of the High Plains aquifer, referred to collectively as the Elkhorn-Loup Model, were developed to predict the effects of groundwater irrigation on stream base flow in the Elkhorn and Loup River Basins, Nebraska. Simulations described the stream-aquifer system from predevelopment through 2005 [including predevelopment (pre-1895), eAuthorsJennifer S. Stanton, Steven M. Peterson, Michael N. FienenApparent Resistivity and Estimated Interaction Potential of Surface Water and Groundwater along Selected Canals and Streams in the Elkhorn-Loup Model Study Area, North-Central Nebraska, 2006-07
In 2005, the State of Nebraska adopted new legislation that in part requires local Natural Resources Districts to include the effect of groundwater use on surface-water systems in their groundwater management plan. In response the U.S. Geological Survey, in cooperation with the Upper Elkhorn, Lower Elkhorn, Upper Loup, Lower Loup, Middle Niobrara, Lower Niobrara, Lewis and Clark, and Lower PlatteAuthorsAndrew Teeple, Joseph Vrabel, Wade H. Kress, James C. CanniaStreamflow Simulations and Percolation Estimates Using the Soil and Water Assessment Tool for Selected Basins in North-Central Nebraska, 1940-2005
The U.S. Geological Survey, in cooperation with the Upper Elkhorn, Lower Elkhorn, Upper Loup, Lower Loup, Middle Niobrara, Lower Niobrara, Lewis and Clark, and Lower Platte North Natural Resources Districts, used the Soil and Water Assessment Tool to simulate streamflow and estimate percolation in north-central Nebraska to aid development of long-term strategies for management of hydrologically coAuthorsKellan R. Strauch, Joshua I. LinardSimulation of Ground-Water Flow and Effects of Ground-Water Irrigation on Base Flow in the Elkhorn and Loup River Basins, Nebraska
Irrigated agriculture is vital to the livelihood of communities in the Elkhorn and Loup River Basins in Nebraska, and ground water is used to irrigate most of the cropland. Concerns about the sustainability of ground-water and surface-water resources have prompted State and regional agencies to evaluate the cumulative effects of ground-water irrigation in this area. To facilitate understanding ofAuthorsSteven M. Peterson, Jennifer S. Stanton, Amanda T. Saunders, Jesse R. BradleyStreamflow Measurements in North-Central Nebraska, November 2006
Streamflow measurements were made during November of 2006 in the Elkhorn and Loup River basins and selected streams in the Niobrara and Platte River basins in north-central Nebraska. At these 531 sites, flows ranging from no flow to 2,600 ft3/s were measured or observed. The data are presented in a table along with the quality of measurement and the method that was used. Maps show the location ofAuthorsSteven M. Peterson, Kellan R. Strauch - Software
Below are software products associated with this project.
Soil-Water-Balance (SWB) for estimating groundwater recharge
The Soil-Water-Balance (SWB) model has been developed to allow estimates of potential recharge to be made quickly and easily. The code calculates components of the water balance at a daily time-step by means of a modified version of the Thornthwaite-Mather soil-moisture-balance approach.
- Partners