In the Elkhorn River and Loup River Basins, Natural Resources Districts (Upper Elkhorn, Lower Elkhorn, Upper Loup, Lower Loup, Middle Niobrara, Lower Niobrara, Lewis and Clark, and Lower Platte North) are collecting data and developing tools to assist with water resource planning. Critical planning issues in the Elkhorn River and Loup River basins are focused on the availability of the groundwater resource, the effect of anthropogenic stresses on the groundwater resource, and the interaction of groundwater and surface water. Specifically, the Natural Resource Districts and the Nebraska Department of Natural Resources are concerned with the effect of groundwater withdrawal on the availability of surface water and the long-term effects of groundwater withdrawal on the groundwater resource.
The Natural Resources Districts (Upper Elkhorn, Lower Elkhorn, Upper Loup, Lower Loup, Middle Niobrara, Lower Niobrara, Lewis and Clark, and Lower Platte North; referred to as NRDs) and the Nebraska Department of Natural Resources (NDNR) are concerned with the effect of groundwater withdrawal on the availability of surface water and the long-term effects of groundwater withdrawal on the groundwater resource in the Elkhorn River and Loup RIver Basins. The Elkhorn-Loup Model, is a USGS Nebraska Water Science Center project, done in cooperation with the NRDs and NDNR, and is designed to assist the NRDs and NDNR by characterizing the groundwater system within the Elkhorn River and Loup RIver Basins and by providing a regional groundwater-flow model.
The Elkhorn-Loup Model, a multi-phase project, is a study of surface-water and groundwater resources in the Elkhorn River basin upstream from Norfolk, Nebraska, and the Loup River basin upstream from Columbus, Nebraska. The study area covers approximately 30,800 square miles, and extends north to the Niobrara River and south to the Platte River. The eastern boundary coincides with the approximate location of the westernmost extent of glacial till in eastern Nebraska.
Phase One
The first phase of the study began with construction of a groundwater-flow model using previously collected data. The model was constructed with a single layer vertically to represent the aquifers of the Tertiary-age Ogallala Group and Quaternary-age alluvial deposits, with a uniform node spacing of 2 miles. The model was calibrated to measured groundwater levels and estimated groundwater discharge to streams for the pre-groundwater-development period (approximately 1940) and the simulation of the 1940-2005 period was calibrated to measured groundwater-level changes. The calibrated groundwater-flow model was used to assess current and future impacts of groundwater pumping on surface water, and could be used to provide information to the NRDs for groundwater-management planning.
Phase Two
Continuation of the study, phase two, was part of a larger, ongoing effort to enhance the current knowledge of hydrogeology, improve the understanding of stream-aquifer interactions, and compile reliable data describing hydrogeologic properties such groundwater recharge, groundwater pumpage for irrigation, and groundwater discharge to evapotranspiration in the study area.
Phase two included updates to the groundwater-flow simulation using
- newly collected data,
- supporting analyses done in 2007 and 2008,
- improved simulation calibration methods, and
- additional approaches for analyzing the effects of agricultural irrigation using the simulation.
Newly collected data include
- revisions to the base-of-aquifer map using test-hole drilling and surface and borehole geophysics,
- synoptic base-flow measurements along stream reaches,
- a runoff-recharge watershed model to estimate long-term patterns of recharge, and
- geophysical mapping of resistivity patterns in canals and streams.
In addition to enhancing the data to the simulations, parameter-estimation techniques were used for phase-two simulation calibration, providing a more robust calibration. Other enhancements to the simulations included refining the grid discretization, using time-variable recharge from precipitation, time-variable base-flow estimates, improved estimates of groundwater withdrawals for irrigation, and refined delineation of active evapotranspiration grid cells.
Phase Three
The third phase of the study continues to use new methods and data to refine the groundwater-flow model developed in phases one and two. Implementation of these new methods and data will increase the understanding of the availability of groundwater and the effect of anthropogenic stresses on the groundwater and surface-water resources in the Elkhorn and Loup River basins. Phase-three objectives include
- An investigation of the phase-two model sensitivity to recharge using the Soil-Water-Balance (SWB) model, newly developed by USGS. SWB will help assimilate readily available public data (climate, soils, land use, etc.) to estimate the spatial and temporal patterns of recharge.
- Continued collection of geologic data to better characterize the aquifer. The combination of test-hole drilling, bore geophysical logging, and surface geophysical surveys will provide a more detailed picture of the aquifer units and base of the aquifer.
- Installation of monitoring wells in test-hole drilling locations to give NRDs better information on water levels.
- Spatial and temporal refinement of the groundwater-flow model including re-discretization of the model grid to ½-mile-cell spacing and the refinement of stress periods from an annual time step to at least seasonal so that the model can represent input changes that occur within one model year.
Finally, the results of the phase-three model will undergo calibration via parameter estimation similar to the calibration done for phase two, as well as the completion of additional analysis runs.
Below are multimedia items associated with this project.
Below are publications associated with this project.
Simulation of groundwater flow, 1895–2010, and effects of additional groundwater withdrawals on future stream base flow in the Elkhorn and Loup River Basins, central Nebraska—Phase three
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 partners associated with this project.
- Overview
In the Elkhorn River and Loup River Basins, Natural Resources Districts (Upper Elkhorn, Lower Elkhorn, Upper Loup, Lower Loup, Middle Niobrara, Lower Niobrara, Lewis and Clark, and Lower Platte North) are collecting data and developing tools to assist with water resource planning. Critical planning issues in the Elkhorn River and Loup River basins are focused on the availability of the groundwater resource, the effect of anthropogenic stresses on the groundwater resource, and the interaction of groundwater and surface water. Specifically, the Natural Resource Districts and the Nebraska Department of Natural Resources are concerned with the effect of groundwater withdrawal on the availability of surface water and the long-term effects of groundwater withdrawal on the groundwater resource.
Elkhorn-Loup Model area showing the Natural Resources Districts that participated in the study. The Natural Resources Districts (Upper Elkhorn, Lower Elkhorn, Upper Loup, Lower Loup, Middle Niobrara, Lower Niobrara, Lewis and Clark, and Lower Platte North; referred to as NRDs) and the Nebraska Department of Natural Resources (NDNR) are concerned with the effect of groundwater withdrawal on the availability of surface water and the long-term effects of groundwater withdrawal on the groundwater resource in the Elkhorn River and Loup RIver Basins. The Elkhorn-Loup Model, is a USGS Nebraska Water Science Center project, done in cooperation with the NRDs and NDNR, and is designed to assist the NRDs and NDNR by characterizing the groundwater system within the Elkhorn River and Loup RIver Basins and by providing a regional groundwater-flow model.
The Elkhorn-Loup Model, a multi-phase project, is a study of surface-water and groundwater resources in the Elkhorn River basin upstream from Norfolk, Nebraska, and the Loup River basin upstream from Columbus, Nebraska. The study area covers approximately 30,800 square miles, and extends north to the Niobrara River and south to the Platte River. The eastern boundary coincides with the approximate location of the westernmost extent of glacial till in eastern Nebraska.
Phase One
The first phase of the study began with construction of a groundwater-flow model using previously collected data. The model was constructed with a single layer vertically to represent the aquifers of the Tertiary-age Ogallala Group and Quaternary-age alluvial deposits, with a uniform node spacing of 2 miles. The model was calibrated to measured groundwater levels and estimated groundwater discharge to streams for the pre-groundwater-development period (approximately 1940) and the simulation of the 1940-2005 period was calibrated to measured groundwater-level changes. The calibrated groundwater-flow model was used to assess current and future impacts of groundwater pumping on surface water, and could be used to provide information to the NRDs for groundwater-management planning.
Phase Two
Continuation of the study, phase two, was part of a larger, ongoing effort to enhance the current knowledge of hydrogeology, improve the understanding of stream-aquifer interactions, and compile reliable data describing hydrogeologic properties such groundwater recharge, groundwater pumpage for irrigation, and groundwater discharge to evapotranspiration in the study area.
Phase two included updates to the groundwater-flow simulation using
USGS Nebraska Water Science Center Elkhorn-Loup Model project chief, Steve Peterson, making a stream discharge measurement. The project collected hundreds of discharge measurements in 2006 to determine base flow in the study area.(Credit: Robert B Swanson, USGS Nebraska Water Science Center. Public domain.) - newly collected data,
- supporting analyses done in 2007 and 2008,
- improved simulation calibration methods, and
- additional approaches for analyzing the effects of agricultural irrigation using the simulation.
Newly collected data include
- revisions to the base-of-aquifer map using test-hole drilling and surface and borehole geophysics,
- synoptic base-flow measurements along stream reaches,
- a runoff-recharge watershed model to estimate long-term patterns of recharge, and
- geophysical mapping of resistivity patterns in canals and streams.
In addition to enhancing the data to the simulations, parameter-estimation techniques were used for phase-two simulation calibration, providing a more robust calibration. Other enhancements to the simulations included refining the grid discretization, using time-variable recharge from precipitation, time-variable base-flow estimates, improved estimates of groundwater withdrawals for irrigation, and refined delineation of active evapotranspiration grid cells.
Phase Three
The third phase of the study continues to use new methods and data to refine the groundwater-flow model developed in phases one and two. Implementation of these new methods and data will increase the understanding of the availability of groundwater and the effect of anthropogenic stresses on the groundwater and surface-water resources in the Elkhorn and Loup River basins. Phase-three objectives include
- An investigation of the phase-two model sensitivity to recharge using the Soil-Water-Balance (SWB) model, newly developed by USGS. SWB will help assimilate readily available public data (climate, soils, land use, etc.) to estimate the spatial and temporal patterns of recharge.
- Continued collection of geologic data to better characterize the aquifer. The combination of test-hole drilling, bore geophysical logging, and surface geophysical surveys will provide a more detailed picture of the aquifer units and base of the aquifer.
- Installation of monitoring wells in test-hole drilling locations to give NRDs better information on water levels.
- Spatial and temporal refinement of the groundwater-flow model including re-discretization of the model grid to ½-mile-cell spacing and the refinement of stress periods from an annual time step to at least seasonal so that the model can represent input changes that occur within one model year.
Finally, the results of the phase-three model will undergo calibration via parameter estimation similar to the calibration done for phase two, as well as the completion of additional analysis runs.
- Multimedia
Below are multimedia items associated with this project.
- Publications
Below are publications associated with this project.
Simulation of groundwater flow, 1895–2010, and effects of additional groundwater withdrawals on future stream base flow in the Elkhorn and Loup River Basins, central Nebraska—Phase three
The U.S. Geological Survey, in cooperation with the Lewis and Clark, Lower Elkhorn, Lower Loup, Lower Platte North, Lower Niobrara, Middle Niobrara, Upper Elkhorn, and the Upper Loup Natural Resources Districts, designed a study to refine the spatial and temporal discretization of a previously modeled area. This updated study focused on a 30,000-square-mile area of the High Plains aquifer and consAuthorsAmanda T. Flynn, Jennifer S. StantonEffects 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 - Partners
Below are partners associated with this project.