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An Integrated Hydrologic Model to Support the Central Platte Natural Resources District Groundwater Management Plan, Central Nebraska

Scientific Investigations Report 2023-5024
Prepared in cooperation with the Central Platte Natural Resources District and the Nebraska Natural Resources Commission
By: , , and 
https://doi.org/10.3133/sir20235024

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Abstract

The groundwater and surface-water supply of the Central Platte Natural Resources District supports a large agricultural economy from the High Plains aquifer and Platte River, respectively. This study provided the Central Platte Natural Resources District with an advanced numerical modeling tool to assist with the update of their Groundwater Management Plan.

An integrated hydrologic model, called the Central Platte Integrated Hydrologic Model, was constructed using the MODFLOW-One-Water Hydrologic Model code with the Newton solver. This code integrates climate, landscape, surface water, and groundwater-flow processes in a fully coupled approach. Model framework included 163 rows; 327 columns; 2,640 feet cell sides; and 3 vertical layers. A predevelopment model simulated steady-state hydrologic conditions prior to April 30, 1895, and a development period model discretized into 610 stress periods simulated transient hydrologic conditions from May 1, 1895, to December 31, 2016, using 170 biannual stress periods from 1895 to 1980, and monthly stress periods from May 1, 1980, to December 31, 2016.

Calibration of the Central Platte Integrated Hydrologic Model involved two phases: a manual adjustment of parameters, followed by the automated calibration completed using BeoPEST that was facilitated by the employment of the singular value decomposition-assist features of PEST that specified 50 super parameters assembled from the 435 adjustable parameters and Tikhonov regularization. The average absolute groundwater-level residuals for model layers one, two, and three were 6.1, 12.4, and 7.4 feet, respectively. Calibrated horizontal hydraulic conductivity was about 70, 32, and 35 feet per day for layers 1, 2, and 3, respectively. The largest development period inflow to groundwater was recharge from deep percolation past the root zone, averaging 1,122,257 acre-feet per year (2.7 inches per year), and the largest outflow was to irrigation wells, averaging 693,171 acre-feet per year (10.2 inches per year for the Central Platte Natural Resources District). Other substantial groundwater outflows included evapotranspiration and base flow. For the total development period, there was a net change in storage of −122,393 acre-feet per year (−0.3 inch per year).

The calibrated Central Platte Integrated Hydrologic Model was used to simulate eight different potential future climate and irrigation pumping conditions from January 1, 2017, to December 31, 2049. Simulated future groundwater levels within the Central Platte Natural Resources District varied significantly between scenarios and locally, from 13.8 feet below to 7.6 feet above baseline 1982 groundwater levels. Most areas exhibited groundwater-level declines for the drought scenarios and rises for the alternate irrigation scenarios. Changes in scenario groundwater levels correlated with the relations between farm net recharge and irrigation pumping. Linear “first order second moment” techniques indicated that the uncertainty in projected groundwater altitudes was reduced by 15.33 feet through model calibration.

Suggested Citation

Traylor, J.P., Guira, M., and Peterson, S.M., 2023, An integrated hydrologic model to support the Central Platte Natural Resources District Groundwater Management Plan, central Nebraska: U.S. Geological Survey Scientific Investigations Report 2023–5024, 143 p., https://doi.org/10.3133/sir20235024.

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Integrated Hydrologic Model
  • Assumptions and Limitations
  • Potential Topics for Additional Study
  • Summary
  • References Cited
  • Appendix 1. Canal diversions, final Farm Process parameter values, and preliminary parameter sensitivities
  • Appendix 2. Additional Calibration Statistics that Include Measured and Simulated Plots and Residual Value Distribution Histograms by Observation Group
  • Appendix 3. Additional Average Landscape Water and Groundwater-Flow Budget Tables for the Development Period Central Platte Integrated Hydrologic Model and Groundwater Management Areas as Volumetric Rates and Net Volumetric Rates
  • Appendix 4. Additional Average Landscape Water and Groundwater-Flow Budget Tables for Each Scenario of the Central Platte Integrated Hydrologic Model by Groundwater Management Area as Area Normalized Volumetric Rates and Net Volumetric Rates
  • Appendix 5. Additional Simulated Groundwater-Levels for Each Scenario and Groundwater Management Area
Publication type Report
Publication Subtype USGS Numbered Series
Title An integrated hydrologic model to support the Central Platte Natural Resources District Groundwater Management Plan, central Nebraska
Series title Scientific Investigations Report
Series number 2023-5024
DOI 10.3133/sir20235024
Year Published 2023
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Nebraska Water Science Center
Description Report: xii, 143 p.; 2 Tables; Data Release; Dataset; 3 Figures: 11.00 x 8.50 inches
Country United States
State Nebraska
Other Geospatial Platte River
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
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