Simulations of the groundwater-flow system in the Cache and Grand Prairie Critical Groundwater Areas, northeastern Arkansas (ver. 3.0, April 2026)

The Mississippi Alluvial Plain (MAP) is one of the most important agricultural regions in the United States and underlies about 32,000 square miles of Missouri, Kentucky, Tennessee, Mississippi, Louisiana, and Arkansas. The MAP region supports a multibillion-dollar agricultural industry. The MAP is part of the Mississippi Embayment with several water-bearing units that make up the Mississippi Embayment Regional Aquifer System (MERAS). These water bearing units include the Mississippi River Valley Alluvial aquifer, Claiborne aquifers and Wilcox aquifers. The Cache and Grand Prairie areas in northeastern Arkansas have been designated because of decades of groundwater declines that resulted from past and current water use. This data release includes a preliminary groundwater model for the Cache region and is associated with the journal article Traylor and others (2023). Two historical calibration models, one for the Cache region and another for the Grand Prairie region, are associated with the model development and documentation report Traylor and others (2024). This part of the data release is version 1.0. Multiple forecast scenario models were developed and run for the Cache region and the Grand Prairie region; those forecast scenario models are associated with the preprint report (Traylor and others, 2026, in review). The forecast scenario models are version 2.0 of the data release.

The objective of the journal article associated with the preliminary Cache calibration model is to understand the effects of auto-adaptive localization on a model calibration. The objective of the report associated with the calibration model data release is to document and describe the construction, calibration, and results of two inset groundwater-flow models developed for the Cache River Critical Groundwater Area and Grand Prairie Critical Groundwater Area using the latest MODFLOW-6 code. Both models derived boundary conditions from the parent MERAS 3 regional model to provide higher resolution simulations in the Cache and Grand Prairie focus areas (Leaf and others, 2023 https://doi.org/10.3133/sir20235100). The objective of the report for the scenario models is to describe and document the development and construction of the forecast scenario models for the Cache and Grand Prairie regions and discuss the results. This data release includes four child items: the Cache groundwater-flow model, the Grand Prairie groundwater-flow model, and the associated forecast scenario models titled Cache Forecast Scenario Groundwater-Flow Models and Grand Prairie Forecast Scenario Groundwater-Flow Models.

References cited

Leaf, A.T., Duncan, L.L., Haugh, C.J., Hunt, R.J., and Rigby, J.R., 2023, Simulating groundwater flow in the Mississippi Alluvial Plain with a focus on the Mississippi Delta: U.S. Geological Survey Scientific Investigations Report 2023–5100, 143 p., https://doi.org/10.3133/sir20235100.

Traylor, J.P., Hunt, R.J., White, J.T., Fienen, M.N., 2023, Effects of Auto-Adaptive Localization on a Model Calibration Using Ensemble Methods, Groundwater 62, no.1 (Special Issue on Modflow‐and‐More 2022), p. 140-149

Traylor, J.P., Duncan, L.L., Leaf, A.T., Weisser, A.R., Dietsch, B.J., and Guira, M., 2024, Inset groundwater-flow models for the Cache and Grand Prairie Critical Groundwater Areas, northeastern Arkansas: U.S. Geological Survey Scientific Investigations Report 2024–5088, 152 p., https://doi.org/10.3133/sir20245088.

Traylor, J.P., Guira, M., Duncan, L.L., Dietsch, B.J., Kaminski, S.J., Reba, M., Massey, J., 2026, Scenarios to assess the future water availability in the Cache and Grand Prairie Regions of Arkansas, U.S. Geological Survey preprint (in review)