Groundwater Modeling

Groundwater resources in hydraulic connection with the Red River above Lake Texoma are limited to alluvial aquifers composed of valley-bottom alluvium and older Quaternary-age terrace deposits. This task of the Red River Focus Area Study (RRFAS) is an investigation of the groundwater system of the principal aquifers in the upper Red River Basin to determine the flow between groundwater and surface water, and how the system responds to changes in precipitation related to drought periods and changing groundwater use in aquifers connected to streams in the surface-water system. This study will use existing hydrological information, water-use data, and numerical groundwater-flow models to construct a transient groundwater model coupled with the output of the rainfall-runoff model for the aquifers in the upper Red River Basin.

Study Component Lead

Derek Ryter

California Water Science Center

Objectives

Analyzing and modeling the groundwater system of the principal alluvial aquifers in the upper Red River basin, in particular the connection between groundwater and surface water, and estimating effects of water use or drought on groundwater resources, the effects on groundwater flow to and from streams, and how this affects available surface water and ecological flow in the upper Red River Basin. This will be done by constructing and calibrating one or more numerical groundwater models for alluvial aquifers that are hydraulically connected to major streams in the upper Red River Basin.

Methods

The study area is defined as the Red River Basin upstream from Lake Texoma, which impounds streamflow from the Red River where it forms the border between Oklahoma and Texas westward into the Texas panhandle and western Oklahoma. Principal aquifers are defined as those that are directly connected to the streams and depending on the season or location provide base flow to the stream or receive infiltration of streamflow. Alluvial aquifers were chosen because they are the primary source for base flow to streams in the upper Red River Basin, and they are affected by precipitation that provides recharge.

The hydrogeological characteristics these aquifers influence streamflow by providing base flow during dry periods, and water withdrawal from the aquifers can potentially cause streamflow depletion.

Final Report

The groundwater model and results that are compiled during the study will archived according to USGS policy. The methods used during the study and a summary of results will be documented in a USGS Scientific Investigations Report.