MODFLOW-NWT model used in simulation of groundwater flow and availability in the North Fork Red River aquifer, southwest Oklahoma, 1980-2013

Release Date

2017-01-01

Start Date

1980-01-01

End Date

2013-12-31

Publication Date

2023-09-15

Smith, S.J., Ellis, J.H., Wagner, D.L., and Peterson, S.M., 2017, MODFLOW-NWT model used in simulation of groundwater flow and availability in the North Fork Red River aquifer, southwest Oklahoma, 1980-2013: U.S. Geological Survey data release, https://doi.org/10.5066/F7JQ0ZXH.

Type: Related Primary Publication Type: browseImage

The 1973 Oklahoma Water Law (82 OK Stat § 82-1020.5) requires the Oklahoma Water Resources Board to conduct hydrologic investigations of the State’s aquifers to support a determination of the maximum annual yield (MAY) for each groundwater basin. The MAY is defined as the amount of fresh groundwater that can be withdrawn annually while ensuring a minimum 20-year life of the groundwater basin. For alluvium and terrace aquifers, the groundwater-basin-life requirement is satisfied if, after 20 years of MAY withdrawals, 50 percent of the groundwater basin retains a saturated thickness of at least 5 ft. When a MAY has been established, the amount of land owned or leased by a permit applicant determines the annual volume of water allocated to that permit applicant. The annual volume of water allocated per acre of land is known as the equal-proportionate-share (EPS) pumping rate. The Oklahoma Water Resources Board established the MAY (343,042 acre-feet per year) and EPS pumping rate (1.0 acre-foot per acre per year) for the North Fork Red River aquifer in 1981 based on hydrologic investigations by Kent (1980) and Paukstaitis (1981) that used a numerical groundwater-flow model to evaluate the effects of potential groundwater withdrawals on groundwater availability in the North Fork Red River aquifer. Every 20 years, the Oklahoma Water Resources Board is statutorily required to update the hydrologic investigation on which the MAY and EPS were based. Because 20 years have elapsed since the MAY and EPS were established, the U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, conducted an updated hydrologic investigation and developed a calibrated numerical groundwater-flow model to evaluate the effects of potential groundwater withdrawals on groundwater flow and availability in the North Fork Red River aquifer. Groundwater-availability scenarios were performed by using the calibrated numerical groundwater-flow model to (1) estimate the EPS pumping rate that guarantees a minimum 20-, 40-, and 50-year life of the aquifer, (2) quantify the potential effects of projected well withdrawals on groundwater storage over a 50-year period, and (3) simulate the potential effects of a hypothetical (10-year) drought on groundwater storage and lake storage. The results of these groundwater-availability scenarios could be used by the Oklahoma Water Resources Board to reevaluate the maximum annual yield of groundwater from the North Fork Red River aquifer in Oklahoma. The development of the model input and output files included in this data release are documented in the U.S. Geological Survey Scientific Investigations Report 2017-5098 (https://doi.org/10.3133/sir20175098).

• Model Data Management Function (MDMF)