MODFLOW model used in simulation of groundwater flow and analysis of projected water use for the Rush Springs aquifer, western Oklahoma

Release Date

2018-01-01

Start Date

1979-01-01

End Date

2015-12-31

Publication Date

2023-09-15

Ellis, J.H., 2018, MODFLOW model used in simulation of groundwater flow and analysis of projected water use for the Rush Springs aquifer, western Oklahoma: U.S. Geological Survey data release, https://doi.org/10.5066/F7Q52NXK.

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 The MAY is defined as the amount of fresh groundwater that can be withdrawn annually while ensuring a minimum 20-year life of the groundwater basin.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 bedrock 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 15 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. A permanant MAY and EPS have not been established for the Rush Springs aquifer thus, the U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, conducted calibration and simulations of a numerical groundwater-flow model to evaluate the effects of potential groundwater withdrawals on groundwater flow and availability in the Rush Springs 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 Rush Springs 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 2018-5136 (https://doi.org/10.3133/sir20185136).

• Model Data Management Function (MDMF)