Oklahoma statutes direct the OWRB to conduct hydrologic investigations to determine the amount of fresh groundwater available for appropriation. Staff hydrogeologists, modelers, engineering consultants, and federal agencies assist in characterizing hydrologic properties of aquifers and determine recharge, effects of pumping, and water demand. Investigations include the determination of the upper, lower, and lateral boundaries of the groundwater basin as well as aquifer properties, such as saturated thickness, hydraulic conductivity, transmissivity, specific yield, and storage coefficient to understand the storage and yield capacity of the basin.

Status of investigation for Oklahoma's 22 major aquifers and related scientific reports:

• Ada-Vamoosa
• Antlers
• Arbuckle-Simpson
• Arbuckle-Timbered Hills
• Arkansas River
• Blaine
• Boone-Roubidoux
• Canadian River
• Cimarron River
• Elk City Sandstone
• Enid Isolated Terrace
• Garber-Wellington
• Gerty Sand
• North Canadian River
• North Fork of the Red River
• Ogallala-Northwest
• Ogallala-Panhandle
• Ogallala-Roger Mills
• Red River Reach 1-2
• Rush Springs
• Salt Fork of the Arkansas River
• Salt Fork of the Red River
• Tillman Terrace
• Washita River Reach 1
• Washita River Reach 3-4

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Ada-Vamoosa

The Ada-Vamoosa aquifer underlies 1,975 square miles of northern and central Oklahoma, including portions of Creek, Lincoln, Okfuskee, Osage, Pawnee, Payne, Pontotoc, Pottawatomie, and Seminole counties. Wells commonly yield 1.2 to 290 gallons per minute. The aquifer is primarily used for public supply and domestic purposes.

• Study in progress. Contact the OWRB for more information.
• Aquifer tests and characterization of transmissivity, Ada-Vamoosa aquifer on the Osage Reservation, Osage County, Oklahoma 2006 (2008)
• Water quality of the Quaternary and Ada-Vamoosa aquifers on the Osage Reservation, Osage County, Oklahoma, 1997 (2000)
• Geohydrology of the Vamoosa-Ada aquifer east-central Oklahoma with a section on chemical quality of water (1986)

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Antlers

The Antlers aquifer underlies 4,400 square miles of southeast Oklahoma, including portions of McCurtain, Choctaw, Pushmataha, Bryan, Atoka, Love, Marshall, Carter, and Johnston counties. Wells commonly yield 100 to 500 gallons per minute. The saturated thickness is up to 1,000 feet. The aquifer is primarily used for domestic purposes.

• Study in progress. Contact the OWRB for more information.
• Simulation of ground-water flow in the Antlers aquifer in southeastern Oklahoma and northeastern Texas (1992)
• Geohydrology of the Antlers aquifer (Cretaceous), southeastern Oklahoma (1981)

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Arbuckle-Simpson

The Arbuckle-Simpson aquifer underlies 612 square miles of south-central Oklahoma, including portions of Carter, Coal, Johnston, Murray, and Pontotoc counties. Wells commonly yield 100 to 500 gallons per minute. The mean saturated thickness is 3,400 feet. The aquifer is primarily used for public supply and irrigation.

• Hydrogeology and Simulation of Groundwater Flow in the Arbuckle-Simpson Aquifer, South-Central Oklahoma (2011)
• Board Order Determining the Maximum Annual Yield for the Arbuckle-Simpson Groundwater Basin (2013)
• Arbuckle-Simpson Groundwater Basin Buffer Zones Map
• Arbuckle-Simpson Hydrology Study Fact Sheet
• Senate Bill 288
• Arbuckle-Simpson Study Background and Meetings
• Arbuckle-Simpson Hydrology Study Timeline of Events

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Arbuckle-Timbered Hills

The Arbuckle-Timbered Hills aquifer underlies 376 square miles of southwest Oklahoma, including portions of Caddo, Comanche, and Kiowa counties. Wells commonly yield greater than 50 gallons per minute. The aquifer is primarily used for irrigation, agriculture, public supply, and domestic purposes.

• Study pending. Contact the OWRB for more information.
• Analytical assessment of ground-water availability for communities and rural water districts in Comanche County, southwestern Oklahoma (1986)

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Arkansas River

The Arkansas River aquifer underlies 858 square miles of northeast Oklahoma, including portions of Haskell, Kay, Le Flore, Muskogee, Noble, Osage, Pawnee, Sequoyah, Tulsa, and Wagoner counties. Wells commonly yield greater than 100 gallons per minute. The aquifer is primarily used for irrigation, public supply, and domestic purposes.

• Study pending. Contact the OWRB for more information.
• Aquifers of Arkansas-protection, management, and hydrologic and geochemical characteristics of groundwater resources in Arkansas (2014)

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Blaine

The Blaine aquifer underlies 930 square miles of southwest Oklahoma, including portions of Beckham, Harmon, Greer, and Jackson counties. Wells commonly yield 300 to 2,000 gallons per minute. The aquifer is primarily used for irrigation.

• Study in progress. Contact the OWRB for more information.
• Blaine aquifer in the Hollis Basin of southwest Oklahoma; structure-contour map and stratigraphic-hydrologic data (2019)
• Brackish groundwater in the Blaine aquifer system, north-central Texas (2016)
• Demonstration and Evaluation of Artificial Recharge to the Blaine Aquifer in Southwestern Oklahoma (1997)
• Hydrogeologic data for the Blaine aquifer and associated units in southwestern Oklahoma and Northwestern Texas (1997)
• Hydrogeology and karst of the Blaine Gypsum-Dolomite aquifer, southwestern Oklahoma (1990)
• Hydrogeology and recharge of a gypsum-dolomite karst aquifer in southwestern Oklahoma (1985)
• Groundwater resources Harmon and parts of Greer and Jackson counties, Oklahoma (1965)

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Boone-Roubidoux

The Boone-Roubidoux aquifer underlies 4,600 square miles of northeast Oklahoma, including portions of Adair, Cherokee, Craig, Delaware, Haskell, Le Flore, Mayes, Muskogee, Nowata, Ottawa, Rogers, Sequoyah, and Wagoner counties. Wells commonly yield 3.5 to 1,000 gallons per minute. The aquifer is primarily used for public supply and domestic purposes.

• Study in progress. Contact the OWRB for more information.
• Hydrogeologic units, contour maps, and cross sections of the Boone and Roubidoux aquifers, northeastern Oklahoma, 2020 (2020)
• Hydrogeology and hydrologic conditions of the Ozark Plateaus aquifer system (2016)
• Hydrogeologic Investigation Report of the Boone Groundwater Basin, Northeastern Oklahoma (2001)
• Geohydrology and water quality of the Roubidoux Aquifer, northeastern Oklahoma (1990)
• Data Collection in the Boone and Roubidoux aquifers, northeastern Oklahoma

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Canadian River Reach 1

The Canadian River aquifer underlies 242 square miles (Reach 1) of west-central Oklahoma and 364 square miles (Reach 2) of central and east-central Oklahoma. Reach 1 includes portions of Blaine, Caddo, Custer, Dewey, Ellis, and Roger Mills counties. Reach 2 includes portions of Caddo, Canadian, Cleveland, McClain, McIntosh, Pittsburg, Pontotoc, Pottawatomie, and Seminole counties. Wells commonly yield more than 100 gallons per minute. The saturated thickness up to 90 feet. The aquifer is primarily used for irrigation and public supply.

• Hydrogeology and Simulation of Groundwater Flow and Analysis of Projected Water Use for the Canadian River Alluvial Aquifer, Western and Central Oklahoma (2016)

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Cimarron River

The Cimarron River Alluvium and Terrace aquifer underlies 1,342 square miles of northwest Oklahoma, including portions of Alfalfa, Garfield, Kingfisher, Lincoln, Major, and Woods counties. Wells commonly yield 100 to 300 gallons per minute. The mean saturated thickness is 30 feet. The aquifer is primarily used for irrigation and public supply.

• Hydrologic data for the alluvium and terrace deposits of the Cimarron River from Freedom to Guthrie, Oklahoma (1994)
• Groundwater Resources of the Terrace Deposits Along the Northeast Side of the Cimarron River in Alfalfa, Garfield, Kingfisher, and Major Counties, OK (1953)

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Elk City Sandstone

The Elk City Sandstone aquifer underlies 519 square miles of west-central Oklahoma, including portions of Beckham, Custer, Roger Mills, and Washita counties. Wells commonly yield more than 50 gallons per minute. The saturated thickness is up to 199 feet, with a mean of 56 feet. The aquifer is primarily used for public supply and irrigation.

• Hydrologic Investigation of the Elk City Sandstone Aquifer in West Oklahoma (2019)
• Evaluation of Aquifer Performance and Water Supply Capabilities of the Elk City Aquifer (1982)

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Enid Isolated Terrace

The Enid Isolated Terrace aquifer underlies 174 square miles of north-central Oklahoma, including portions of Alfalfa and Garfield counties. Wells commonly yield 20 to 250 gallons per minute. The saturated thickness is up to 65 feet, with a mean of 14.8 feet. The aquifer is primarily used for public supply and irrigation.

• Hydrologic Investigation Update of the Enid Isolated Terrace Aquifer in North-Central Oklahoma (2014)
• Evaluation of Aquifer Performance and Water Supply Capabilities of the Enid Isolated Terrace Aquifer in Garfield County, OK (1982)

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Garber-Wellington

The Garber-Wellington aquifer underlies 3,000 square miles of central Oklahoma, including portions of Payne, Logan, Lincoln, Oklahoma, Cleveland, and Pottawatomie counties. Wells commonly yield 1 to 290 gallons per minute. The saturated thickness is up to 920 feet. The aquifer is primarily used for public water supply.

• Hydrogeology and simulation of groundwater flow in the Central Oklahoma (Garber-Wellington) Aquifer, Oklahoma, 1987 to 2009, and simulation of available water in storage (2010)
• Garber-Wellington Staff Report (2019)
• Garber-Wellington Tentative Maximum Annual Yield

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Gerty Sand

The Gerty Sand aquifer underlies 97 square miles of south-central Oklahoma, including portions of Garvin, McClain, and Pontotoc counties. Wells commonly yield 100 gallons per minute. The saturated thickness is up to 64 feet, with a mean of 14 feet. The aquifer is primarily used for irrigation and public supply.

• Study in progress. Contact the OWRB for more information.
• Evaluation of Aquifer Performance and Water Supply Capabilities of the Isolated Terrace (Gerty Sand) in Garvin, McClain, and Pontotoc Counties (1987)

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North Canadian River

The North Canadian River aquifer underlies 874 square miles (Reach 1) and 371 square miles (Reach 2) of northwest Oklahoma. Reach 1 includes portions of Blaine, Dewey, Ellis, Harper, Major and Woodward counties. Reach 2 includes portions of Blaine and Canadian counties. Wells commonly yield 100 to 300 gallons per minute. The mean saturated thickness is 36 feet in Reach 1 and 29 feet in Reach 2. The aquifer is primarily used for irrigation and public supply.

• Hydrogeological framework, numerical simulation of groundwater flow, and effects of projected water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma (2015)

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North Fork of the Red River

The North Fork Red River aquifer underlies 777 square miles of southwest Oklahoma, including portions of Beckham, Greer, Jackson, Kiowa, and Roger Mills counties. Wells commonly yield 10 to 450 gallons per minute. The mean saturated thickness is 38 feet. The aquifer is primarily used for irrigation and public supply.

• Hydrogeology and simulated groundwater flow and availability in the North Fork Red River aquifer, southwest Oklahoma, 1980-2013 (2017)
• Evaluation of Aquifer Performance and Water Supply Capabilities of Alluvial and Terrace Deposits of the North Fork of the Red River in Beckham, Greer, Kiowa, and Jackson Counties, OK (1980)

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Ogallala-Northwest

The Ogallala - Northwest aquifer underlies 1,465 square miles of northwest Oklahoma, including portions of Dewey, Ellis, Harper, and Woodward counties. Wells commonly yield more than 50 gallons per minute. The mean saturated thickness is 95 feet in Ellis and Woodward counties and 24 feet in Harper County. The aquifer is primarily used for irrigation and public supply.

• Study in progress. Contact the OWRB for more information.
• Water flow in the High Plains aquifer in northwestern Oklahoma (2000)
• Hydrogeology, water use, and simulation of flow in the High Plains aquifer in northwestern Oklahoma, southeastern Colorado, southwestern Kansas, northeastern New Mexico, and northwestern Texas (1999)

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Ogallala-Panhandle

The Ogallala - Panhandle aquifer underlies 5,233 square miles of northwest Oklahoma, including portions of Beaver, Cimarron, and Texas counties. Wells commonly yield 500 gallons per minute. The mean saturated thickness ranges from 67 feet in Cimarron County to 200 feet in Texas County. The aquifer is primarily used for irrigation and public supply.

• Study in progress. Contact the OWRB for more information.
• Water flow in the High Plains aquifer in northwestern Oklahoma (2000)
• Hydrogeology, water use, and simulation of flow in the High Plains aquifer in northwestern Oklahoma, southeastern Colorado, southwestern Kansas, northeastern New Mexico, and northwestern Texas (1999)
• Water Resources Investigation 25-75 Ogallala Aquifer - Oklahoma Panhandle (1973)

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Ogallala-Roger Mills

The Ogallala - Roger Mills aquifer underlies 385 square miles of west-central Oklahoma. The saturated thickness is up to 166 feet, with a mean of 45 feet. Wells commonly yield more than 50 gallons per minute. The aquifer is primarily used for irrigation and public supply.

• Hydrologic Investigation Report of the Ogallala Aquifer in Roger Mills County, Oklahoma (2020)
• Hydrogeologic investigation of the Ogallala aquifer in Roger Mills and Beckham counties, western Oklahoma (2002)
• Hydrogeology, water use, and simulation of flow in the High Plains aquifer in northwestern Oklahoma, southeastern Colorado, southwestern Kansas, northeastern New Mexico, and northwestern Texas (1999)

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Red River Reach 1-2

The Red River Reach 1-2 aquifer underlies 336 square miles (Reach 1) and 286 square miles (Reach 2) of southwest and south-central Oklahoma. Reach 1 includes portions of Cotton, Harmon, Jackson, and Tillman counties. Reach 2 includes portions of Cotton, Jefferson, and Love counties. Wells commonly yield 2 to 1,200 gallons per minute. The mean saturated thickness is 18 feet. The aquifer is primarily used forirrigation and public supply.

• Study in progress. Contact the OWRB for more information.

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Rush Springs

The Rush Springs aquifer underlies 4,692 square miles of west-central Oklahoma, including portions of Blaine, Caddo, Canadian, Comanche, Custer, Grady, Stephens, and Washita counties. Wells commonly yield 50 gallons per minute. The saturated thickness is up to 432 feet, with a mean of 181 feet. The aquifer is primarily used for irrigation and public supply.

• Hydrologic Investigation Report of the Rush Springs Aquifer in West-Central Oklahoma, 2015 (2018)
• Hydrogeology, water quality, and geochemistry of the Rush Springs aquifer, western Oklahoma (1998)
• Rush Springs Fact Sheet

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Salt Fork of the Arkansas River

The Salt Fork Arkansas River aquifer underlies 851 square miles of north-central Oklahoma, including portions of Alfalfa, Kay, Noble, Grant, and Woods counties. Wells commonly yield 100 gallons per minute. The mean saturated thickness is 22 feet. The aquifer is primarily used for public supply and irrigation.

• Study in progress. Contact the OWRB for more information.
• Surface-Groundwater study of the alluvium and terrace aquifer of the Salt Fork of the Arkansas River and saline surface water in north Oklahoma (1994)

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Salt Fork of the Red River

The Salt Fork Red River aquifer underlies 274.5 square miles of southwest Oklahoma, including portions of Greer, Harmon, and Jackson counties. Wells commonly yield 100 gallons per minute. The mean saturated thickness is 28.5 feet. The aquifer is primarily used for and public supply.

• Hydrogeology and Model-Simulated Groundwater Availability in the Salt Fork Red River Aquifer, Southwestern Oklahoma, 1980-2015 (2021)

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Tillman Terrace

The Tillman Terrace aquifer underlies 290 square miles of Tillman County in southwest Oklahoma. Wells commonly yield 400 gallons per minute. The mean saturated thickness is 23 feet. The aquifer is primarily used for irrigation.

• Study pending. Contact the OWRB for more information.
• Update of the hydrologic survey of the Tillman Terrace groundwater basin, southwestern Oklahoma (2002)
• Ground water resources of the terrace deposits and alluvium of western Tillman County, Oklahoma (1953)

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Washita River (Reach 1)

Reach 1 of the Washita River aquifer underlies 136 square miles of west-central Oklahoma, including portions of Custer and Roger Mills counties. Wells commonly yield 100 gallons per minute. The mean saturated thickness is 118 feet. The aquifer is primarily used for irrigation.

• Hydrogeology, Numerical Simulation of Groundwater Flow, and Effects of Future Water Use and Drought for Reach 1 of the Washita River Alluvial Aquifer, Roger Mills and Custer Counties, Western Oklahoma, 1980–2015 (2020)
  
• Evaluation of Aquifer Performance and Water Supply Capabilities of the Washita River Alluvium in Oklahoma (1984)

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Washita River (Reach 3-4)

The Washita River Reach 3 alluvial aquifer extends from approximately the city of Anadarko, OK, for about 65 channel miles to between the towns of Alex and Bradley, OK, and is 247 square miles in area. Reach 4 extends from the southeastern end of Reach 3 to just south of the town of Dougherty, OK, a total of about 100 channel miles and is 282 square miles in area. Reaches 3 and 4 are contained within the OWCP Lower Washita region, and include parts of Caddo, Grady, McClain, Garvin, Murray, and Carter counties.

• Study in progress. Contact the OWRB for more information.
• Evaluation of aquifer performance and water supply capabilities of the Washita River alluvium in Oklahoma (1984)