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Groundwater Studies
Current Studies
 Newsletter
The Rush Springs aquifer, which occurs primarily in western Oklahoma, is comprised of the Permian-age Rush Springs and Marlow Formations. The Rush Springs Formation is a massive fine-grained poorly cemented sandstone with some interbedded dolomite, gypsum, and shale. The Marlow Formation is composed of interbedded sandstones, siltstones, mudstones, gypsum-anhydrite, and dolomite. Water is not produced from the Marlow Formation as it acts as a confining unit that retards downward movement of the groundwater. Aquifer thickness ranges from less than 200 feet in the south to about 330 feet in northern areas and is generally less than 250 feet thick through the central part of the aquifer.
The aquifer is used primarily for irrigation, but it also supplies water for industrial, municipal, and domestic use. Most groundwater withdrawn from the Rush Springs aquifer is in Caddo County. Wells commonly yield 25 to 400 gpm while some irrigation wells are reported to exceed 1,000 gpm. Yields from the Marlow Formation are much smaller than from the Rush Springs Formation.
Water from the Rush Springs aquifer tends to be very hard yet suitable for most uses. Levels of dissolved solids are generally less than 500 mg/L. Nitrate, sulfate, and arsenic concentrations exceed drinking water standards in some areas, limiting its use for drinking water.
Information on this specific study can be found at USGS
 The Garber-Wellington aquifer, also referred to as the Central Oklahoma aquifer, is comprised primarily of the Permian-age Garber Sandstone and Wellington Formation. Also included in the aquifer are the Permian-age Chase, Council Grove, and Admire Groups (formerly classified as the Pennsylvanian-age Oscar Group). The aquifer consists of fine-grained sandstone interbedded with siltstone and shale. The total thickness of the combined formations is about 1,000 feet. Depth to water varies from less than 100 feet to 350 feet; saturated thickness ranges from 150 to 650 feet. Non-domestic wells completed in the aquifer can yield as much as 600 gpm but generally yield from 200 to 400 gpm.
Water from the aquifer is normally suitable for public water supply but in some areas concentrations of nitrate, arsenic, chromium, uranium, and selenium may exceed drinking water standards. Elevated concentrations of nitrate occur in shallow water which can be a concern for domestic well users. Elevated concentrations of arsenic, chromium, and selenium occur in deep parts of the aquifer, which mostly affects public supply wells. The highest concentrations of arsenic tend to occur in the western portion of the aquifer, where it is overlain by the younger Hennessey Group.
The Garber-Wellington aquifer is an important source of domestic and public water supply. The aquifer is overlain in places by alluvial aquifers along the North Canadian and Canadian Rivers. Water is available from both aquifers. With the exception of Oklahoma City, all the major communities in central Oklahoma rely either solely or partly on groundwater from the Garber-Wellington.
Abstracts from the current USGS studies:
Reach 1
Reach 2
The North Canadian River Alluvium and Terrace Aquifer is a major aquifer located in northwest Oklahoma. It lies within the Western Sand Dune Belt geomorphic province where the climate is dry to sub-humid (Davis, 1981), (Christenson, 1983). Primarily used for irrigation; the aquifer also provides water for industrial, municipal, stock, and domestic use (Davis, 1981).
The aquifer is composed of Quaternary age alluvium and terrace deposits, Holocene to Pleistocene respectively, that band the Beaver and North Canadian Rivers. The deposits principally consist of poorly sorted, fine-to-coarse-grained, unconsolidated, quartz sand with minor amounts of clay, silt, and basal gravel. High terrace deposits, derived as a reworking of the Ogallala Formation and adjacent Permian formations, also contain minor amounts of volcanic ash, bentonite, and soft caliche. Dune sand, while not vertically or horizontally extensive, consists mainly of well sorted, fine-to-medium-grained quartz sand. The aquifer is underlain unconformably by the Tertiary Ogallala Formation in the northwest and in most places by the relatively impermeable Permian red beds that act as a barrier to vertical and lateral flow of water (Davis, 1981).
The Oklahoma Water Resources Board (OWRB) is working with the U.S. Geological Survey (USGS) to conduct a 20-year update investigating Reach I and II of the North Canadian River. Reach I is defined as that part of the river from the Beaver / Harper county line to the Canton Lake Dam (Davis, 1981). Reach II is defined as that part of the river between Canton Lake Dam and Lake Overholser (Christenson, 1983). The width and thickness of the aquifer are greatest in the northwest and least in the southeast; ranging in width from 0.5 to 11 mi with deposits ranging from 20 to 300 ft thick (Davis, 1981), (Christenson, 1983). Above the Canton Lake Dam the North Canadian River and its major tributaries are gaining streams; these include: Kiowa, Clear, Bent, Indian, Wolf, and Persimmon Creeks (Davis, 1981). No tributaries are present below Canton Lake and the average discharge was calculated to be 12.5 cfs (Christenson, 1983). The aquifer is recharged by precipitation, which is estimated to be about 1.0 in/yr (Davis, 1981), (Christenson, 1983).
The primary objective of this project is to update the hydrologic surveys of the Beaver-North Canadian alluvial aquifer and to construct new digital groundwater-flow models of Reach I and Reach II to provide the OWRB with information that will enable that agency to evaluate allocation of water rights of the aquifer and to manage water resources of the basin. Information needed to meet that objective will be quantifying projected effects of groundwater withdrawals from the aquifer on (1) water levels in the aquifer, (2) the volume of water in storage in the aquifer, and (3) groundwater discharge to the Beaver-North Canadian River. (Osborn, 2011)
The North Fork of the Red River is an alluvial terrace aquifer consisting of layers of sand, silt, clay and gravel with an average thickness of 40 feet and a maximum thickness of 150 feet overlying Permian age formations (Kent, 1980). The aquifer extends over an area of approximately 575 square miles in Beckham, Greer, Kiowa, and Jackson Counties. It is mainly used for public water supply, irrigation, and domestic supply (Paukstaitis, 1981).
Natural recharge to the aquifer occurs primarily as infiltration of precipitation. The sandy soil of the eolian and alluvial deposits has a high infiltration capacity. Burton (1965) estimated a recharge rate between 3.3 and 14 inches per year for the alluvium and terrace deposits in Beckham County, based on comparisons with areas of similar geology and precipitation. Discharge from the aquifer consists of transpiration by plants (where the water table is shallow), withdrawals by wells, and natural discharge to streams. Burton (1965) found that the movement of groundwater in Beckham County is generally northward and eastward toward the river. The North Fork of the Red River is, for the most part, a gaining stream within the study area, meaning that groundwater from the terrace deposits supplies water as base flow to the river most of the year (Paukstaitis, 1981). However, during the summer months, there are often dry sections of the river.
The Oklahoma Water Resources Board (OWRB) is working with the U.S. Geological Survey (USGS) to conduct a 20-year update investigating the North Fork of the Red River and developing a new groundwater model.
Download 1980 OWRB Report
Groundwater in about 1,100 square miles of alluvial and terrace deposits along the Canadian River in western and central Oklahoma, comprising the Canadian River alluvial aquifer is used for irrigation, municipal, mining (oil and gas), livestock, and domestic supplies. Groundwater discharge from the alluvial aquifer sustains streamflow in the Canadian River during most of the year. Groundwater from this aquifer is part of the water pumped by several municipalities including Norman, Lexington, Tuttle, Goldsby, and Noble. The 2012 Oklahoma Comprehensive Water Plan (Oklahoma Water Resources Board, 2012) determined that the Canadian River watershed is the most likely in the state to have shortages in surface water and the third most likely watershed to have shortages of groundwater by 2060.
The Canadian River alluvial aquifer is poorly defined in terms of areal and vertical extent, hydrology, and water quality. Previous studies of the Canadian River alluvial aquifer or parts of the aquifer and its groundwater resources have been generalized (Wood and Burton, 1968; Marcher, 1969; Bingham and Moore, 1975; Carr and Bergman, 1976; and Johnson, 1983), without groundwater-flow models needed to examine relations between water use, climate, groundwater in storage, and streamflows having been done for the aquifer.
The Oklahoma Water Resources Board (OWRB) is working with the U.S. Geological Survey (USGS) to conduct a hydrologic investigation of the Canadian River. The objectives of this study are to conduct a hydrologic survey and characterize the water chemistry of the Canadian River alluvial aquifer in western and central Oklahoma, and to use groundwater-flow models to test the effects of groundwater withdrawals on aquifer storage and streamflow. Results from the proposed project can be used by the OWRB to evaluate the allocation of water rights of the aquifer and to manage water resources of the Canadian River watershed.
The Elk City Aquifer is located in the southwest region of Oklahoma, primarily within Washita and Beckman counties with parts of the aquifer in Custer and Roger Mills counties. The total area of the Elk City Aquifer is approximately 246 square miles. Elk City, Sayre and smaller municipalities such as Dill city, Burns Flat, and Canute are supplied by the aquifer. Municipalities and irrigation are the main use of the aquifer. In the southwest region the climate is semi-arid with an average temperature of 58.8°F and an average annual precipitation of approximately 24.5 inches per year. The natural discharge of this aquifer is through evapotranspiration, springs, and streams. The aquifer is recharged predominantly by precipitation with some recharge by subsurface inflow and return irrigation flow. The Elk City Aquifer consists of the Elk City Sandstone, which is fine grained and a reddish color. It is the uppermost Permian-age unit in the Anadarko Basin and has a maximum thickness of 220-260 feet. Underlying the Elk City Sandstone is the Doxey Shale. The Doxey Shale is approximately 160-195 feet thick and is exposed near the edges of the aquifer, creating a natural boundary preventing the downward flow of water. As a result, seeps and springs occur at the edges of the aquifer. Above the Elk City Sandstone are sediment deposits of Late Tertiary on the western side and Quaternary on the eastern side.
The Oklahoma Water Resource Board will be conducting a 20-year update study of the aquifer that is scheduled to be completed by the end of 2014. The goals of the study include: 1) updating aquifer maps such as saturated thickness, aquifer thickness, and potentiometric surface, 2) compile groundwater use from the aquifer and, 3) incorporate Oklahoma Comprehensive Water Plan projections for management purposes.
Download 1982 OWRB Report
The Enid Isolated Terrace Aquifer is 81 mi² located in north central Oklahoma in the western half of Garfield County. The aquifer’s geology ranges from Lower Permian to Quaternary in age. Permian units are classified as the Hennessey Group and the El Reno Group. The Kingman Formation of the Hennessey Group is present at the north eastern boundary of the aquifer, to the south west lies the Salt Plains Formation and the Bison Formation also part of the Hennessey Group. The Cedar Hills Sandstone Formation of the El Reno Group denotes the south western edge of the aquifer. Overlying the Permian units unconformably is the Quaternary age deposits. The Terrace deposits are located in central part of the aquifer with Aeolian Dune Sands in the north west part of the Terrace deposits. The Alluvium trends north-east to south-west in the western edge of the aquifer. The aquifer is an unconfined system, meaning the water table is the upper boundary and the Hennessey Group is the lower boundary. Within the aquifer itself, distinguishing between the Terrace deposits and the Cedar Hills Sandstone is difficult because weathered Cedar Hills Sandstone is similar to the Terrace deposits. This leads to an undifferentiated aquifer especially in the western half of the aquifer where the Terrace deposits and the underlying Cedar Hills Sandstone behave the same hydraulically. Main uses from the aquifer is ranching, farming, oil refining, and municipal by the city of Enid. Precipitation (33.60 inches annual average) is the major source of recharge to the aquifer with an average recharge rate of 2.3 inches per year. Headwaters for tributaries of the Cimarron and Salt Fork Rivers originate over the aquifer.
The OWRB will be conducting a 20 year update study of the aquifer that is schedule to be completed by the end of 2014. Goals of the aquifer study include 1) updating aquifer maps such as saturated thickness, aquifer thickness, and potentiometric surface; 2) compile groundwater use from the aquifer; and 3) incorporating Oklahoma Comprehensive Water Plan projections for management purposes.
Download 1982 OWRB Report
What is an aquifer? What is groundwater?
 An aquifer is a rock layer or group of rocks (formation) that has the ability to hold and move water underground. This water is held in pores between grains such as sand in a sandstone or it is held in fractures if no pores are present like a limestone. Not every rock or formation is an aquifer, but all have the capacity, if the conditions are right, though some are better than others. In Oklahoma the sandstone aquifers that dominate the Western part of the state tend to be more reliable and productive than the limestone aquifers that dominate the Eastern portion of our state. This is the reason that Eastern Oklahoma relies much more on surface water (rivers, lakes, etc.).
 The OWRB separates aquifers into two different categories, major aquifers and minor groundwater basins; within those categories are bedrock and alluvial aquifers. The major aquifers produce greater amounts of water at least 50 gallons per minute for bedrock aquifers and 150 gallons per minute for alluvial aquifers. The minor basins produce significantly less amounts of water. The terms alluvial and bedrock are mainly descriptive of the proximity the aquifer is to a river. The alluvial aquifers are products of river movements over thousands of years. These loosely cemented materials recharge from the river, the degree by which can be directly influenced by the water levels in the river. Bedrock aquifers are typically older, more cemented, and larger than the alluvial aquifers. Their recharge is often slower and vary over time.
For more information on groundwater and aquifers visit the USGS Water Science School website.
Hydrologic Investigations
The first step in any hydrologic investigation
is characterization of the resource. Initially, upper, lower, and lateral boundaries of the groundwater basin are determined, and then aquifer properties—such as saturated thickness, hydraulic conductivity (ft/day), transmissivity (ft²/day), specific yield, and storage coefficient—are determined to understand the storage and yield capacity of the basin. Groundwater basins are dynamic; aquifers adjust constantly to short-term and long-term changes in climate, groundwater withdrawals, and land uses. Thus, the amount of water entering the basin (recharge) and the amount of water leaving the basin (discharge) are also important factors in the evaluation of groundwater availability.
Hydrogeologists use a variety of methods to estimate aquifer parameters, recharge, discharge, and water quality of the basins. These include physical measurements, such as water levels in wells, stream flow measurements, aquifer pumping tests, tracer tests, and water quality sampling. Other methods are indirect such as developing water budgets and utilizing computer groundwater flow models. Computer models enhance our understanding of current conditions as well as assist in the prediction of aquifer response to future climatic or land use changes.
Groundwater Allocation
Consistent with state law, the OWRB conducts maximum annual yield (MAY) studies to determine amounts of water that may be withdrawn from Oklahoma's groundwater basins by permitted water users. The resulting figure is considered to be the amount of water that can be safely withdrawn from an aquifer to ensure a minimum basin life of 20 years.
To arrive at a basin's MAY, investigators map the total land overlying the basin-often divided into sub-basins for yield determinations-and estimate the amount of water in storage. Next, they determine the rate of natural recharge and total discharge, transmissivity, and potential for pollution from natural sources. The balance of the available water is then allocated proportionately to each acre of land overlying the basin. Prior to final consideration of this prorated amount, hearings are held to allow public input to be included into the determinations.
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