Prepared in cooperation with the Oklahoma Water Resources Board

Hydrogeology and Simulated Groundwater Flow and 

Availability in the North Fork Red River Aquifer,

Southwest Oklahoma, 1980–2013

Scientific Investigations Report 2017–5098

U.S. Department of the Interior

U.S. Geological Survey
Front cover, Boat ramp at Lake Altus, Okla., during hydrologic drought conditions, December 20, 2012. 

Photo by Kevin A. Smith, used with permission.

Back cover, Lake Altus Dam near Lugert, Okla., January 4, 2003. Photo by S. Jerrod Smith.
Hydrogeology and Simulated Groundwater 

Flow and Availability in the North Fork 

Red River Aquifer, Southwest Oklahoma, 

1980–2013

By S. Jerrod Smith, John H. Ellis, Derrick L. Wagner, and Steven M. Peterson

Prepared in cooperation with the Oklahoma Water Resources Board

Scientific Investigations Report 2017–5098

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

RYAN K. ZINKE, Secretary

U.S. Geological Survey

William H. Werkheiser, Acting Director

U.S. Geological Survey, Reston, Virginia: 2017

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Suggested citation:

Smith, S.J., Ellis, J.H., Wagner, D.L., and Peterson, S.M., 2017, Hydrogeology and simulated groundwater flow and 

availability in the North Fork Red River aquifer, southwest Oklahoma, 1980–2013: U.S. Geological Survey Scientific 

Investigations Report 2017–5098, 107 p., https://doi.org/10.3133/sir20175098.

ISSN 2328-031X (print)

ISSN 2328-0328 (online)
iii

Acknowledgments

The project documented in this report was conducted as part of the U.S. Geological Survey 

(USGS) Cooperative Water Program in cooperation with the Oklahoma Water Resources Board 

(OWRB). The authors value the contributions of many OWRB and USGS staff that led to the 

successful completion of the project. The authors thank the OWRB for support on this project 

and OWRB Water Resources geologist Christopher Neel for help with defining study objectives 

and providing hydrogeologic data. OWRB geologist Jon Sanford compiled drawdown data from 

well completion reports. 

The authors also thank former USGS employees Noel Osborn, who provided initial project 

coordination and management, and Trevor Grout, who compiled, organized, and analyzed 

available hydrologic and spatial data. USGS employees Marty Phillips and Martin Schneider 

measured stream base flow, and Kevin Smith measured hydraulic conductivity and water-table 

altitudes in addition to siting and maintaining continuous water-level recorder wells. Shana 

Mashburn provided guidance on recharge estimation techniques and facilitated data entry to 

the National Water Information System database. The authors acknowledge and appreciate the 

professionalism, experience, and dedication of these helpful colleagues.

v

Contents

Acknowledgments .......................................................................................................................................iii

Abstract ..........................................................................................................................................................1

Introduction ....................................................................................................................................................2

Purpose and Scope .............................................................................................................................2

Description of Study Area ..................................................................................................................3

Climate Characteristics and Trends ..................................................................................................9

Land Cover ..........................................................................................................................................12

Groundwater-Use Characteristics and Trends .............................................................................12

Streamflow Characteristics and Trends ........................................................................................18

Groundwater Quality .........................................................................................................................18

Hydrogeology of the North Fork Red River Aquifer ...............................................................................25

Quaternary Alluvium and Terrace ...................................................................................................25

Bedrock Units .....................................................................................................................................25

Tertiary Ogallala Formation .....................................................................................................25

Permian Bedrock Units ............................................................................................................25

Cambrian Wichita Granite Group ...........................................................................................25

Hydrogeologic Framework ........................................................................................................................26

Aquifer Extent .....................................................................................................................................26

Potentiometric Surface .....................................................................................................................26

Textural and Hydraulic Properties of Aquifer Material ................................................................27

Lithologic Log Standardization and Calculation of Percentage-Coarse-Material 

Values ............................................................................................................................27

Spatial Distribution of Percentage-Coarse-Material Values .............................................27

Hydraulic Properties ................................................................................................................29

Conceptual Groundwater-Flow Model ....................................................................................................32

Hydrologic Boundaries .....................................................................................................................32

Recharge ....................................................................................................................................32

Lateral Groundwater Flows .....................................................................................................35

Streambed Seepage .................................................................................................................35

Lakebed Seepage .....................................................................................................................38

Springs and Seeps ....................................................................................................................38

Saturated-Zone Evapotranspiration ......................................................................................38

Well Withdrawals, Water-Level Response, and Storage Change ....................................39

Conceptual Groundwater-Flow Model Water Budget .................................................................39

Numerical Groundwater-Flow Model ......................................................................................................41

Spatial and Temporal Discretization ...............................................................................................41

Simulation of Hydrologic Boundaries .............................................................................................41

Recharge and the Soil-Water-Balance Code ......................................................................41

Lateral Groundwater Flows .....................................................................................................43

Streams .......................................................................................................................................43

Lakes ...........................................................................................................................................46

Springs and Seeps ....................................................................................................................46

Saturated-Zone Evapotranspiration ......................................................................................46
vi

Well Withdrawals .....................................................................................................................46

Calibration ...........................................................................................................................................47

Calibration Targets ....................................................................................................................47

Water-Table-Altitude Observations ..............................................................................48

Base Flow and Net Streambed Seepage .....................................................................48

Lake Altus Stage ..............................................................................................................49

Calibration Results ....................................................................................................................49

Simulated Aquifer Thickness and Saturated Thickness ...........................................49

Comparison of Simulated and Observed Values ........................................................50

Calibrated Water Budget ................................................................................................62

Calibrated Parameter Values and Sensitivities ..........................................................64

Differences in Numerical Groundwater-Flow Models ................................................................69

Groundwater Availability Scenarios ........................................................................................................69

Equal Proportionate Share ...............................................................................................................69

Projected (50-Year) Pumping ...........................................................................................................72

Hypothetical (10-Year) Drought .......................................................................................................75

Model Limitations ........................................................................................................................................80

Summary .......................................................................................................................................................80

References Cited .........................................................................................................................................82

Figures

1. Map showing the North Fork Red River aquifer study area, southwest Oklahoma .........4

2. Map showing major geographic and surface-water features in and near the 

North Fork Red River watershed, southwest Oklahoma and northwest Texas .................5

3. Graphs showing annual mean precipitation; annual mean temperature; and 

depth to water in selected wells, southwest Oklahoma, 1895–2015 .................................10

4. Graphs showing mean monthly precipitation and mean monthly temperature, 

southwest Oklahoma, 1895–2015 and 1980–2013 .................................................................11

5. Map and pie charts showing land and crop cover over the North Fork Red 

River aquifer, southwest Oklahoma, 2010–15 ........................................................................13

6. Map showing land areas and wells permitted for groundwater use from the 

North Fork Red River aquifer, southwest Oklahoma, 2015 ..................................................14

7. Graph showing annual reported groundwater use by type from the North Fork 

Red River aquifer, 1967–2013 ...................................................................................................15

8. Graph showing annual reported groundwater use by county from the North 

Fork Red River aquifer, 1980–2013 ...........................................................................................17

9. Boxplot showing statistics for reported yields of wells completed in the North 

Fork Red River aquifer ...............................................................................................................18

10. Map showing groundwater-quality stations in the North Fork Red River aquifer, 

southwest Oklahoma, 1944–62 and July–August 2014 ........................................................19

11. Stratigraphic chart showing surficial geologic and hydrogeologic units of the 

North Fork Red River aquifer study area, southwest Oklahoma ........................................22

12. Map showing surficial geologic units and major structural features of the North 

Fork Red River aquifer study area, southwest Oklahoma ...................................................23

13. Piper diagram showing groundwater-quality samples of water produced from 

the North Fork Red River aquifer, 1944–62 and July–August 2014 ....................................24
vii

14. Map showing potentiometric surface contours and general direction of 

groundwater flow in the North Fork Red River aquifer, 2013 ..............................................28

15. Graph and boxplot showing distributions of estimated hydraulic conductivity 

observations in the North Fork Red River aquifer ................................................................30

16. Graph showing mean annual flow by water-budget category for the conceptual 

model and the calibrated numerical model of the North Fork Red River aquifer, 

1980–2013 ....................................................................................................................................33

17. Graph showing daily precipitation and depth to water in continuous water-level 

recorder wells completed in the North Fork Red River aquifer, February 2013 

through January 2015 ................................................................................................................34

18. Map showing base-flow measurements with gaining and losing reaches of the 

North Fork Red River and tributaries, March 2013 ...............................................................36

19. Graphs showing monthly streamflow, monthly base flow, and annual base-flow 

index for Sweetwater streamgage (07301420) on Sweetwater Creek; Carter 

streamgage (07301500) on North Fork Red River; and Headrick streamgage 

(07305000) on North Fork Red River, 1980–2013 ....................................................................37

20. Graphs showing annual water-level measurements and mean annual waterlevel change by county for Oklahoma Water Resources Board Mass 

Measurement Program wells completed in the North Fork Red River aquifer, 

1978–2014 ....................................................................................................................................40

21. Map showing active area, boundary conditions, and parameter zones for the 

numerical groundwater-flow model of the North Fork Red River aquifer, 

southwest Oklahoma .................................................................................................................42

22. Graph showing annual precipitation and annual groundwater recharge 

computed by using the Soil-Water-Balance code for the North Fork Red River 

aquifer, 1980–2013. .....................................................................................................................44

23. Map showing mean annual groundwater recharge computed by using the SoilWater-Balance code for the North Fork Red River aquifer, 1980–2013 ............................45

24. Graph showing monthly water demand by groundwater-use type from the North 

Fork Red River aquifer, 1980–2013 ...........................................................................................47

25. Graphs showing temporal distribution of water-table-altitude observations and 

streamflow observations for the numerical groundwater-flow model of the North 

Fork Red River aquifer, 1980–2015 ...........................................................................................49

26. Graphs showing observed and simulated water-table altitudes and water-tablealtitude residual distributions for the numerical groundwater-flow model of the 

North Fork Red River aquifer, 1980–2013 ...............................................................................51

27. Map showing spatial distribution of mean water-table-altitude residuals for the 

numerical groundwater-flow model of the North Fork Red River aquifer, 

1980–2013 ....................................................................................................................................52

28. Graphs showing observed and simulated water-table altitudes for the numerical 

groundwater-flow model of the North Fork Red River aquifer, 1980–2013 .......................53

29. Graphs showing observed streamflow, observed base flow, and simulated base 

flow at Sweetwater streamgage (07301420) on Sweetwater Creek; Carter 

streamgage (07301500) on North Fork Red River; Headrick streamgage (07305000) 

on North Fork Red River; and Snyder streamgage (07307010) on Otter Creek 

for the numerical groundwater-flow model of the North Fork Red River aquifer, 

southwest Oklahoma, 1980–2013 ............................................................................................58

30. Graphs showing Lake Altus stage and simulated storage for the numerical 

groundwater-flow model of the North Fork Red River aquifer, 1980–2013 .......................61
viii

31. Graphs showing annual inflows and outflows and annual change in groundwater 

storage for the numerical groundwater-flow model of the North Fork Red River 

aquifer, 1980–2013 ......................................................................................................................63

32. Graphs showing mean monthly aquifer inflows and outflows and mean monthly 

change in groundwater storage for the North Fork Red River aquifer, 1980–2013 .........65

33. Graphs showing annual lake inflows and outflows and change in lake storage 

for Lake Altus in the numerical groundwater-flow model of the North Fork Red 

River aquifer, 1980–2013 ...........................................................................................................66

34. Graph showing observation group sensitivity by parameter group in the 

numerical groundwater-flow model for the North Fork Red River aquifer, 

1980–2013 ....................................................................................................................................67

35. Graph showing monthly mean precalibration recharge and monthly mean 

calibrated recharge for the numerical groundwater-flow model of the North 

Fork Red River aquifer, 1980–2013 ...........................................................................................67

36. Map showing horizontal hydraulic conductivity (Kh) for the calibrated numerical 

groundwater-flow model of the North Fork Red River aquifer, southwest 

Oklahoma ....................................................................................................................................68

37. Graph showing percentage of the North Fork Red River aquifer with less than 

5 feet of saturated thickness after 20 years of continuous equal-proportionateshare groundwater pumping ...................................................................................................70

38. Map showing simulated saturated thickness and base flow after 20 years of 

continuous equal-proportionate-share groundwater pumping in the North Fork 

Red River aquifer, southwest Oklahoma ................................................................................71

39. Graphs showing changes in simulated base flow and simulated groundwater 

storage during 50 years of continuous equal-proportionate-share groundwater 

pumping in the North Fork Red River aquifer, southwest Oklahoma ................................72

40. Graphs showing simulated groundwater storage and simulated mean 

annual base flow through 50 years of groundwater pumping at selected rates in 

the North Fork Red River aquifer, southwest Oklahoma .....................................................73

41. Graph showing changes in groundwater storage resulting from a hypothetical 

10-year drought (1984–93) for the North Fork Red River aquifer, 1980–97 .......................76

42. Graphs showing changes in simulated base flow at Sweetwater streamgage 

(07301420) on Sweetwater Creek; Carter streamgage (07301500) on North Fork 

Red River; Headrick streamgage (07305000) on North Fork Red River; and 

Snyder streamgage (07307010) on Otter Creek resulting from a hypothetical 

10-year drought (1984–93) for the North Fork Red River aquifer, 1980–97 .......................77

43. Graphs showing changes in Lake Altus stage and Lake Altus storage resulting 

from a hypothetical 10-year drought (1984–93) for the North Fork Red River 

aquifer, 1980–97 ..........................................................................................................................79
ix

Tables

1. Selected data-collection stations in and near the North Fork Red River aquifer 

study area, southwest Oklahoma ............................................................................................88

2. Mean annual streamflow and mean annual base flow for selected streamgages 

in and near the North Fork Red River aquifer study area, 1980–2013 .................................6

3. Mean annual precipitation and mean annual temperature data summaries from 

selected regions and stations in and near the North Fork Red River aquifer study 

area, southwest Oklahoma ......................................................................................................11

4. Mean annual reported groundwater use by type for the North Fork Red River 

aquifer, 1967–2013 ......................................................................................................................16

5. Statistical summary of reported yields of wells completed in the North Fork Red 

River aquifer, 1936–2015. ...........................................................................................................17

6. Statistical summary of groundwater-quality data from 20 wells completed in 

the North Fork Red River aquifer, July–August 2014 ...........................................................20

7. Hydraulic properties calculated from hydraulic profiling tool test holes and 

multi-well aquifer tests in the North Fork Red River aquifer ..............................................31

8. Conceptual groundwater-flow model mean annual water budget for the North 

Fork Red River aquifer, 1980–2013 ...........................................................................................32

9. Observation group contribution to the objective function for the automated 

calibration of the numerical groundwater-flow model of the North Fork Red 

River aquifer, 1980–2013 ...........................................................................................................48

10. Statistical summary of aquifer thickness, saturated thickness, and hydraulic 

properties for the calibrated numerical groundwater-flow model of the North 

Fork Red River aquifer, 1980–2013 ...........................................................................................50

11. Statistical summary of water-table-altitude residuals for the numerical 

groundwater-flow model of the North Fork Red River aquifer, 1980–2013 .......................51

12. Statistical summary of base-flow residuals for the numerical groundwater-flow 

model of the North Fork Red River aquifer, 1980–2013 ........................................................60

13. Statistical summary of lake-stage residuals for the numerical groundwater-flow 

model of the North Fork Red River aquifer, 1980–2013 ........................................................61

14. Mean annual water budget for the numerical groundwater-flow model of the 

North Fork Red River aquifer, 1980–2013 ...............................................................................62

15. Equal-proportionate-share pumping rates for the North Fork Red River aquifer, 

southwest Oklahoma .................................................................................................................70

16. Changes in groundwater storage and mean annual base flow after 50 years of 

groundwater pumping at selected rates for the North Fork Red River aquifer, 

southwest Oklahoma .................................................................................................................74
x

Conversion Factors

U.S. customary units to International System of Units

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 4,047 square meter (m2

)

acre 0.4047 hectare (ha)

acre 0.4047 square hectometer (hm2

) 

acre 0.004047 square kilometer (km2

)

square mile (mi2

) 259.0 hectare (ha)

square mile (mi2

) 2.590 square kilometer (km2) 

Volume

acre-foot (acre-ft) 1,233 cubic meter (m3

)

acre-foot (acre-ft) 0.001233 cubic hectometer (hm3

) 

Flow rate

acre-foot per year (acre-ft/yr) 1,233 cubic meter per year (m3

/yr)

acre-foot per year (acre-ft/yr) 0.001233 cubic hectometer per year (hm3

/yr)

foot per second (ft/s) 0.3048 meter per second (m/s)

foot per day (ft/d) 0.3048 meter per day (m/d)

foot per year (ft/yr) 0.3048 meter per year (m/yr)

cubic foot per second (ft3

/s) 0.02832 cubic meter per second (m3/s)

cubic foot per day (ft3

/d) 0.02832 cubic meter per day (m3/d)

gallon per minute (gal/min) 0.06309 liter per second (L/s)

inch per year (in/yr) 25.4 millimeter per year (mm/yr)

mile per hour (mi/h) 1.609 kilometer per hour (km/h) 

Hydraulic conductivity

foot per day (ft/d) 0.3048 meter per day (m/d)

Hydraulic gradient

foot per mile (ft/mi) 0.1894 meter per kilometer (m/km)

Transmissivity

foot squared per day (ft2

/d) 0.09290 meter squared per day (m2/d) 

Leakance

foot per day per foot [(ft/d)/ft] 1 meter per day per meter

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as 

°F = (1.8 × °C) + 32.

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as 

°C = (°F – 32) / 1.8.
xi

Datum

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Altitude, as used in this report, refers to distance above the vertical datum.

Supplemental Information

Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times 

foot of aquifer thickness [(ft3/d)/ft2]ft. In this report, the mathematically reduced form, foot 

squared per day (ft2/d), is used for convenience.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 

25 °C).

Concentrations of chemical constituents in water are given in either milligrams per liter (mg/L) 

or micrograms per liter (μg/L).

Abbreviations

BFI base-flow index

DEM digital elevation model

EFRR Elm Fork Red River inflow for Streamflow-Routing package

ELK Elk Creek inflow for Streamflow-Routing package

EPS equal proportionate share

ET evapotranspiration

GHB general-head boundary

HPT Hydraulic Profiling Tool

IDW inverse distance weighted

Kh horizontal hydraulic conductivity

LAID Lugert-Altus Irrigation District

MAY maximum annual yield

NFRR North Fork Red River inflow for Streamflow-Routing package

NWIS National Water Information System

OWRB Oklahoma Water Resources Board

RMSE root-mean-square error

SFR streamflow routing
xii

SWB soil-water balance

SWEE Sweetwater Creek inflow for Streamflow-Routing package

Sy specific yield

TDS total dissolved solids

USGS U.S. Geological Survey

WTF water-table fluctuation
Hydrogeology and Simulated Groundwater Flow and 

Availability in the North Fork Red River Aquifer, 

Southwest Oklahoma, 1980–2013

By S. Jerrod Smith,1 John H. Ellis,1 Derrick L. Wagner,2 and Steven M. Peterson1

Abstract

On September 8, 1981, the Oklahoma Water Resources 

Board established regulatory limits on the maximum annual 

yield of groundwater (343,042 acre-feet per year) and equalproportionate-share (EPS) pumping rate (1.0 acre-foot per 

acre per year) for the North Fork Red River aquifer. The 

maximum annual yield and EPS were based on a hydrologic 

investigation 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. 

The Oklahoma Water Resources Board is statutorily required 

(every 20 years) to update the hydrologic investigation on 

which the maximum annual yield and EPS were based. 

Because 20 years have elapsed since the final order was 

issued, the U.S. Geological Survey, in cooperation with the 

Oklahoma Water Resources Board, conducted an updated 

hydrologic investigation and evaluated the effects of potential 

groundwater withdrawals on groundwater flow and availability 

in the North Fork Red River aquifer in Oklahoma. This report 

describes a hydrologic investigation of the North Fork Red 

River aquifer that includes an updated summary of the aquifer 

hydrogeology. As part of this investigation, groundwater 

flow and availability were simulated by using a numerical 

groundwater-flow model.

The North Fork Red River aquifer in Beckham, Greer, 

Jackson, Kiowa, and Roger Mills Counties in Oklahoma 

is composed of about 777 square miles (497,582 acres) of 

alluvium and terrace deposits along the North Fork Red River 

and tributaries, including Sweetwater Creek, Elk Creek, Otter 

Creek, and Elm Fork Red River. The North Fork Red River 

is the primary source of surface-water inflow to Lake Altus, 

which overlies the North Fork Red River aquifer. Lake Altus 

is a U.S. Bureau of Reclamation reservoir with the primary 

purpose of supplying irrigation water to the Lugert-Altus 

Irrigation District. 

A hydrogeologic framework was developed for the North 

Fork Red River aquifer and included a definition of the aquifer 

extent and potentiometric surface, as well as a description of 

the textural and hydraulic properties of aquifer materials. The 

hydrogeologic framework was used in the construction of a 

numerical groundwater-flow model of the North Fork Red 

River aquifer described in this report. A conceptual model of 

aquifer inflows and outflows was developed for the North Fork 

Red River aquifer to constrain the construction and calibration 

of a numerical groundwater-flow model that reasonably 

represented the groundwater-flow system. The conceptualmodel water budget estimated mean annual inflows to and 

outflows from the North Fork Red River aquifer for the period 

1980–2013 and included a sub-accounting of mean annual 

inflows and outflows for the portions of the aquifer that were 

upgradient and downgradient from Lake Altus. The numerical 

groundwater-flow model simulated the period 1980–2013 

and was calibrated to water-table-altitude observations at 

selected wells, monthly base flow at selected streamgages, net 

streambed seepage as estimated for the conceptual model, and 

Lake Altus stage. 

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 base flow 

and groundwater storage. The results of the groundwateravailability 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. 

EPS scenarios for the North Fork Red River aquifer 

were run for periods of 20, 40, and 50 years. The 20-, 40-, 

and 50-year EPS pumping rates under normal recharge 

conditions were 0.59, 0.52, and 0.52 acre-foot per acre per 

year, respectively. Given the 497,582-acre aquifer area, these 

rates correspond to annual yields of about 294,000, 259,000, 

and 259,000 acre-feet per year, respectively. Groundwater 

storage at the end of the 20-year EPS scenario was about 

951,000 acre-feet, or about 1,317,000 acre-feet (58 percent) 

less than the starting EPS scenario storage. This decrease in 

storage was equivalent to a mean water-level decline of about 

22 feet. Most areas of the active alluvium near the North Fork 

1

U.S. Geological Survey.

2

Oklahoma Water Resources Board.
2 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Red River, Elk Creek, and Elm Fork Red River remained 

partially saturated through the end of the EPS scenario because 

of streambed seepage. Lake Altus storage was reduced to zero 

after 6–7 years of EPS pumping in each scenario.

Projected 50-year pumping scenarios were used to 

simulate the effects of selected well withdrawal rates on 

groundwater storage of the North Fork Red River aquifer 

and base flows in the North Fork Red River upstream from 

Lake Altus. The effects of well withdrawals were evaluated 

by comparing changes in groundwater storage and base flow 

between four 50-year scenarios using (1) no groundwater 

pumping, (2) mean pumping rates for the study period (1980–

2013), (3) 2013 pumping rates, and (4) increasing demand 

pumping rates. The increasing demand pumping rates assumed 

a 20.4-percent increase in pumping over 50 years based on 

2010–60 demand projections for southwest Oklahoma.

Groundwater storage after 50 years with no pumping was 

about 2,606,000 acre-feet, or 137,000 acre-feet (5.5 percent) 

greater than the initial groundwater storage; this groundwater 

storage increase is equivalent to a mean water-level increase 

of 2.3 feet. Groundwater storage after 50 years with the mean 

pumping rate for the study period (1980–2013) was about 

2,476,000 acre-feet, or about 7,000 acre-feet (0.3 percent) 

greater than the initial groundwater storage; this groundwater 

storage increase is equivalent to a mean water-level increase 

of 0.1 foot. Groundwater storage at the end of the 50-year 

period with 2013 pumping rates was about 2,398,000 acrefeet, or about 70,000 acre-feet (2.8 percent) less than the initial 

storage; this groundwater storage decrease is equivalent to a 

mean water-level decline of 1.2 feet. Groundwater storage at 

the end of the 50-year period with increasing demand pumping 

rates was about 2,361,000 acre-feet, or about 107,000 acrefeet (4.3 percent) less than the initial storage; this groundwater 

storage decrease is equivalent to a mean water-level decline 

of 1.8 feet. Mean annual base flow simulated at the Carter 

streamgage (07301500) on North Fork Red River increased 

by about 4,000 acre-feet (10 percent) after 50 years with no 

pumping and decreased by about 5,400 acre-feet (13 percent) 

after 50 years with increasing demand pumping rates. Mean 

annual base flow simulated at the North Fork Red River inflow 

to Lake Altus increased by about 7,400 acre-feet (15 percent) 

after 50 years with no pumping and decreased by about 

5,800 acre-feet (12 percent) after 50 years with increasing 

demand pumping rates.

A hypothetical 10-year drought scenario was used 

to simulate the effects of a prolonged period of reduced 

recharge on groundwater storage and Lake Altus stage and 

storage. Drought effects were quantified by comparing the 

results of the drought scenario to those of the calibrated 

numerical model (no drought). To simulate the hypothetical 

drought, recharge in the calibrated numerical model was 

reduced by 50 percent during the simulated drought period 

(1984–1993). Groundwater storage at the end of the drought 

period was about 2,271,000 acre-feet, or about 426,000 acrefeet (15.8 percent) less than the groundwater storage of the 

calibrated numerical model. This decrease in groundwater 

storage is equivalent to a mean water-table-altitude decline of 

7.1 feet. At the end of the 10-year hypothetical drought period, 

base flows at the Sweetwater (07301420), Carter (07301500), 

Headrick (07305000), and Snyder (07307010) streamgages 

had decreased by about 37, 61, 44, and 45 percent, 

respectively. The minimum Lake Altus storage simulated 

during the drought period was 403 acre-feet, which was a 

decline of 92 percent from the nondrought storage. Reduced 

base flows in the North Fork Red River were the primary 

cause of Lake Altus storage declines. 

Introduction

The 1973 Oklahoma Water Law (82 OK Stat 

§ 82-1020.5) requires the Oklahoma Water Resources 

Board (OWRB) to conduct hydrologic investigations of the 

State’s aquifers (called groundwater basins) 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 (OWRB, 

2010). For alluvium and terrace aquifers, the groundwaterbasin-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 OWRB issued a final order on September 8, 1981, 

that established the MAY (343,042 acre-feet per year 

[acre-ft/yr]) and EPS pumping rate (1.0 acre-foot per acre per 

year) for the North Fork Red River aquifer (OWRB, 2015a). 

The MAY and EPS were based on hydrologic investigations 

by Kent (1980) and Paukstaitis (1981) that used a numerical 

groundwater-flow model (Trescott and others, 1976) to 

evaluate the effects of potential groundwater withdrawals 

on groundwater availability in the North Fork Red River 

aquifer. Every 20 years, the OWRB is statutorily required to 

update the hydrologic investigation on which the MAY and 

EPS were based. Because 20 years have elapsed since the 

final order was issued, the U.S. Geological Survey (USGS), 

in cooperation with the OWRB, conducted an updated 

hydrologic investigation and evaluated the effects of potential 

groundwater withdrawals on groundwater flow and availability 

in the North Fork Red River aquifer.

Purpose and Scope

The purpose of this report is to describe a hydrologic 

investigation of the North Fork Red River aquifer that 

includes an updated summary of the aquifer hydrogeology and 

results of the simulation of groundwater flow and availability 
Introduction 3

obtained by using a numerical groundwater-flow model. The 

numerical groundwater-flow model was calibrated to observed 

data and used to compute a mean annual water budget for 

the study period 1980–2013. 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 the groundwater-availability scenarios could be used 

by the OWRB to reevaluate the MAY of groundwater from 

the North Fork Red River aquifer in Oklahoma. The calibrated 

numerical groundwater-flow model and groundwateravailability scenarios were archived and released in Smith and 

others (2017).

The geographic scope of the hydrologic investigation is 

the alluvium and terrace deposits of the North Fork Red River 

aquifer and the underlying Permian bedrock units. Though the 

alluvium and terrace deposits of the North Fork Red River and 

Sweetwater Creek extend west into Texas, this investigation 

was focused on the OWRB jurisdictional extent of the North 

Fork Red River aquifer in Beckham, Greer, Jackson, Kiowa, 

and Roger Mills Counties of southwest Oklahoma (fig. 1). The 

alluvium and terrace deposits of the North Fork Red River 

also extend south into Tillman County, Oklahoma, where they 

are known as the Tillman Terrace aquifer (fig. 1); the Tillman 

Terrace aquifer was not included in the investigation described 

in this report because the OWRB manages that aquifer 

separately from the North Fork Red River aquifer. 

Description of Study Area

The North Fork Red River aquifer in Beckham, Greer, 

Jackson, Kiowa, and Roger Mills Counties in Oklahoma is 

composed of about 777 square miles (mi2) (497,582 acres) of 

alluvium and terrace deposits along the North Fork Red River. 

This area includes alluvium and terrace deposits along several 

major tributaries to the North Fork Red River including 

Sweetwater Creek, Elk Creek, Otter Creek, and Elm Fork Red 

River in southwest Oklahoma (fig. 1). The North Fork Red 

River and tributaries, which compose the North Fork Red 

River watershed, drain about 4,500 mi2

 of land area in Texas 

and Oklahoma before connecting with the Red River (fig. 2). 

Groundwater discharge from the North Fork Red River aquifer 

sustains streamflow to the North Fork Red River during 

most of the year (Smith and Wahl, 2003); however, some 

gaged reaches of the North Fork Red River and tributaries 

commonly have no flow (defined as streamflow less than 

1 cubic foot per second [ft3/s]) in the late summer when water 

demands for irrigation, public supply, and evapotranspiration 

(ET) are greatest. The Carter streamgage (07301500; fig. 1, 

table 1, at end of report) on the North Fork Red River, for 

example, recorded no flow from June 6, 2011, to January 6, 

2012, during a 7-month period of exceptional drought (USGS, 

2015a). Though a few storms in that period produced enough 

runoff to sustain streamflow for a few hours, no day in that 

period had daily streamflow greater than 1 ft3

/s.

The North Fork Red River is the primary source 

of surface-water inflow to Lake Altus, a U.S. Bureau of 

Reclamation reservoir with the primary purpose of supplying 

irrigation water to the Lugert-Altus Irrigation District (LAID) 

(fig. 2). Lake Altus supplies a dependable annual yield of 

47,100 acre-ft/yr but is over-allocated with permitted surfacewater withdrawals of 85,630 acre-ft/yr to the LAID and 

4,800 acre-ft/yr to the city of Altus (OWRB, 2012a). For the 

study period 1980–2013, about half of the annual surfacewater inflow to Lake Altus was supplied by base flow (as 

observed at the Carter streamgage [07301500] and computed 

by using the USGS Groundwater Toolbox [Barlow and others, 

2015]), which is the component of streamflow supplied by 

the discharge of groundwater to streams (Barlow and Leake, 

2012) (table 2). However, the total annual base flow and the 

base-flow index (the ratio of total annual base flow to total 

annual streamflow) generally have been increasing (while 

peak flows generally have been decreasing) since the 1960s at 

the Carter streamgage (07301500), just upstream from Lake 

Altus (Smith and Wahl, 2003; Esralew and Lewis, 2010). 

The reasons for these increasing trends in base flow and 

base-flow index are not clear but could include increases in 

the number of impoundments (stock ponds and floodwaterretarding structures) or changes in agricultural practices that 

reduce runoff and promote artificial recharge to the aquifer 

(Smith and Wahl, 2003). In recent years (2000–13) at the 

Carter streamgage (07301500), the base-flow index exceeded 

60 percent in 4 out of 14 years with a maximum base-flow 

index of 81.1 percent in 2011 (table 2). 

Elk Creek (through Bretch Canal) and West Otter Creek 

supply inflow to Tom Steed Reservoir, a U.S. Bureau of 

Reclamation reservoir that provides water (16,100 acre-ft/

yr, permitted) to the Oklahoma cities of Altus, Snyder, and 

Frederick, as well as the Hackberry Flat Wildlife Management 

Area (U.S. Bureau of Reclamation, 2015a; fig. 2). During 

times of runoff, surplus water is diverted from Elk Creek 

through the Bretch Canal to augment supply at Tom Steed 

Reservoir (fig. 2). Unlike Lake Altus, which is dependent 

on base flows from the North Fork Red River aquifer for 

replenishment, Tom Steed Reservoir is near the edge of the 

aquifer and primarily is replenished by surface-water runoff 

from areas outside of the North Fork Red River aquifer. Base 

flows in Elk Creek originate from several sources including 

the Elk City aquifer, the North Fork Red River aquifer, and, 

following periods of runoff, numerous floodwater-retarding 

structures in the Elk Creek watershed (figs. 1–2). 
4 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

0 6 12 18 24 MILES

0 6 12 18 24 KILOMETERS

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

Altus

Blair

Carter

Dodson

Elk City

Erick

Gould

Granite

Headrick

Hobart

Hollis

Lone

Wolf

Mangum

New

Cordell Sayre

Snyder

Texola

Willow

H aystackC reek

LakeCre ek

Cave Creek

Glen Creek

Buffalo Creek

LittleEl k

Creek

D eep

RedC reek

EastOtter Creek

Elm Fork

Red

River

Trai l Creek

Sa ltForkRed River

Tepee Creek

WashitaRi ver

SpringCreek

West OtterCreek

Fish Creek

Long

Creek

Elm Creek

Elk Creek

Sand Creek

Bu ckCreek

Bull Creek

Bitter Creek

Turkey Creek

Starvation Creek

Sweetwater

Creek

NorthElm

Creek

Sa n d Creek

GrapeCreek

Stinking Creek

Deer Creek

Timber Creek

BoggyCreek

Cavalry Creek

HorseBranch

Salt Creek

 Otter

Creek

1 40

33

47

49

27

32

35

53

10

07301420

07301500

07303000

07303400

07303500 07304500

07305000

07307010

07301420

07301500

07303000

07303400

07303500 07304500

07305000

07307010

HOBA

342944

349668

340184

347952

346035

348299

HPT1 HPT2

HPT4

HPT5

9088 9089

9438

9444

9448

9450 9451

9453 9454

9458

9460

9096 9100 9098

9101

9106

9108 9109

9113

9119 9114

9534

9535

9536

9538

9539 9540

9543

9545

9549 9553

9107

9122 9123

CR3

CR2

CR1

AT2

AT3

AT1

AT4

TEXAS

OKLAHOMA

Study

area

North

Fork

Red

River

Lake

Altus

Tom Steed

Reservoir

ROGER MILLSCOUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY

KIOWA

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN COUNTY

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

EXPLANATION

North Fork Red River aquifer boundary (modified from Oklahoma Water Resources Board, 2015b)

Incorporated area (U.S. Census Bureau, 2000)

Tillman Terrace aquifer (Oklahoma Water Resources Board, 2015b)

National Climatic Data Center (2015)

Oklahoma Mesonet (2015)

Streamgage (U.S. Geological Survey, 2015a; table 1)

Elk City aquifer (Oklahoma Water Resources Board, 2015b)

Continuous water-level recorder well (U.S. Geological Survey, 2015a; table 1)

Multi-well aquifer test location (table 1)

Geoprobe hydraulic profiling tool test hole (table 1)

Water-table-altitude observation and Mass Measurement Program well (Oklahoma Water

Resources Board, 2015b; table 1, only wells discussed in this report are labeled)

Historical water-table altitude observation well (U.S. Geological Survey, 2015a; table 1)

Climate station (table 1)

Figure 1. The North Fork Red River aquifer study area, southwest Oklahoma.
Basin 32

Basin

33

Basin

34

Basin

36

Basin 37

Basin 42

Basin 43

Basin 39

Basin 41 Basin 38

Basin 40

Bear Creek

North Pease River

Red

River

Ca nadian R ive r

Quitaque Creek

Mulberry Creek

Elm

Fork Red River

Trail C re e k

McClellan Creek

Elm

Creek

Elk C re e k

Sandy Creek

Buck Creek

Bitte r Cre e k

T ur k e yC r ee k

Sweetwater Creek

Gypsum

Creek

Little Red River

Tule Cre e k

Indian Creek

B

Gageby

Creek

W a s h itaRi ve r

North Fork Red River

Red River

TimberCreek

07301300

07301410 07301420

07303000

07303400

073050

07301500

07303500 07304500

07301300

07301410

07301420

07303000

07303400

073050

07301500

07303500

07304500

11120303 11120304

11120301 11120302

MOORE

COUNTY

HUTCHINSON

COUNTY

ROBERTS

COUNTY HEMPHILL

COUNTY

ROGER

MILLS

COUNTY

POTTER

COUNTY

CARSON

COUNTY

GRAY

COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY 

RANDALL

COUNTY

ARMSTRONG

COUNTY

DONLEY

COUNTY COLLINGSWORTH COUNTY

GREER

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

HALL

COUNTY

CHILDRESS

COUNTY

HARDEMAN

COUNTY

WILBARGER

COUNTY

HALE

COUNTY

FLOYD

COUNTY

MOTLEY

COUNTY COTTLE

COUNTY

Lake

Altus

Lake

McClellan

Altus

Amarillo

Borger

Childress

Chillicothe

Elk City

F

Miami

Pampa

Plainview

Wellington

BC

Altus

Canal

101°40' 101°20' 101° 100°40' 100°20' 100° 99°40' 99°20' 

35°40'35°20'

35°

34°40'34°20'

TEXAS

OKLAHOMA

0 10 20 0 10 20 30 40 

Base modified from U.S. Geological Survey digital dataUniversal Transverse Mercator, zone 14North American Datum of 1983

EXPLANATION

Incorporated area (U.S. Census Bureau, 2000) Permitted diversion (Oklahoma Water Resources BLugert-Altus Irrigation District (LAID)Hackberry Flat Wildlife Management AreaNorth Fork Red River watershed

Diversion canalOklahoma Comprehensive Water Plan

water-management planning basin, Southwest Region, with number

Floodwater-retarding structure in the North Fo

(Smith and Esralew, 2010)

Streamgage

Subwatershed boundary (Smith and Esralew, 2010)

Figure 2.

Major geographic and surface-water features in and near the North Fork Red River watershed, southwest Oklahoma and northwest Texas
6 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 2. Mean annual streamflow and mean annual base flow for selected streamgages in and near the North Fork Red River aquifer 

study area, 1980–2013.

[Base flow computed by using BFI method in the U.S. Geological Survey Groundwater Toolbox (Barlow and others, 2015; streamflow data from U.S. 

Geological Survey, 2015a); Mean Lake Altus releases were assumed to be the same as mean streamflow at the Lugert streamgage; ft3/s, cubic feet per second; 

acre-ft/yr, acre-feet per year; %, percent; BFI, base-flow index; --, data not available or not applicable]

Year

Shamrock streamgage (07301300) on 

North Fork Red River

Kelton streamgage (07301410) on 

Sweetwater Creek

Sweetwater streamgage (07301420) on 

Sweetwater Creek

Mean 

streamflow

(ft3

/s)

Mean base flow Mean 

streamflow

(ft3/s)

Mean base flow Mean 

streamflow

(ft3/s)

Mean base flow

ft3

/s % (BFI) ft3/s % (BFI) ft3/s % (BFI)

1980 12.0 1.3 11.1 8.1 5.7 71.0 -- -- --

1981 13.1 0.7 5.1 10.1 5.7 55.7 -- -- --

1982 48.1 0.8 1.6 13.3 8.0 60.7 -- -- --

1983 29.5 1.1 3.6 8.0 6.1 76.1 -- -- --

1984 11.8 0.4 3.0 5.1 3.8 74.2 -- -- --

1985 43.9 3.9 8.8 15.6 7.0 45.2 -- -- --

1986 36.3 9.8 26.9 17.2 9.9 57.7 -- -- --

1987 28.3 9.7 34.4 16.9 12.2 72.0 31.5 22.0 69.8

1988 46.5 11.3 24.3 17.8 11.7 65.8 28.8 18.8 65.2

1989 58.6 3.8 6.5 18.4 12.1 65.6 25.8 18.2 70.3

1990 28.0 5.5 19.7 12.5 9.9 79.5 19.6 15.3 78.0

1991 -- -- -- 9.8 7.6 77.0 16.1 11.7 72.8

1992 -- -- -- 11.4 8.8 77.1 19.4 14.3 73.6

1993 -- -- -- 10.0 7.8 77.9 17.7 13.3 75.1

1994 -- -- -- 5.9 4.4 73.6 9.9 7.2 72.7

1995 -- -- -- 17.3 8.9 51.4 28.8 14.2 49.3

1996 -- -- -- 16.5 10.5 63.7 26.0 18.6 71.5

1997 -- -- -- 34.9 18.8 54.0 55.5 33.1 59.6

1998 -- -- -- 14.9 11.6 78.0 29.8 21.7 72.8

1999 -- -- -- 13.4 9.8 73.4 24.6 17.2 70.0

2000 -- -- -- 12.2 6.5 52.9 29.9 16.8 56.3

2001 29.9 15.0 50.1 14.4 10.2 70.7 31.9 21.3 66.8

2002 26.1 11.4 43.6 10.5 7.9 75.2 20.4 14.8 72.4

2003 27.0 9.7 36.0 9.0 7.7 85.0 16.8 12.1 72.3

2004 31.3 10.5 33.6 9.6 6.2 64.5 16.9 10.4 61.7

2005 26.6 11.8 44.4 8.4 6.3 74.8 14.5 10.4 71.7

2006 20.6 3.7 17.9 5.5 3.8 68.4 8.9 5.2 57.8

2007 45.8 19.9 43.5 14.2 8.8 61.8 25.6 16.0 62.6

2008 30.6 15.1 49.5 16.3 10.6 64.8 24.8 15.5 62.5

2009 22.9 12.5 54.6 11.9 9.6 80.5 20.5 14.0 68.0

2010 61.5 18.9 30.7 14.0 9.1 64.5 27.8 15.1 54.4

2011 8.2 4.5 55.0 4.0 3.5 89.1 8.3 6.7 80.7

2012 11.4 5.0 44.2 2.5 1.4 55.3 5.3 2.8 52.4

2013 15.1 5.7 37.9 3.3 1.8 52.5 9.5 3.9 41.3

Mean 29.7 8.0 28.6 12.1 8.0 67.9 22.0 14.5 66.0

Mean, in acreft/yr21,526 5,794 8,798 5,827 15,954 10,480
Introduction 7

Table 2. Mean annual streamflow and mean annual base flow for selected streamgages in and near the North Fork Red River aquifer 

study area, 1980–2013.—Continued

[Base flow computed by using BFI method in the U.S. Geological Survey Groundwater Toolbox (Barlow and others, 2015; streamflow data from U.S. 

Geological Survey, 2015a); Mean Lake Altus releases were assumed to be the same as mean streamflow at the Lugert streamgage; ft3/s, cubic feet per second; 

acre-ft/yr, acre-feet per year; %, percent; BFI, base-flow index; --, data not available or not applicable]

Year

Carter streamgage (07301500) on 

North Fork Red River

Lugert streamgage (07303000) on North 

Fork Red River below Lake Altus dam

Carl streamgage (07303400) on 

Elm Fork Red River

Mean 

streamflow

(ft3

/s)

Mean base flow Mean 

streamflow

(ft3

/s)

Mean Lake Altus 

releases

Mean 

streamflow

(ft3

/s)

Mean base flow

ft3

/s % (BFI) ft3/s % (BFI) ft3/s % (BFI)

1980 45.7 19.7 43.1 1.0 1.0 -- -- -- --

1981 27.8 8.5 30.4 0.1 0.1 -- -- -- --

1982 174.0 42.1 24.2 0.0 0.0 -- -- -- --

1983 66.9 33.1 49.5 0.4 0.4 -- -- -- --

1984 34.3 14.2 41.6 0.2 0.2 -- -- -- --

1985 72.3 26.5 36.6 0.1 0.1 -- -- -- --

1986 205.2 48.1 23.4 0.1 0.1 -- -- -- --

1987 239.4 109.2 45.6 303.9 303.9 -- -- -- --

1988 131.5 65.6 49.9 78.9 78.9 -- -- -- --

1989 193.4 85.6 44.3 110.3 110.3 -- -- -- --

1990 132.1 56.1 42.5 98.5 98.5 -- -- -- --

1991 93.2 44.3 47.5 1.3 1.3 -- -- -- --

1992 94.4 60.7 64.4 28.2 28.2 -- -- -- --

1993 125.6 72.2 57.4 142.4 142.4 -- -- -- --

1994 36.3 21.7 59.8 1.0 1.0 -- -- -- --

1995 253.8 48.8 19.2 77.6 77.6 -- 115.9 25.1 21.7

1996 155.2 76.9 49.6 41.2 41.2 -- 37.7 24.2 64.1

1997 364.3 182.7 50.1 378.9 378.9 -- 91.1 48.2 52.9

1998 184.2 114.2 62.0 201.8 201.8 -- 50.4 33.4 66.2

1999 145.7 85.9 58.9 37.0 37.0 -- 48.3 27.9 57.7

2000 134.7 60.9 45.2 4.4 4.4 -- 38.2 17.6 46.1

2001 173.0 90.2 52.1 77.2 77.2 -- 47.4 25.3 53.4

2002 70.4 45.2 64.2 0.5 0.5 -- 15.6 12.0 77.0

2003 73.4 41.0 55.8 0.1 0.1 -- 27.3 7.2 26.5

2004 95.0 50.5 53.2 0.1 0.1 -- 22.2 10.6 47.4

2005 85.6 52.1 60.9 0.4 0.4 -- 17.1 11.4 66.9

2006 37.8 17.2 45.5 0.4 0.4 -- 10.1 4.5 44.8

2007 223.5 96.3 43.1 58.0 58.0 -- 30.2 14.3 47.4

2008 92.8 54.1 58.3 1.0 1.0 -- 18.3 11.3 61.7

2009 72.0 46.3 64.3 0.6 0.6 -- 10.0 8.4 84.0

2010 126.9 54.3 42.8 0.8 0.8 -- 18.6 7.6 40.8

2011 23.1 18.7 81.1 0.3 0.3 -- 4.1 3.4 84.5

2012 12.1 7.0 58.4 0.1 0.1 -- 3.1 1.7 53.2

2013 6.6 1.4 21.0 0.0 0.0 -- 4.4 2.2 51.1

Mean 117.7 54.4 48.4 48.4 48.4 -- 32.1 15.6 55.1

Mean, in acreft/yr85,278 39,445 35,089 35,089 23,259 11,301
8 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 2. Mean annual streamflow and mean annual base flow for selected streamgages in and near the North Fork Red River aquifer 

study area, 1980–2013.—Continued

[Base flow computed by using BFI method in the U.S. Geological Survey Groundwater Toolbox (Barlow and others, 2015; streamflow data from U.S. 

Geological Survey, 2015a); Mean Lake Altus releases were assumed to be the same as mean streamflow at the Lugert streamgage; ft3/s, cubic feet per second; 

acre-ft/yr, acre-feet per year; %, percent; BFI, base-flow index; --, data not available or not applicable]

Year

Hobart streamgage (07304500) on 

Elk Creek

Headrick streamgage (07305000) on 

North Fork Red River

Snyder streamgage (07307010) on 

Otter Creek

Mean 

streamflow

(ft3

/s)

Mean base flow Mean 

streamflow

(ft3/s)

Mean base flow Mean 

streamflow

(ft3/s)

Mean base flow

ft3

/s % (BFI) ft3/s % (BFI) ft3/s % (BFI)

1980 59.9 4.5 7.5 208.3 42.7 20.5 -- -- --

1981 35.1 4.1 11.6 88.0 23.3 26.5 -- -- --

1982 146.0 20.6 14.1 311.1 66.4 21.3 -- -- --

1983 144.4 20.6 14.3 232.6 43.6 18.8 -- -- --

1984 21.3 11.0 51.7 53.8 32.3 60.0 -- -- --

1985 54.4 9.9 18.1 127.2 38.5 30.3 -- -- --

1986 323.8 59.7 18.4 895.4 246.7 27.6 -- -- --

1987 230.6 74.4 32.3 909.8 401.7 44.1 -- -- --

1988 134.0 55.2 41.2 398.7 164.9 41.4 -- -- --

1989 141.8 45.9 32.4 471.6 90.0 19.1 -- -- --

1990 89.9 29.4 32.6 446.5 122.5 27.4 -- -- --

1991 88.1 19.1 21.7 356.9 96.5 27.0 -- -- --

1992 151.4 57.7 38.1 388.8 141.0 36.3 -- -- --

1993 -- -- -- 815.0 294.5 36.1 -- -- --

1994 -- -- -- 105.2 58.9 56.0 -- -- --

1995 -- -- -- 874.4 179.8 20.6 -- -- --

1996 -- -- -- 450.3 189.5 42.1 -- -- --

1997 -- -- -- 1,274.0 491.9 38.6 -- -- --

1998 -- -- -- 561.5 248.1 44.2 -- -- --

1999 -- -- -- 303.1 94.6 31.2 -- -- --

2000 -- -- -- 210.4 74.5 35.4 -- -- --

2001 -- -- -- 327.3 119.0 36.4 35.8 10.1 28.2

2002 -- -- -- 84.2 35.9 42.6 4.8 1.1 22.7

2003 -- -- -- 83.0 29.8 35.9 7.1 0.3 3.9

2004 -- -- -- 233.2 53.3 22.8 10.4 0.4 4.0

2005 -- -- -- 158.1 68.2 43.2 4.3 0.2 5.5

2006 -- -- -- 72.5 22.4 30.8 4.7 0.9 20.0

2007 -- -- -- 460.9 173.1 37.6 89.1 21.4 24.0

2008 -- -- -- 157.1 53.0 33.7 -- -- --

2009 -- -- -- 70.6 32.1 45.4 -- -- --

2010 -- -- -- 164.3 35.1 21.3 -- -- --

2011 -- -- -- 51.6 13.1 25.3 -- -- --

2012 -- -- -- 45.2 12.2 26.9 -- -- --

2013 -- -- -- 17.2 6.4 37.1 -- -- --

Mean 124.7 31.7 25.7 335.5 111.6 33.6 22.3 4.8 15.5

Mean, in acreft/yr90,318 22,964 243,074 80,860 16,166 3,477
Introduction 9

The 2012 Oklahoma Comprehensive Water Plan 

prioritized 12 water-management planning basins where 

water-supply shortages were most likely to occur by 2060 

based on available hydrologic data and projected demands; 

3 of the 12 prioritized water-management planning basins 

(34, which includes Elk Creek; 36, which includes Lake 

Altus; and 42, which includes part of the Elm Fork Red River; 

fig. 2) are in the North Fork Red River watershed. Surfacewater resources are fully allocated in water-management 

planning basins 34, 36, and 42, and physical and chemical 

resource limitations in these basins were projected to 

cause surface-water shortages by 2020, 2050, and 2050, 

respectively (OWRB, 2012b, p. 116–118). Water-management 

planning basin 36, which encompasses a portion of the North 

Fork Red River aquifer upgradient from Lake Altus, was 

identified as the Oklahoma water-management planning 

basin most susceptible to shortages in alluvium and terrace 

groundwater by 2060. Water-management planning basin 42, 

which encompasses a portion of the North Fork Red River 

aquifer along the Elm Fork Red River, was identified as the 

second most susceptible to shortages in alluvium and terrace 

groundwater by 2060.

Climate Characteristics and Trends

The climate of the North Fork Red River aquifer 

study area is classified as humid subtropical (Kottek and 

others, 2006). Daily maximum temperatures usually exceed 

100 degrees Fahrenheit (°F) for 20 to 35 days in summer, and 

the maximum recorded temperature was 120 °F at Altus in 

1936 (Oklahoma Climatological Survey, 2015a). The period 

of greatest monthly precipitation usually occurs in May and 

June, and a secondary period of greater precipitation often 

occurs in September and October. Monthly precipitation 

usually is least in the winter months when snow totals of 1 to 

10 inches (in.) are common (Oklahoma Climatological Survey, 

2015a). Winds average about 10 miles per hour annually and 

are prevailingly from the south and southeast (Oklahoma 

Climatological Survey, 2015a). 

Historical data from selected climate stations in 

southwest Oklahoma (climate division 7) have been quality 

assured, bias-corrected, and summarized monthly as part of 

the U.S. Historical Climatology Network (National Climatic 

Data Center, 2015; fig. 3, table 3). The monthly summarized 

data were used to calculate and graph annual and monthly 

temperature and precipitation statistics for the study area, 

and the data from some individual climate stations (National 

Climatic Data Center, 2015; Oklahoma Climatological 

Survey, 2015a) were summarized to show the variability of 

these statistics within the study area. A lowess smooth line 

(Cleveland, 1979) was used to delineate periods of below- and 

above-average precipitation. 

The mean annual precipitation in the study area for the 

period of record 1895–2015 was about 27.6 inches per year 

(in/yr) (fig. 3A, table 3). A relatively long dry period occurred 

in 1930–80 with 33 of 51 years (65 percent) recording 

below-average precipitation. Within this dry period, years 

were grouped into four 5- to 12-year spans of below-average 

precipitation punctuated by 3- to 5-year spans of aboveaverage precipitation. The period 1981–2000 was a historically 

unprecedented wet period in which 16 of 20 years (80 percent) 

had above-average precipitation (fig. 3A). The period 2010–14 

was noteworthy as an exceptionally dry period.

The mean annual temperature in the study area for the 

period of record 1895–2015 was about 61.2 °F (fig. 3B, 

table 3). Mean annual temperatures increase to the southeast 

from about 60 °F at the Erick climate station in Beckham 

County to about 62 °F at the Altus Dam climate station in 

Kiowa County.

The mean annual temperature was about 0.4 °F greater 

and the mean annual precipitation was about 1.6 in/yr greater 

for the study period 1980–2013 compared to the period of 

record (table 3). Over the study period, the annual mean 

precipitation was greater than the mean for the period of 

record in 20 of 34 years. The 20-year wet period 1981–2000 

and the 17-year (and continuing) warm period 1996–2013 

were unprecedented in the period of record (fig. 3). The mean 

monthly precipitation for the study period 1980–2013 was 

greatest (4.2 in.) in May and least (1.1 in.) in January (fig. 4A). 

The mean monthly temperature for the study period 1980–

2013 was greatest (84 °F) in July and least (39 °F) in January 

(fig. 4B). 

Multi-year to decadal droughts are not uncommon for 

the study area. The 1929–41 (“Dust Bowl”), 1952–56, and 

1961–72 drought periods were among the most severe in the 

20th century; a shorter and less severe 1976–81 drought period 

also occurred in the late 20th century. The 21st century began 

with the drought periods 2002–06 and 2010–14 (Tortorelli, 

2008; Shivers and Andrews, 2013) (fig. 3A). The most severe 

of these droughts developed from extended periods of belowaverage precipitation paired with above-average temperature. 

The precipitation and temperature characteristics of the 

1952–56 drought period were similar to those of the 2010–14 

drought period, and the effects of these drought periods on 

aquifer water levels also were comparable (fig. 3). 

Climate models used by the Climate Model 

Intercomparison Program predict about a 5-°F increase in 

annual minimum and maximum temperatures in the study area 

between the historical period 1950–2005 and the future period 

2050–74 (Alder and Hostetler, 2013). These climate models 

also predict a slight decrease in mean annual precipitation 

between the historical period 1950–2005 and the future period 

2050–74 (Alder and Hostetler, 2013). If these predictions 

come to pass, they are likely to cause increased water demand, 

especially for irrigation; more water would be required to 

grow the same crops under the predicted warmer and drier 

climate conditions. 
10 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

58

59

60

61

62

63

64

65

Annual mean temperature, in degrees Fahrenheit

10

15

20

25

30

35

40

45

Annual mean precipitation, in inches per year

Study period 1980–2013

Study period 1980–2013

A

B

C

Date

1895 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015

Cool

period

Warm

period

Wet period Dry period

27.62

61.16

Southwest Oklahoma drought periods, modified from 

Tortorelli (2008) and Shivers and Andrews (2013):

Data for southwest Oklahoma, Climate Division 7 (National Climatic Data Center, 2016)

Data for southwest Oklahoma, Climate Division 7 (National Climatic Data Center, 2016)

1929–41 1952–56 1961–72 1976–81 2002–06 2010–14

0

10

20

30

40

50

60

70

Depth to water, in feet below land surface

Study period 1980–2013

Southwest Oklahoma drought periods, modified from 

Tortorelli (2008) and Shivers and Andrews (2013): 1929–41 1952

–56 1961–72 1976

–81

2002

–06

2010

–14

351125099414301

08N-24W-02 DDD 1 

(near well 9096)

351306099564601

09N-25W-34 BBB 1

(near well 9101)

9096 

351400099533501

09N-25W-31 BCB 1

Source: U.S. Geological Survey (2015a)

historical water-table-altitude observation wells

Source: Oklahoma Water Resources Board 

(2015b) Mass Measurement Program wells

351402099533501

09N-25W-19 CCC 1

9101 

9119

9106

9107

351617099585201

09N-26W-08 BCB 1

No data

EXPLANATION

Annual mean precipitation

Lowess smooth

Mean annual precipitation

for the period of record 27.62

EXPLANATION

Annual mean temperature

Lowess smooth

Mean annual temperature

for the period of record 61.16

Figure 3. A, Annual mean precipitation; B, annual mean temperature; and C, depth to water in selected wells, southwest Oklahoma, 

1895–2015.
Introduction 11

Table 3. Mean annual precipitation and mean annual temperature data summaries from selected regions and stations in and near the 

North Fork Red River aquifer study area, southwest Oklahoma.

[°F, degrees Fahrenheit; --, data not available or not used]

Region or 

station number

Region or 

station name

Period of 

record1

Number 

of years

Mean annual precipitation

(inches per year)

Mean annual temperature

(°F)

1947–79 1980–2013 Period of 

record 1947–79 1980–2013 Period of record

Climate region summary (National Climatic Data Center, 2015)

Climate 

Division 7

Southwest 

Oklahoma

1895–2015 121 26.39 29.20 27.62 60.86 61.56 61.16

Climate station summary (Oklahoma Climatological Survey, 2015a)

340184 Altus Dam 1945–2013 62 22.42 28.74 26.84 62.55 62.04 62.31

342944 Erick 1904–2013 96 22.40 25.29 24.40 60.10 60.80 60.16

346035 Moravia 1941–2013 68 22.63 26.38 25.53 -- -- --

347952 Sayre2 1936–2013 77 21.35 25.59 23.98 61.60 -- 61.14

348299 Snyder 1906–2011 77 22.73 25.76 26.84 -- -- --

349668 Willow 1980–2013 34 -- 27.30 27.30 -- -- --

 1Period of record may not be continuous. 

2

Station not in aquifer boundary, used for temperature data only. 

A

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Jan. Feb. Mar. Apr. May June

Month

Mean monthly precipitation, in inches per month

July Aug. Sept. Oct. Nov. Dec.

Study period, 1980–2013

Period of record, 1895–2015

EXPLANATION

B

Mean monthly temperature, in degrees Fahrenheit

Jan. Feb. Mar. Apr. May June

Month

July Aug. Sept. Oct. Nov. Dec.

0

10

20

30

40

50

60

70

80

100

90

Study period, 1980–2013

Period of record, 1895–2015

EXPLANATION

Figure 4. A, Mean monthly precipitation and B, mean monthly temperature, southwest Oklahoma, 1895–2015 and 1980–2013. Data for 

southwest Oklahoma, Climate Division 7 (National Climatic Data Center, 2015).
12 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Land Cover

During the period 2010–15, shrubs/range and crops each 

covered about a third of the land overlying the North Fork 

Red River aquifer (Fry and others, 2011; National Agricultural 

Statistics Service, 2016; fig. 5). Grass/pasture composed 

most of the remaining third (fig. 5), though scattered wooded 

(forest) areas and towns (developed areas) including Texola, 

Erick, Carter, Willow, Snyder, and Mangum also overlie the 

aquifer. Other towns, including Elk City, Sayre, Lone Wolf, 

and Granite, which mostly do not overlie the aquifer, draw 

water from the North Fork Red River aquifer for public 

supply.

Winter wheat (72.9 percent of cropland by area) was 

the dominant crop type overlying the North Fork Red River 

aquifer during the period 2010–15. Cotton (7.7 percent), rye 

(5.6 percent), alfalfa (3.3 percent), and sorghum (1.7 percent) 

accounted for at least 1 percent of cropland by area, and other 

crops, including peanuts (1.1 percent) and barley (1.0 percent), 

accounted for 4.6 percent of cropland by area (fig. 5). About 

4 percent of cropland by area was fallow or idle. Though crop 

types may change with economic and hydrologic factors, the 

areal percentages of total crop land cover and individual crop 

types did not change much over the period 2010–15 (National 

Agricultural Statistics Service, 2016).

The frost-free growing season is about 200 days and 

lasts from mid-April to late October (National Agricultural 

Statistics Service, 2015; Oklahoma Climatological Survey, 

2015b). Most crops including corn, cotton, peanuts, sorghum, 

soybeans, sunflowers, and canola are grown in this season, but 

winter wheat is planted in the early fall and harvested in June. 

The length of the growing season and the water requirement 

for crops in a given year vary with the climate characteristics 

of that year (Masoner and others, 2003). 

Groundwater-Use Characteristics and Trends

The OWRB permits and regulates groundwater use, 

with the exception of groundwater use of less than 

5 acre-ft/yr for domestic and agricultural purposes and 

groundwater use for irrigation of less than 3 acres of land. 

Groundwater-use data for Oklahoma are self-reported 

annually to the OWRB by permitted users, and the OWRB 

staff reviewed groundwater-use data described in this report 

to ensure the quality and completeness of the data. In 2013, 

412 long-term temporary and prior-right groundwater-use 

permits were active for the North Fork Red River aquifer 

(OWRB, 2015b) (fig. 6). Each permit may include multiple 

wells that share the allocated groundwater use. Most 

groundwater-use permits were allocated for irrigation and 

public supply (fig. 7, table 4). Groundwater-use permits for 

irrigation were tied to wells and land areas that were relatively 

evenly distributed across the aquifer; most groundwater-use 

permits for public supply, in contrast, were tied to wells and 

land areas concentrated south of Sayre in Beckham County 

and northeast of Willow in Greer County (fig. 6). 

The mean annual reported groundwater use was 

15,279 acre-ft/yr for the period of record 1967–2013 

and 15,859 acre-ft/yr for the study period 1980–2013 

(table 4; Christopher Neel, OWRB, written commun., 

2015). The year with the greatest reported groundwater 

use (26,714 acre-feet [acre-ft]) was 2011. Below-average 

precipitation and above-average temperatures in that year 

likely contributed to the increased groundwater use. The 

year with the least reported groundwater use (9,875 acre-ft) 

was 1975, and the year with the least reported groundwater 

use per permit (about 77 acre-ft) was 1997; both 1975 and 

1997 were years with above-average precipitation (fig. 3). 

The groundwater-use period of record 1967–2013 was 

separated into three smaller periods (1967–85, 1986–97, and 

1998–2013) to illustrate trends in the reported groundwater 

use. The mean annual reported groundwater use decreased 

from 13,503 to 12,246 acre-ft/yr from the period 1967–85 

to the period 1986–97, and then increased from 12,246 to 

19,429 acre-ft/yr from the period 1986–97 to the period 

1998–2013 (table 4, fig. 7). 
Introduction 13

Altus

Blair

Carter

Dodson

Elk City

Erick

Gould

Granite

Headrick

Hobart

Hollis

Lone

Wolf

Mangum

New

Cordell

Sayre

Snyder

Texola

Willow

ROGER MILLS COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN COUNTY

Lake

Altus

Tom Steed

Reservoir

Elm Fork

Red

River

Elk Creek

Sweetwater

Creek

 Otter

Creek

North

Fork

Red

River

Elm Fork

Red

River

Elk Creek

Sweetwater

Creek

 Otter

Creek

North

Fork

Red

River

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

0 6 12 18 24 MILES

0 6 12 18 24 KILOMETERS

North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board (2015b)

Land cover from National Agricultural

Statistics Service (2016)

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

EXPLANATION

Other (water, wetland, and barren)

Land-cover type, 2015

Winter wheat

Cotton

Rye

Alfalfa

Sorghum

Fallow/idle

Other crops

Developed

Barren

Forest

Shrubs/range

Grass/pasture

Crop cover type

North Fork Red River aquifer boundary

Incorporated area (U.S. Census Bureau, 2000)

72.9

7.7

5.6

4.4

4.6

Crop cover type, 2010–15, in percent

Winter

wheat

Cotton

Rye Alfalfa (3.3)

Sorghum (1.7)

Fallow/

idle

Other

35.7 crops

35.2

16.2

Shrubs/range

Crops

Grass/pasture

Forest (5.9)

Developed (4.6)

Other (2.4)

Land cover type, 2010–15, in percent

Total area: 472,300 acres

Total area: 166,100 acres

Components may not sum to totals because of rounding.

Figure 5. Land and crop cover over the North Fork Red River aquifer, southwest Oklahoma, 2010–15.
14 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Altus

Blair

Carter

Dodson

Elk City

Erick

Gould

Granite

Headrick

Hobart

Hollis

Lone

Wolf

Mangum

New

Cordell Sayre

Snyder

Texola

Willow

ROGER MILLS COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY

KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN

COUNTY

Lake

Altus

Tom Steed

Reservoir

EXPLANATION

Allocated groundwater rights (permitted land areas

and permitted wells; Oklahoma Water Resources Board, 2015b)

Irrigation

Public Supply

Other

Incorporated area (U.S. Census Bureau, 2000)

North Fork Red River aquifer boundary

0 6 12 18 24 MILES

0 6 12 18 24 KILOMETERS

North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board (2015b)

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

Figure 6. Land areas and wells permitted for groundwater use from the North Fork Red River aquifer, southwest Oklahoma, 2015.
Introduction 15

0

5,000

10,000

15,000

20,000

25,000

30,000

1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015

Annual reported groundwater use, in acre-feet

Year

No dataNo data

Study period: 1980–2013

63%

36%

Industrial, mining,

commercial, recreation, 

agricultural, and other (1%)

Groundwater-use type

Irrigation

Public Supply

Industrial

Mining

Commercial

Recreation

Agricultural

Other

EXPLANATION

Figure 7. Annual reported groundwater use by type from the North Fork Red River aquifer, 1967–2013. Data from the Oklahoma Water 

Resources Board water-use database (Christopher Neel, Oklahoma Water Resources Board, written commun., 2015).
16 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 4. Mean annual reported groundwater use by type for the North Fork Red River aquifer, 1967–2013.

[Data from Oklahoma Water Resources Board water-use database (Christopher Neel, Oklahoma Water Resources Board, written commun., 2015); PWS, public 

water supply; values in parentheses are percentage of total groundwater use]

Period Mean annual reported groundwater use, in acre-feet per year (and percentage), by type1

Irrigation PWS Industrial Mining Commercial Recreation Agriculture Other Total

1967–85 9,446 3,828 139 0 93 0 0 0 13,503

(70.0) (28.3) (1.0) (0.0) (0.7) (0.0) (0.0) (0.0) (100)

1986–97 6,993 5,046 30 0 172 5 0 0 12,246

(57.1) (41.2) (0.2) (0.0) (1.4) (0.0) (0.0) (0.0) (100)

1998–2013 12,872 6,389 16 30 74 17 4 41 19,429

(66.3) (32.9) (0.1) (0.2) (0.4) (0.1) (0.0) (0.2) (100)

Study period, 

1980–2013

9,928 5,754 24 14 115 10 2 20 15,859

(62.6) (36.3) (0.2) (0.1) (0.7) (0.1) (0.0) (0.1) (100)

Period of record, 

1967–2013

9,980 5,096 69 10 107 7 1 14 15,279

(65.3) (33.4) (0.5) (0.1) (0.7) (0.0) (0.0) (0.1) (100)

1

Excludes water use of less than 5 acre-feet per year for domestic and agricultural purposes and water use for irrigation of less than 3 acres of land.

Though three of the four greatest individual users of 

groundwater were municipalities (Elk City, Mangum, and 

Sayre), irrigation was the major groundwater-use type for 

the period of record 1967–2013. Irrigation accounted for 

about 70 percent of reported groundwater use for the period 

1967–85, about 57 percent of reported groundwater use 

for the period 1986–97, and about 66 percent of reported 

groundwater use for the period 1998–2013 (fig. 7, table 4). 

Annual irrigation use averaged 9,446 acre-ft/yr for the 

period 1967–85, 6,993 acre-ft/yr for the period 1986–97, and 

12,872 acre-ft/yr for the period 1998–2013 (table 4). Reported 

groundwater use for irrigation notably increased in 1998 

and generally continued to increase through 2013 (fig. 7). 

The number of reporting permits also notably increased in 

1998 and continued to increase during the period 1998–

2013. These increases in reported groundwater use and the 

number of reporting permits likely resulted from decreased 

precipitation in 1998 as compared to the 3 previous years. 

Sustained increases in reported groundwater use for the period 

1998–2013 also coincided with and may be related to a period 

of above-average annual mean temperature (1996–2015, 

fig. 3B). Most of the increase in reported groundwater use for 

the period 1998–2013 was for irrigation in Beckham County 

which increased from about 30 to 50 percent of reported 

groundwater use in that period (fig. 8). 

Yields of wells completed in the North Fork Red River 

aquifer vary with location and depth. Well yields reported for 

irrigation, public-supply, and domestic plus non-irrigation 

agricultural use were mostly 100–450, 150–250, and 

10–25 gallons per minute (gal/min), respectively (OWRB, 

2015b; USGS, 2015a; table 5, fig. 9). Irrigation and publicsupply wells with the greatest reported yields (greater than or 

equal to 800 gal/min) generally were located in west-central 

Beckham County north of Erick, Okla., and near Lake Altus 

east of Granite, Okla. Wells with the greatest reported yields 

generally were greater than 150 feet (ft) in depth. 
Introduction 17

100

90

80

70

60

50

40

30

20

10

0

198019811982198319841985198619871988198919901991199219931994199519961997

1998199920002001200220032004200520062007200820092010201120122013

Annual reported groundwater use by county, in percent

Year

EXPLANATION

Beckham County, public supply

Greer County, public supply

Kiowa County, public supply

Jackson County, public supply

Other

Jackson County, irrigation

Kiowa County, irrigation

Greer County, irrigation

Beckham County, irrigation

Figure 8. Annual reported groundwater use by county from the North Fork Red River aquifer, 1980–2013. Data from the Oklahoma 

Water Resources Board water-use database (Christopher Neel, Oklahoma Water Resources Board, written commun., 2015).

Table 5. Statistical summary of reported yields of wells completed in the North Fork Red River aquifer, 1936–2015.

[Data compiled from the Oklahoma Water Resources Board (2015b) and U.S. Geological Survey (2015a)]

Water-use type

Number of wells 

with reported 

yield values

Statistics for reported well-yield values, in gallons per minute1

Minimum 25th 

percentile Median 75th percentile Maximum Mean

Irrigation 500 15 100 250 450 1,500 333

Public supply 126 15 150 198 250 900 215

Industrial and mining 55 5 35 60 70 1,200 94

Domestic and agriculture 

(non-irrigation)

682 1 10 15 25 300 25

1

Well-yield values less than 1 gallon per minute were excluded.
18 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

x

x

x

x

x

x

x

x

x

x

x

xx

x

x

x

xx

x

x

x

x

x

x

x

x

o

o 15

250

198

Domestic 

plus

non-irrigation

agricultural

Public Irrigation

supply

10

20

30

50

40

200

300

400

500

2,000

3,000

4,000

100

1

2

3

4

5

1,000

5,000

Well yield, in gallons per minute

Water-use type

126 500 682

EXPLANATION 

Number of wells

x

x

o

o

Upper adjacent

75th percentile

Median, with

value in gallons

per minute

25th percentile

Lower adjacent

Lower outside

Lower detached

Upper detached

Upper outside

15

682

Figure 9. Statistics for reported yields of wells completed in the 

North Fork Red River aquifer. Data compiled from the Oklahoma 

Water Resources Board (2015b) and the U.S. Geological Survey 

(2015a).

Streamflow Characteristics and Trends

According to data collected at the Carter streamgage 

(07301500), the North Fork Red River upstream from Lake 

Altus has become increasingly dependent on base flow 

since the beginning of the period of record in the late 1930s 

(Smith and Wahl, 2003; Esralew and Lewis, 2010). Though 

annual precipitation in west central Oklahoma (climate 

division 4; National Climatic Data Center, 2015) significantly 

increased over the streamgage period of record, no trends in 

annual streamflow were apparent at the Carter streamgage 

(07301500). Annual peak streamflow and annual number 

of zero-flow days at this streamgage significantly decreased 

over the period of record while annual base flow and annual 

base-flow index significantly increased over the period of 

record (Esralew and Lewis, 2010). The causes of these trends 

in annual streamflow statistics are not clear. Increasing 

trends in base flow could be related to changes in irrigation 

practices that may promote artificial recharge of applied 

water and contribute additional base flow to streams. Another 

possible cause of these trends in streamflow statistics is the 

construction of impoundments (Kennon, 1966) in the North 

Fork Red River watershed. Though no large impoundments 

overlie the North Fork Red River aquifer upstream from the 

Carter streamgage (07301500), several floodwater-retarding 

structures were constructed on the North Fork Red River 

tributaries Timber Creek (in the early 1960s) and McClellan 

Creek (in the 1980s) (U.S. Army Corps of Engineers, 2015a) 

(fig. 2). Floodwater-retarding structures were designed to 

impound runoff and slowly release it downstream; therefore, 

these structures could contribute to the decreasing trends in 

annual peak streamflow and annual number of zero-flow days 

as well as the increasing trends in annual base flow and annual 

base-flow index. Whatever the cause, these trends in annual 

streamflow statistics are important considerations for water 

resources planning for irrigation and public-supply surfacewater use at Lake Altus.

Groundwater Quality

The groundwater quality in some parts of the North 

Fork Red River aquifer may limit groundwater use for some 

purposes. Groundwater-quality data for the North Fork 

Red River aquifer were collected between July 28, 2014, 

and August 13, 2014, as part of the OWRB Groundwater 

Monitoring and Assessment Program (OWRB, 2015c). 

Groundwater was sampled from 20 wells; 14 were in 

Beckham County, 5 were in Greer County, and 1 was in 

Kiowa County (fig. 10). The groundwater samples were 

analyzed for selected parameters including physical properties 

(specific conductance, temperature, and pH), major ions, 

nutrients, and trace metals (table 6). Total dissolved solids 

(TDS) concentrations of groundwater ranged from 295 to 

3,520 milligrams per liter (mg/L) with a mean concentration of 

895 mg/L and a median concentration of 543 mg/L (table 6). 

The U.S. Environmental Protection Agency (2017) has 

established a secondary drinking-water standard of 500 mg/L 

for TDS, but the State of Oklahoma designates a domestic 

beneficial use for groundwater with TDS concentrations 

below 3,000 mg/L (OWRB, 2015c). Specific conductance 

values ranged from 508 to 4,830 microsiemens per centimeter 

at 25 degrees Celsius (μS/cm at 25 °C) with a mean value 

of 1,340 μS/cm and a median value of 862 μS/cm. All 

groundwater samples from the North Fork Red River aquifer 

were classified as hard (hardness concentration exceeded 

180 mg/L). Nitrate plus nitrite was the only parameter with 

measured concentrations exceeding a U.S. Environmental 

Protection Agency (2017) primary drinking-water standard 

(10 mg/L). Nitrate plus nitrite concentrations exceeded this 

standard in six samples; the maximum measured nitrate 

plus nitrite concentration was 19.4 mg/L, the median was 

7.95 mg/L, and the 75th percentile was 10.73 mg/L.
Introduction 19

ROGER MILLS COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY

KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN COUNTY

Lake

Altus

Tom Steed

Reservoir

Sayre

well

field

Elk

City

well

field

Elm Fork

Red

River

Elk

Creek

Sweetwater

Creek

 Otter

Creek

Elm Fork

Red

River

Elk

Creek

Sweetwater

Creek

 Otter

Creek

Fork

Red

River

North

EXPLANATION

Milliequivalents per liter

40 20 0 20 40

Groundwater-quality station (USGS, 2015a), 1944–62, 

 with Stiff (1951) diagram

Calcium

Magnesium

Sodium plus potassium Chloride plus fluoride

Bicarbonate

Sulfate

Beckham County Fault (Gouin, 1927); triangle points to the

North Fork Red River aquifer boundary upthrown side

Incorporated area (U.S. Census Bureau, 2000)

Milliequivalents per liter

40 20 0 20 40

Calcium

Magnesium

Sodium plus potassium Chloride plus fluoride

Bicarbonate

Sulfate

Total dissolved solids, in 

milligrams per liter

Groundwater-quality station (OWRB, 2015c), 2014, 

 with Stiff (1951) diagram

1,930

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

0 6 12 18 24 MILES

0 6 12 18 24 KILOMETERS

North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board (2015b)

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

3,520

1,930

1,500

1,610

1,370

1,190

1,130

676

623

555

530

448

428

388

420

311

349

295

324 313

3,520

1,930

1,500

1,610

1,370

1,190

1,130

676

623

555

530

448

428

388

420

311

349

295

324 313

Figure 10. Groundwater-quality stations in the North Fork Red River aquifer, southwest Oklahoma, 1944–62 and July–August 2014.
20 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 6. Statistical summary of groundwater-quality data from 20 wells completed in the North Fork Red River aquifer, July–

August 2014.

[All data are from OWRB (2015c). μS/cm at 25 °C, microsiemens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; 

mg/L, milligrams per liter; <, less than analytical detection limit; μg/L, micrograms per liter; --, not calculated because more than 10 analyses were below 

analytical detection limit; +, includes samples with different analytical detection limits]

Water-quality 

constituent

Units of 

measurement

Number of 

samples 

less than 

detection 

limit

Mean of 

detections Minimum

Percentile

Maximum

25 50 75

Specific conductance μS/cm at 25 °C 0 1,340 508 631 862 1,840 4,830

Temperature °C 0 21.5 18.9 20.1 21.1 22.2 30.6

pH standard units 0 7.06 6.85 6.99 7.06 7.16 7.26

Alkalinity (as CaCO3

) mg/L 0 225 134 199 232 252 331

Total dissolved solids mg/L 0 895 295 379 543 1,230 3,520

Hardness mg/L 0 487 187 265 342 794 1,180

Calcium mg/L 1 121 53.2 71.8 94.9 172 312

Magnesium mg/L 1 34.6 10.3 17 23 46.9 81.6

Sodium mg/L 1 114 4.4 23.9 37.4 102 905

Potassium mg/L 2 2.56 <0.5 1.5 2.1 3.2 9.3

Bicarbonate mg/L 0 277 165 244 286 310 408

Sulfate mg/L 2 268 <10 38.4 142 383 1,090

Chloride mg/L 5 138 <10 11.6 24.8 79.8 981

Fluoride mg/L 8 0.295 <0.2 <0.2 0.28 0.42 0.74

Bromide μg/L 1 593 <100 265 329 613 1,960

Silica mg/L 0 23.2 9.95 13.9 24.9 27.4 43.7

Nitrate plus nitrate (as 

nitrogen)

mg/L 0 8.29 0.83 5.58 7.95 10.73 19.4

Phosphorous μg/L 5 0.029 <0.005 0.015 0.023 0.042 0.103

Aluminum+ μg/L 20 -- <50 <50 <50 <50 <50

Arsenic+ μg/L 7 1.92 <1.0 -- 1.6 2.6 7.6

Barium+ μg/L 0 131 10.8 38.6 89 173 577

Boron+ μg/L 1 193 <20 57.2 97.6 178 1,460

Cadmium μg/L 20 -- <5 <5 <5 <5 <5

Chromium μg/L 20 -- <5 <5 <5 <5 <5

Copper μg/L 17 -- <5 <5 <5 <5 51.7

Iron+ μg/L 19 -- <50 <50 <50 <50 32.9

Lead+ μg/L 20 -- <10 <10 <10 <10 <10

Manganese+ μg/L 15 -- <5.0 <5.0 <5.0 5.5 7.6

Molybdenum+ μg/L 19 -- <5.0 <5.0 <5.0 <5.0 12.8

Uranium μg/L 5 4.1 <1 1.6 3.4 5.1 12.9

Vanadium+ μg/L 6 9.8 <5.0 <5.0 7.9 14.2 29.3

Zinc+ μg/L 12 -- <5.0 <5.0 4.3 16.2 91.7
Introduction 21

The 2014 OWRB major-ion groundwater-quality data 

for each site were graphed on Stiff (1951) diagrams and 

mapped on figure 10. Historical (1944–62) Stiff diagrams 

showing available groundwater-quality data from the USGS 

National Water Information System (NWIS) database (USGS, 

2015a) were added to figure 10 for visual comparison. The 

2014 samples from Beckham County mostly were below the 

mean and median TDS values, indicating relatively fresh 

groundwater in those areas that may have lower groundwater 

residence times, possibly near zones of greater recharge. Stiff 

diagram distribution for these sites displayed low sodium, 

potassium, magnesium, chloride, and sulfate levels, with small 

spikes in calcium and bicarbonate, possibly derived from 

the dissolution of calcium-carbonate caliche. Three samples 

from Beckham County had greater TDS, calcium, and sulfate 

signatures, likely caused by dissolution of gypsum from the 

Cloud Chief or Blaine Formations (fig. 11). Of the six 2014 

samples from Greer and Kiowa Counties, four had greater 

than average TDS concentrations and had high concentrations 

of sodium, chloride, calcium, and sulfate. These four sites are 

near the confluence of the Elm Fork Red River and the North 

Fork Red River. These increased constituent concentrations 

likely were from dissolution of halite and gypsum beds of 

the Blaine Formation of Permian age, which is exposed 

in the headwaters of the Elm Fork Red River watershed 

(figs. 11–12).

Major-ion groundwater-quality data (OWRB, 2015c; 

USGS, 2015a) were graphed on a Piper (1944) diagram 

(fig. 13) for visualization of groundwater types and mixing 

trends between groundwater of the North Fork Red River 

aquifer and the adjacent Permian bedrock. Groundwater 

samples from Permian bedrock units showed a downgradient 

transition from calcium- and sulfate-dominated water (in the 

Rush Springs Sandstone and Dog Creek Shale) to sodiumand chloride-dominated water (in the Flowerpot Shale and 

Hennessey Group). Groundwater samples from the North 

Fork Red River aquifer showed a similar pattern when 

grouped by county (fig. 13). Calcium was the dominant 

cation and bicarbonate was the dominant anion in most of 

the groundwater samples from the North Fork Red River 

aquifer, especially those from Beckham County (fig. 13). 

In some samples from Beckham County, however, sulfate 

was the dominant anion, which may indicate influence from 

gypsum-rich units in the underlying Permian bedrock. In 

most downgradient samples from the North Fork Red River 

aquifer (in Greer, Kiowa, and Jackson Counties), sodium was 

the dominant cation, and chloride or sulfate was the dominant 

anion. These groundwater samples were characteristic of 

samples from the Flowerpot Shale and Hennessey Group of 

Permian age (figs. 11–13). 
22 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Modified from Smith and Wahl, 2003

System Hydrogeologic

Unit

Thickness, 

in feet 

Description

Quaternary North Fork Red

River aquifer 0–250

Silt, sand, and clay deposited by North Fork and

tributaries often reworked by wind; occasionally 

containing quartzitic gravel and slightly cemented 

by calcium carbonate. 

Tertiary

High Plains

(Ogallala)

aquifer

0–600

Brown to light tan to salmon, mostly unconsolidated

clay, silt, sand, and gravel with zones of caliche near 

the surface. 

Elk City

Sandstone Elk City aquifer

Reddish-brown, fine-grained sandstone with silt and

clay, weakly cemented by iron oxide, calcium

carbonate, and gypsum. 

Doxey Shale Reddish-brown, silty shale and siltstone.

0–400

Reddish-brown to orange-brown shale interbedded

with siltstone and sandstone; some dolomite and

much gypsum near base. 

Rush Springs

Formation 

Western

Oklahoma

minor aquifer 

Red to pink, massive, fine-grained, gypsiferous

sandstone.

Marlow

Formation 

Orange-brown, fine-grained sandstone and siltstone

with some dolomite and gypsum. 

Dog Creek Shale 0–80 Red, brown, and green gypsiferous shales with several

beds of siltstone, sandstone, and dolomite. 

Blaine Formation 0–140

Beds of white massive gypsum and thin beds of gray

medium-grained dolomite or dolomitic limestone

separated by well-defined units of red and green shale. 

Flowerpot Shale 0–150

Duncan (San 

Angelo)

Sandstone 

0–40

Grayish-brown to buff, indurated, highly cross-bedded, 

ripple-marked, nonfossiliferous, silty to very fine-grained 

dolomitic sandstone with interbedded shale. 

0–500 Yellowish gray to buff unfossiliferous shale with

calcareous fine-grained siltstone. 

Cambrian Igneous rocks of Wichita Uplift.

Geologic Unit

Alluvium and terrace

deposits (with colluvium 

and dune deposits)

Ogallala Formation 

Permian

Quartermaster

Formation 

Hennessey Group

0–400

Cloud Chief Formation Whitehorse Group

0–390

El Reno Group

Wichita Granite Group

Red, brown, and maroon blocky shales with green and

gray shales and thin beds of gypsum and dolomite; 

Satin-spar gypsum occurs throughout.

Figure 11. Stratigraphic chart showing surficial geologic and hydrogeologic units of the North Fork Red River aquifer study area, 

southwest Oklahoma.
Introduction 23

ROGER

MILLS

COUNTY

CUSTER

COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY

KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN

COUNTY HARDEMAN

COUNTY

To

Pb

Pdc

Pd

Pdy

Pec

Pf

Pf

Pb

Pf

Pf

Phy

Phy

Phy

Pwh

Pwh

Pwh Pcc

Pcc

Qtd

Qtd

Qtd

Qtd

Qtd

Qtd

Qtd

Qtd

Phy

Qtd

Pqw

Per

Qtd

Per

Per

Qtd

Pwh

Qtd

Lake

Altus

Tom Steed

Reservoir

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

0 6 12 18 24 MILES

0 6 12 18 24 KILOMETERS

North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board

Geology from Texas Bureau of Economic

Geology (1992), Northcutt and Campbell (1995),

Johnson and others (2003), and Stanley and

Miller (2004, 2005)

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

EXPLANATION

Quaternary

Active alluvium (Qal)

Terrace (Qtd), including dunes and colluvium

Tertiary

Ogallala Formation (To)

Permian

Elk City Sandstone (Pec)

Doxey Formation (Pdy)

Quartermaster Formation and Whitehorse 

 Group, undivided (Pqw, in Texas)

Cloud Chief Formation (Pcc)

Whitehorse Group (Pwh), includes 

 Rush Springs and Marlow Formations

Dog Creek Shale (Pdc)

Blaine Formation (Pb)

Flowerpot Shale (Pf)

Duncan (San Angelo) Sandstone (Pd)

El Reno Group, undivided (Per, in Texas)

Hennessey Group (Phy)

Post Oak Formation (Ppo)

Cambrian

Wichita Granite Group (Ci)

Beckham County Fault (Gouin, 1927);

triangle points to the upthrown side

Mountain View Fault Zone (approximate frontal 

 trace in subsurface, Luza, 1989)

Other fault (Johnson and others, 2003; Stanley 

 and Miller, 2004, 2005)

Anticline

Syncline

Surficial geologic unit

Fault (in subsurface)

Fold

North Fork Red River aquifer boundary

OKLAHOMA

Wichita

Uplift

Anadarko

Basin

Mountain View

Fault Zone

Figure 12. Surficial geologic units and major structural features of the North Fork Red River aquifer study area, southwest Oklahoma.
24 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

 100 

 80 

 60 

 40 

 20 

 0 

 0 

 20 

 40 

 60 

 80 

 100 0 

 20 

 40 

 60 

 80 

 100 

 0 

 20 

 40 

 60 

 80 

 100 

 100 

 80 

 60 

 40 

 20 

 0 100 

 80 

 60 

 40 

 20 

 0 

 0 

 20 

 40 

 60 

 80 

 100 

 0 

 20 

 40 

 60 

 80 

 100 100 

 80 

 60 

 40 

 20 

 0 

 100 

 80 

 60 

 40 

 20 

 0 

PERCENT

Plot based on Piper (1944)

Sample locations shown on figure 10

Calcium

Magnesium

Sodium plus potassium

Chloride plus fluoride

Bicarbonate

Sulfate

Sulfate plus chloride

Calcium plus magnesium

PERCENT

PERCENT

EXPLANATION

Groundwater-quality sample of water produced

from the North Fork Red River aquifer, 2014

(Oklahoma Water Resources Board, 2015c)

Groundwater-quality sample of water produced

from the North Fork Red River aquifer, 1947–62

(U.S. Geological Survey, 2015a)

Groundwater-quality sample of water produced

from the Permian-age bedrock units adjacent

to the North Fork Red River aquifer, 1944–61

(U.S. Geological Survey, 2015a) 

Rush Springs Formation (Whitehorse Group) and Dog Creek Shale

Flowerpot Shale and Hennessey Group

Blaine Formation

downgradient

downgradient

downgradient

Greer County

Kiowa County

Jackson County

Beckham County

Greer County

Kiowa County

Jackson County

Beckham County

Figure 13. Piper diagram showing groundwater-quality samples of water produced from the North Fork Red River aquifer, 1944–62 and 

July–August 2014.
Hydrogeology of the North Fork Red River Aquifer 25

Hydrogeology of the North Fork Red 

River Aquifer

In northern Beckham County, the North Fork Red River 

parallels the Mountain View Fault Zone (fig. 12), which 

was most active in the late Paleozoic but has been relatively 

dormant in recent geologic time (Johnson, 1989). The 

Mountain View Fault Zone separates the Wichita Uplift and 

the southern limb of the Anadarko Basin, a broad syncline 

with an axis trending west-northwest to east-southeast 

(fig. 12). In southeastern Beckham County, the North Fork 

Red River turns south and then southwest as it traverses the 

Wichita Uplift (fig. 12). The Paleozoic sedimentary rocks of 

the Anadarko Basin can be tens of thousands of feet thick. The 

Paleozoic sedimentary rocks of the Wichita Uplift are only 

hundreds to thousands of feet thick and are not present where 

igneous rocks outcrop. 

Quaternary Alluvium and Terrace

The Quaternary alluvium and terrace deposits 

(figs. 11–12) that compose the North Fork Red River aquifer 

were transported primarily by water and range from clay 

to gravel in size. The terrace material includes windblown 

deposits (Burton, 1965) that form dunes as high as 30 ft in the 

adjacent deposits of the Tillman Terrace aquifer (Barclay and 

Burton, 1953). Narrow rings of boulder-size gravel formed 

adjacent to the slopes of granitic mountains and coalesced 

with terrace deposits, but these colluvial (talus) deposits are a 

minor component of the aquifer in terms of geographic extent 

(Stanley and Miller, 2004). Discontinuous and poorly sorted 

layers of clay, silt, sand, and gravel generally become coarser 

with depth in the alluvium and terrace deposits, and quartzite 

gravels often occur near the contact with underlying bedrock 

(Barclay and Burton, 1953; Merritt, 1958; Burton, 1965; 

Hollowell, 1965a, b). Zones of calcium-carbonate caliche are 

common in the aquifer, especially near the land surface in 

Beckham County (Burton, 1965).

Bedrock Units

Tertiary Ogallala Formation

Strata of the Ogallala Formation outcrop in the far 

northwest part of the study area (figs. 11–12). The Ogallala 

Formation is composed of gravel, sand, silt, and clay 

sediments loosely held together by calcium carbonate cement 

which locally forms layers of caliche (Belden and Osborn, 

2002). These sediments were eroded from the ancestral Rocky 

Mountains and were deposited in alluvial fans that coalesced 

to form a large piedmont (Gutentag and others, 1984). Strata 

of the Ogallala Formation may underlie the Quaternary 

alluvium and terrace deposits north of the North Fork Red 

River in the vicinity of Sweetwater Creek in northwest 

Beckham County. The extent of subcrop areas of the Ogallala 

Formation is not well defined because the loosely consolidated 

materials of the Ogallala Formation, especially as found in 

drill cuttings, resemble those of the overlying alluvium and 

terrace deposits. 

Permian Bedrock Units

Mesozoic sedimentary rocks are absent, and Paleozoic 

(Permian) bedrock units underlie most of the Quaternary 

alluvium and terrace deposits in the study area (figs. 11–12). 

The Permian bedrock units (often referred to as red beds) 

generally are fine grained and are composed of red to orangebrown shale, siltstone, and fine sandstone interbedded with 

dolomite and gypsum (Stanley and Miller, 2004, 2005). The 

Permian bedrock units in Beckham County generally are 

coarser grained than Permian bedrock units in other parts of 

the study area and are dominated by the Elk City Sandstone 

and Doxey Shale (known as the Quartermaster Formation, 

undivided, in Texas), Cloud Chief Formation, and Whitehorse 

Group (Stanley and Miller, 2004, 2005) (figs. 11–12). 

Compared with the overlying Quaternary alluvium and 

terrace deposits, these Permian bedrock units generally act as 

barriers to groundwater flow, though some members of these 

units are minor aquifers in the study area. The most notable 

of these members is the youngest member of the Whitehorse 

Group, the Rush Springs Formation, which constitutes the 

Rush Springs aquifer to the east of the study area (fig. 11). 

Stratigraphically below the Whitehorse Group are the Dog 

Creek Shale, Blaine Formation, Flowerpot Shale, and Duncan 

(San Angelo) Sandstone, collectively known as the El Reno 

Group of Permian age (figs. 11–12). These mostly fine grained 

clastic and evaporite units underlie the Quaternary alluvium 

and terrace deposits in southern Beckham and northern Greer 

Counties (figs. 11–12) (Stanley and Miller, 2004, 2005). The 

shale-rich Flowerpot Shale and Hennessey Group, which 

generally act as barriers to groundwater flow, underlie the 

Quaternary alluvium and terrace deposits in the southern part 

of the study area south of Lake Creek (figs. 11–12) (Stanley 

and Miller, 2004, 2005). 

Cambrian Wichita Granite Group

South and east of Lake Altus, the Quaternary alluvium 

and terrace deposits of the North Fork Red River aquifer are 

interrupted by igneous rocks of the Wichita Granite Group, 

the oldest unit exposed in the study area (figs. 11–12). These 

igneous rocks outcrop as isolated, steep-sided hills and 

mountains near Lake Altus and Tom Steed Reservoir. These 

igneous rocks are generally found at shallower depths in 

the Wichita Uplift than in surrounding geologic provinces 

(like the Anadarko Basin); however, detailed maps of depth 

to subsurface occurrences of igneous rocks have not been 

presented in publicly available literature. Igneous rocks of the 

Wichita Granite Group generally are assumed to be barriers to 

groundwater flow.
26 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Hydrogeologic Framework

A hydrogeologic framework is a three-dimensional 

representation of the aquifer and the surrounding geologic 

units at a scale that captures the regional controls on 

groundwater flow. A hydrogeologic framework was developed 

for the North Fork Red River aquifer and included a definition 

of the aquifer extent and potentiometric surface, as well as a 

description of the textural and hydraulic properties of aquifer 

materials. The hydrogeologic framework was used in the 

construction of the numerical groundwater-flow model of the 

North Fork Red River aquifer described in this report.

Aquifer Extent

The geographic extent of the North Fork Red River 

aquifer was updated from the OWRB (2015b) by using 

geologic maps (Johnson and others, 2003; Miller and Stanley, 

2004; Stanley and Miller, 2004, 2005) and available well (and 

test-hole) completion reports (OWRB, 2015b; USGS, 2015a). 

The aquifer extent was expanded to include (1) the mapped 

alluvium adjacent to Elk Creek and tributaries up to the 

Washita County border, (2) the mapped alluvium and selected 

terrace deposits adjacent to Elm Fork Red River and tributaries 

in Greer County, (3) the mapped alluvium and terrace deposits 

along Sweetwater Creek near the Roger Mills County border, 

and (4) relatively thin terrace deposits along the southwest 

margin of a large terrace lobe in northern Jackson County 

(fig. 12). The update of the aquifer extent also resulted in the 

removal of areas previously designated as North Fork Red 

River aquifer, most notably a lobe of elevated terrace deposits 

in northwest Beckham County that the geologic maps show 

as small discontinuous areas of terrace deposits surrounded 

by Permian bedrock. Some areas of the North Fork Red River 

aquifer, though designated as Permian bedrock on the geologic 

maps (fig. 12), were included in the aquifer extent because 

they contained permitted wells (fig. 6) thought to produce 

water from the North Fork Red River aquifer (based on 

lithologic log evidence); the most notable examples of these 

areas are (1) south of Tom Steed Reservoir in southern Kiowa 

County and (2) west of Lake Altus in eastern Greer County. 

Where present, the top of the North Fork Red River 

aquifer was defined for this report as the land-surface altitude 

obtained from a 10-meter (horizontal resolution) digital 

elevation model (DEM) (USGS, 2015b). The base of the 

North Fork Red River aquifer was mapped previously by Kent 

(1980) from a limited number of well logs and seismic data 

points. The Kent (1980) map of the aquifer base was verified 

for this report by using test-hole completion reports from 

Burton (1965), Hollowell (1965a, b), and Steele and Barclay 

(1965). The Kent (1980) map of the aquifer base also was 

modified for this report to incorporate additional data collected 

since 1980; these additional data included well (and test hole) 

completion reports from the USGS (2015a) and the OWRB 

(2015b). Well completion reports that included drillers’ 

lithologic logs were analyzed for the presence of terms 

representing consolidated Permian bedrock units (such as 

“redbed,” “gypsum,” “mudrock,” and “bedrock”). The altitude 

associated with the first occurrence of these terms in the 

logs was used as the altitude of the aquifer base. The lowest 

altitude listed on the lithologic log was considered to be the 

maximum possible altitude of the aquifer base at that location 

for logs that did not fully penetrate the North Fork Red River 

aquifer. Well completion reports and lithologic logs were 

available for most of the aquifer extent; however, few well 

completion reports and lithologic logs were available near the 

major streams of the study area. To provide bedrock-altitude 

control in areas near major streams, synthetic logs were 

placed about every mile along the major streams overlying 

the aquifer and given an aquifer base altitude that was 35 ft 

below land surface; this 35-ft estimate was the approximate 

mean depth of near-stream test-hole and cross-section data 

reported in literature from the study area (Barclay and Burton, 

1953; Burton, 1965; Hollowell, 1965a, b). As part of this 

investigation, four Geoprobe hydraulic profiling tool (HPT) 

test holes (fig. 1) were drilled along the North Fork Red River 

in Beckham County; these test holes reached a mean depth of 

about 28 ft in the aquifer, but some of those holes may have 

stopped at impenetrable caliche zones before reaching the full 

depth to bedrock. 

Several faults are known to dissect the Permian bedrock 

units in parts of Beckham County (fig. 12); these faults were 

not evident in logs of the unconsolidated aquifer materials 

and, therefore, are not expected to affect groundwater flow. 

Gouin (1927) identified the Beckham County Fault (fig. 12) 

primarily from the thickness of North Fork Red River aquifer 

deposits; wells on the southern (upthrown) side of the fault 

penetrated about 50 ft of aquifer thickness, and wells on the 

northern (downthrown) side of the fault penetrated up to 200 ft 

of aquifer thickness. Some areas of the aquifer, usually those 

with few well completion reports, had less than 30 ft of aquifer 

thickness, and these areas were assigned a minimum aquifer 

thickness of 30 ft for this report. The aquifer thickness, as 

used in this report, is the difference between the land-surface 

(aquifer-top) altitude and the bedrock (aquifer-base) altitude; 

the aquifer saturated thickness, as used in this report, is the 

difference between the water-table altitude and the bedrock 

(aquifer-base) altitude. 

Potentiometric Surface 

A potentiometric surface shows the altitude at which 

the water level would have stood in tightly cased wells 

at a specified time; the potentiometric surface is usually 

contoured or spatially interpolated from synoptic watertable-altitude measurements in many wells across the aquifer 

extent. A 1979 potentiometric map from Kent (1980) was 

used to define the potentiometric surface around 1980. A 

2013 potentiometric surface was contoured from waterlevel altitudes measured between December 2012 and 
Hydrogeologic Framework 27

January 2013 in about 100 selected wells (fig. 14) by using 

measurement methods described in Cunningham and Schalk 

(2011). Those water-table-altitude measurements also were 

used as calibration data for the numerical groundwater-flow 

model described in this report (table 1; USGS 2015a). The 

1979 and 2013 potentiometric surface maps did not include 

enough colocated water-level measurements to allow direct 

comparisons of water-level altitudes, but those maps are useful 

for showing the general directions of groundwater flow in the 

aquifer; groundwater flows perpendicular to potentiometric 

contours in the direction of decreasing contour altitudes 

(fig. 14). The general patterns and directions of groundwater 

flow were the same for the 1979 and 2013 potentiometric 

surface maps. 

Textural and Hydraulic Properties of Aquifer 

Materials

The distribution and variability of textural and hydraulic 

properties of aquifer materials were assumed to be the primary 

controls on groundwater flow in the North Fork Red River 

aquifer. Drillers’ lithologic log data were used to determine the 

textural properties of aquifer materials. Textural terms in each 

lithologic log (OWRB, 2015b) were standardized, categorized, 

and converted to percentage-coarse-material values by using 

the methods of Mashburn and others (2013). The percentagecoarse-material value for each lithologic log then was used to 

estimate and spatially interpolate the hydraulic properties of 

the North Fork Red River aquifer materials. 

Lithologic Log Standardization and Calculation of 

Percentage-Coarse-Material Values

Lithologic logs included terms such as “redbed,” “shale,” 

“mudrock,” and “gypsum” to describe Permian bedrock 

units and terms such as “gravel,” “sand,” “silt,” and “clay” to 

describe the texture of unconsolidated alluvium and terrace 

deposits of the North Fork Red River aquifer. However, 

terms used for lithologic descriptions varied between drillers. 

To simplify and standardize the lithologic logs, lithologic 

descriptions of unconsolidated deposits were reclassified 

into four lithologic categories (clay, silt, sand, and gravel) 

that were assumed to have quartile ranges of percentagecoarse material (0–25, 25–50, 50–75, and 75–100 percent 

coarse material, respectively). The midpoint of the respective 

quartile range (12.5, 37.5, 62.5, or 87.5 percent coarse 

material, respectively) was, thus, assigned to each lithologic 

depth interval by using the same method as Mashburn and 

others (2013). The percentage-coarse-material value for 

each lithologic log was computed as the thickness-weighted 

mean of percentage-coarse-material values assigned to the 

unconsolidated lithologic categories in the log. The maximum 

percentage-coarse-material value for any lithologic log was 

87.5 percent (all gravel), and the minimum percentage-coarsematerial value for any lithologic log was 12.5 percent (all 

clay). 

More than 1,500 lithologic logs were used for the 

percentage-coarse-material analysis, and at least 500 of 

those logs fully penetrated the aquifer. Limitations of using 

lithologic logs include errors in spatial location, depths of 

intervals, and detail of lithologic descriptions. Logs with 

obvious errors were corrected to extract as much useful 

information as possible; logs with inscrutable errors were 

discarded. The bedrock contact was interpolated by using 

professional judgment and geologic information from previous 

publications; the bedrock contact was approximated in areas 

where few lithologic logs were available. 

Spatial Distribution of Percentage-CoarseMaterial Values

The percentage-coarse-material values for each lithologic 

log were spatially interpolated across the aquifer by using the 

inverse-distance-weighted (IDW) interpolation method (Esri, 

Inc., 2017), where values nearest the interpolated location 

have the greatest influence on the interpolated value at that 

location. The IDW interpolation used a power of 3 and a 

neighborhood of 300. The power is the exponent to which the 

inverse of the distance between the interpolated location and 

nearby values is raised, and the neighborhood is the maximum 

number of nearby values used in the interpolation.
28 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

ROGER MILLS COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY

KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN COUNTY

Lake

Altus

Tom Steed

Reservoir

1,900

1,800

1,900

1,500

2,100

1,400

1,400

1,400

1,400

1,500

1,600

1,600

1,500

1,700

2,000

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

0 6 12 18 24 MILES

0 6 12 18 24 KILOMETERS

North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board (2015b)

Potentiometric surface contours modified

from Kent (1980)

EXPLANATION

General direction of groundwater flow

Well with depth-to-water measurement, 2013

U.S. Geological Survey (2015a)

Oklahoma Water Resources Board (2015b)

Potentiometric surface contour, 2013—Shows the

altitude at which the water level would have

stood in tightly cased wells. Interval is 20 feet.

Dashed where approximately located.

Incorporated area (U.S. Census Bureau, 2000)

North Fork Red River aquifer boundary

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

Figure 14. Potentiometric surface contours and general direction of groundwater flow in the North Fork Red River aquifer, 2013.
Hydrogeologic Framework 29

Hydraulic Properties

Ellis and others (2017) developed a linear mathematical 

relation between percentage-coarse-material values and 

horizontal hydraulic conductivity (Kh) determined from core 

material. The core material was obtained from alluvium and 

terrace deposits of the Canadian River in western Oklahoma 

that were similar to the North Fork Red River alluvium and 

terrace deposits in terms of geologic setting and provenance. 

The estimated mean Kh for each lithologic log location in the 

North Fork Red River aquifer was calculated by using the Ellis 

and others (2017) relation:

Kh = (1.25 × Pcm) – 12.4 (1)

where

Kh is the horizontal hydraulic conductivity in feet 

per day; and

Pcm is the percentage-coarse-material value.

Using the Ellis and others (2017) relation, the estimated 

Kh determined for lithologic logs in the North Fork Red River 

aquifer must be within the range of 3 to 97 feet per day (ft/d; 

12.5 to 87.5 percent coarse material). The mean and median 

estimated Kh determined from lithologic logs were 52 ft/d 

and 57 ft/d, respectively. The range and distribution of Kh 

estimated from lithologic logs were similar to the range and 

distribution of Kh measured with depth in four Geoprobe HPT 

logs (McCall, 2010; Geoprobe Systems, 2015; figs. 1 and 15). 

Kh measured in the HPT logs ranged from 1 to 97 ft/d with a 

median of 64 ft/d (fig. 15) and a mean of 61 ft/d (table 7). The 

Kh measured from the HPT logs generally was greater than 

the Kh estimated from the lithologic logs; however, these Kh 

values are difficult to compare because they were determined 

by using different methods. The Kh values measured from the 

HPT logs represent point measurements of Kh at every 0.6 in. 

of depth at only four locations (all near the present channel of 

the North Fork Red River, fig. 1), and the Kh values estimated 

from the lithologic logs were averaged from generalized 

descriptions of drill cuttings. 

The relation between percentage-coarse-material (or Kh) 

values and specific yield (Sy) is nonlinear and depends on 

the sorting and dominant size of aquifer materials (Johnson, 

1967). In general, Sy is maximized for medium to coarse sand, 

which tends to be well sorted; Sy decreases as the aquifer 

materials become finer (and a greater percentage of pore water 

is retained by surface tension) or coarser (and sorting becomes 

poorer) (Johnson, 1967). Dominant grain size and sorting 

cannot be derived from lithologic logs, and Sy is usually 

estimated by using long-duration multi-well aquifer tests 

(Neuman, 1987). 

Three multi-well aquifer tests (AT1, AT2, and AT3, 

fig. 1, table 7) were performed in the alluvium and terrace 

deposits of the North Fork Red River aquifer in Beckham 

County in November–December 1954 by the USGS and the 

OWRB (then known as the Oklahoma Planning and Resource 

Board) (USGS, 2015a). The aquifer tests were performed on 

pumping (irrigation) wells, each with three observation wells 

170–360 ft away. The irrigation wells were pumped for up to 

66 hours at a constant rate while drawdown was measured in 

the observation wells. The aquifer test data (observation-well 

water-level changes over time) were analyzed by using the 

modified Theis (1935) nonequilibrium methods of Cooper 

and Jacob (1946). Mean transmissivities resulting from these 

aquifer tests (AT1, AT2, and AT3) were 7,500, 5,900, and 

7,900 feet squared per day (ft2

/d), respectively, and mean 

hydraulic conductivities were 90.4, 40.7, and 95.2 ft/d, 

respectively. Sy values calculated from these aquifer tests 

were 0.064, 0.051, and 0.152 respectively (table 7). 

Another multi-well aquifer test (AT4, fig. 1, table 7) was 

performed near Lake Altus by Kent (1980) and Paukstaitis 

(1981). A well was pumped at a rate of 100 gal/min for 

50 hours while measurements of drawdown were recorded 

at an observation well 75 ft away. The aquifer-test data were 

analyzed for this report by using the modified Theis (1935) 

nonequilibrium method of Cooper and Jacob (1946). The 

transmissivity calculated from this aquifer test by using the 

Prickett (1965) late match method was 4,480 ft2/d, and the 

hydraulic conductivity was 124 ft/d (Kent, 1980). An Sy value 

of 0.057 was calculated from the Kent (1980) and Paukstaitis 

(1981) aquifer test data by using the Cooper and Jacob (1946) 

method with the Prickett (1965) late-match transmissivity 

(table 7); however, the numerical groundwater-flow model of 

Kent (1980) used a mean Sy value of 0.246. A set of multiwell aquifer tests from the nearby and contiguous Tillman 

Terrace aquifer (fig. 1) also produced Sy values lower than 

those used in the Kent (1980) model for the North Fork Red 

River aquifer; these Sy values ranged from 0.010 to 0.087, 

with a mean of 0.036 (Barclay and Burton, 1953). However, 

Barclay and Burton (1953) stated that the maximum estimated 

Sy value (0.087) was most representative of the aquifer 

because the other Sy values were estimated from multi-well 

aquifer tests of short duration. 

Based on available multi-well aquifer test data (table 7) 

and published studies (Ryter and Correll, 2016; Ellis and 

others, 2017), a mean Sy value of 0.12 was estimated for 

the North Fork Red River aquifer. Values for selected other 

hydraulic properties were assumed because they were too 

difficult or expensive to measure and because they were not 

available in published reports about the study area. The ratio 

of horizontal to vertical hydraulic conductivity (anisotropy) 

of the Quaternary alluvium and terrace deposits was assumed 

to be 3, which matched the anisotropy used for a numerical 

groundwater-flow model of the Canadian River alluvial 

aquifer of western Oklahoma (Ellis and others, 2017). The 

hydraulic conductivity for the Permian bedrock units was 

assumed to be constant at 0.003 ft/d and was comparable to 

hydraulic conductivity estimates for Permian shale units in 

southwest Oklahoma reported by Sullivan (1998). The specific 

storage and anisotropy values for the Permian bedrock units 

were assumed to be constant at 0.00001 and 10, respectively; 

these values were comparable to those used by Ryter and 

Correll (2016) and Ellis and others (2017) for Permian 

bedrock units in northwest Oklahoma.
30 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

B

A

0

5

10

15

20

25

0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100

Percent of observations

Estimated hydraulic conductivity, in feet per day

0

20

40

60

80

100

120

Estimated hydraulic conductivity, in feet per day

EXPLANATION

Number of observations

Upper outside

Upper adjacent

75th percentile

25th percentile

Median

Lower outside

Lower adjacent

Hydraulic profiling tool (HPT) logs; values 

 represent point measurements of hydraulic 

 conductivity at every 0.6 inch of depth at 

 only four locations

Lithologic logs; averaged from generalized 

 descriptions of drill cuttings 

1,564

1,986 1,564

Figure 15. Distributions of estimated hydraulic conductivity observations in the North Fork Red River aquifer.
Table 7. Hydraulic properties calculated from hydraulic profiling tool test holes and multi-well aquifer tests in the North Fork Red River aquifer.[NAD 83, North American Datum of 1983; Sy, specific yield; ft2/d, foot squared per day; Kh, hydraulic conductivity; ft/d, foot per day; --, data not available]

Station 

name 

(fig. 1)

Data source Date County Analysis methods

Test hole or pumping well H

Station 

number

Latitude

(NAD 83 

degrees)

Longitude

(NAD 83 

degrees)

Mean 

Sy

Hydraulic profiling tool test holes

HPT1 U.S. Geological 

Survey (2015a)

4/1/2014 Beckham McCall (2010) 351800099524801 35.300113 -99.879995 -- 

HPT2 U.S. Geological 

Survey (2015a)

4/1/2014 Beckham McCall (2010) 351759099492401 35.299716 -99.82335 -- 

HPT4 U.S. Geological 

Survey (2015a)

4/2/2014 Beckham McCall (2010) 351552099414001 35.264451 -99.694512 -- 

HPT5 U.S. Geological 

Survey (2015a)

4/2/2014 Beckham McCall (2010) 350949099302701 35.163637 -99.507607 -- 

Mean: -- 

Range: -- 

Multi-well aquifer tests 

AT1 U.S. Geological 

Survey (2015a)

December 7–9, 1954 Beckham Cooper and Jacob 

(1946)

351657099584701 35.282552 -99.980108 0.064 

AT2 U.S. Geological 

Survey (2015a)

November 15–19, 

1954

Beckham Cooper and Jacob 

(1946)

351339099424001 35.227551 -99.711487 0.051 

AT3 U.S. Geological 

Survey (2015a)

November 12–17, 

1954

Beckham Cooper and Jacob 

(1946)

351438099370801 35.24394 -99.619262 0.152 

AT4 Paukstaitis (1981) 

and Kent (1980)

March 15–18, 1979 Kiowa Cooper and Jacob 

(1946)

-- 34.969 -99.321 -- 

Prickett (1965), 

early match

-- 34.969 -99.321 -- 

Prickett (1965), 

late match with Cooper and Jacob (1946) analysis of Sy

-- 34.969 -99.321 10.057 

Mean2: 0.081 

Range2: 0.057–

0.152

1Calculated using data from Paukstaitis (1981, fig. 21) and Kent (1980, p. 19). Paukstaitis (1981) and Kent (1980) did not calculate specific yield, but presented the informatio

yield. 

2Except for Sy, mean and range do not include Prickett (1965) analysis for AT4.
32 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Conceptual Groundwater-Flow Model

A conceptual groundwater-flow model (hereafter referred 

to as the conceptual model) is a simplified description of the 

major inflow and outflow sources (hydrologic boundaries) 

of a groundwater-flow system as well as an accounting of 

the estimated mean flows from those sources (water budget, 

table 8) for a specified period of time. A conceptual model was 

developed for the North Fork Red River aquifer to constrain 

the construction and calibration of a numerical groundwaterflow model (hereafter referred to as the numerical model) 

that reasonably represented the groundwater-flow system. 

The conceptual-model water budget (table 8) estimated 

mean annual inflows to and outflows from the North Fork 

Red River aquifer for the period 1980–2013 and included a 

sub-accounting of mean annual inflows and outflows for the 

portions of the aquifer that were upgradient and downgradient 

from Lake Altus, which were determined by using the 

11120302 subwatershed boundary (figs. 2 and 16).

Hydrologic Boundaries

Hydrologic boundaries in the conceptual model represent 

real-world sources (inflows) and sinks (outflows) of water to 

the aquifer. Boundaries that act as both inflows and outflows, 

depending on which flow component dominates, may be 

referred to as net inflows or outflows. 

Recharge

Recharge is the predominant inflow to the North Fork 

Red River aquifer. Recharge, as defined in this report, is the 

amount of precipitation (over a given time) that reaches the 

saturated zone through the process of infiltration through 

the unsaturated zone. Factors that affect recharge rates are 

precipitation rates, ET rates, permeability and moisture 

capacity of the unsaturated zone, and slope of the land surface. 

Recharge rates are difficult to measure directly because they 

vary over short spatial and temporal scales; therefore, recharge 

Table 8. Conceptual groundwater-flow model mean annual water budget for the North Fork Red River aquifer, 1980–2013.

[All units in acre-feet per year; --, not quantified; ET, evapotranspiration; %, percent]

Conceptual model

Water-budget 

category

Upgradient 

from Lake 

Altus

Downgradient 

from Lake 

Altus

Total Percentage 

of water 

budget

Notes

Aquifer area

(percent) 54.6% 45.4% 100.0%

Inflow

Recharge 62,790 52,210 115,000 95% 9.5 percent of mean annual precipitation, 1980–2013

Net change in 

groundwater 

storage1

3,358 2,792 6,150 5% Computed from changes in aquifer water levels

Net lakebed seepage2 -- -- -- -- Assumed to be negligible inflow (less than 1 percent 

of budget)

Total inflow 66,148 55,002 121,150 100%

Outflow

Net streambed 

seepage2

27,824 44,010 71,835 59% Calculated from base-flow data at streamgages 

(table 2)

Saturated-zone ET 10,720 16,080 26,800 22% About 60 percent of saturated zone ET assumed to 

be downgradient from Lake Altus

Well withdrawals 13,322 2,537 15,859 13% Known to be increasing over the period 1980–2013

Net lateral 

groundwater flow, 

springs, and seeps2

2,782 4,401 7,183 6% Springs and seeps were estimated to be no greater 

than 10 percent of net streambed seepage

Total outflow 54,648 67,029 121,677 100%

1

Positive values indicate loss of groundwater storage from the aquifer. Loss of groundwater storage is reported as an aquifer inflow for comparison with the 

numerical groundwater-flow model in which storage loss is represented as a positive value for mass balance purposes (fig. 16, table 14). 

2

Net lakebed seepage, net streambed seepage, and net lateral groundwater flow represent the net effect of aquifer inflows and outflows.
Conceptual Groundwater-Flow Model 33

-100,000

-50,000

50,000

0

100,000

150,000

Recharge Well

withdrawals

Net 

change in

groundwater

storage1

Net lakebed

seepage

Net lateral

groundwater

flow, springs,

and seeps

Mean annual flow, 1980–2013, in acre-feet per year

Water-budget category

Net

streambed

seepage

Saturatedzone

evapotranspiration

Positive values indicate

loss of groundwater storage

from the aquifer.

1

Loss of groundwater storage is reported as an aquifer inflow 

for comparison with the numerical groundwater-flow model in 

which storage loss is represented as a positive value for mass 

balance purposes (table 14).

Upgradient from Lake Altus

Downgradient from Lake Altus

Calibrated numerical model (total)

Conceptual model

EXPLANATION

Figure 16. Mean annual flow by water-budget category for the conceptual model and the calibrated numerical model of the North Fork 

Red River aquifer, 1980–2013.

rates are often estimated by using multiple methods. Some 

methods estimate recharge at specified points, and some 

methods estimate recharge at the basin or regional scale. The 

basin-scale RORA and PART (Rorabaugh, 1964; Rutledge, 

1998) methods, which are based on streamgage data, were 

most appropriate for the scale of this study; however, most 

streams in the study area violated the assumptions of these 

methods because (1) they were losing streams during part 

of the year, (2) they were regulated by large reservoirs, or 

(3) they exceeded the recommended drainage-basin area limit 

of 500 mi2. 

The RORA method uses a recession-curve displacement 

technique to estimate groundwater recharge from each 

storm period based on a one-dimensional analytical model 

of groundwater discharge to a fully penetrating stream (the 

streambed altitude is the aquifer-base altitude) in an idealized 

aquifer with uniform spatial recharge (Rorabaugh, 1964; 

Rutledge, 1998). This method approximates recharge at times 

when ET and groundwater use are minimal, during which 

base flow is assumed to be groundwater discharge that is 

approximately equal to recharge. The RORA method was used 

to estimate annual recharge at the Sweetwater streamgage 

(07301420) on Sweetwater Creek, which has a drainage-basin 

area of 437 mi2

. This streamgage was the only streamgage in 

the study area that did not violate the suggested drainage-area 

limitation for application of the RORA method. Annual 

recharge at the Sweetwater streamgage (07301420) for the 

period of record 1986–2013 ranged from 0.10 in/yr in 2012 to 

1.45 in/yr in 1997; the RORA-estimated mean annual recharge 

for that period was 0.60 in/yr or about 2.4 percent of the mean 

annual precipitation (25.29 in/yr) for the 1980–2013 period 

at the Erick (342944) climate station. The RORA-estimated 

mean annual recharge (0.60 in/yr) was about 31 percent of the 

mean annual recharge (1.91 in/yr) computed by using the SoilWater-Balance (SWB) code (Westenbroek and others, 2010); 

the application of the SWB code is described in detail in the 

Recharge and the Soil-Water-Balance Code section of this 

report. The RORA-estimated mean annual recharge could be 

biased low, however, if recharge flowed across the drainagebasin boundary without discharging to Sweetwater Creek. 

The water-table fluctuation (WTF) method (Healy 

and Cook, 2002) also was used to estimate recharge to the 

North Fork Red River aquifer. The WTF method is based 

on the premise that short-term (hours to a few days) rises 

in continuously recorded groundwater levels in unconfined 

aquifers are caused by recharge arriving at the saturated 

zone following a period of precipitation. The method is 

best applied to aquifers with shallow water tables that 

display rapid water-level rises and declines in response to 

precipitation. The method cannot distinguish between recharge 
34 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

from precipitation and recharge from other sources such as 

irrigation return flow or streambed seepage. Using the WTF 

method, recharge (R) was calculated as the sum of individual 

water-level rises in response to precipitation:

R = Sy Δh/Δt (2)

where 

Sy is the specific yield (dimensionless), 

Δh is the change in water level, in inches, and 

Δt is the change in time, in months. 

Continuous water-level recorder wells CR1 and CR2 

(fig. 1), which were downgradient from many permitted 

production wells, were not ideal for estimating recharge 

by using the WTF method because few water-level rises in 

response to precipitation were observed. Monthly recharge 

during 2014 was estimated at continuous water-level recorder 

well CR3 (fig. 1), which was upgradient from permitted 

production wells. The barometric-pressure-corrected waterlevel hydrograph from CR3 (fig. 17, table 1) showed some 

water-level rises in response to precipitation, which totaled 

22.4 in. at the Hobart climate station (HOBA, fig. 1) in 

2014 (Oklahoma Mesonet, 2015). The minimum estimated 

monthly recharge at CR3 was 0.0 in. for the month of 

January because no precipitation was observed in that month. 

When using an Sy of 0.12, the maximum estimated monthly 

recharge at CR3 was 0.5 in. during May, and estimated annual 

recharge at CR3 was 2.4 in. (about 11 percent of precipitation) 

during 2014.

Estimates of mean annual recharge rates for other 

Quaternary alluvium and terrace deposits with similar climate 

in western Oklahoma include 2.3 in/yr (Adams and Bergman, 

1996), about 8 percent of mean annual precipitation for that 

study; 3.15 in/yr (Barclay and Burton, 1953), about 11 percent 

of mean annual precipitation for that study; and 1.74 in/yr 

25.0

25.5

26.0

26.5

27.0

27.5

28.0

28.5

29.0

29.5

30.0

CR2

(350755099283201):

Beckham County

1,730.73 LS

Frost-free growing season 

(National Agricultural

Statistics Service, 2015)

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Daily precipitation, in inches

Depth to water, in feet below land surface

Date

2013 2014 2015

Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Jan.

Frost-free growing season 

(National Agricultural

Statistics Service, 2015)

82.0

82.5

83.0

83.5

84.0

84.5

85.0

85.5

86.0

86.5

87.0

CR1

(351521099522901):

Beckham County

2,033.77 LS

10.0

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

15.0

CR3

(345759099163401):

Kiowa County

1,567.99 LS

LS, land-surface altitude in feet above North American Vertical Datum of 1988;

Precipitation data from Oklahoma Mesonet (2015) Hobart weather station;

Depth to water data from U.S. Geological Survey (2015a)

Daily precipitation

at Hobart (HOBA) climate

station (Oklahoma Mesonet, 2015)

Depth to water

Time

Estimation of water-level rise

in response to precipitation

Water-level

rise dh (tj)

CR3 CR2 CR1

Figure 17. Daily precipitation and depth to water in continuous water-level recorder wells completed in the North Fork Red River 

aquifer, February 2013 through January 2015.
Conceptual Groundwater-Flow Model 35

(Steele and Barclay, 1965), about 7 percent of mean annual 

precipitation for that study. Based on estimated annual 

recharge percentages from these studies and the WTF method, 

the mean annual recharge rate to the North Fork Red River 

aquifer for the period 1980–2013 was estimated to be about 

2.77 in/yr or 9.5 percent of the mean annual precipitation 

(29.2 in/yr, table 3) for the same period. This 1980–2013 mean 

annual recharge rate of 2.77 in/yr (0.231 feet per year [ft/yr]), 

multiplied by the aquifer area of 497,582 acres, is equivalent 

to a mean annual recharge volume of about 115,000 acre-ft/yr 

(table 8). The mean annual recharge volumes upgradient and 

downgradient from Lake Altus, apportioned by percentage of 

aquifer area (54.6 and 45.4 percent, respectively), were about 

62,800 and 52,200 acre-ft/yr, respectively (table 8). 

Lateral Groundwater Flows

Upgradient from Lake Altus, the alluvium and terrace 

deposits of Wheeler County, Texas (fig. 12), which are 

adjacent to the deposits of the North Fork Red River aquifer, 

were assumed to exchange lateral groundwater flow with the 

aquifer. The rate and direction of lateral groundwater flow 

across the Texas border may vary, however, during seasonally 

and decadally alternating wet and dry periods. During a 

severe drought in 2013 (fig. 3), the Texas border was roughly 

perpendicular to most of the mapped potentiometric surface 

contours (fig. 14) and, therefore, was roughly parallel to the 

direction of most groundwater flow (generally toward the 

North Fork Red River). Based on the configuration of the 2013 

potentiometric surface (fig. 14), the net lateral groundwater 

flow across the Texas border may have accounted for a small 

inflow to the aquifer in 2013. The potentiometric surfaces for 

1951 and 1979 (Kent, 1980), also mapped during dry periods 

(fig. 3A), show a configuration similar to that of fig. 14. No 

water-table-altitude data were available from west of the Texas 

border; therefore, rates of lateral groundwater flow across the 

Texas border could not be quantified. 

Downgradient from Lake Altus, lateral groundwater 

flows across the Tillman County border were expected to be 

outflows based on the potentiometric surfaces of the North 

Fork Red River aquifer (fig. 14) and the Tillman Terrace 

aquifer (Barclay and Burton, 1953; Osborn, 2002). Based 

on estimates of the mean hydraulic gradient, hydraulic 

conductivity, and saturated thickness in the area, net lateral 

groundwater flows across the Tillman County border were 

estimated to be small outflows of about 1,100 acre-ft/yr. 

Net lateral groundwater flows exchanged with the 

surrounding Permian bedrock units (predominantly shale and 

siltstone with relatively low hydraulic conductivity) were 

assumed to be a negligible part of the conceptual-model water 

budget of the North Fork Red River aquifer. No estimates of 

the flow between the Permian bedrock and the aquifer were 

available in published reports. 

Streambed Seepage

Synoptic streamflow measurements (also known as 

seepage-run measurements) were collected by using the 

methods of Rantz and others (1982) during a period of 

minimal runoff on March 11–13, 2013 (USGS, 2015a). These 

measurements were intended to capture tributary-inflow 

and base-flow conditions across the aquifer at one point in 

time. The synoptic streamflow measurements were used to 

calculate net streambed seepage and classify stream reaches 

as gaining (having a downstream increase in base flow) or 

losing (having a downstream decrease in base flow). These 

March 2013 streambed-seepage data (fig. 18) show that 

(1) most small tributaries that originate away from the aquifer 

carried negligible (less than 1 ft3/s) base flows to the North 

Fork Red River, (2) stream reaches upstream from the Texas 

border generally were gaining, (3) stream reaches between 

the Texas border and Lake Altus generally were losing, and 

(4) stream reaches downstream from Lake Altus generally 

were gaining. However, the March 2013 streambed-seepage 

data were collected during a severe drought period (fig. 3) and 

therefore may be more representative of less-frequent drought 

conditions than typical late-winter base-flow conditions. 

Other synoptic streamflow measurements were reported by 

Smith and others (2003) and Stephens (2003) for reaches 

upstream from Lake Altus, but most of these measurements 

captured some streamflow runoff component and were not 

ideal for base-flow comparisons. A set of synoptic streamflow 

measurements from July 2003 (Stephens, 2003), another dry 

year, reinforced that reaches of the North Fork Red River 

upstream from Lake Altus can be losing or dry in the summer 

months when ET, irrigation, and public-supply water demands 

are greatest.

Annual and monthly base flows (fig. 19; table 2, 

only mean annual base flows shown) were computed at 

streamgages for the period 1980–2013 by using the BaseFlow Index (BFI) code (Wahl and Wahl, 1995) in the USGS 

Groundwater Toolbox (Barlow and others, 2015) and 

streamflow data from USGS (2015a). The BFI code uses 

the minimum streamflow in a moving n-day window as a 

basis for hydrograph separation, and a window of 5 days 

was used for all streamgages. Base-flow computation at 

regulated streamgages can be complicated by releases from 

large reservoirs and floodwater-retarding structures because 

these releases (and the subsequent bank storage releases 

associated with these releases) are usually indistinguishable 

from natural base flows. For this reason, hydrograph 

separation methods may overestimate base flows at regulated 

streamgages; the base flows computed for those regulated 

streamgages are useful, however, as a maximum limit on 

estimated base flow.
36 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Haystack Creek

LakeC reek

Otter Creek

Cav eCreek

Salt Creek

Salt ForkRed River

Little Elk

Creek

Gypsu mC reek

Red River

Deep Red Creek

Bear Creek

Elm ForkRed River

Crow Creek

Trail Creek

Wa shitaRiv er

Buf falo Creek

Tep ee C reek

Sa ndstone C reek

East Otter Creek

Fish Creek

Long Creek

El m Creek

I ndian Creek

Sand Creek

Elk Creek

Buck Creek

Tur key Creek

Stinking Creek

TurkeyC reek

Sandy Creek

GlenCreek

Sweetwater Cre ek

BitterCree k

Starvat ion

Cree k

GrapeCreek

Sa n d Creek

Nort hElm Creek

TimberCree k

Deer Creek

OakCreek

Turkey Creek

Cavalry Creek

BoggyCreek

NorthFork Red River

H orseBranch

Sa ltCreek

ROGER

MILLS

COUNTY

CUSTER

COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY

KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN

COUNTY HARDEMAN

COUNTY

Lake

Altus

Tom Steed

Reservoir

Altus

Blair

Carter

Clinton

Dodson

Elk

City

Erick

Gould

Granite

Headrick

Hobart

Hollis

Lone

Wolf

Mangum

New

Cordell Sayre

Shamrock Texola

Tipton

Wellington

Wheeler

Willow

9535

CR2

Sweetwater

Carl

Lake

Creek

0.11

0.22

0.03

-0.52

-3.05

0.42

-0.13

0.03

0.07

1.48

-0.22

-0.49

0.13

-0.47

-0.02

66.7 46.4

37.5

33.1

22.9

17.8

0.03

6.46

8.03

12.1

15.1

40

13

11 0.25 0.41

5.14

5.92

6.21

2.36

3.54

1.45

0

0

0

0

5.9

7

66.7 46.4

37.5

33.1

22.9

17.8

0.03

6.46

8.03

12.1

15.1

40

13

11 0.25 0.41

5.14

5.92

6.21

2.36

3.54

1.45

0

0

0

0

5.9

7

0 6 12 18 24

0 6 12 18 24 KILOMETERS

MILES North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board (2015b)

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

EXPLANATION

North Fork Red River aquifer boundary

Incorporated area (U.S. Census Bureau, 2000)

North Fork Red River base-flow measurement

Tributary base-flow measurement

Base-flow gain or loss, March 2013, in cubic feet per second per mile

1.48 Gaining

reach

Losing

reach

0.22 to 0.42

0.01 to 0.13

–0.22 to –0.01

–0.52 to –0.47

–3.05

15.1

5.9

1.48

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

Figure 18. Base-flow measurements with gaining and losing reaches of the North Fork Red River and tributaries, March 2013.
Conceptual Groundwater-Flow Model 37

EXPLANATION

EXPLANATION

Monthly streamflow

Monthly releases from Lake Altus

Monthly base flow

Annual base-flow index

Annual base-flow index 

 5-year moving average

Monthly streamflow

Monthly base flow

Annual base-flow index

Annual base-flow index 

 5-year moving average

EXPLANATION

Monthly streamflow

Monthly base flow

Annual base-flow 

 index

Annual base-flow 

 index 5-year 

 moving average

C. Headrick streamgage (07305000) on North Fork Red River

B. Carter streamgage (07301500) on North Fork Red River

A. Sweetwater streamgage (07301420) on Sweetwater Creek

0 0

2,000

4,000

6,000

8,000

10,000

Monthly flow, in acre-feet per month Monthly streamflow, in acre-feet per month Monthly flow, in acre-feet per month

Monthly mean flow, in cubic feet per second

100,000

0

663

1,656

331

1,325

994

66.3

165.6

33.1

132.5

99.4

0

40,000

20,000

80,000

60,000

198019811982198319841985

19861987198819891990199119921993

19941995

1996199719981999

2000

2001

200220032004200520062007200820092010201120122013

Year

0 0

350,000

280,000

210,000

140,000

70,000

No data

2,319

5,797

1,159

4,638

3,478

Annual base-flow index, in percent

100

0

40

20

80

60

Annual base-flow index, in percent

100

0

40

20

80

60

Annual base-flow index, in percent

100

0

40

20

80

60

Figure 19. Monthly streamflow, monthly base flow, and annual base-flow index for A, Sweetwater streamgage (07301420) on 

Sweetwater Creek; B, Carter streamgage (07301500) on North Fork Red River; and C, Headrick streamgage (07305000) on North Fork Red 

River, 1980–2013.
38 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Streambed seepage is the predominant outflow from 

the North Fork Red River aquifer. The annual net streambed 

seepage upgradient from Lake Altus was estimated to be 

27,824 acre-ft/yr (table 8) and was calculated as the mean 

annual base flow at the Carter streamgage (07301500) minus 

the mean annual base flows at the Shamrock (07301300) 

and Kelton (07301410) streamgages (table 2). Because no 

streamgages are located between the Carter streamgage 

(07301500) and Lake Altus (a distance of about 27 river 

miles), additional streambed seepage may occur in this 

reach that was not represented in the calculation. The annual 

net streambed seepage downgradient from Lake Altus was 

estimated to be 44,010 acre-ft/yr (table 8) and was calculated 

as the mean annual base flows at the Headrick (07305000) 

and Snyder (07307010) streamgages minus the mean annual 

base flows at the Carl (07303400) and Hobart (07304500) 

streamgages plus 50 percent of the mean annual releases from 

Lake Altus (table 2). This 50-percent figure was assumed to 

represent the unknown portion of annual releases that flowed 

to the North Fork Red River aquifer as bank storage and 

streambed seepage and was later discharged to the North Fork 

Red River as base flow. Mean annual releases from Lake Altus 

for the period 1980–2013 were about 35,100 acre-ft/yr (U.S. 

Bureau of Reclamation, 2015b). 

Lakebed Seepage

Net lakebed seepage between the North Fork Red River 

aquifer and Lake Altus or Tom Steed Reservoir was not 

measured but probably was a small component of the water 

budget of the aquifer. Lakebed seepage flows were expected 

to vary seasonally with changes in lake stage, which generally 

was highest in the late spring months and lowest in the fall 

months. Annual lakebed seepage flows probably alternate 

between being aquifer inflows and outflows. The annual 

lakebed seepage of Lake Altus, for example, probably is an 

aquifer outflow during drought years when the lake stage is 

relatively low and an aquifer inflow when the lake is full. The 

annual lakebed seepage of Tom Steed Reservoir, however, 

probably is an aquifer inflow in most years because the lake 

stage is typically at a higher altitude than the surrounding 

aquifer materials. The net lakebed seepage of Lake Altus 

and Tom Steed Reservoir (combined) was assumed to 

be a negligible aquifer inflow (less than 1 percent of the 

conceptual-model water budget for the period 1980–2013).

Springs and Seeps

Few springs in alluvium and terrace deposits of the 

study area have been documented in published reports. Some 

reports, however, contain brief references to small springs, 

seeps, or perennial streams that are assumed to be springfed in the Quaternary alluvium and terrace deposits near the 

contact with underlying Permian bedrock. Steele and Barclay 

(1965) mentioned the presence of abundant small springs in 

the terrace deposits along the Elm Fork Red River northeast of 

Mangum, Okla. (figs. 1 and 12). Burton (1965), in describing 

the alluvium and terrace deposits of Beckham County, 

mentioned that Spring Creek was the only perennial stream in 

that area. Barclay and Burton (1953) mentioned small springs 

along the eastern edge of the terrace deposits of Otter Creek 

just outside of the North Fork Red River aquifer study area. 

According to the available literature for the study area, small 

distributed springs and seeps and not large point discharges 

are most typical in the alluvium and terrace deposits of the 

North Fork Red River aquifer. Published flow rates for springs 

and seeps discharging from the North Fork Red River aquifer 

were not available, but they were expected to be a small part 

of the conceptual-model water budget; flows to springs and 

seeps were assumed to be proportional to base flow and were 

estimated to be no more than 10 percent of net streambed 

seepage for the study period.

Saturated-Zone Evapotranspiration

ET is the process by which water is transferred to the 

atmosphere directly through evaporation (or sublimation 

in the case of snow and ice) and indirectly through plant 

transpiration. Much of this process, however, occurs at or 

near the land surface as precipitation pools as surface water 

or infiltrates the soil unsaturated zone and becomes available 

to the plant root zone. These surface-water and unsaturatedzone components of ET were not considered to be a part of 

the conceptual model for the North Fork Red River aquifer 

because they occur before infiltrating precipitation has 

become groundwater recharge (reached the saturated zone). A 

supplementary component of ET, however, occurs in areas of 

the aquifer where the saturated zone intersects the plant root 

zone, most commonly in lower lying areas near streams; this 

component of ET (saturated-zone ET) was an important part 

of the conceptual-model water budget. 

Rates of saturated-zone ET are difficult to estimate over 

a large area but should be roughly proportional to (1) the area 

where the saturated zone intersects the plant root zone, (2) the 

mean depth to groundwater in that area during the growing 

season, and (3) the mean rate of transpiration associated with 

the assemblage of plants in that area. The area where the 

saturated zone intersects the plant root zone probably is small 

(compared to the entire North Fork Red River aquifer area) 

and confined to the 107,200-acre area of active alluvium (Qal, 

fig. 12; Johnson and others, 2003; Stanley and Miller, 2004) 

along perennial or near-perennial streams. About 21 percent 

(22,300 acres) of the active alluvium area was classified 

as wetland (land area with frequently saturated or flooded 

soils) by the National Wetlands Inventory (U.S. Fish and 

Wildlife Service, 2015). The area where the saturated zone 

intersects the plant root zone probably is slightly larger than 

the area classified as wetland, however, because land areas 

do not have to be flooded to contribute to saturated-zone ET. 

About 25 percent (26,800 acres) of the active alluvium area 

(107,200 acres), therefore, was assumed to contribute to 

saturated-zone ET. Saturated-zone ET also was assumed to 
Conceptual Groundwater-Flow Model 39

be proportional to and no greater than the potential ET minus 

the actual ET computed by using the Hargreaves and Samani 

(1985) method as described by Westenbroek and others 

(2010). This assumption resulted in the summed components 

of ET not exceeding the potential ET. The saturated-zone 

component of ET was assumed to be active for about half the 

year (182.5 days), greatest annually in wet and hot years, and 

greatest monthly in early summer (Scholl and others, 2005) 

when precipitation and temperature are above average (fig. 4). 

By using the assumptions previously listed, groundwater 

outflow by saturated-zone ET could be estimated from daily 

water-level fluctuation data at wells with shallow depths to 

water according to methods of White (1932). Wells with these 

data were not available in the study area, but gage height data 

from selected streamgages (07301500, 07303400, 07304500, 

and 07305000; USGS, 2015a) showed daily declines in 

stream stage during summer low-flow conditions. These daily 

declines in stream stage (with rebounds at night) indicated that 

saturated-zone ET was an active process throughout the North 

Fork Red River aquifer, but the declines were too small to be 

accurately measured from the gage height data.

White (1932) estimated annual saturated-zone ET rates 

of 0.75–1.9 ft/yr for undisturbed salt grass cover in southwest 

Utah with a mean depth to water of 1–2 ft. Because ET rates 

in the high desert of Utah are likely to be greater than those in 

Oklahoma, an annual saturated-zone ET rate of about 1.0 ft/yr 

was assumed to be appropriate for the North Fork Red River. 

If about 25 percent (26,800 acres) of the active alluvium area 

(107,200 acres) had similar cover and depths to water, this 

assumed rate would correspond to an annual saturated-zone 

ET outflow of 26,800 acre-ft/yr (table 8). Annual saturatedzone ET was expected to be greater downgradient than 

upgradient from Lake Altus because the water table of the 

active alluvium tends to be shallower downgradient from Lake 

Altus (where gaining streams are more common, fig. 18). 

About 60 percent of the annual saturated-zone ET for the 

aquifer was allocated to the smaller downgradient portion of 

the aquifer (table 8), because that portion had mostly gaining 

reaches (and presumably more area with near-surface water 

table) according to the streambed-seepage data (fig. 18). 

Well Withdrawals, Water-Level Response, and 

Storage Change 

Mean annual well withdrawals were assumed to 

equal the mean annual reported groundwater use for the 

period 1980–2013, or 15,859 acre-ft/yr (table 4). About 

84 percent of the annual well withdrawals for that period 

were from permitted wells upgradient from Lake Altus 

(mostly in Beckham and Greer Counties, fig. 8, table 8). Well 

withdrawals were greatest in dry and hot years because more 

water was required in those years to grow healthy crops. The 

water table generally falls during dry and hot years (especially 

during extended droughts) and rises during wet and cool 

years (fig. 3). The degree to which the water table fluctuates 

annually at a location is related in part to the volume of nearby 

ET and well withdrawals. For the study period 1980–2013, the 

OWRB (2015b) Mass Measurement Program recorded annual 

water-level measurements (usually in winter) from wells in the 

North Fork Red River aquifer. Those measurements show a 

general rise in water-level altitudes over the cooler and wetter 

early period (1980–2000) and a general decline in water-level 

altitudes over the hotter and drier late period (2001–2013) 

(figs. 20 and 3). Mean water levels for the period 1980–2013 

fell 4.95 ft in Beckham County, fell 5.85 ft in Greer County, 

and rose 0.27 ft in Kiowa County (fig. 20). Assuming an Sy of 

0.12 and a mean water-level decline of about 3.5 ft (the mean 

water-level change), the North Fork Red River aquifer lost 

about 209,000 acre-ft (6,150 acre-ft/yr) of storage during the 

period 1980–2013 (table 8). 

Conceptual Groundwater-Flow Model 

Water Budget

The conceptual-model water budget (table 8) summarized 

mean water flows (fluxes) between each hydrologic boundary 

and the North Fork Red River aquifer for the period 1980–

2013. Recharge accounts for most (95 percent) of the inflows 

to the North Fork Red River aquifer, and net streambed 

seepage accounts for most (59 percent) of the outflows from 

the North Fork Red River aquifer (fig. 16, table 8). The 

expected mean annual net change in groundwater storage 

(6,150 acre-ft/yr) was reported as an aquifer inflow for 

later comparison with the calibrated numerical model water 

budget (fig. 16, table 8). Estimated inflows exceeded outflows 

upgradient from Lake Altus, and estimated outflows exceeded 

inflows downgradient from Lake Altus; therefore, inflows 

upgradient and outflows downgradient from Lake Altus may 

have been overestimated in the conceptual-model water 

budget. 
Depth to water, in feet below land surface

Year

0

102030405060

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006

2008

2010

2012

2014

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006

2008

2010

2012

2014

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

A. Beckham County B. Greer County C. Kiowa County

9090

OWRBwell ID:

OWRBwell ID:

OWRBwell ID:

9454

95439549953495409536955395399535

94609450945194539458

908990889096909891229101

Mean annual water-level 

change, in feet per year

–4

0

–2

248

Mean water-level change, 1980–2013: –5.85 feet Mean water-l

6 Mean water-level change, 1980–2013: –4.95 feet

Study period 1980–2013 Study period 1980–2013 Study pe

Figure 20. Annual water-level measurements and mean annual water-level change by county for Oklahoma Water Resources Board Mass Measure

completed in the North Fork Red River aquifer, 1978–2014. [OWRB well ID, Oklahoma Water Resources Board well identifier; data from Oklahoma Wat
Numerical Groundwater-Flow Model 41

Numerical Groundwater-Flow Model

A finite-difference numerical model of the North Fork 

Red River aquifer was constructed by using MODFLOW-2005 

(Harbaugh, 2005) with the Newton formulation solver 

(MODFLOW-NWT; Niswonger and others, 2011) for 

improved solution of problems involving drying and rewetting. 

In the modular design of MODFLOW, each hydrologic 

boundary of the conceptual model, such as streambed seepage, 

recharge, or well withdrawal, is included as a package that, 

when activated, adds new inflow and outflow terms to the 

groundwater-flow equation being solved. Data inputs for each 

package are specified in machine-readable text files. Model 

space is discretized into cells, and the cell size is the finest 

resolution at which spatially varying properties (such as landsurface altitude or hydraulic conductivity) may be represented 

and varied. Model time is discretized into time steps within 

stress periods. The stress period length is the finest resolution 

at which temporally varying inflows and outflows may be 

represented and varied, and the time step length is the finest 

length of time for which model outputs may be written. The 

numerical model represents hydraulic properties that appear 

reasonable on the basis of water-table-altitude, base-flow, 

and lake-stage observations, but may not be unique. Different 

combinations of model input parameters may result in an 

equally reasonable fit to the observations. The calibrated 

numerical groundwater-flow model inputs and outputs are 

available in Smith and others (2017).

Spatial and Temporal Discretization

The numerical model of the North Fork Red River 

aquifer had 385 rows, 460 columns, about 27,600 active cells 

of 886 by 886 ft (270 by 270 meters), and 2 convertible layers. 

The cell size was chosen to minimize model-processing time 

while reasonably representing the variability of properties 

being modeled. The top layer (layer 1) represented the 

undifferentiated Quaternary alluvium and terrace deposits 

with variable thickness determined from the hydrogeologic 

framework, and the bottom layer (layer 2) represented the 

Permian bedrock with a nominal thickness of about 100 ft. The 

aquifer top altitude was multiplied by 1.001 in the numerical 

model to prevent confined aquifer conditions that occur when 

the simulated water-table altitude exceeds the aquifer top 

altitude.

The model active area (fig. 21) was created from the 

North Fork Red River aquifer extent (modified from the 

OWRB [2015b]), and expanded in some areas to ensure that 

each active cell was in connection with at least one other 

active cell. One terrace lobe in northern Beckham County was 

not included in the model active area because it was almost 

separated spatially and hydraulically from the rest of the North 

Fork Red River aquifer (fig. 21). Though the conceptual model 

divided the aquifer into areas upgradient and downgradient 

from Lake Altus, the numerical model described in this report 

combined both areas.

The numerical model was temporally discretized into 

408 monthly transient stress periods (each with 2 time steps to 

improve model stability) representing the period 1980–2013. 

An initial steady-state stress period, in which the groundwaterflow equation had no storage component, represented mean 

annual inflows to and outflows from the aquifer and produced 

a solution that was used as the initial condition for subsequent 

transient stress periods. Though other units for length and time 

are used in this report, the numerical model was constructed 

by using units of meters and days. 

Simulation of Hydrologic Boundaries

Hydrologic boundaries in the numerical model define 

where and how water may enter or leave the model (fig. 21) 

and include specified-head, specified-flux, and headdependent boundaries. A specified-head boundary was 

used to simulate lakebed seepage at Tom Steed Reservoir. 

Specified-flux boundaries were used to simulate recharge and 

well withdrawals. Head-dependent boundaries were used to 

simulate saturated-zone ET, lateral groundwater flow between 

adjacent alluvium and terrace deposits, springs and seeps, 

streambed seepage, and lakebed seepage at Lake Altus.

Recharge and the Soil-Water-Balance Code

Conceptual-model recharge to the North Fork Red River 

aquifer was spatially and temporally distributed for each 

month of the study period 1980–2013 by using the SWB 

code (Westenbroek and others, 2010). The SWB code uses a 

modified Thornthwaite and Mather (1957) soil-water-balance 

method on a gridded data structure to compute the daily 

amount of precipitation infiltration that exceeds the storage 

capacity of the plant root zone and the demand from plants for 

ET. The Hargreaves and Samani (1985) method for a reference 

latitude range of 34.5–35.5 degrees was used to compute 

ET. Land-cover and soil properties were used to estimate the 

amount of daily precipitation that entered the soil profile and 

the amount of daily precipitation runoff. Land-cover types 

(Multi-Resolution Land Characteristics Consortium, 2011) 

were used to assign runoff curve numbers and plant root-zone 

depths. The default SWB plant root-zone depths for shrubs/

range, grass/pasture, and crops (the dominant land-cover 

types overlying the aquifer, fig. 5) varied with soil texture 

and ranged from 2.0 to 3.6 ft (Dripps, 2003; Westenbroek 

and others, 2010). Soil properties (available water capacity 

and hydrologic soil group) were derived from the Soil 

Survey Geographic database (SSURGO; Natural Resources 

Conservation Service, 2015). Digital elevation models 

(USGS, 2015b) were used to determine the surface-waterflow direction for each grid cell as described in Westenbroek 

and others (2010). The grid cell size used for the SWB code 

was 886 by 886 ft (270 by 270 meters). The land-cover, soil, 

and altitude inputs were assumed to remain constant during 

the study period, but climate data inputs varied daily. Climate 

data inputs included interpolated grids of daily precipitation, 
42 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

ROGER MILLS COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN COUNTY

ELK

SWEE

EFRR

NFRR

07301420

07301481

07301500

07303000

07303400

07303500 07304500

07305000

07305500

07307010

Elm Fork

Red

River

Elk

North

Fork

Red

River

Creek

Sweetwater

Creek

 Otter

Creek

Elm Fork

Red

River

Elk

North

Fork

Red

River

Creek

Sweetwater

Creek

 Otter

Creek

drn1

drn1

ghb1

ghb1

drn2

drn2

drn3

drn4

drn5 drn6

drn7

drn8

kh6

kh9

kh1

kh0

kh10

kh2

kh4

kh7

kh5

kh3

kh8

kh11

kh12

Unmodeled 

terrace lobe

Lake

Altus

Tom Steed

Reservoir

EXPLANATION

Streamflow-routing inflow, with name

Streamgage, with name

General-head boundary, with parameter

zone number

Well

Drain, with parameter zone number

Streamflow routing

Lake (Lake Altus)

Time-variant specified head (Tom Steed Reservoir)

Saturated-zone evapotranspiration

Other active model area and recharge (The edge of the active

model area is a no-flow boundary unless specified otherwise)

Hydraulic conductivity parameter zone, with parameter

zone number

0 6 12 18 24

0 6 12 18 24 KILOMETERS

Base modified from U.S. Geological Survey digital data MILES

Universal Transverse Mercator, zone 14

North American Datum of 1983

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

Figure 21. Active area, boundary conditions, and parameter zones for the numerical groundwater-flow model of the North Fork Red 

River aquifer, southwest Oklahoma.
Numerical Groundwater-Flow Model 43

maximum temperature, and minimum temperature data from 

selected climate stations (National Climatic Data Center, 

2015; Oklahoma Mesonet, 2015; table 1) in and near the study 

area (fig. 1). 

The initial SWB-estimated mean annual recharge for the 

North Fork Red River aquifer study area for the period 1980–

2013 was 1.38 in/yr (fig. 22) or 50 percent of the mean annual 

recharge (2.77 in/yr) estimated for the conceptual model. 

The initial SWB code used default plant root-zone depths 

that were developed for use in northern Wisconsin where 

crops are grown in soils overlying thick, loosely consolidated 

deposits of glacial till (Dripps, 2003). Plant root-zone depths 

in western Oklahoma were assumed to be less than those of 

Wisconsin, and the default plant root-zone depths were scaled 

to 70 percent to reduce the simulated interception of soil 

moisture and increase estimated recharge to the aquifer. With 

the scaled plant root-zone depths (1.4 to 2.5 ft), the SWBestimated mean annual recharge was 2.08 in/yr (fig. 22) or 

75 percent of the mean annual recharge (2.77 in/yr) estimated 

for the conceptual model. The plant root-zone depths were not 

decreased further to avoid unreasonable values. The SWBoutput monthly recharge grids were converted to mean daily 

recharge grids by dividing by the number of days per month; 

the mean daily recharge grids were used as precalibration 

numerical model inputs. The remaining difference (0.69 in/yr) 

between the SWB-estimated mean annual recharge (2.08 in/

yr) and the conceptual-model-estimated mean annual recharge 

(2.77 in/yr) was gained by scaling the SWB monthly recharge 

grids with multipliers during the numerical model calibration.

The minimum and maximum SWB-estimated annual 

recharge amounts for the period 1980–2013 were about 0.2 in. 

(2012) and 4.7 in. (1986), respectively (fig. 22). Spatially, 

recharge was greatest in areas of active alluvium along the 

North Fork Red River and in selected areas of the terrace 

deposits (Qtd) where windblown sand (dune) deposits were 

abundant (figs. 12 and 23). Mean monthly recharge for the 

period 1980–2013 was greatest in May and June, when 

precipitation was greatest (fig. 4). Mean monthly recharge 

normalized by the mean monthly precipitation was greatest in 

the winter months, when ET was at a minimum. 

Lateral Groundwater Flows

Lateral groundwater flows between the North Fork Red 

River aquifer and adjoining alluvium and terrace deposits in 

Texas were simulated by using the General-Head Boundary 

(GHB) package (Harbaugh and others, 2000) (fig. 21). 

The flow to or from a GHB cell is the product of the GHB 

conductance and the difference between the water-table 

altitude and the GHB altitude. The GHB conductance was 

roughly equivalent to the hydraulic conductivity of the 

aquifer multiplied by the numerical model cell size. Based 

on the potentiometric surfaces of the North Fork Red River 

aquifer (fig. 14) and the Tillman Terrace aquifer (Osborn, 

2002; Barclay and Burton, 1953), lateral groundwater flows 

across the Tillman County border were expected to always be 

outflows. Therefore, lateral groundwater outflows from the 

North Fork Red River aquifer to the Tillman Terrace aquifer 

were simulated by using the Drain package (Harbaugh and 

others, 2000) (drn8, fig. 21). The drain conductance was 

roughly equivalent to the hydraulic conductivity of the aquifer 

multiplied by the numerical model cell size. Flow between the 

aquifer and drain cells functions the same way as the GHB 

package, except that there is no drain flow when the watertable altitude is less than the drain altitude. 

Streams

Named streams (Horizon Systems Corporation, 2015) 

were simulated by using the Streamflow-Routing package, 

version 2 (SFR) (Niswonger and Prudic, 2005) (fig. 21). Only 

base flow was simulated in SFR streams. Inflows for SFR 

streams include base flows routed from upstream segments, 

specified inflows (base flows) from tributary streams, and 

streambed seepage from the water table; SFR outflows include 

base flows routed downstream and streambed seepage to the 

water table. The SFR package exchanges flow between the 

aquifer and the stream according to Darcy’s Law (Darcy, 

1856); the flow exchanged between the aquifer and the stream 

is the product of the streambed conductance and the difference 

between the water-table altitude and the stream stage. 

Simulated base flows are calculated for each part of the stream 

contained in a model cell, known as reaches, until the end of 

a segment, or group of cells with uniform or linear hydraulic 

properties, is reached during each time step. Computation of 

flows repeats in a downstream direction until flows are routed 

out of the numerical model active area.

All SFR stream segments were assigned an assumed 

streambed thickness of 6.6 ft and an estimated streambed 

conductivity of 16.4 ft/d. This streambed conductivity value 

was within the expected range of hydraulic conductivity 

determined from the aquifer hydrogeologic framework and 

was about 26 percent greater than the streambed conductivity 

used for a numerical model of the Beaver-North Canadian 

River alluvial aquifer (Ryter and Correll, 2016). The channel 

widths of stream segments were estimated from 2013 aerial 

photographs (Natural Resources Conservation Service, 

2015) and ranged from 6.6 to 197 ft, gradually increasing 

downstream. The streambed altitude of each stream segment 

was derived from 10-meter DEMs (USGS, 2015b). Monthly 

base-flow inflows at the boundary of the numerical model 

active area were specified for Sweetwater Creek (SWEE), 

North Fork Red River (NFRR), Elk Creek (ELK), and Elm 

Fork Red River (EFRR) (fig. 21). These specified inflows 

were assigned based on distance-weighted flow between the 

nearest upstream and downstream streamgages. For periods 

when streamgage data were not available, mean monthly baseflow values averaged over the available period of record were 

used as specified inflows. All other streams were assumed to 

have no specified inflows at the boundary of the numerical 
44 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Recharge, 80-percent plant root-zone depth

Recharge, 70-percent plant root-zone depth Mean recharge, 70-percent plant 

 root-zone depth, 1980–2013

Mean recharge, 80-percent plant 

 root-zone depth, 1980–2013 Recharge, 90-percent plant root-zone depth

Mean recharge, 90-percent plant 

 root-zone depth, 1980–2013

Recharge, 100-percent (default) plant root-zone 

 depth (Westenbroek and others, 2010)

Mean recharge, 100-percent (default) plant 

 root-zone depth, 1980–2013

Mean annual precipitation, 1980–2013

EXPLANATION

1980198119821983

19841985

1986

1987

1988

1989

1990

1991

1992

1993

19941995

1996

1997

199819992000

2001

2002200320042005

20062007

2008

2009

201020112012

2013

Year

0

1

2

3

4

5

6

Soil-Water-Balance code estimated annual recharge, in inches

Soil-Water-Balance code estimated annual precipitation, in inches

0

5

10

15

20

25

30

35

40

45

0

41,000

83,000

124,000

166,000

207,000

249,000

7

8

9

290,000

332,000

373,000

Soil-Water-Balance code estimated annual recharge, in acre-feet

1.38

1.58

1.81

2.08

27.3

Figure 22. Annual precipitation and annual groundwater recharge computed by using the Soil-Water-Balance code (Westenbroek and 

others, 2010) for the North Fork Red River aquifer, 1980–2013. 
Numerical Groundwater-Flow Model 45

ROGER MILLS COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN

COUNTY

Lake

Altus

Tom Steed

Reservoir

EXPLANATION

Spatially distributed mean annual recharge, in inches,

1980–2013, from the Soil-Water-Balance code;

recharge was scaled upward (increased) for use in the

numerical groundwater-flow model

North Fork Red River aquifer boundary

0.00 to 0.30

0.31 to 0.50

0.51 to 0.75

0.76 to 1.40

1.41 to 2.10

2.11 to 3.00

3.01 to 5.00

5.01 to 16.75

0 6 12 18 24

0 6 12 18 24 KILOMETERS

MILES North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board (2015b)

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

Figure 23. Mean annual groundwater recharge computed by using the Soil-Water-Balance code (Westenbroek and others, 2010) for 

the North Fork Red River aquifer, 1980–2013.
46 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

model active area. Withdrawals from Lake Altus for irrigation 

(LAID, permit 19390023) and public supply (city of Altus, 

permit 19260006) were simulated in the model. Permitted 

diversions from streams were not simulated; although these 

diversions were allocated about 5,000 acre-ft/yr by OWRB 

(2015b), the diversions were mostly on small intermittent 

streams (USGS, 2015b) with minimal to no base flow for 

much of the year and were considered a minor component in 

the overall water budget for the study area. 

Lakes

Tom Steed Reservoir was simulated as a specified-head 

boundary by using the Time-Variant Specified-Head package 

(fig. 21). Simulated lake stage was varied monthly according 

to historical lake-stage records (U.S. Bureau of Reclamation, 

2015c). Monthly lakebed seepage for Tom Steed Reservoir 

was governed by the hydraulic conductivity of the aquifer.

Lake Altus was simulated by using the Lake package 

(Merritt and Konikow, 2000; Niswonger and Prudic, 2005) 

(fig. 21). Lake Altus bathymetry and stage-storage relation 

data were obtained from a 2007 sedimentation survey (U.S. 

Bureau of Reclamation, 2014) and the relation was assumed 

to remain the same through all simulations. Lakebed seepage 

at Lake Altus was governed by a lakebed leakance factor of 

1.3 feet per day per foot. Other data for components of the 

Lake Altus water budget varied monthly and were obtained 

from a variety of sources. Estimated lake-surface precipitation 

and evaporation data were supplied by the U.S. Army Corps 

of Engineers (2015b) and Andy Kmetz (U.S. Army Corps 

of Engineers, written commun., September 15, 2014). Lakewithdrawal volumes for irrigation and public-supply use were 

supplied by the U.S. Bureau of Reclamation (2015b). Floodcontrol releases were estimated by averaging release data from 

the U.S. Bureau of Reclamation (2015b) and North Fork Red 

River streamflows at the Lugert streamgage (07303000, fig. 1; 

USGS, 2015a). Flood-control releases from Lake Altus were 

not routed to the downstream SFR segments of the North Fork 

Red River. Surface-water inflows to Lake Altus were routed 

as SFR-simulated base flows from the North Fork Red River 

where it enters the lake (fig. 21). Runoff inflows to Lake Altus 

were assumed to equal the BFI-estimated runoff component 

of streamflow at the Carter streamgage (07301500). The 

Lake package simulation of Lake Altus is the only part of 

the numerical model that includes the runoff component of 

streamflow; inclusion of runoff was necessary to simulate the 

correct lake stage.

Springs and Seeps

Some groundwater was expected to leave the North 

Fork Red River aquifer through distributed spring and seep 

discharge areas where terrace deposits extend across major 

groundwater divides. These spring and seep discharge areas 

(drn1–drn7; fig. 21) were simulated by using the Drain 

package. The flow from the aquifer at a drain cell is the 

product of the drain conductance and the difference between 

the water-table altitude and the drain altitude. Flow between 

the aquifer and drain cells functions the same way as the 

GHB package, except that there is no drain flow when the 

water-table altitude is less than the drain altitude. The drain 

conductance varied by location but was roughly equivalent 

to the hydraulic conductivity of the aquifer multiplied by the 

numerical model cell size.

Saturated-Zone Evapotranspiration

Saturated-zone ET was simulated by using the 

Evapotranspiration package (Harbaugh and others, 2000) and 

was limited to the active alluvium areas near streams in the 

North Fork Red River aquifer (fig. 21). Maximum rates of 

saturated-zone ET were assumed to be proportional to and no 

greater than the potential minus actual ET as computed by the 

SWB code. The ET extinction depth, or the depth below land 

surface at which the saturated zone becomes inaccessible to 

plants, was set to 2.6 ft, which was about the area-weighted 

mean plant root-zone depth specified in the SWB code. 

Well Withdrawals

Well withdrawals were simulated by using the Well 

package (Harbaugh and others, 2000). Annual reported 

groundwater use for each permit was distributed evenly to all 

of the wells attached to that permit (OWRB, 2015b). These 

annual well withdrawals then were distributed into monthly 

well withdrawals by using monthly demand distributions 

(fig. 24) for Oklahoma Comprehensive Water Plan watermanagement planning basin 36 (fig. 2) (OWRB, 2012a). 

Annual irrigation well withdrawals were multiplied by 

the monthly irrigation demand (as a percentage of annual 

groundwater withdrawals), and annual public-supply well 

withdrawals were multiplied by the monthly public-supply 

demand (as a percentage of annual groundwater withdrawals). 

Annual well withdrawals for other purposes were distributed 

evenly to all months of the year. Domestic withdrawals, 

which are not regulated or reported by the OWRB, were not 

simulated; these withdrawals were expected to be a minor 

component of total withdrawals because the rural population 

of the study area was small and most of the study area was 

served by rural or municipal public water-supply systems 

(OWRB, 1998). 

Groups of wells attached to a single permit were 

not allowed to exceed (cumulatively) the annual 

permitted amount. Individual well withdrawals greater than 

405 acre-ft/yr (equivalent to a continuous annual pumping rate 

of 250 gal/min) were considered unreasonable for this aquifer 

and were reduced to that threshold value to avoid instability 

in the numerical model. Steady-state well withdrawals were 

determined as the mean of withdrawals during the study 

period.
Numerical Groundwater-Flow Model 47

Irrigation

Basin 36

Public supply

0

5

10

15

20

25

30

35

40

45

Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec.

Monthly water demand, as a percentage of annual groundwater use

Month

Other

Figure 24. Monthly water demand by groundwater-use type 

from the North Fork Red River aquifer, 1980–2013. Modified from 

Oklahoma Water Resources Board (2012a).

Calibration

Model calibration is the process of systematically 

changing initial model input values (within reasonable 

limits) to improve the fit between model-simulated data and 

observed data (calibration targets). The preferred calibration 

results (1) minimize the differences between the simulated 

and observed data (residuals) and (2) conform to the 

conceptual model. The calibration process for the numerical 

model included manual adjustment of selected model inputs 

(parameters) followed by automated adjustment of parameters 

by using the parameter estimation code PEST (Doherty, 

2010). The automated calibration approach used singular 

value decomposition-assist (Doherty, 2010) to reduce run 

times associated with the calibration of a large number of 

parameters. 

For the North Fork Red River numerical model 

automated calibration, six parameter groups representing 

a total of 348 parameters were defined. These parameter 

groups included 323 parameters for recharge, 14 parameters 

for Kh (13 zone multipliers [kh0–kh12; fig. 21] and 

1 array multiplier), 8 parameters for drain conductance, 

and 1 parameter each for GHB conductance, ET, and Sy. 

The locations of the Kh, drain conductance, and GHB 

conductance parameter zones are shown in figure 21. The 

recharge parameter group was composed of temporal 

recharge-rate multipliers for SWB-determined recharge in 323 

of the 409 stress periods; the remaining 86 stress periods had 

negligible recharge. Kh values were grouped into 13 parameter 

zones (fig. 21), with each zone representing an area where Kh 

was thought to be relatively uniform. A rate multiplier was 

specified for each Kh zone and adjusted during calibration. 

The GHB and drain conductances were adjusted until the 

water table in the simulated alluvium and terrace locations 

approached the observed water table. An array multiplier was 

used to adjust the saturated-zone ET rates and was applied 

uniformly to all ET arrays for each stress period. 

Calibration Targets

The numerical model was calibrated to water-tablealtitude observations at selected wells, monthly base flow at 

selected streamgages, net streambed seepage as estimated for 

the conceptual model, and Lake Altus stage (table 9). Prior 

to the calibration process, weights were used to account for 

data quality. Weights were assigned as the inverse of the 

standard deviation, and the weighted calibration targets 

were placed into four observation groups on the basis 

of observation type (table 9). The objective function, or 

squared sum of the weighted residuals, provides a measure of 

the fit between observed and simulated data. The observation 

group contributions to the objective function (table 9) were 

adjusted prior to the start of the calibration process to ensure 

a balance between each group so that no single observation 

group dominated the calibration process. The base-flow 

observation group was assigned the greatest contribution 

to the objective function (37 percent) because those 

measurements were thought to have the greatest accuracy 

and temporal coverage during the model period 1980–2013. 

The water-table-altitude observation group was assigned 

the second greatest contribution to the objective function 

(30 percent) because those measurements were thought to 

have the greatest spatial coverage during the model period 

1980–2013.
48 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 9. Observation group contribution to the objective function for the automated calibration of the numerical groundwater-flow 

model of the North Fork Red River aquifer, 1980–2013.

[ft, feet; ft3/s, cubic feet per second]

Observation group Source Number of 

observations

Group 

contribution

(percent)

Objective 

function

Water-table altitude Water-table-altitude observations (Oklahoma Water Resources 

Board, 2015b; U.S. Geological Survey, 2015a) 

1

1,695 30 29,122

Base flow Sweetwater streamgage (07301420; U.S. Geological Survey, 2015a) 331 9 8,540

Carter streamgage (07301500; U.S. Geological Survey, 2015a) 408 20 19,849

Headrick streamgage (07305000; U.S. Geological Survey, 2015a) 408 8 8,332

Lake stage Lake Altus stage (U.S. Bureau of Reclamation, 2015b) 408 22 21,556

Net streambed 

seepage

Conceptual groundwater-flow model (table 8) 1 11 10,818

3,251 100 98,217

1

Of the 2,079 water-table-altitude observations (table 11), 384 were removed from the automated calibration because they showed little sensitivity to any 

parameter changes.

Water-Table-Altitude Observations

The automated numerical model calibration used 

1,695 water-table-altitude observations at 150 wells in 

the study area (table 1); 384 of the 2,079 water-tablealtitude observations were removed from the automated 

calibration because they showed little sensitivity to any 

parameter changes. The majority of the water-table-altitude 

observations were annual measurements from OWRB (2015b) 

Mass Measurement Program wells, and those wells were 

distributed across most of the aquifer (some locations shown 

on fig. 1). Supplemental water-table-altitude observations 

were obtained from the USGS (2015a) (locations not shown 

on fig. 1). Most years in the study period 1980–2013 had 

greater than 60 total water-table-altitude observations 

(fig. 25A), but the number of water-table-altitude observations 

in each year generally decreased over time. Water-tablealtitude observations during February–March 1980 were used 

as calibration targets for the steady-state stress period, and 

water-table-altitude observations during February–March 2014 

were used as December 2013 calibration targets. All watertable-altitude observations were originally collected as depthto-water measurements; water-table altitudes were calculated 

by subtracting the measured depth to water from the landsurface altitude specified by a 10-meter DEM (USGS, 2015b).

Weights were determined based on the location and 

altitude accuracy of each water-table-altitude observation 

well using methods of Clark and Hart (2009) and Hill and 

Tiedeman (2007). The location and altitude accuracy values 

recorded in the NWIS (USGS, 2015a) and OWRB (2015b) 

databases are based on the measurement methods, typically 

either a Global Positioning System or a topographic map. The 

recorded location accuracy was between 0.1 and 9.2 arcseconds for water-table-altitude observation wells completed 

in the North Fork Red River aquifer. A radius equal to the 

location accuracy was created for each observation well, and 

the standard deviation of DEM land-surface altitudes in that 

radius was calculated. The standard deviation of the altitude 

accuracy was calculated by dividing half of the altitude 

accuracy code (in feet) by the critical value of a 95-percent 

confidence interval (Hill and Tiedeman, 2007). Standard 

deviations for the water-table-altitude observation wells 

ranged from 0.13 to 15.9 ft with a mean of 3.1 ft.

Base Flow and Net Streambed Seepage

The numerical model was manually calibrated to baseflow observations at six streamgages (fig. 25B), but the 

automated calibration only used base-flow observations from 

three streamgages that had long periods of record covering 

most of the model period (table 9). Monthly base-flow 

observations were available for each monthly stress period at 

the Carter (07301500) and Headrick (07305000) streamgages 

and for each monthly stress period since May 1986 at the 

Sweetwater streamgage (07301420) (fig. 25B, table 1). 

These 1,147 monthly base-flow observations were used as 

transient calibration targets. Monthly base-flow observations 

were available for shorter periods at other streamgages, but 

those observations were not used in the automated numerical 

model calibration. The base-flow observation uncertainty was 

determined by using the accuracy code for the streamflow 

data at each streamgage in NWIS. The majority of the field 

streamflow measurements during the transient period received 

a “fair” rating in NWIS, which corresponds to a 95-percent 

confidence interval of ±15 percent of true streamflow (USGS, 

2015c). The standard deviation for the base-flow observations 

at each streamgage was then calculated as 15 percent of 

the base flow, divided by the critical value of a 95-percent 

confidence interval.
Numerical Groundwater-Flow Model 49

Number of water-table-altitude observations

Year

0

20

40

60 Mean number of water-tablealtitude observations (59)

80

100

120

1980 1985 1990 1995 2000 2005 2010 2015

Year

1980 1985 1990 1995 2000 2005 2010 2015

07301300

07301410

07301420

07301500

07303000

07303400

07304500

07305000

07307010

Streamgage 

A

B

1, used for manual numerical groundwater-flow model calibration;

2, used for automated numerical groundwater-flow model calibration

1,2

1,2

1,2

1

1

1

Figure 25. Temporal distribution of A, water-table-altitude 

observations and B, streamflow observations for the numerical 

groundwater-flow model of the North Fork Red River aquifer, 

1980–2015.

Net streambed seepage upgradient from Lake Altus 

(table 8) also was used as a calibration target. The simulated 

net streambed seepage upgradient from Lake Altus was 

determined as the sum of the “Flow to Aquifer” column in the 

SFR flow file divided by the 408 monthly stress periods for the 

transient simulation (Smith and others, 2017). Weights for the 

streambed seepage were assigned by using methods from Hill 

and Tiedeman (2007) and were given a 95-percent confidence 

interval of ±15 percent of actual flow. The standard deviations 

and variance of the base flow at each streamgage during 

the transient period were calculated, and the upstream and 

downstream streamgage variances were summed to produce a 

standard deviation for the streambed seepage. 

Lake Altus Stage

Lake Altus stage observations from the U.S. Bureau of 

Reclamation (2015b) were referenced to the National Geodetic 

Vertical Datum of 1929; therefore, a conversion factor of 

0.5 ft (National Oceanic and Atmospheric Administration, 

2015) was added to reference these observations to the North 

American Vertical Datum of 1988 (NAVD 88). At normalpool stage (1,559.5 ft above NAVD 88), Lake Altus storage 

was about 134,000 acre-ft; at inactive-pool stage (1,518.0 ft 

above NAVD 88), Lake Altus storage was about 1,600 acre-ft 

(U.S. Bureau of Reclamation, 2014). Because the inactivepool storage was relatively small, it was not removed from 

estimates of Lake Altus storage used in this report.

Calibration Results

Calibration results were evaluated on the basis of the 

reduction of residuals and the fit of the calibrated numerical 

model water-budget components to those of the conceptualmodel water budget. Residuals were calculated as observed 

minus simulated values; positive residuals indicate lower 

simulated than observed values, and negative residuals 

indicate higher simulated than observed values. 

Simulated Aquifer Thickness and Saturated Thickness

The simulated mean aquifer thickness was 71 ft, and 

the simulated mean aquifer saturated thickness at the end of 

the simulation was 38 ft (table 10). The simulated maximum 

aquifer thickness was 326 ft and was located in cells adjacent 

to mountains downgradient from Lake Altus (table 10). These 

cells represent colluvium materials that were considered to 

be part of the aquifer, but probably have minimal saturated 

thickness. The large aquifer thickness in those cells was an 

artifact of the steep slope of the mountains downgradient 

from Lake Altus combined with the 886-by-886-ft model 

cell size, which resulted in overestimation of the aquifer top 

altitude. The simulated maximum aquifer thickness of 267 ft 

upgradient from Lake Altus (in central Beckham County) is 

more representative of the actual maximum aquifer thickness 

(table 10).
50 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 10. Statistical summary of aquifer thickness, saturated thickness, and hydraulic properties for the calibrated numerical 

groundwater-flow model of the North Fork Red River aquifer, 1980–2013.

[mi2, square miles; ft, feet; ft/d, feet per day]

Aquifer part Cell 

count

Area 

(mi2

)

Aquifer 

thickness 

(ft)

Aquifer 

saturated thickness 

(ft)

Hydraulic 

conductivity 

(ft/d) Specific 

yield

Minimum Mean Maximum Minimum Mean Maximum Minimum Mean Maximum

Upgradient 

from Lake 

Altus

15,075 424 31 79 267 0 41 183 8.4 36.5 114 0.12

Downgradient 

from Lake 

Altus 

12,547 353 31 62 1

326 0 35 82 16.1 57.8 119 0.12

Total 

(weighted)

27,622 777 31 71 1

326 0 38 183 8.4 46.2 119 0.12

1

The calibrated maximum aquifer thickness downgradient from Lake Altus is found in cells adjacent to mountains. The large aquifer thickness in those 

cells was an artifact of the steep slope of the mountains downgradient from Lake Altus combined with the 886-ft-by-886-ft model cell size, which resulted in 

overestimation of the aquifer-top altitude. The calibrated maximum aquifer thickness of 267 ft upgradient from Lake Altus (in cells of central Beckham County) 

is more representative of the actual maximum aquifer thickness.

Comparison of Simulated and Observed Values

Simulated and observed water levels were compared 

by using standard graphs (fig. 26) and statistical summaries 

(table 11). The combined mean residual for steady-state and 

transient simulations was –0.6 ft, indicating that, on average, 

simulated water levels were slightly higher than observed 

water levels. The combined water-table altitude root-meansquare error (RMSE) was 11.8 ft, and 75 percent of residuals 

were within ±13.9 ft of observed measurements (table 11). 

The simulated water-table relief was 799 ft (2,110–1,311 ft), 

and the combined RMSE as a percentage of this water-table 

relief was 1.5 percent. These error statistics were about double 

those for Reach I of the Canadian River alluvial aquifer (Ellis 

and others, 2017); however, the North Fork Red River aquifer 

had a more complex geologic setting and much greater well 

withdrawals than the Canadian River alluvial aquifer. 
Numerical Groundwater-Flow Model 51

0

50

100

150

200

250

300

350

400

Frequency

Water-table-altitude residual (observed minus simulated), in feet

Simulated = 0.9887(Observed) + 19.71

Coefficient of determination (R2) = 0.9972

1,200

1,300

1,400

1,500

1,600

1,700

1,800

1,900

2,000

2,100

2,200

1,200 1,300 1,400 1,500 1,600 1,700 1,800 1,900 2,000 2,100 2,200

Simulated water-table altitude, in feet above NAVD 88

Observed water-table altitude, in feet above NAVD 88

less than –32

–32 to –28–28 to –24–24 to –20–20 to –16–16 to –12

–12 to –8

–8 to –4

–4 to 0

0 to 44 to 8

8 to 12

12 to 1616 to 2020 to 2424 to 2828 to 32

greater than 32

A

B

Figure 26. A, Observed and simulated water-table altitudes and 

B, water-table-altitude residual distributions for the numerical 

groundwater-flow model of the North Fork Red River aquifer, 

1980–2013. [NAVD 88, North American Vertical Datum of 1988]

Table 11. Statistical summary of water-table-altitude residuals 

for the numerical groundwater-flow model of the North Fork Red 

River aquifer, 1980–2013.

[±, plus or minus; RMSE, root-mean-square error]

Statistic Steadystate Transient Combined

Observation count 67 2,012 2,079

Mean residual, in feet –0.9 –0.6 –0.6

75th-percentile residual range, 

in feet ±16 ±13.9 ±13.9

RMSE, in feet 14.1 11.8 11.8

RMSE percentage of watertable relief (799 feet) 1.8 1.5 1.5

Water-table-altitude residuals were generally largest 

(observed greater than simulated) in the most upgradient (from 

local streams) terrace, where observed hydraulic gradients 

up to 60 feet per mile steeply slope towards the North 

Fork Red River and tributary streams (fig. 27). In contrast, 

simulated water levels near the active alluvium (base-flow 

discharge areas) were generally higher than observed water 

levels, particularly at altitudes between 1,700 and 1,800 ft 

in the central part of the study area (figs. 26–27). Simulated 

water levels that are less than observed in the upgradient 

terrace and greater than observed in the downgradient active 

alluvium (base-flow discharge areas) could both be explained 

by differences between the complexity (resolution) of the 

simulated and observed aquifer. Because of generalizations 

inherent in spatial discretization, modeled flow paths are 

likely to be simplified and shortened versions of actual flow 

paths (Mandelbrot, 1983). Simulated hydraulic gradients and 

recharge-to-discharge travel times, therefore, are likely to be 

smaller than observed. Simulated well hydrographs generally 

matched the trends of observed well hydrographs, but the 

magnitude of the simulated water-level change was typically 

less than the magnitude of the observed water-level change 

(fig. 28).
52 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Altus

Blair

Carter

Dodson

Elk City

Erick

Gould

Granite

Headrick

Hobart

Hollis

Lone

Wolf

Mangum

New

Cordell Sayre

Snyder

Texola

Willow

ROGER MILLS COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY

KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN

COUNTY

Lake

Altus

Tom Steed

Reservoir

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

0 6 12 18 24 MILES

0 6 12 18 24 KILOMETERS

North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board (2015b)

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

EXPLANATION

Mean water-table-altitude residual

(observed minus simulated), in feet, 1980–2013

Incorporated area (U.S. Census Bureau, 2000)

North Fork Red River aquifer boundary

–43.2 to –30.0

–29.9 to –20.0

–19.9 to –12.0

–11.9 to –6.0

–5.9 to 6.0

6.1 to 12.0

12.1 to 20.0

20.1 to 30.0

30.1 to 49.1

Figure 27. Spatial distribution of mean water-table-altitude residuals for the numerical groundwater-flow model of the North Fork Red 

River aquifer, 1980–2013.
Numerical Groundwater-Flow Model 53

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

1,660

1,670

1,680

1,690

1,700

9089 350839099303001

1,720

1,730

1,740

1,750

1,760

9098 351301099323301

2,080

2,090

2,100

2,110

2,120

9101 351327099595901

1,870

1,880

1,890

1,900

9108 351413099451601

1,840

1,850

1,860

1,870

1,880

9096 351222099395801

1,760

1,770

1,780

1,790

1,800

1,810

1,820

9100 351308099353601

1,980

1,990

2,000

2,010

2,020

2,030

1980 1985 1990 1995 2000 2005 2010 2015 1980 1985 1990 1995 2000 2005 2010 2015

9106 351400099533501

Year Year

Water-table altitude, in feet above North American Vertical Datum of 1988

1,660

1,670

1,680

1,690

1,700

1,710

1,720

1,730

9088 350727099274901

Map name (fig. 1, table 1; Oklahoma

Water Resources Board, 2015b)

Station identifier (table 1;

U.S. Geological Survey, 2015a)

Figure 28. Observed and simulated water-table altitudes for the numerical groundwater-flow model of the North Fork Red River 

aquifer, 1980–2013.
54 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

1,900

1,910

1,920

1,930

1,940

9114 351512099472401

2,060

2,070

2,080

2,090

2,100

9122 352328099560001

2,070

2,080

2,090

2,100

2,110

9123 352426099572801

1,480

1,490

1,500

1,510

1,520

1,530

9438 345356099212801

1,510

1,520

1,530

1,540

9444 345528099255801

1,560

1,570

1,580

1,590

1,600

1,610

9448 345758099345601

1,830

1,840

1,850

1,860

9113 351512099411001

1,760

1,770

1,780

1,790

1,800

1,810

1,820

1,830

9109 351426099372701

Water-table altitude, in feet above North American Vertical Datum of 1988

Map name (fig. 1, table 1; Oklahoma

Water Resources Board, 2015b)

Station identifier (table 1;

U.S. Geological Survey, 2015a)

1980 1985 1990 1995 2000 2005 2010 2015 1980 1985 1990 1995 2000 2005 2010 2015

Year Year

Figure 28. Observed and simulated water-table altitudes for the numerical groundwater-flow model of the North Fork Red River 

aquifer, 1980–2013.—Continued
Numerical Groundwater-Flow Model 55

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

1,680

1,690

1,700

1,710

1,720

1,730

1,740

1,750

1,760

9453 350411099274101

1,650

1,660

1,670

1,680

1,690

1,700

1,710

1,720

1,730

1,740

9454 350457099254201

1,700

1,710

1,720

1,730

1,740

1,750

1,760

1,770

9458 350523099303501

1,600

1,610

1,620

1,630

1,640

1,650

9460 350615099242301

1,290

1,300

1,310

1,320

1,330

9534 343846099000501

1,300

1,310

1,320

1,330

1,340

1,350

1,360

9535 343903098580001

1,590

1,600

1,610

1,620

1,630

1,640

9450 350055099204901

1,600

1,610

1,620

1,630

1,640

1,650

1,660

1,670

9451 350121099232701

Water-table altitude, in feet above North American Vertical Datum of 1988

Map name (fig. 1, table 1; Oklahoma

Water Resources Board, 2015b)

Station identifier (table 1;

U.S. Geological Survey, 2015a)

1980 1985 1990 1995 2000 2005 2010 2015 1980 1985 1990 1995 2000 2005 2010 2015

Year Year

Figure 28. Observed and simulated water-table altitudes for the numerical groundwater-flow model of the North Fork Red River 

aquifer, 1980–2013.—Continued
56 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

EXPLANATION

Observed

Simulated

1,300

1,310

1,320

1,330

1,340

1,350

1,360

9539 344149098582301

1,320

1,330

1,340

1,350

1,360

9540 344210098593501

1,380

1,390

1,400

1,410

9543 344745099083001

1,520

1,530

1,540

1,550

1,560

1,570

9545 345659099162001

1,520

1,530

1,540

1,550

1,560

1,570

1,580

1,590

9549 345824099165901

1,520

1,530

1,540

1,550

1,560

1,570

9553 345857099193001

1,310

1,320

1,330

1,340

1,350

1,360

1,370

9536 343913098564801

1,310

1,320

1,330

1,340

9538 344005098591001

Water-table altitude, in feet above North American Vertical Datum of 1988

Map name (fig. 1, table 1; Oklahoma

Water Resources Board, 2015b)

Station identifier (table 1;

U.S. Geological Survey, 2015a)

1980 1985 1990 1995 2000 2005 2010 2015 1980 1985 1990 1995 2000 2005 2010 2015

Year Year

Figure 28. Observed and simulated water-table altitudes for the numerical groundwater-flow model of the North Fork Red River 

aquifer, 1980–2013.—Continued
Numerical Groundwater-Flow Model 57

Automated calibration of the numerical model used 

base-flow data from the Sweetwater (07301420), Carter 

(07301500), and Headrick (07305000) streamgages, and 

manual calibration also incorporated base-flow data from the 

Carl (07303400), Hobart (07304500), and Snyder (07307010) 

streamgages (fig. 29, table 12). The mean simulated base flow 

was lower than the mean observed base flow for three of the 

six streamgages (table 12). For the two streamgages on North 

Fork Red River (Carter and Headrick), the RMSE was less 

than 10 percent of the range in observed base flow (table 12). 

For the four tributary streamgages, the RMSE was between 

about 2 and 15 percent of the range in observed base flow 

(table 12). The simulated base flows at the Carl (07303400) 

and Hobart (07304500) streamgages were mostly determined 

from specified inflows a short distance upstream and, 

therefore, are not shown in figure 29. 

Periods of near zero flow occurring at most streamgages 

during summer months could not be completely reproduced 

(fig. 29, table 12). These overestimated summer low flows 

could be the result of underestimated saturated-zone ET, which 

is greatest in the summer months; however, saturated-zone 

ET could not be increased without also increasing recharge 

or negatively affecting residuals of other calibration targets. 

Base-flow residuals were generally larger during spring and 

fall high-flow periods than during summer low-flow periods 

(fig. 29), possibly indicating that observed base flows were 

overestimated by the BFI code (either because of reservoir 

releases or recharge processes such as bank storage flow or 

interflow that mostly operate on a submonthly time scale). The 

primary source of water to the aquifer is recharge, so large 

positive base-flow residuals (observed greater than simulated) 

also could be caused by underestimated or incorrectly 

distributed (spatially) recharge. Base-flow residuals were 

largest for the Headrick streamgage (07305000) (table 12). 

The observed base flow for the Headrick streamgage 

(07305000) is, to some degree, related to releases from Lake 

Altus that occurred during the study period, particularly during 

years 1986–88, 1993, 1997–98, and 2007 (fig. 29). No reliable 

or justifiable method was found for removing the effects of the 

Lake Altus and Tom Steed Reservoir releases on the observed 

base flows at the respective Headrick (07305000) and Snyder 

(07307010) streamgages. 

The mean Lake Altus stage residual was 0.4 ft (table 13), 

indicating that the mean simulated stage was slightly lower 

than the mean observed stage (fig. 30). The RMSE was 

3.7 ft, and 75 percent of the lake-stage residuals were within 

±4.2 ft of observed stage. The maximum observed and 

simulated stage were both 1,561 ft, whereas the minimum 

simulated stage was 3 ft higher than the minimum observed 

stage. The largest Lake Altus stage residuals occurred in late 

1981, late 1985, late 1994, and late 1998 when lake storage 

was relatively low; simulated Lake Altus stage also poorly 

matched observed stage during drought conditions in 2011–13 

(fig. 30). 
58 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Base flow, observed

Base flow, simulated

Streamflow, observed

EXPLANATION

A. Sweetwater streamgage (07301420) on Sweetwater Creek

B. Carter streamgage (07301500) on North Fork Red River 

0

20

40

60

80

100

120

140

160

Streamflow or base flow, in cubic feet per second

Streamflow, in cubic

feet per second

0

1,000

2,000

0

100

200

300

400

500

600

700

800

19801981198219831984

1985

1986

198719881989

19901991

19921993

1994199519961997

1998

1999

2000

2001

20022003

2004200520062007

2008

2009

2010

2011

20122013

Base flow, in cubic feet per second

Year

Figure 29. Observed streamflow, observed base flow, and simulated base flow at A, Sweetwater streamgage (07301420) on 

Sweetwater Creek; B, Carter streamgage (07301500) on North Fork Red River; C, Headrick streamgage (07305000) on North Fork Red 

River; and D, Snyder streamgage (07307010) on Otter Creek for the numerical groundwater-flow model of the North Fork Red River 

aquifer, southwest Oklahoma, 1980–2013.
Numerical Groundwater-Flow Model 59

Base flow, observed

Base flow, simulated

Streamflow, observed

Releases from Lake Altus 

 (streamflow observed 

 at 07303000)

EXPLANATION

Base flow, observed

Base flow, simulated

Streamflow, observed

Releases from Tom Steed 

 Reservoir (U.S. Bureau 

 of Reclamation, 2015c)

EXPLANATION

C. Headrick streamgage (07305000) on North Fork Red River 

D. Snyder streamgage (07307010) on Otter Creek

Base flow or releases, in cubic feet per second Base flow or releases, in cubic feet per second

Streamflow, in cubic

feet per second

Streamflow, in cubic

feet per second

0

3,000

6,000

0

400

800

1,200

1,600

2,000

2,400

0

300

600

0

40

80

120

160

200

240

19801981198219831984

1985

1986

198719881989

19901991

19921993

1994199519961997

1998

1999

2000

2001

20022003

2004200520062007

2008

2009

2010

2011

20122013

Year

Figure 29. Observed streamflow, observed base flow, and simulated base flow at A, Sweetwater streamgage (07301420) on 

Sweetwater Creek; B, Carter streamgage (07301500) on North Fork Red River; C, Headrick streamgage (07305000) on North Fork Red 

River; and D, Snyder streamgage (07307010) on Otter Creek for the numerical groundwater-flow model of the North Fork Red River 

aquifer, southwest Oklahoma, 1980–2013.—Continued
Table 12. Statistical summary of base-flow residuals for the numerical groundwater-flow model of the North Fork Red River aquifer, 1980–2013. [Residual is calculated as the observed minus the simulated value; thus, a negative number indicates higher simulated than observed values. ft3/s, cubic foot per second; RMSE, 

or minus] Station Available data in the study period 1980–2013 Drainage area (square miles) Observed base flow (ft3/s) Simulated base flow (ft3/s) Base-flow 

(ft3

Begin End Mini- mum Mean1 Maximum Mini- mum Mean Maximum Mean 75t

perc

tile r

Sweetwater streamgage (07301420) on Sweetwater Creek 4/22/1986 12/31/2013 437 0.0 14.6 65.5 1.7 14.3 59.5 0.2 ±1

Carter streamgage (07301500) on North Fork Red River 1/1/1980 12/31/2013 2,652 0.0 54.6 477.2 9.4 61.5 266.2 -6.8 ±30

Carl streamgage (07303400) on Elm Fork Red River 10/1/1994 12/31/2013 438 0.2 15.5 124.2 1.4 21.2 129.6 -5.6 ±6

Hobart streamgage (07304500) on Elk Creek 1/1/1980 9/30/1993 549 0.1 36.0 356.6 0.0 35.9 385.6 0.0 ±4

Headrick streamgage (07305000) on North Fork Red River 1/1/1980 12/31/2013 4,560 0.0 111.6 1,306.6 6.7 88.3 600.3 23.3 ±46

Snyder streamgage (07307010) on Otter Creek 7/1/2000 10/5/2008 162 0.0 4.8 81.9 2.6 4.9 21.1 -0.1 ±3

1Mean observed base flow may differ from values in table 2 because of rounding and inclusion of partial years of record.
Numerical Groundwater-Flow Model 61

Table 13. Statistical summary of lake-stage residuals for the 

numerical groundwater-flow model of the North Fork Red River 

aquifer, 1980–2013.

[RMSE, root-mean-square error; ±, plus or minus]

Observation Lake stage

Minimum Mean Maximum

Observed, in feet 1,523 1,546 1,561

Simulated, in feet 1,526 1,546 1,561

Mean residual, in feet 0.4

RMSE, in feet 3.7

75th-percentile residual 

range, in feet

±4.2

EXPLANATION

Observed

Simulated

Normal pool

A

B

1,520

1,525

1,530

1,535

1,540

1,545

1,550

1,555

1,560

1,565

1,570

Lake stage, in feet above North American Vertical Datum of 1988 Lake storage, in acre-feet

0

30,000

60,000

90,000

120,000

150,000

180,000

1980

19811982

198319841985

19861987

19881989

1990

1991

19921993

1994

1995

1996

1997

19981999

2000

2001

20022003

2004

2005

2006

2007

20082009

20102011

2012

2013

Year

Figure 30. Lake Altus A, stage and B, simulated storage for the numerical groundwater-flow model of the North Fork Red River aquifer, 

1980–2013.
62 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Calibrated Water Budget

The calibrated water budget (table 14) lists mean annual 

inflows and outflows for the calibrated numerical model for 

the period 1980–2013; a sub-accounting for areas upgradient 

and downgradient from Lake Altus was computed by using 

the ZONEBUDGET utility (Harbaugh, 1990). The calibrated 

water budget shows more inflow and outflow categories 

than the conceptual model (table 8), because subcomponents 

of the net water-budget categories can be quantified in the 

calibrated water budget. Simulated recharge (79 percent of 

inflows) was the largest inflow for the calibrated numerical 

model; seepage from streams was about 14 percent, lakebed 

seepage was about 4 percent, and lateral groundwater inflow 

was about 3 percent of inflows. Seepage to streams (56 percent 

of outflows) was the largest outflow for the calibrated 

numerical model; saturated-zone ET was about 23 percent, 

lateral groundwater outflow (with springs and seeps) was 

about 10 percent, well withdrawals were about 8 percent, and 

lakebed seepage was about 2 percent of outflows.

Recharge for the calibrated numerical model (about 

122,000 acre-ft/yr or 2.94 in/yr over the aquifer area 

of 497,582 acres, table 14) was about 6 percent greater 

than that of the conceptual model (fig. 16, table 8). Net 

streambed seepage for the calibrated numerical model was 

about 4 percent less than that of the conceptual model. This 

difference could be caused in part by streambed seepage 

between Carter (07301500) and Lake Altus that was not 

estimated in the conceptual model. Saturated-zone ET for the 

calibrated numerical model, which was estimated by using 

many assumptions, was about 40 percent greater than that 

of the conceptual model (but less than the saturated-zone 

ET for the similar Reach I calibrated numerical models of 

Ryter and Correll [2016] and Ellis and others [2017]). The 

67-percent (about 4,800-acre-ft/yr) increase in simulated 

lateral flow, seeps, and springs as compared to the conceptual 

model reflects uncertainty in estimating these components 

without published flow rates. The simulated well withdrawals 

were about 16 percent less than the conceptual-model well 

withdrawals because of (1) previously described thresholds 

(see Well Withdrawals section of this report) applied to 

permits and wells and (2) a lack of adequate simulated 

saturation in some areas of the terrace; well withdrawal rates 

specified in the model are automatically reduced when the 

simulated saturated thickness nears zero.

Table 14. Mean annual water budget for the numerical groundwater-flow model of the North Fork Red River aquifer, 1980–2013.

[All units in acre-feet per year; net budget totals are calculated as inflow minus outflow; therefore, positive values indicate net inflow, and negative numbers 

indicate net outflow; components may not sum to totals because of rounding]

Water-budget category Upgradient 

from Lake Altus

Downgradient 

from Lake Altus Total Percentage of water budget

Inflow

Recharge 68,054 54,247 1

122,301 79%

Streambed seepage from streams 9,597 12,082 21,679 14%

Lakebed seepage inflow 5,009 1,320 6,328 4%

Lateral groundwater inflow 4,701 0 4,701 3%

Total inflow 87,360 67,648 155,009 100%

Outflow

Streambed seepage to streams 43,879 46,530 90,409 56%

Saturated-zone evapotranspiration 21,868 15,591 37,459 23%

Lateral groundwater outflow, springs, and seeps 7,529 9,223 16,752 10%

Well withdrawals 11,472 1,899 13,371 8%

Lakebed seepage outflow 2,630 667 3,297 2%

Total outflow 87,377 73,910 161,288 100%

Net water-budget totals

Net streambed seepage –34,282 –34,448 –68,730

Net lateral flow, springs, and seeps –2,828 –9,223 –12,051

Net lakebed seepage 2,379 652 3,031

Net change in groundwater storage2 4,165 2,117 6,282

1

Equals 2.94 inches per year over the aquifer area of 497,582 acres. 

2

Positive net change in groundwater storage indicates loss of groundwater storage from the aquifer; loss of groundwater storage is reported as an aquifer 

inflow in the numerical groundwater-flow model mass balance.
Numerical Groundwater-Flow Model 63

Simulated groundwater storage generally increased 

during a relatively long period of above-average precipitation 

(fig. 3) and recharge (fig. 31) in 1985–2000. This period was 

followed by a period of generally near-average to belowaverage precipitation (fig. 3) and recharge (fig. 31) during 

2001–13 when simulated groundwater storage decreased, 

particularly during 2010–13. The period 2010–13 coincides 

with a regional drought in southwest Oklahoma (fig. 3). A 

correlated water-level response to these precipitation trends 

is demonstrated in the hydrographs of water-table-altitude 

observation wells located in the terrace, particularly wells 

9089, 9096, 9100, 9101, 9108, and 9109 (fig. 28). Because 

recharge accounts for nearly 80 percent of the total calibrated 

model inflow to the aquifer (fig. 16; table 14), changes in 

precipitation have a large effect on groundwater storage and 

the annual water budget. The annual water budget during years 

when recharge was large relative to the period of record mean, 

such as 1986–87 and 1995 (fig. 31), was greater than the 

annual water budget during other years of the study period. At 

the end of the study period, mean simulated outflows exceeded 

inflows by about 6,300 acre-ft/yr (table 14). This difference is 

equivalent to a cumulative net change in groundwater storage 

Recharge

Saturated-zone ET

Well withdrawals

Net streambed seepage

Net lateral flow

Net lakebed seepage

EXPLANATION

EXPLANATION

Annual net change in storage

Cumulative net change in storage

A

B

–350,000

–300,000

–250,000

–200,000

–150,000

–100,000

–50,000

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

Aquifer inflow or outflow, in acre-feet Change in groundwater storage, in acre-feet

–250,000

–200,000

–150,000

–100,000

–50,000

0

50,000

100,000

150,000

200,000

250,000

Aquifer outflow Aquifer inflow

1980

19811982

1983

19841985

1986

1987

19881989

1990

1991

19921993

1994

1995

1996

19971998

1999

2000

2001

2002

20032004

2005

2006

2007

20082009

20102011

20122013

Year

Figure 31. A, Annual inflows and outflows and B, annual change in groundwater storage for the numerical groundwater-flow model of 

the North Fork Red River aquifer, 1980–2013.
64 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

of about 214,000 acre-ft (fig. 31) for 1980–2013 (34 years), 

or a cumulative net water-level decline of about 3.6 ft. This 

net change in groundwater storage was about the same as the 

one calculated from annual water-level measurements for the 

conceptual model (6,150 acre-ft/yr, table 8).

Mean monthly simulated aquifer inflows, primarily from 

recharge and seepage from streams, tended to be greatest 

during May and June (fig. 32A), which corresponds to the 

months of greatest precipitation (fig. 4). Mean monthly 

simulated aquifer outflows, primarily from seepage to streams, 

saturated-zone ET, and well withdrawals, were greatest in July 

and August (fig. 32A). During those summer months, seepage 

to streams was reduced by water-level declines from large 

saturated-zone ET outflows and well withdrawals (mostly 

for irrigation use). In July, mean saturated-zone ET equaled 

or exceeded all other outflows and nearly equaled the sum of 

all inflows (fig. 32A). Though mean inflows exceeded mean 

outflows in 9 of 12 months, the magnitude of mean outflows 

in July and August (fig. 32B) caused mean annual outflows to 

exceed mean annual inflows for the study period (table 14). 

Simulated storage in Lake Altus decreased by about 

25,000 acre-ft during the study period 1980–2013 (fig. 33B). 

Lake Altus and the surrounding North Fork Red River aquifer 

are hydrologically connected, so some declines in Lake Altus 

stage and storage were expected to occur during periods 

of declining water-table altitudes in the aquifer. Simulated 

annual lakebed seepage to the aquifer and direct lake-surface 

precipitation, however, were a minimal part of the Lake Altus 

water budget (fig. 33A). Periods of decreased Lake Altus 

stage and storage typically occurred during years of decreased 

base flow (figs. 30, 33, and 19B). Because nearly half of the 

streamflow in the North Fork Red River upstream from Lake 

Altus (at the Carter streamgage [07301500]) occurs as base 

flow (fig. 19B, table 2), water-table-altitude declines in the 

aquifer upgradient from Lake Altus had a greater effect on 

simulated Lake Altus stage and storage than did water-tablealtitude declines near Lake Altus.

Calibrated Parameter Values and Sensitivities

A sensitivity analysis was performed by using 

sensitivities generated by PEST (Doherty, 2010) to ensure 

that the parameters used during the calibration process were 

effective in reducing the objective function and the numerical 

model error. During calibration, PEST records the sensitivity 

of each calibration target to regular percentage changes in 

parameters. These sensitivities are a measure of the change in 

residuals affected by adjustments to a parameter; parameters 

with greater sensitivities more greatly affect residuals. 

Sensitivities were calculated by using the Jacobian matrix 

output from PEST and were summed for each parameter group 

(fig. 34).

The observation groups were most sensitive to changes in 

the recharge and hydraulic conductivity parameters (fig. 34). 

Recharge was the largest aquifer inflow (table 14), which, 

when combined with the high hydraulic conductivity alluvium 

and terrace deposits, affected the water-table altitude, base 

flows, streambed seepage, and lake stage. Several watertable-altitude observations were located near drain cells along 

the southernmost model boundary, and these observations 

had a relatively large sensitivity to the drain conductance. 

Also, several drain cells were located near Lake Altus (drn4, 

fig. 21), resulting in a relatively large sensitivity to the drain 

conductance. Saturated-zone ET changes resulted in a large 

sensitivity for the lake-stage observations because surfacewater inflows contributed the majority of inflow to Lake 

Altus. The observation groups also were sensitive to changes 

in Sy. The GHB cells in the model were located only at the 

Texas border (fig. 21); therefore, most observation groups had 

little sensitivity to changes in the GHB conductance values. 

The lake-stage observation group typically had the greatest 

sensitivity of the four observation groups; this observation 

group was most sensitive to recharge and least sensitive to 

GHB conductance (fig. 34). 

Recharge multipliers applied to the monthly SWB 

grids increased the mean annual recharge from about 

87,000 acre-ft/yr (fig. 22) to about 122,000 acre-ft/yr 

(table 14). Recharge for 72 percent of the stress periods was 

less than 20 percent of the mean recharge for the study period. 

Recharge multipliers applied in the remaining 28 percent 

of the stress periods, therefore, caused the majority of the 

increase in mean annual recharge for the calibrated model. 

Monthly mean calibrated recharge was greater than monthly 

mean precalibrated recharge for all months except April 

(fig. 35). With the exception of April, monthly mean calibrated 

recharge was 27–85 percent greater than the respective 

monthly mean precalibrated recharge (fig. 35). 

Upgradient from Lake Altus, calibrated Kh ranged from 

about 8 to 114 ft/d and averaged 36.5 ft/d (fig. 36, table 10). 

Downgradient from Lake Altus, calibrated Kh ranged from 

about 16 to 119 ft/d and averaged 57.8 ft/d (fig. 36, table 10). 

About 0.5 percent of the calibrated Kh values in the numerical 

model were outside of the Kh range (1–97 ft/d) defined in the 

hydrogeologic framework. The increase in mean calibrated Kh 

from upgradient to downgradient from Lake Altus is consistent 

with even greater mean Kh (117 ft/d) reported for the most 

downgradient aquifer, the Tillman Terrace aquifer (Osborn, 

2002; fig. 1). The calibrated Sy (0.12) was unchanged from the 

hydrogeologic framework. 
Numerical Groundwater-Flow Model 65

Lakebed seepage out

Well withdrawals

Lateral outflow

Saturated-zone ET

Seepage to streams

Lakebed seepage in

EXPLANATION

Lateral inflow

Seepage from streams

Recharge

Change in storage

EXPLANATION

EXPLANATION

Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec.

Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec.

A

B

–250,000

–275,000

–225,000

–200,000

–175,000

–150,000

–125,000

–100,000

–75,000

–50,000

–25,000

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

275,000

Aquifer inflow or outflow, in acre-feet

–100,000

–50,000

0

50,000

100,000

150,000

–150,000

Change in groundwater storage 

(inflows minus outflows), 

in acre-feet

Month

Aquifer outflow Aquifer inflow

Figure 32. A, Mean monthly aquifer inflows and outflows and B, mean monthly change in groundwater storage for the North Fork Red 

River aquifer, 1980–2013.
66 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Surface-water inflow

Runoff

Direct lake-surface precipitation

Evaporation

Withdrawals and releases

Net lakebed seepage

Annual net change in storage

Cumulative net change in storage

EXPLANATION

EXPLANATION

198019811982

198319841985

1986

198719881989

1990

199119921993199419951996

199719981999

200020012002200320042005

20062007200820092010201120122013

Year

A

B

–350,000

–300,000

–250,000

–200,000

–150,000

–100,000

–50,000

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

Annual lake inflow or outflow, in acre-feet Change in lake storage, in acre-feet

–150,000

–100,000

–50,000

0

50,000

100,000

–125,000

–75,000

–25,000

25,000

75,000

125,000

150,000

Figure 33. A, Annual lake inflows and outflows and B, change in lake storage for Lake Altus in the numerical groundwater-flow model 

of the North Fork Red River aquifer, 1980–2013.
Numerical Groundwater-Flow Model 67

Lake stage

Observation group

Water-table altitude

Base flow

Streambed seepage

EXPLANATION

Recharge Drain

conductance

Saturated-zone

evapotranspiration

Specific

yield

General-head

boundary (GHB)

conductance

Hydraulic

conductivity

1

10

100

1,000

10,000

100,000

1,000,000

10,000,000

Dimensionless sensitivity for calibration targets

Parameter group

Figure 34. Observation group sensitivity by parameter group in the numerical groundwater-flow model for the North Fork Red River 

aquifer, 1980–2013.

70%

36%

57%

–20%

55%

43%

85%

32%

40% 27%

30% 57%

70%

36%

57%

–20%

55%

43%

85%

32%

40% 27%

30% 57%

0

0.11

0.22

0.33

0.44

0.55

0

4,560

9,120

13,680

18,240

22,800

Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec.

Recharge, in inches per month

Recharge, in acre-feet per month

Month

Monthly mean precalibration recharge, 1980–2013

Monthly mean calibrated recharge, 1980–2013—Percentage

shown is the percentage of the monthly mean calibrated

recharge that is greater than or less than the respective

monthly mean precalibration recharge

Mean monthly precalibration recharge, 1980–2013

Mean monthly calibrated recharge, 1980–2013

EXPLANATION

Figure 35. Monthly mean precalibration recharge and monthly mean calibrated recharge for the numerical groundwater-flow model of 

the North Fork Red River aquifer, 1980–2013. Note that aquifer area of 497,582 acres was used to convert acre-feet to inches.
68 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

ROGER MILLS COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

CHILDRESS

COUNTY

TILLMAN

COUNTY

Lake

Altus

Tom Steed

Reservoir

0 6 12 18 24 MILES

0 6 12 18 24 KILOMETERS

North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board (2015b)

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

EXPLANATION

Calibrated horizontal hydraulic conductivity (Kh), in feet per day

Lithologic log location (Oklahoma Water Resources Board, 2015b).

Logs shown outside of the North Fork Red River aquifer were not

used to determine Kh, but were used to delineate the aquifer extent. 

North Fork Red River aquifer boundary

8.4 to 29.9

30.0 to 44.9

45.0 to 59.9

60.0 to 74.9

75.0 to 89.9

90.0 to 104.9

105.0 to 118.8

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

Figure 36. Horizontal hydraulic conductivity (Kh) for the calibrated numerical groundwater-flow model of the North Fork Red River 

aquifer, southwest Oklahoma.
Groundwater Availability Scenarios 69

Differences in Numerical Groundwater-Flow 

Models

Though the Kent (1980) hydrologic investigation and the 

one described in this report both used numerical models to 

simulate groundwater flow, those investigations had a number 

of differences regarding the study area conceptualization and 

numerical model inputs. The Kent (1980) numerical model 

area was 536 mi2, which was about 31 percent smaller than 

the numerical model area described in this report (777 mi2). 

The Kent (1980) numerical model used the Trescott and 

others (1976) code with a cell size of 2,640 by 2,640 ft, and 

the investigation described in this report used the updated 

MODFLOW-NWT code with a cell size of 886 by 886 ft, or 

about one-ninth the area of the Kent (1980) model cells. The 

conceptual model of Kent (1980) used a mean Kh of about 

92 ft/d, whereas the mean Kh determined from the results 

of the hydrogeologic framework for this investigation was 

52 ft/d (46 ft/d for the calibrated numerical model). Maps of 

transmissivity from Kent (1980), however, suggest that much 

smaller values of Kh may have been used in the Kent (1980) 

calibrated numerical model. The Sy value (0.12) used in the 

calibrated numerical model described in this report was about 

half of that used in the Kent (1980) calibrated numerical 

model (0.246). 

Recharge for the numerical model of Kent (1980) 

was 2.28 in/yr, or 9.38 percent of the Kent (1980) mean 

annual precipitation (24.28 in/yr); recharge for the 

calibrated numerical model described in this report was 

about 122,000 acre-ft/yr (2.94 in/yr over the aquifer area of 

497,582 acres, table 14), or 10.1 percent of the mean annual 

precipitation during 1980–2013 (29.2 in/yr, table 3). Unlike 

the numerical model described in this report, however, the 

Kent (1980) numerical model supplemented recharge from 

precipitation with estimated recharge from irrigation return 

flow. The Kent (1980) numerical model simulated total 

streamflow, but the numerical model described in this report 

simulated only base flow, excepting Lake Altus. Many other 

differences in the numerical models could be listed, but those 

listed here were expected to have the greatest influence on 

simulated groundwater flow and availability in each model. 

Groundwater Availability Scenarios

Three types of predictive scenarios were run on the 

calibrated numerical model. These scenarios were used to 

(1) estimate the equal-proportionate-share (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 base flow and groundwater storage. 

Groundwater storage was calculated by multiplying the Sy 

(0.12) by the saturated thickness in each active model cell. The 

inputs and outputs for the groundwater-availability scenarios 

are available in Smith and others (2017). 

Equal Proportionate Share

EPS scenarios for the North Fork Red River aquifer were 

run for periods of 20, 40, and 50 years. The 2013 simulated 

water table from the calibrated numerical model was used as 

the starting water table in each EPS scenario. Model inputs for 

recharge, saturated-zone ET, Tom Steed Reservoir stage, and 

stream inflows to the model active area were configured as the 

mean of each annual period used in the calibrated numerical 

model. Annual stress periods were used in these scenarios 

instead of the monthly stress periods to simplify the analysis 

and improve model stability. To determine the EPS pumping 

rate, hypothetical wells were placed in each layer 1 active 

cell (covering 18 acres) and pumped at the same rate for the 

duration of the scenario. If at the end of the scenario more 

than 50 percent of the active cells had a saturated thickness 

of at least 5 ft, the pumping rate was increased by about 

35 cubic feet per day (1 cubic meter per day). The scenario 

was repeated until 50 percent of the cells had a saturated 

thickness of less than 5 ft. To account for potential climate 

variability, this process was repeated with recharge increased 

and decreased by 10 percent.

The 20-, 40-, and 50-year EPS pumping rates under 

normal recharge conditions were 0.59, 0.52, and 0.52 acrefoot per acre per year, respectively (fig. 37, table 15; values 

rounded to the nearest hundredth). Given the 497,582-acre 

aquifer area, these rates correspond to annual yields of about 

294,000, 259,000, and 259,000 acre-ft/yr, respectively. 

For the 20-year EPS scenario, decreasing and increasing 

recharge by 10 percent resulted in a 5–7-percent change in 

the EPS pumping rate; for the 40- and 50-year EPS scenarios, 

decreasing and increasing recharge by 10 percent resulted 

in a 6–8-percent change in the EPS pumping rate (fig. 37, 

table 15). 

Groundwater storage at the end of the 20-year EPS 

scenario was about 951,000 acre-ft, or about 1,317,000 acre-ft 

(58 percent) less than the starting EPS scenario storage. This 

decrease in storage was equivalent to a mean water-level 

decline of about 22 ft. Most areas of the active alluvium near 

the North Fork Red River, Elk Creek, and Elm Fork Red 

River remained partially saturated through the end of the EPS 

scenario because of streambed seepage (fig. 38). Where the 

terrace was sufficiently thick—about 80 ft or greater—or a 

shallow hydraulic gradient was present, partial saturation was 

sustained though the entire EPS scenario (fig. 38). At the end 

of the 20-year EPS scenario, the greatest remaining saturated 

thickness was in the network of paleochannels along the 

Beckham County Fault (fig. 12). Saturated thickness greater 

than 5 ft also remained along Elk Creek, Sweetwater Creek, 

Elm Fork Red River, and North Fork Red River (except for 

the reach between the Carter streamgage [07301500] and Lake 

Altus), which were sustained by simulated SFR inflows (ELK, 
70 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

SWEE, EFRR, and NFRR, respectively) (fig. 38). Other 

terrace areas generally had less than 5 ft of saturated thickness 

except for areas near the Texas border, where saturated 

thickness was sustained by GHB cells, and near Lake Altus 

and Tom Steed Reservoir, where saturated thickness was 

sustained by lakebed seepage (fig. 38).

At the end of the 20-year EPS scenario, mean annual 

base-flow declines of 100 and 86 percent occurred at the 

Carter streamgage (07301500) and Headrick streamgage 

(07305000), respectively, compared to the start of the EPS 

scenario. The decrease in base flow was greater upstream 

from Lake Altus because of the smaller inflows to Sweetwater 

Creek and the North Fork Red River from Texas compared to 

inflows to the Elm Fork Red River and Elk Creek. The aquifer 

water table was below the bottom of the streams during most 

of the EPS scenario, resulting in streambed seepage outflows 

from the stream to the aquifer (losing streams). With the 

exception of streams receiving base-flow inflows from outside 

the active model area, the majority of streams in the study area 

were dry (base flow of 0.0–5.0 ft3

/s) at the end of the 20-year 

EPS scenario (fig. 38). 

For the 40-year and 50-year EPS scenarios, most 

(90 percent) of the dewatering of the aquifer occurred during 

the first 20 years (fig. 39). During that time, annual EPS 

pumping decreased in the numerical model as the thinner parts 

of the aquifer went dry. Annual storage changes decreased as 

annual EPS pumping decreased, and approximate steady-state 

conditions were reached after about 30 years (fig. 39). These 

approximate steady-state conditions explain why the 40- 

and 50-year EPS pumping rates are the same. Groundwater 

storage at the end of the 50-year EPS scenario was about 

948,000 acre-ft, or about 1,320,000 acre-ft (58 percent) less 

than the starting EPS scenario storage.

Lake Altus storage was reduced to zero after 6–7 years 

of EPS pumping in each scenario. Surface-water inflow from 

the North Fork Red River was the primary inflow to Lake 

Altus (fig. 33), so Lake Altus storage quickly decreased when 

the North Fork Red River ceased flowing. When the EPS 

scenarios were run without simulating Lake Altus, the EPS 

decreased by less than 0.1 acre-foot per acre per year for each 

scenario.

EXPLANATION

20-year equal-proportionate-share groundwater 

 pumping under normal recharge conditions

Recharge decreased by 10 percent

Recharge increased by 10 percent

Note: Values above the vertical dashed lines are the

equal-proportionate-share pumping rate, rounded to

the nearest hundredth, resulting in 50 percent of basin

with less than 5 feet of saturated thickness for each scenario

43

44

45

46

47

48

49

50

51

52

53

0.49 0.51 0.53 0.55 0.57 0.59 0.61 0.63 0.65

Percentage of basin with less than 5 feet of saturated thickness

Equal-proportionate-share groundwater pumping 

rate, in acre-feet per acre per year

50 percent of basin with less than 

5 feet of saturated thickness

0.55 0.59 0.62

Figure 37. Percentage of the North Fork Red River aquifer with 

less than 5 feet of saturated thickness after 20 years of continuous 

equal-proportionate-share groundwater pumping.

Table 15. Equal-proportionate-share (EPS) pumping rates for the 

North Fork Red River aquifer, southwest Oklahoma.

Period 

(years)

EPS pumping rate 

(acre-feet per acre per year)

Recharge 

reduced by 

10 percent

Normal 

recharge

Recharge 

increased by 

10 percent

20 0.55 0.59 0.62

40 0.49 0.52 0.56

50 0.48 0.52 0.56
Groundwater Availability Scenarios 71

ROGER MILLS COUNTY

WHEELER

COUNTY

BECKHAM

COUNTY

WASHITA

COUNTY

COLLINGSWORTH

COUNTY

GREER

COUNTY KIOWA

COUNTY

HARMON

COUNTY

JACKSON

COUNTY

TILLMAN COUNTY

CHILDRESS

COUNTY

07301420

07301481

07301500

07303000

07303400

07303500

07304500

07305000

07305500

07307010

Lake

Altus

(no storage)

Tom Steed

Reservoir

(storage not

simulated)

Tom Steed

Elm Fork

Red

River

Elk Creek

Sweetwater

Creek

 Otter

Creek

North

Fork

Red

River

Elm Fork

Red

River

Elk Creek

Sweetwater

Creek

 Otter

Creek

North

Fork

Red

River

ELK

SWEE

EFRR

NFRR

North Fork Red River aquifer boundary modified

from Oklahoma Water Resources Board (2015b)

0 6 12 18 24 MILES

0 6 12 18 24 KILOMETERS

Base modified from U.S. Geological Survey digital data

Universal Transverse Mercator, zone 14

North American Datum of 1983

EXPLANATION

Saturated thickness, in feet, after 20 years of equalproportionate-share groundwater pumping

Base flow, in cubic feet per second, after 20 years of equalproportionate-share groundwater pumping

North Fork Red River aquifer boundary

0.0 to 5.0

5.1 to 10.0

10.1 to 15.0

15.1 to 25.0

25.1 to 40.0

40.1 to 60.0

60.1 to 85.0

85.1 to 130.4

0.0 to 5.0

5.1 to 10.0

10.1 to 15.0

15.1 to 20.0

20.1 to 25.0

25.1 to 32.5

Streamgage, with station number

Streamflow-routing inflow, with name

100°00' 99°40' 99°20' 99°00'

35°20'

35°

34°40'

Figure 38. Simulated saturated thickness and base flow after 20 years of continuous equal-proportionate-share groundwater pumping 

in the North Fork Red River aquifer, southwest Oklahoma.
72 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

EXPLANATION

EXPLANATION

0

20

40

60

80

100

0

5

10

15

20

25

30

35

40

0 5 10 15 20 25 30 35 40 45 50

Cumulative simulated

change in groundwater

storage, in percent

Simulated mean annual base flow,

in cubic feet per second

Time elapsed, in years

Cumulative change in 

 groundwater storage

Groundwater storage

Carter streamgage (07301500) on 

 North Fork Red River 

Headrick streamgage (07305000) 

 on North Fork Red River 

Simulated groundwater 

storage, in thousands 

of acre-feet

0

454

907

1,361

1,814

2,268

A

B

Figure 39. Changes in A, simulated base flow and B, simulated groundwater storage during 50 years of continuous equalproportionate-share groundwater pumping in the North Fork Red River aquifer, southwest Oklahoma.

Projected (50-Year) Pumping

Projected 50-year pumping scenarios were used to 

simulate the effects of selected well withdrawal rates on 

groundwater storage of the North Fork Red River aquifer and 

base flows in the North Fork Red River upstream from Lake 

Altus. The effects of well withdrawals were evaluated by 

comparing changes in groundwater storage (and base flow) 

between four 50-year scenarios using (1) no groundwater 

pumping, (2) mean pumping rates for the study period 

(1980–2013), (3) 2013 pumping rates, and (4) increasing 

demand pumping rates. The increasing demand pumping 

rates assumed a 20.4-percent increase in pumping over 

50 years based on 2010–60 demand projections for southwest 

Oklahoma (OWRB, 2012b). The projected water-use scenarios 

began in 1980 and ran until 2029. The scenarios did not begin 

in 2013 and run until 2062 because the calibrated numerical 

model ended in drought conditions, and the low initial (2013) 

groundwater storage caused all four scenarios to show nonintuitive gradual increases in groundwater storage. Model 

stresses were configured as the mean of each monthly stress 

period from the calibrated model, and the scenarios assumed 

that future climate conditions were similar to those of the 

1980–2013 study period. 

Groundwater storage after 50 years with no pumping 

was about 2,606,000 acre-ft, or 137,000 acre-ft (5.5 percent) 

greater than the initial groundwater storage; this groundwater 

storage increase is equivalent to a mean water-level increase 

of 2.3 ft (fig. 40, table 16). Groundwater storage after 50 years 

with the mean pumping rate for the study period (1980–

2013) was about 2,476,000 acre-ft, or about 7,000 acre-ft 

(0.3 percent) greater than the initial groundwater storage; 

this groundwater storage increase is equivalent to a mean 

water-level increase of 0.1 ft (fig. 40, table 16). Groundwater 

storage at the end of the 50-year period with 2013 pumping 

rates was about 2,398,000 acre-ft, or about 70,000 acre-ft 

(2.8 percent) less than the initial storage; this groundwater 

storage decrease is equivalent to a mean water-level decline 

of 1.2 ft (fig. 40, table 16). Groundwater storage at the end of 

the 50-year period with increasing demand pumping rates was 

about 2,361,000 acre-ft, or about 107,000 acre-ft (4.3 percent) 

less than the initial storage; this groundwater storage decrease 

is equivalent to a mean water-level decline of 1.8 ft (fig. 40, 

table 16). 
Groundwater Availability Scenarios 73

EXPLANATION

North Fork Red River inflow to Lake Altus, 

 mean pumping rate, 1980–2013

North Fork Red River inflow to Lake Altus, 

 no pumping

Carter streamgage (07301500) on North Fork 

 Red River, mean pumping rate, 1980–2013

Carter streamgage (07301500) on North Fork 

 Red River, no pumping

North Fork Red River inflow to Lake Altus, 

 2013 pumping rate

North Fork Red River inflow to Lake Altus, 

 increasing demand pumping rate 

 (20.4-percent increase over 50 years)

Carter streamgage (07301500) on North Fork 

 Red River, 2013 pumping rate

Carter streamgage (07301500) on North Fork 

 Red River, increasing demand pumping rate 

 (20.4-percent increase over 50 years)

EXPLANATION

2013 pumping rate

Mean pumping rate, 1980–2013

No pumping

Increasing demand pumping rate 

 (20.4-percent increase over 50 years)

2,300,000

2,350,000

2,400,000

2,450,000

2,500,000

2,550,000

2,600,000

2,650,000

Simulated groundwater storage, in acre-feet 

30,000

35,000

40,000

45,000

50,000

55,000

0 10 20 30 40 50

Simulated mean annual base flow, in acre-feet 

60,000

41.4

48.3

55.2

62.1

69.0

75.9

Simulated mean annual base flow, in cubic feet per second

82.8

A 

B

Time elapsed, in years

Figure 40. A, Simulated groundwater storage and B, simulated mean annual base flow through 50 years of groundwater pumping at 

selected rates in the North Fork Red River aquifer, southwest Oklahoma.
74 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 16. Changes in groundwater storage and mean annual base flow after 50 years of groundwater pumping at selected rates for 

the North Fork Red River aquifer, southwest Oklahoma.

[Values reported may vary from those calcluated using this table because of rounding errors]

Projected (50-year) 

pumping scenario

Groundwater storage

Groundwater 

storage at 

beginning 

of scenario

(acre-feet)

Groundwater 

storage at end 

of scenario

(acre-feet)

Change in 

groundwater 

storage

(acre-feet)

Change in 

groundwater 

storage

(percent)

Mean change 

in water table

(feet)

No pumping 2,469,000 2,606,000 137,000 5.5 2.3

Mean pumping rate, 1980–2013 2,469,000 2,476,000 7,000 0.3 0.1

2013 pumping rate 2,468,000 2,398,000 –70,000 –2.8 –1.2

Increasing demand pumping 

rate (20.4-percent increase 

over 50 years)

2,468,000 2,361,000 –107,000 –4.3 –1.8

Projected (50-year) 

pumping scenario

Mean annual base flow at Carter streamgage (07301500) on North Fork Red River

Mean base flow for 

first year of scenario

(acre-feet)

Mean base flow for 

last year of scenario

(acre-feet)

Change in 

base flow

(acre-feet)

Change in 

base flow

(percent)

No pumping 41,278 45,284 4,005 9.7

Mean pumping rate, 1980–2013 40,799 40,246 –552 –1.4

2013 pumping rate 40,072 36,042 –4,029 –10.1

Increasing demand pumping rate 

(20.4-percent increase over 

50 years)

40,066 34,687 –5,380 –13.4

Projected (50-year) 

pumping scenario

Mean annual base flow at North Fork Red River inflow to Lake Altus

Mean base flow for 

first year of scenario

(acre-feet)

Mean base flow for 

last year of scenario

(acre-feet)

Change in 

base flow

(acre-feet)

Change in 

base flow

(percent)

No pumping 49,313 56,683 7,370 14.9

Mean pumping rate, 1980–2013 48,757 49,034 277 0.6

2013 pumping rate 48,083 43,983 –4,099 –8.5

Increasing demand pumping rate 

(20.4-percent increase over 

50 years)

48,078 42,272 –5,806 –12.1
Groundwater Availability Scenarios 75

Mean annual base flow simulated at the Carter 

streamgage (07301500) on North Fork Red River increased 

by about 4,000 acre-ft (10 percent) after 50 years with no 

pumping and decreased by about 5,400 acre-ft (13 percent) 

after 50 years with increasing demand pumping rates (fig. 40, 

table 16). Mean annual base flow simulated at the North Fork 

Red River inflow to Lake Altus increased by about 7,400 

acre-ft (15 percent) after 50 years with no pumping and 

decreased by about 5,800 acre-ft (12 percent) after 50 years 

with increasing demand pumping rates (fig. 40, table 16).

Hypothetical (10-Year) Drought

A hypothetical 10-year drought scenario was used to 

simulate the effects of a prolonged period of reduced recharge 

on groundwater storage and Lake Altus stage and storage. 

The period of January 1984 to December 1993, which had 

base flows similar to the mean annual base flow for the study 

period, was chosen as the simulated drought period. Drought 

effects were quantified by comparing the results of the 

drought scenario to those of the calibrated numerical model 

(no drought). To simulate the hypothetical drought, recharge 

in the calibrated numerical model was reduced by 50 percent 

during the simulated drought period (1984–1993). Upstream 

inflows to the North Fork Red River and tributaries were 

reduced by 37 percent, which was the mean decrease in annual 

base flow during the drought of years 1976–81 as compared 

to the study period 1980–2013 at the Carter (07301500) and 

Carl (07303400) streamgages (Barlow and others, 2015; 

USGS, 2015a). The rates of direct lake-surface precipitation 

(a small component of the lake inflows, fig. 33A), evaporation, 

and nonstream runoff to Lake Altus were unchanged from 

the calibrated numerical model. Withdrawals from lake 

storage also were unchanged, with the exception of monthly 

withdrawals in six stress periods (in months 121–156) that 

were reduced by 25 percent to fix model instability problems 

caused by near-zero storage in Lake Altus.

Groundwater storage at the end of the drought 

period (month 120) was about 2,271,000 acre-ft, or about 

426,000 acre-ft (15.8 percent) less than the groundwater 

storage of the calibrated numerical model (fig. 41). This 

decrease in groundwater storage is equivalent to a mean watertable-altitude decline of 7.1 ft. 

The largest water-level declines (as great as 49 ft) 

occurred in the terrace areas most upgradient from the 

North Fork Red River and tributaries. Excluding areas near 

Lake Altus, Tom Steed Reservoir, and the Texas border, 

groundwater storage in the upgradient terrace was supplied 

entirely by recharge, so decreases in recharge have substantial 

effects on terrace water levels. The decreased saturated 

thickness in some areas of the terrace caused a reduction in 

simulated well withdrawals as compared to the calibrated 

numerical model. The saturated thickness of areas near the 

North Fork Red River and major tributaries changed little 

during the hypothetical drought, but the simulated base flow 

in streams in those areas decreased rapidly. After 12 months 

of the hypothetical drought, simulated base flows at the 

Sweetwater (07301420), Carter (07301500), and Headrick 

(07305000) streamgages had all decreased by greater than 

30 percent as compared to the calibrated numerical model 

(fig. 42). At the end of the 10-year hypothetical drought 

period, simulated base flows at the Sweetwater (07301420), 

Carter (07301500), Headrick (07305000), and Snyder 

(07307010) streamgages had decreased by about 37, 61, 44, 

and 45 percent, respectively (fig. 42). 

Substantial declines in the Lake Altus stage began around 

month 30 (fig. 43) in conjunction with base-flow decreases 

of more than 50 percent at the Carter streamgage (07301500) 

(fig. 42B). These lake-stage declines outpaced water-level 

declines in the surrounding aquifer. During the drought, 

simulated storage in seven monthly stress periods (in July 

and August between months 55 and 128) decreased below the 

dead pool storage of 633 acre-ft (U.S. Bureau of Reclamation, 

2015b). The minimum Lake Altus storage simulated during the 

drought period was 403 acre-ft in month 116 (fig. 43), which 

was a decline of 92 percent from the nondrought storage. The 

drought effects persisted years after the end of the simulated 

drought, and the minimum Lake Altus storage during the study 

period (350 acre-ft) was simulated in month 129 (fig. 43). 

Reduced base flows in the North Fork Red River were the 

primary cause of simulated Lake Altus storage declines.

Because Lake Altus storage approached zero during the 

summer months of the hypothetical 10-year drought (fig. 43), 

the numerical model automatically reduced withdrawal rates 

from Lake Altus by about 12 percent. After the end of the 

hypothetical 10-year drought period, withdrawal rates from 

Lake Altus remained about 10 percent lower than nondrought 

conditions until August 2011. From August 2011 to June 2015, 

water was not withdrawn from Lake Altus for irrigation use 

at LAID, and the observed lake stage was at or below 1,536 ft 

(U.S. Bureau of Reclamation, 2015b) (fig. 30). At this stage, 

Lake Altus storage was about 30,000 acre-ft (12 percent of 

the normal-pool storage capacity) (fig. 30). If this storage 

threshold for withdrawals was implemented during the 

hypothetical 10-year drought scenario, withdrawals from Lake 

Altus would not occur during 60 percent of summer months, 

when irrigation demand was largest. 
76 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

EXPLANATION

Simulated groundwater storage, no drought

(calibrated numerical model)

Simulated groundwater storage, with drought

(recharge reduced 50 percent from calibrated model)

Change in simulated groundwater storage

Simulated groundwater storage, in acre-feet

Year

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997

0

10

20

Change in groundwater

storage, in percent

Hypothetical 10-year drought period

2,200,000

2,300,000

2,400,000

2,500,000

2,600,000

2,700,000

2,800,000

2,900,000

3,000,000

0 12

Months after beginning of simulated drought (add 49 for stress-period number)

24 36 48 60 72 84 96 108 120 132 144 156 168

Figure 41. Changes in groundwater storage resulting from a hypothetical 10-year drought (1984–93) for the North Fork Red River 

aquifer, 1980–97.
Groundwater Availability Scenarios 77

EXPLANATION

Percentage decrease in simulated

base flow

Simulated base flow, with drought

(recharge reduced 50 percent)

Simulated base flow, with no drought

 (calibrated numerical model)

Simulated base flow, with no drought

 (calibrated numerical model)

Percentage decrease in simulated

base flow

Simulated base flow, with drought

(recharge reduced 50 percent)

EXPLANATION

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997

Hypothetical 10-year drought period

Hypothetical 10-year drought period

A. Sweetwater streamgage (07301420) on Sweetwater Creek

B. Carter streamgage (07301500) on North Fork Red River

0

10

20

30

40

50

60

Simulated base flow, in cubic feet per second

Year

0

50

100

150

200

250

Simulated base flow, in cubic feet per second

0

15

30

45

60

75

0

15

30

45

60

75

Percentage decrease

in simulated base flow

Percentage decrease 

in simulated base flow

0 12

Months after beginning of simulated drought (add 49 for stress-period number)

24 36 48 60 72 84 96 108 120 132 144 156 168

Figure 42. Changes in simulated base flow at A, Sweetwater streamgage (07301420) on Sweetwater Creek; B, Carter streamgage 

(07301500) on North Fork Red River; C, Headrick streamgage (07305000) on North Fork Red River; and D, Snyder streamgage (07307010) 

on Otter Creek resulting from a hypothetical 10-year drought (1984–93) for the North Fork Red River aquifer, 1980–97.
78 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Simulated base flow, with no drought

 (calibrated numerical model)

Percentage decrease in simulated

base flow

Simulated base flow, with drought

(recharge reduced 50 percent)

EXPLANATION

Simulated base flow, with no drought

 (calibrated numerical model)

Percentage decrease in simulated

base flow

Simulated base flow, with drought

(recharge reduced 50 percent)

EXPLANATION

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997

Year

Hypothetical 10-year drought period

Hypothetical 10-year drought period

C. Headrick streamgage (07305000) on North Fork Red River

D. Snyder streamgage (07307010) on Otter Creek

Simulated base flow, in cubic feet per second Simulated base flow, in cubic feet per second

0

5

10

15

20

25

0

100

200

300

400

500

600

0

15

30

45

60

75

0

15

30

45

60

75

0 12

Months after beginning of simulated drought (add 49 for stress-period number)

24 36 48 60 72 84 96 108 120 132 144 156 168

Percentage decrease

in simulated base flow

Percentage decrease 

in simulated base flow

Figure 42. Changes in simulated base flow at A, Sweetwater streamgage (07301420) on Sweetwater Creek; B, Carter streamgage 

(07301500) on North Fork Red River; C, Headrick streamgage (07305000) on North Fork Red River; and D, Snyder streamgage (07307010) 

on Otter Creek resulting from a hypothetical 10-year drought (1984–93) for the North Fork Red River aquifer, 1980–97.—Continued
Groundwater Availability Scenarios 79

EXPLANATION

Simulated, no drought (calibrated numerical model)

Simulated, with drought (recharge reduced 50 percent)

Normal pool

A

B

0 12

Months after beginning of simulated drought (add 49 for stress-period number)

24 36 48 60 72 84 96 108 120 132 144 156 168

Hypothetical 10-year drought period

Hypothetical 10-year drought period

1,520

1,515

1,525

1,530

1,535

1,540

1,545

1,550

1,555

1,560

1,565

1,570

0

30,000

60,000

90,000

120,000

150,000

180,000

Lake stage, in feet above North American Vertical Datum of 1988

Year

Lake storage, in acre-feet

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997

Figure 43. Changes in A, Lake Altus stage and B, Lake Altus storage resulting from a hypothetical 10-year drought (1984–93) for the 

North Fork Red River aquifer, 1980–97.
80 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Model Limitations

Some assumptions and simplifications were necessary 

in the simulation of groundwater flow. The use of the 

MODFLOW code required the assumptions that groundwater 

flows are governed by Darcy’s Law (Darcy, 1856), water 

is incompressible and of uniform density, and the aquifer 

hydrogeology can be simulated appropriately by the cell size 

and number of layers present. Computing and time limitations 

prevented the use of cell sizes that could better represent the 

true variability of hydrogeologic characteristics; therefore, 

results generated by the model may be more applicable to a 

regional, rather than local, area.

An uneven spatial and temporal distribution of 

water-table-altitude observations caused data gaps in the 

calibration data. Though the simulated water table in areas 

with fewer observations is in an expected water-tablealtitude range, more site-specific and local calibration target 

data could facilitate a more detailed characterization of watertable conditions. Additionally, base-flow gain to the North 

Fork Red River is based on the simulated water table and 

may not be well represented in locations where water-tablealtitude observation data were relatively sparse. 

The stream network used in the numerical model is a 

simplification of the actual stream geometry and hydraulic 

properties. Refined measurement of the stream channel 

width and streambed conductance at the local scale might 

improve the numerical model calibration because these 

factors control the amount of streambed seepage exchange 

with the aquifer. The numerical model was calibrated 

primarily to base-flow estimates; therefore, collection of 

more streamflow and base-flow data during other hydrologic 

conditions also could further reduce uncertainty in local-scale 

simulation results. 

Lake Altus inflows (base flows) simulated by the 

numerical model are likely to be of interest to surface-water 

resource managers. Because no streamgages are located 

between Carter (07301500) and Lake Altus (a distance of 

about 27 river miles), additional streambed seepage may 

occur in this reach that was not represented in the calibrated 

numerical model. Additional long-term streamgage data 

near the lake inflow point and seasonal synoptic base-flow 

measurements over a range of hydrologic conditions would 

be needed to increase confidence that the calibrated numerical 

model was adequately reproducing observed base flows in 

that reach. 

Exact amounts of annual groundwater use are unknown 

because groundwater wells are not metered, and groundwateruse data are based on estimates submitted to the OWRB by 

permit holders. Additionally, groundwater use by domestic 

wells, though assumed to be relatively small, was not 

included in the numerical model. 

Summary

On September 8, 1981, the Oklahoma Water Resources 

Board (OWRB) established regulatory limits on the maximum 

annual yield of groundwater (343,042 acre-feet per year) and 

equal-proportionate-share (EPS) pumping rate (1.0 acre-foot 

per acre per year) for the North Fork Red River aquifer. The 

maximum annual yield and EPS were based on a hydrologic 

investigation 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. The OWRB is statutorily required (every 20 years) to 

update the hydrologic investigation on which the maximum 

annual yield and EPS were based. Because 20 years have 

elapsed since the final order was issued, the U.S. Geological 

Survey, in cooperation with the OWRB, conducted an updated 

hydrologic investigation and evaluated the effects of potential 

groundwater withdrawals on groundwater flow and availability 

in the North Fork Red River aquifer in Oklahoma. This report 

describes a hydrologic investigation of the North Fork Red 

River aquifer that includes an updated summary of the aquifer 

hydrogeology. As part of this investigation, groundwater 

flow and availability were simulated by using a numerical 

groundwater-flow model.

The North Fork Red River aquifer in Beckham, Greer, 

Jackson, Kiowa, and Roger Mills Counties in Oklahoma 

is composed of about 777 square miles (497,582 acres) of 

alluvium and terrace deposits along the North Fork Red River 

and tributaries, including Sweetwater Creek, Elk Creek, Otter 

Creek, and Elm Fork Red River. The North Fork Red River 

is the primary source of surface-water inflow to Lake Altus, 

which overlies the North Fork Red River aquifer. Lake Altus 

is a U.S. Bureau of Reclamation reservoir with the primary 

purpose of supplying irrigation water to the Lugert-Altus 

Irrigation District. The mean annual precipitation and the 

mean annual temperature in the study area for the period 

of record 1895–2015 were about 27.6 inches per year and 

about 61.2 degrees Fahrenheit, respectively. The mean annual 

temperature was about 0.4 degree Fahrenheit greater and 

the mean annual precipitation was about 1.6 inches per year 

greater for the study period 1980–2013 compared to the period 

of record. The mean annual reported groundwater use was 

15,279 acre-feet per year for the period of record 1967–2013 

and 15,859 acre-feet per year for the period 1980–2013. The 

year with the greatest reported groundwater use (26,714 acrefeet) was 2011. Though three of the four greatest individual 

users of groundwater were municipalities, irrigation was 

the major groundwater-use type for the period of record 

1967–2013.

A hydrogeologic framework was developed for the North 

Fork Red River aquifer and included a definition of the aquifer 

extent and potentiometric surface, as well as a description of 

the textural and hydraulic properties of aquifer materials. The 

estimated horizontal hydraulic conductivity determined for 

lithologic logs in the North Fork Red River aquifer ranged 
Summary 81

from 3 to 97 feet per day, with a mean of 52 feet per day. 

Based on available multi-well aquifer test data and published 

studies, a mean specific yield value of 0.12 was estimated 

for the North Fork Red River aquifer. The hydrogeologic 

framework was used in the construction of a numerical 

groundwater-flow model of the North Fork Red River aquifer 

described in this report. 

A conceptual model of aquifer inflows and outflows was 

developed for the North Fork Red River aquifer to constrain 

the construction and calibration of a numerical groundwaterflow model that reasonably represented the groundwaterflow system. The conceptual-model water budget estimated 

mean annual inflows to and outflows from the North Fork 

Red River aquifer for the period 1980–2013 and included a 

sub-accounting of mean annual inflows and outflows for the 

portions of the aquifer that were upgradient and downgradient 

from Lake Altus. Recharge is the predominant inflow to the 

North Fork Red River aquifer. Based on estimated annual 

recharge rates from published studies and selected methods, 

the mean annual recharge rate to the North Fork Red River 

aquifer for the period 1980–2013 was estimated to be about 

2.77 inches per year or 9.5 percent of the mean annual 

precipitation (29.2 inches per year) for the same period. 

This 1980–2013 mean annual recharge rate is equivalent to 

a mean annual recharge volume of about 115,000 acre-feet 

per year. Streambed seepage is the predominant outflow from 

the North Fork Red River aquifer. The annual net streambed 

seepage upgradient from Lake Altus was estimated to be 

27,824 acre-feet per year, and the annual net streambed 

seepage downgradient from Lake Altus was estimated to be 

44,010 acre-feet per year.

The numerical groundwater-flow model simulated the 

period 1980–2013 and was calibrated to water-table-altitude 

observations at selected wells, monthly base flow at selected 

streamgages, net streambed seepage as estimated for the 

conceptual model, and Lake Altus stage. Groundwateravailability 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 base flow and groundwater 

storage. The results of the groundwater-availability scenarios 

could be used by the OWRB to reevaluate the maximum 

annual yield of groundwater from the North Fork Red River 

aquifer.

EPS scenarios for the North Fork Red River aquifer were 

run for periods of 20, 40, and 50 years. The 20-, 40-, and 

50-year EPS pumping rates under normal recharge conditions 

were 0.59, 0.52, and 0.52 acre-foot per acre per year, 

respectively. Given the 497,582-acre aquifer area, these rates 

correspond to annual yields of about 294,000, 259,000, and 

259,000 acre-feet per year, respectively. For the 20-year EPS 

scenario, decreasing and increasing recharge by 10 percent 

resulted in a 5–7-percent change in the EPS pumping rate; for 

the 40- and 50-year EPS scenarios, decreasing and increasing 

recharge by 10 percent resulted in a 6–8-percent change in 

the EPS pumping rate. Groundwater storage at the end of the 

20-year EPS scenario was about 951,000 acre-feet, or about 

1,317,000 acre-feet (58 percent) less than the starting EPS 

scenario storage. This decrease in storage was equivalent to a 

mean water-level decline of about 22 feet. Most areas of the 

active alluvium near the North Fork Red River, Elk Creek, 

and Elm Fork Red River remained partially saturated through 

the end of the EPS scenario because of streambed seepage. 

Lake Altus storage was reduced to zero after 6–7 years of EPS 

pumping in each scenario.

Projected 50-year pumping scenarios were used to 

simulate the effects of selected well withdrawal rates on 

groundwater storage of the North Fork Red River aquifer 

and base flows in the North Fork Red River upstream from 

Lake Altus. The effects of well withdrawals were evaluated 

by comparing changes in groundwater storage and base flow 

between four 50-year scenarios using (1) no groundwater 

pumping, (2) mean pumping rates for the study period (1980–

2013), (3) 2013 pumping rates, and (4) increasing demand 

pumping rates. The increasing demand pumping rates assumed 

a 20.4-percent increase in pumping over 50 years based on 

2010–60 demand projections for southwest Oklahoma.

Groundwater storage after 50 years with no pumping was 

about 2,606,000 acre-feet, or 137,000 acre-feet (5.5 percent) 

greater than the initial groundwater storage; this groundwater 

storage increase is equivalent to a mean water-level increase 

of 2.3 feet. Groundwater storage after 50 years with the mean 

pumping rate for the study period (1980–2013) was about 

2,476,000 acre-feet, or about 7,000 acre-feet (0.3 percent) 

greater than the initial groundwater storage; this groundwater 

storage increase is equivalent to a mean water-level increase 

of 0.1 foot. Groundwater storage at the end of the 50-year 

period with 2013 pumping rates was about 2,398,000 acrefeet, or about 70,000 acre-feet (2.8 percent) less than the initial 

storage; this groundwater storage decrease is equivalent to a 

mean water-level decline of 1.2 feet. Groundwater storage at 

the end of the 50-year period with increasing demand pumping 

rates was about 2,361,000 acre-feet, or about 107,000 acrefeet (4.3 percent) less than the initial storage; this groundwater 

storage decrease is equivalent to a mean water-level decline 

of 1.8 feet. Mean annual base flow simulated at the Carter 

streamgage (07301500) on North Fork Red River increased 

by about 4,000 acre-feet (10 percent) after 50 years with no 

pumping and decreased by about 5,400 acre-feet (13 percent) 

after 50 years with increasing demand pumping rates. Mean 

annual base flow simulated at the North Fork Red River inflow 

to Lake Altus increased by about 7,400 acre-feet (15 percent) 

after 50 years with no pumping and decreased by about 

5,800 acre-feet (12 percent) after 50 years with increasing 

demand pumping rates.
82 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

A hypothetical 10-year drought scenario was used 

to simulate the effects of a prolonged period of reduced 

recharge on groundwater storage and Lake Altus stage and 

storage. Drought effects were quantified by comparing the 

results of the drought scenario to those of the calibrated 

numerical model (no drought). To simulate the hypothetical 

drought, recharge in the calibrated numerical model was 

reduced by 50 percent during the simulated drought period 

(1984–93). Groundwater storage at the end of the drought 

period was about 2,271,000 acre-feet, or about 426,000 acrefeet (15.8 percent) less than the groundwater storage of the 

calibrated numerical model. This decrease in groundwater 

storage is equivalent to a mean water-table-altitude decline of 

7.1 feet. At the end of the 10-year hypothetical drought period, 

base flows at the Sweetwater (07301420), Carter (07301500), 

Headrick (07305000), and Snyder (07307010) streamgages 

had decreased by about 37, 61, 44, and 45 percent, 

respectively. The minimum Lake Altus storage simulated 

during the drought period was 403 acre-feet, which was a 

decline of 92 percent from the nondrought storage. Reduced 

base flows in the North Fork Red River were the primary 

cause of Lake Altus storage declines. 

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7.2014.959958.
88 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

Continuous-record streamgages (U.S. Geological Survey, 2015a)

07301300 Shamrock 

streamgage

North Fork Red River near 

Shamrock, Tex. 

35.2642 -100.2418 Wheeler 2/19/1964 present 

(2015)

--

07301410 Kelton streamgage Sweetwater Creek near Kelton, 

Tex.

35.4731 -100.1210 Wheeler 11/16/1961 present 

(2015)

--

07301420 Sweetwater 

streamgage

Sweetwater Creek near 

Sweetwater, Okla.

35.4223 -99.9693 Beckham 4/22/1986 present 

(2015)

--

07301500 Carter streamgage North Fork Red River near 

Carter, Okla.

35.1681 -99.5073 Beckham 10/1/1944 present 

(2015)

--

07303000 Lugert streamgage North Fork Red River below 

Altus Dam near Lugert, 

Okla.

34.8895 -99.3070 Greer 10/1/2007 present 

(2015)

--

07303400 Carl streamgage Elm Fork of North Fork Red 

River (Elm Fork Red River) 

near Carl, Okla.

35.0117 -99.9037 Harmon 10/1/1959 present 

(2015)

--

07304500 Hobart streamgage Elk Creek near Hobart, Okla. 34.9142 -99.1140 Kiowa 10/1/1904 9/30/1993 --

07305000 Headrick 

streamgage

North Fork Red River near 

Headrick, Okla.

34.6381 -99.1037 Tillman 4/1/1905 present 

(2015)

--

07307010 Snyder streamgage Otter Creek near Snyder, Okla. 34.6378 -98.9987 Kiowa 7/1/2000 10/5/2008 --

Climate stations (Oklahoma Mesonet, 2015)

-- ALTU Altus 34.58722 -99.33808 Jackson 1/1/1994 present 

(2015)

1,365

-- CHEY Cheyenne 35.54615 -99.72790 Roger 

Mills

1/1/1994 present 

(2015)

2,277

-- ERIC Erick 35.20494 -99.80344 Beckham 1/1/1994 present 

(2015)

1,978

HOBA HOBA Hobart 34.98971 -99.05283 Kiowa 1/1/1994 present 

(2015)

1,568

-- HOLL Hollis 34.68550 -99.83331 Harmon 1/1/1994 present 

(2015)

1,631

-- MANG Mangum 34.83592 -99.42398 Greer 1/1/1994 present 

(2015)

1,509

-- RETR Retrop 35.12275 -99.36001 Washita 1/1/1994 present 

(2015)

1,765

-- TIPT Tipton 34.43972 -99.13755 Tillman 1/1/1994 present 

(2015)

1,270

Table 1

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]
Table 1 89

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

Continuous-record streamgages (U.S. Geological Survey, 2015a)

07301300 Shamrock 

streamgage

-- 1,369 817 552 yes; since 1930s by Lake McClellan, 

Tex., and since 1980s by floodwaterretarding structures

SFR inflow

07301410 Kelton streamgage -- 297 281 16 no SFR inflow

07301420 Sweetwater 

streamgage

-- 437 410 27 no Recharge (RORA), 

manual and 

automated 

calibration

07301500 Carter streamgage -- 2,652 2,073 579 yes; since 1930s by Lake McClellan 

(Tex.) and since 1960s by floodwaterretarding structures

Outflow, manual 

and automated 

calibration

07303000 Lugert streamgage -- 2,832 2,253 579 yes; since 1945 by Lake Altus LAK releases

07303400 Carl streamgage -- 438 438 0 no SFR inflow

07304500 Hobart streamgage -- 549 549 0 yes; since 1960s by floodwaterretarding structures and since 1970s 

by Bretch Canal

SFR inflow 

07305000 Headrick 

streamgage

-- 4,560 3,981 579 yes; since 1940s by Lake Altus Outflow, manual 

and automated 

calibration

07307010 Snyder streamgage -- 162 162 0 yes; since 1970s by Tom Steed 

Reservoir and floodwater-retarding 

structures

Outflow, manual 

calibration

Climate stations (Oklahoma Mesonet, 2015)

-- ALTU -- -- -- -- -- Recharge (SWB)

-- CHEY -- -- -- -- -- Recharge (SWB)

-- ERIC -- -- -- -- -- Recharge (SWB)

HOBA HOBA -- -- -- -- -- Recharge (SWB)

-- HOLL -- -- -- -- -- Recharge (SWB)

-- MANG -- -- -- -- -- Recharge (SWB)

-- RETR -- -- -- -- -- Recharge (SWB)

-- TIPT -- -- -- -- -- Recharge (SWB)
90 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

Climate stations (National Climatic Data Center, 2015)

-- USC00345648 Mayfield 35.3392 -99.8769 -- 3/14/1948 2/29/2012 2,005

342944 USC00342944 Erick 35.2164 -99.8628 -- 9/1/1904 present 

(2015)

2,060

349668 USC00349668 Willow 35.0522 -99.5125 -- 9/1/1980 present 

(2015)

1,745

-- USC00410157 Allison 35.6103 -100.1022 -- 8/1/2001 present 

(2015)

2,600

340184 USC00340184 Altus Dam 34.8847 -99.2964 -- 8/1/1945 present 

(2015)

1,525

-- USC00349212 Vinson 34.9003 -99.8614 -- 2/26/1940 present 

(2015)

1,880

-- USC00349213 Vinson 6 NW 34.9578 -99.9414 -- 6/15/2011 present 

(2015)

1,912

347952 USC00347952 Sayre 35.3061 -99.6275 -- 6/1/1936 present 

(2015)

1,900

-- USC00418235 Shamrock 35.2 -100.25 -- 7/1/1929 9/30/1987 2,323

-- USC00342125 Cordell 35.3008 -98.9958 -- 7/1/1936 1/22/2013 1,564

-- USC00418236 Shamrock 2 35.215 -100.2503 -- 9/1/1962 present 

(2015)

2,360

-- USC00344202 Hobart 35.0258 -99.1058 -- 5/1/2010 present 

(2015)

1,552

-- USW00093986 Hobart Municipal Airport 34.9894 -99.0525 -- 1/1/1910 present 

(2015)

1,556

-- USC00419662 Wheeler 35.4375 -100.2753 -- 4/1/1979 present 

(2015)

2,495

-- USC00347565 Retrop 35.1597 -99.3658 -- 9/9/1980 present 

(2015)

1,780

-- USC00419565 Wellington 34.8422 -100.2103 -- 4/1/1912 present 

(2015)

2,040

-- USC00345509 Mangum 34.8911 -99.5017 -- 1/1/1920 present 

(2015)

1,595

-- USC00343998 Headrick 34.6286 -99.1394 -- 2/1/1993 present 

(2015)

1,357

-- USC00348016 Sedan 34.9692 -98.7603 -- 7/1/1993 1/22/2013 1,475

-- USC00349629 Wichita Mtn WLR 34.7325 -98.7125 -- 1/1/1906 present 

(2015)

1,665

-- USW00003981 Frederick Municipal Airport 34.3622 -98.9761 -- 2/1/1998 present 

(2015)

1,267

-- USC00341738 Cheyenne 35.6 -99.6833 -- 7/1/1923 12/31/1994 2,005

-- USC00343353 Frederick 34.3861 -99.02 -- 5/1/1904 3/29/2011 1,285

-- USC00348652 Sweetwater 35.4219 -99.9053 -- 9/17/1982 1/22/2013 2,160
Table 1 91

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

Climate stations (National Climatic Data Center, 2015)

-- USC00345648 -- -- -- -- -- Recharge (SWB)

342944 USC00342944 -- -- -- -- -- Recharge (SWB)

349668 USC00349668 -- -- -- -- -- Recharge (SWB)

-- USC00410157 -- -- -- -- -- Recharge (SWB)

340184 USC00340184 -- -- -- -- -- Recharge (SWB)

-- USC00349212 -- -- -- -- -- Recharge (SWB)

-- USC00349213 -- -- -- -- -- Recharge (SWB)

347952 USC00347952 -- -- -- -- -- Recharge (SWB)

-- USC00418235 -- -- -- -- -- Recharge (SWB)

-- USC00342125 -- -- -- -- -- Recharge (SWB)

-- USC00418236 -- -- -- -- -- Recharge (SWB)

-- USC00344202 -- -- -- -- -- Recharge (SWB)

-- USW00093986 -- -- -- -- -- Recharge (SWB)

-- USC00419662 -- -- -- -- -- Recharge (SWB)

-- USC00347565 -- -- -- -- -- Recharge (SWB)

-- USC00419565 -- -- -- -- -- Recharge (SWB)

-- USC00345509 -- -- -- -- -- Recharge (SWB)

-- USC00343998 -- -- -- -- -- Recharge (SWB)

-- USC00348016 -- -- -- -- -- Recharge (SWB)

-- USC00349629 -- -- -- -- -- Recharge (SWB)

-- USW00003981 -- -- -- -- -- Recharge (SWB)

-- USC00341738 -- -- -- -- -- Recharge (SWB)

-- USC00343353 -- -- -- -- -- Recharge (SWB)

-- USC00348652 -- -- -- -- -- Recharge (SWB)
92 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

-- USW00003932 Clinton Sherman Airport 35.21 -99.12 -- 8/17/1958 present 

(2015)

1,922

346035 USC00346035 Moravia 35.1464 -99.4956 -- 8/1/1941 present 

(2015)

1,690

-- USC00347727 Roosevelt 34.8511 -99.0208 -- 11/26/1943 present 

(2015)

1,462

-- USC00347579 Reydon 35.6256 -99.9106 -- 11/15/1941 4/30/2007 2,385

-- USC00344249 Hollis 5 E 34.6808 -99.8136 -- 8/1/1922 1/22/2013 1,621

-- USC00411408 Canadian 22 SE 35.6467 -100.0658 -- 3/1/2003 2/1/2015 2,533

348299 USC00348299 Snyder 34.6867 -98.9483 -- 9/1/1906 1/22/2013 1,370

-- USC00340179 Altus Irig Res Station 34.5903 -99.3344 -- 5/1/1903 1/22/2013 1,380

-- USC00342849 Elk City 4 W 35.3925 -99.5064 -- 5/1/1904 present 

(2015)

2,120

Continuous water-level recorder wells (U.S. Geological Survey, 2015a)

CR1 351521099522901 09N-25W-17 BCC NFRR 01 35.255967 -99.874842 Beckham 4/18/2013 1/14/2015 2,033.77

CR2 350755099283201 08N-22W-25 CDD 1 NFRR 02 35.132094 -99.475564 Beckham 4/17/2013 1/15/2015 1,730.73

CR3 345759099163401 06N-20W-26 ADC 1 NFRR 03 34.966564 -99.276242 Kiowa 4/18/2013 1/14/2015 1,567.99

Geoprobe hydraulic profiling tool test holes

HPT1 351800099524801 10N-25W-31 ADC 1 35.300113 -99.879995 Beckham 4/1/2014 1,923.2

HPT2 351759099492401 10N-25W-35 BCC 1 35.299716 -99.823350 Beckham 4/1/2014 1,904.5

HPT4 351552099414001 09N-24W-12 CDB 1 35.264451 -99.694512 Beckham 4/2/2014 1,823.4

HPT5 350949099302701 08N-22W-15 DCB 1 35.163637 -99.507607 Beckham 4/2/2014 1,685.0

Multi-well aquifer test locations (Kent, 1980; Paukstaitis, 1981; U.S. Geological Survey, 2015a)

AT2 351339099424001 09N-24W-26 BDA 1 35.227551 -99.711487 Beckham 11/15/1954 11/19/1954 --

AT3 351438099370801 09N-23W-22 ABC 1 35.243940 -99.619262 Beckham 11/12/1954 11/17/1954 --

AT1 351657099584701 09N-26W-05 CAB 1 35.282552 -99.980108 Beckham 12/7/1954 12/9/1954 --

AT4 -- -- 34.969435 -99.321235 Kiowa 3/15/1979 3/18/1979 --

Water-quality stations (Oklahoma Water Resources Board, 2015c)

-- 93413 NFRED-003 35.246670 -99.648080 Beckham July–August, 2014 --

-- 44829 NFRED-004 35.250939 -99.932832 Beckham July–August, 2014 --

-- 124090 NFRED-005 34.926030 -99.325240 Greer July–August, 2014 --

-- 78679 NFRED-007 35.210742 -99.541983 Beckham July–August, 2014 --

-- 21104 NFRED-008 35.264902 -99.672168 Beckham July–August, 2014 --

-- 53182 NFRED-009 35.059587 -99.337239 Kiowa July–August, 2014 --

-- 89166 NFRED-011 35.017180 -99.363960 Greer July–August, 2014 --

-- 52044 NFRED-016 35.370513 -99.914917 Beckham July–August, 2014 --

-- 57632 NFRED-019 35.205450 -99.674444 Beckham July–August, 2014 --

-- 27186 NFRED-021 34.884525 -99.339545 Greer July–August, 2014 --

-- 148351 NFRED-022 34.862925 -99.342301 Greer July–August, 2014 --
Table 1 93

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

-- USW00003932 -- -- -- -- -- Recharge (SWB)

346035 USC00346035 -- -- -- -- -- Recharge (SWB)

-- USC00347727 -- -- -- -- -- Recharge (SWB)

-- USC00347579 -- -- -- -- -- Recharge (SWB)

-- USC00344249 -- -- -- -- -- Recharge (SWB)

-- USC00411408 -- -- -- -- -- Recharge (SWB)

348299 USC00348299 -- -- -- -- -- Recharge (SWB)

-- USC00340179 -- -- -- -- -- Recharge (SWB)

-- USC00342849 -- -- -- -- -- Recharge (SWB)

Continuous water-level recorder wells (U.S. Geological Survey, 2015a)

CR1 351521099522901 117 -- -- -- -- --

CR2 350755099283201 75.4 -- -- -- -- --

CR3 345759099163401 59.45 -- -- -- -- Recharge (WTF)

Geoprobe hydraulic profiling tool test holes

HPT1 351800099524801 18.9 -- -- -- -- Hydraulic properties

HPT2 351759099492401 40.4 -- -- -- -- Hydraulic properties

HPT4 351552099414001 25.0 -- -- -- -- Hydraulic properties

HPT5 350949099302701 30.9 -- -- -- -- Hydraulic properties

Multi-well aquifer test locations (Kent, 1980; Paukstaitis, 1981; U.S. Geological Survey, 2015a)

AT2 351339099424001 -- -- -- -- -- Hydraulic properties

AT3 351438099370801 -- -- -- -- -- Hydraulic properties

AT1 351657099584701 -- -- -- -- -- Hydraulic properties

AT4 -- -- -- -- -- -- Hydraulic properties

Water-quality stations (Oklahoma Water Resources Board, 2015c)

-- 93413 -- -- -- -- -- Groundwater quality

-- 44829 -- -- -- -- -- Groundwater quality

-- 124090 -- -- -- -- -- Groundwater quality

-- 78679 -- -- -- -- -- Groundwater quality

-- 21104 -- -- -- -- -- Groundwater quality

-- 53182 -- -- -- -- -- Groundwater quality

-- 89166 -- -- -- -- -- Groundwater quality

-- 52044 -- -- -- -- -- Groundwater quality

-- 57632 -- -- -- -- -- Groundwater quality

-- 27186 -- -- -- -- -- Groundwater quality

-- 148351 -- -- -- -- -- Groundwater quality
94 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

-- 27136 NFRED-023 35.266728 -99.634720 Beckham July–August, 2014 --

-- 44825 NFRED-024 35.267222 -99.796015 Beckham July–August, 2014 --

-- 21131 NFRED-036 35.246866 -99.679087 Beckham July–August, 2014 --

-- 80060 NFRED-044 35.339491 -99.778398 Beckham July–August, 2014 --

-- 118864 NFRED-052 35.205117 -99.725950 Beckham July–August, 2014 --

-- 21327 NFRED-070 35.298109 -99.857739 Beckham July–August, 2014 --

-- 21540 NFRED-073 34.893647 -99.335095 Greer July–August, 2014 --

-- 80000 NFRED-078 35.299360 -99.823090 Beckham July–August, 2014 --

-- 118145 NFRED-098 35.288040 -99.704080 Beckham July–August, 2014 --

Water-quality stations (U.S. Geological Survey, 2015a)

-- 343755099061001 02N-18W-21 BD 1 34.632016 -99.103135 Jackson 9/1/1947 --

-- 343920098584001 02N-17W-10 C 1 34.655626 -98.978132 Kiowa 8/15/1958 --

-- 344037099032901 02N-18W-02 A 1 34.677014 -99.058412 Kiowa 8/8/1959 --

-- 344037099032902 02N-18W-02 A 2 34.677014 -99.058412 Kiowa 8/8/1959 --

-- 344100098581001 03N-17W-34 CCD 1 34.683402 -98.969798 Kiowa 2/15/1961 --

-- 345400099166501 05N-20W-24 B 1 34.900060 -99.268416 Kiowa 8/4/1959 --

-- 345450099282501 05N-22W-13 AAA 1 34.913948 -99.473977 Greer 12/23/1953 --

-- 345820099164501 06N-20W-26 A 1 34.972280 -99.279526 Kiowa 4/25/1961 --

-- 351218099394501 09N-23W-32 CCC 1 35.205052 -99.662874 Beckham 2/26/1952 --

-- 351301099485301 09N-25W-35 BAA 4 35.216996 -99.815102 Beckham 2/26/1952 --

-- 351312099513501 09N-25W-29 DDD 1 35.220052 -99.860103 Beckham 2/27/1952 --

-- 351336099341901 09N-22W-30 CBA 1 35.226718 -99.572316 Beckham 11/1/1951 --

-- 351336099342401 09N-22W-30 BCD 1 35.226718 -99.573705 Beckham 11/1/1951 --

-- 351339099424001 09N-24W-26 BDA 1 35.227551 -99.711487 Beckham 11/15/1954 --

-- 351439099364001 09N-23W-23 BBC 1 35.244218 -99.611484 Beckham 11/1/1951 --

-- 351447099542001 09N-26W-19 AAA 1 35.246441 -99.905939 Beckham 3/5/1952 --

-- 351520099404001 09N-23W-07 CB 1 35.255607 -99.678153 Beckham 11/28/1962 --

-- 351555099431401 09N-24W-10 DDD 1 35.265329 -99.720933 Beckham 2/14/1952 --

-- 351614099383602 09N-23W-09 BCD 2 35.270607 -99.643708 Beckham 11/2/1951 --

-- 351657099584701 09N-26W-05 CAB 1 35.282552 -99.980108 Beckham 12/7/1954 --

-- 351800099510001 10N-25W-35 CBB 1 35.300051 -99.850382 Beckham 3/2/1952 --

Water-table-altitude observation and Mass Measurement Program wells (Oklahoma Water Resources Board, 2015b); 

Land-surface elevations from U.S. Geological Survey (2015b)

9088 350727099274901 08N-21W-31 CBB 1 35.123125 -99.464492 Beckham 3/5/1980 present 

(2015)

1,734.8

9089 350839099303001 08N-22W-27 AAD 1 35.142600 -99.501253 Beckham 3/5/1980 present 

(2015)

1,706.7

9090 351030099385401 08N-23W-17 AAB 1 35.174764 -99.649906 Beckham 3/6/1980 present 

(2015)

1,906.0

9092 351122099435501 08N-24W-09 AAB 1 35.189406 -99.734072 Beckham 3/6/1980 1/20/2000 1,954.1
Table 1 95

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

-- 27136 -- -- -- -- -- Groundwater quality

-- 44825 -- -- -- -- -- Groundwater quality

-- 21131 -- -- -- -- -- Groundwater quality

-- 80060 -- -- -- -- -- Groundwater quality

-- 118864 -- -- -- -- -- Groundwater quality

-- 21327 -- -- -- -- -- Groundwater quality

-- 21540 -- -- -- -- -- Groundwater quality

-- 80000 -- -- -- -- -- Groundwater quality

-- 118145 -- -- -- -- -- Groundwater quality

Water-quality stations (U.S. Geological Survey, 2015a)

-- 343755099061001 9 -- -- -- -- Groundwater quality

-- 343920098584001 50 -- -- -- -- Groundwater quality

-- 344037099032901 -- -- -- -- -- Groundwater quality

-- 344037099032902 -- -- -- -- -- Groundwater quality

-- 344100098581001 53 -- -- -- -- Groundwater quality

-- 345400099166501 70 -- -- -- -- Groundwater quality

-- 345450099282501 35 -- -- -- -- Groundwater quality

-- 345820099164501 15 -- -- -- -- Groundwater quality

-- 351218099394501 63 -- -- -- -- Groundwater quality

-- 351301099485301 22 -- -- -- -- Groundwater quality

-- 351312099513501 49 -- -- -- -- Groundwater quality

-- 351336099341901 58 -- -- -- -- Groundwater quality

-- 351336099342401 60.3 -- -- -- -- Groundwater quality

-- 351339099424001 188 -- -- -- -- Groundwater quality

-- 351439099364001 95 -- -- -- -- Groundwater quality

-- 351447099542001 68 -- -- -- -- Groundwater quality

-- 351520099404001 36 -- -- -- -- Groundwater quality

-- 351555099431401 27 -- -- -- -- Groundwater quality

-- 351614099383602 60 -- -- -- -- Groundwater quality

-- 351657099584701 102 -- -- -- -- Groundwater quality

-- 351800099510001 -- -- -- -- -- Groundwater quality

Water-table-altitude observation and Mass Measurement Program wells (Oklahoma Water Resources Board, 2015b); 

Land-surface elevations from U.S. Geological Survey (2015b)

9088 350727099274901 76 -- -- -- -- Calibration

9089 350839099303001 50 -- -- -- -- Calibration

9090 351030099385401 80 -- -- -- -- Calibration

9092 351122099435501 142 -- -- -- -- Calibration
96 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

9093 351129099415601 08N-24W-02 DCD 1 35.190528 -99.699808 Beckham 1/21/1986 2/6/1990 1,921.3

9094 351215099292401 08N-22W-02 ABB 1 35.203983 -99.492533 Beckham 3/19/1981 present 

(2015)

1,852.6

9095 351216099483501 09N-25W-35 DDD 1 35.207297 -99.806075 Beckham 3/6/1980 2/8/2000 1,991.4

9096 351222099395801 09N-23W-32 CCB 1 35.207914 -99.661567 Beckham 3/5/1980 present 

(2015)

1,882.7

9097 351242099420601 09N-24W-36 BCC 1 35.212608 -99.698836 Beckham 3/7/1980 2/6/1990 1,918.5

9098 351301099323301 09N-22W-33 BBB 1 35.217650 -99.540775 Beckham 3/5/1980 present 

(2015)

1,781.2

9099 351306099515501 09N-26W-33 BBB 1 35.218147 -99.963903 Beckham 3/6/1980 2/21/1996 2,089.1

9100 351308099353601 09N-23W-25 CCD 1 35.219678 -99.591186 Beckham 3/17/1981 present 

(2015)

1,853.0

9101 351327099595901 09N-26W-30 CBA 1 35.225547 -99.995850 Beckham 3/6/1980 present 

(2015)

2,146.7

9102 351334099344001 09N-22W-30 BCC 1 35.226989 -99.575067 Beckham 3/5/1980 1/27/1998 1,786.7

9103 351347099324101 09N-22W-29 AAD 1 35.230336 -99.542769 Beckham 3/5/1980 2/22/1996 1,765.1

9104 351353099383101 09N-23W-28 BAA 1 35.232681 -99.639411 Beckham 3/5/1980 2/13/1991 1,890.4

9105 351353099482701 09N-25W-25 BBB 1 35.233372 -99.805669 Beckham 3/6/1980 3/9/1999 2,008.3

9106 351400099533501 09N-25W-31 BCB 1 35.214633 -99.893617 Beckham 3/6/1980 1/28/2013 2,031.2

9107 351402099533501 09N-25W-19 CCC 1 35.234356 -99.894219 Beckham 3/6/1980 3/19/2001 1,995.0

9108 351413099451601 09N-24W-21 CBC 2 35.237525 -99.752531 Beckham 3/7/1980 2/23/2014 1,930.7

9109 351426099372701 09N-23W-22 BDD 1 35.246361 -99.621225 Beckham 3/5/1980 1/30/2013 1,860.2

9110 351433099544101 09N-26W-24 BCA 1 35.242552 -99.911772 Beckham 3/6/1980 2/21/1996 2,041.2

9111 351446099362401 09N-23W-23 BAA 2 35.246162 -99.607039 Beckham 3/5/1980 2/22/1996 1,840.6

9112 351452099494701 09N-25W-15 DDC 1 35.249042 -99.826822 Beckham 3/6/1980 3/14/1994 2,006.5

9113 351512099411001 09N-24W-13 DAA 1 35.254786 -99.683769 Beckham 3/19/1981 3/17/2010 1,859.0

9114 351512099472401 09N-24W-18 CBB 1 35.255353 -99.788100 Beckham 3/6/1980 2/24/2012 1,937.5

9115 351518099375901 09N-23W-16 ADD 1 35.255078 -99.629367 Beckham 3/19/1981 1/20/2000 1,863.1

9116 351525099560801 09N-26W-15 ADB 2 35.258089 -99.932758 Beckham 3/6/1980 3/9/1999 1,999.2

9117 351557099522601 09N-25W-08 CAC 1 35.265885 -99.874271 Beckham 3/6/1980 2/21/1996 2,000.9

9118 351617099482701 09N-25W-12 BCB 1 35.271667 -99.803819 Beckham 3/6/1980 1/1/2007 1,971.4

9119 351617099590301 09N-26W-08 BCB 1 35.271756 -99.981142 Beckham 3/6/1980 3/17/2010 2,065.4

9120 351637099521001 09N-25W-05 DCC 1 35.277417 -99.868419 Beckham 3/6/1980 3/7/2007 1,986.8

9121 351755099563201 10N-26W-34 BDD 1 35.298663 -99.942607 Beckham 3/6/1980 3/10/1999 2,032.1

9122 352328099560001 11N-26W-34 AAA 1 35.393153 -99.929408 Beckham 3/6/1980 present 

(2015)

2,100.9

9123 352426099572801 11N-26W-21 DCC 1 35.408200 -99.955608 Beckham 3/6/1980 present 

(2015)

2,104.2

9438 345356099212801 05N-20W-19 BBB 1 34.899881 -99.356489 Greer 2/27/1980 2/11/2014 1,525.9

9439 345356099224001 05N-21W-23 AAA 1 34.899736 -99.379369 Greer 2/27/1980 2/20/2001 1,532.7
Table 1 97

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

9093 351129099415601 -- -- -- -- -- Calibration

9094 351215099292401 210 -- -- -- -- Calibration

9095 351216099483501 86 -- -- -- -- Calibration

9096 351222099395801 -- -- -- -- -- Calibration

9097 351242099420601 123 -- -- -- -- Calibration

9098 351301099323301 74 -- -- -- -- Calibration

9099 351306099515501 33 -- -- -- -- Calibration

9100 351308099353601 148 -- -- -- -- Calibration

9101 351327099595901 70 -- -- -- -- Calibration

9102 351334099344001 67 -- -- -- -- Calibration

9103 351347099324101 64 -- -- -- -- Calibration

9104 351353099383101 -- -- -- -- -- Calibration

9105 351353099482701 100 -- -- -- -- Calibration

9106 351400099533501 35 -- -- -- -- Calibration

9107 351402099533501 36 -- -- -- -- Calibration

9108 351413099451601 59 -- -- -- -- Calibration

9109 351426099372701 -- -- -- -- -- Calibration

9110 351433099544101 217 -- -- -- -- Calibration

9111 351446099362401 113 -- -- -- -- Calibration

9112 351452099494701 -- -- -- -- -- Calibration

9113 351512099411001 30 -- -- -- -- Calibration

9114 351512099472401 120 -- -- -- -- Calibration

9115 351518099375901 130 -- -- -- -- Calibration

9116 351525099560801 150 -- -- -- -- Calibration

9117 351557099522601 160 -- -- -- -- Calibration

9118 351617099482701 130 -- -- -- -- Calibration

9119 351617099590301 63 -- -- -- -- Calibration

9120 351637099521001 -- -- -- -- -- Calibration

9121 351755099563201 -- -- -- -- -- Calibration

9122 352328099560001 32 -- -- -- -- Calibration

9123 352426099572801 90 -- -- -- -- Calibration

9438 345356099212801 49 -- -- -- -- Calibration

9439 345356099224001 50 -- -- -- -- Calibration
98 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

9440 345403099202501 05N-20W-17 CCC 1 34.900893 -99.340640 Greer 2/27/1980 3/8/1996 1,532.3

9441 345409099220801 05N-21W-13 CDA 1 34.902560 -99.369252 Greer 2/27/1980 3/8/1996 1,531.0

9442 345554099281201 05N-22W-12 DCD 1 34.914747 -99.471750 Greer 2/27/1980 1/13/2006 1,567.4

9443 345514099240701 05N-21W-10 DBB 1 34.920614 -99.402308 Greer 3/10/1983 3/8/1996 1,554.4

9444 345528099255801 05N-21W-08 ADB 1 34.925200 -99.433750 Greer 2/27/1980 present 

(2015)

1,553.6

9445 345541099193001 05N-20W-08 AAA 1 34.928114 -99.325361 Greer 2/27/1980 1/29/1998 1,584.4

9446 345547099302701 05N-22W-03 DCC 1 34.929780 -99.507867 Greer 2/27/1980 3/8/1996 1,547.0

9447 345554099313001 05N-22W-04 DCB 1 34.931589 -99.528775 Greer 2/27/1980 1/19/2005 1,551.9

9448 345758099345601 06N-23W-25 BDC 1 34.965875 -99.585192 Greer 3/28/1980 present 

(2015)

1,629.2

9449 345818099413201 06N-24W-25 BBAC 1 34.971722 -99.692596 Greer 2/28/1980 3/12/1997 1,625.7

9450 350055099204901 06N-20W-07 ABA 1 35.015747 -99.348425 Greer 3/3/1980 present 

(2015)

1,658.8

9451 350121099232701 06N-21W-02 CBA 1 35.022844 -99.392531 Greer 3/8/1980 present 

(2015)

1,679.7

9452 350239099265301 07N-21W-31 AAA 1 35.044278 -99.449364 Greer 3/3/1980 3/14/2000 1,689.1

9453 350411099274101 07N-21W-19 BCA 1 35.069522 -99.465514 Greer 3/26/1981 present 

(2015)

1,750.4

9454 350457099254201 07N-21W-16 CCB 1 35.076222 -99.429422 Greer 3/5/1980 present 

(2015)

1,709.3

9455 350457099271701 07N-21W-18 ACC 1 35.082554 -99.455088 Greer 3/5/1980 3/15/1994 1,751.1

9456 350516099243901 07N-21W-15 BBB 1 35.086775 -99.411875 Greer 3/5/1980 1/1/2004 1,712.7

9457 350516099282801 07N-22W-13 BAA 1 35.086892 -99.475683 Greer 3/5/1980 3/22/1995 1,769.7

9458 350523099303501 07N-22W-10 CDD 1 35.088972 -99.503475 Greer 3/5/1980 present 

(2015)

1,792.1

9459 350529099255801 07N-21W-08 DDB 1 35.091443 -99.433143 Greer 3/5/1980 3/11/1996 1,719.4

9460 350615099242301 07N-21W-03 CDC 1 35.102453 -99.406267 Greer 3/5/1980 present 

(2015)

1,651.0

9461 350641099274901 07N-21W-06 BCC 1 35.109575 -99.465675 Greer 3/5/1980 1/1/2007 1,747.1

9462 350701099302701 07N-22W-03 ABB 1 35.115958 -99.508781 Greer 3/5/1980 1/1/2004 1,779.7

9502 344637099152801 04N-20W-36 BDC 1 34.777009 -99.258140 Jackson 3/14/1979 3/31/1994 1,689.4

9533 343820098592501 02N-17W-16 DCC 1 34.638960 -98.990632 Kiowa 1/1/1975 1/5/2003 1,330.8

9534 343846099000501 02N-17W-17 ADD 1 34.644542 -99.001514 Kiowa 3/27/1979 present 

(2015)

1,321.8

9535 343903098580001 02N-17W-15 AAA 1 34.652414 -98.968122 Kiowa 3/27/1979 present 

(2015)

1,342.2

9536 343913098564801 02N-17W-12 CCC 1 34.653158 -98.949856 Kiowa 3/27/1979 1/14/2015 1,350.5

9537 343913098592601 02N-17W-09 DCC 1 34.653682 -98.990910 Kiowa 3/24/1981 3/4/1994 1,329.5

9538 344005098591001 02N-17W-04 DDC 1 34.667011 -98.987122 Kiowa 3/24/1981 2/18/2014 1,337.6
Table 1 99

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

9440 345403099202501 58 -- -- -- -- Calibration

9441 345409099220801 50 -- -- -- -- Calibration

9442 345554099281201 -- -- -- -- -- Calibration

9443 345514099240701 66 -- -- -- -- Calibration

9444 345528099255801 52 -- -- -- -- Calibration

9445 345541099193001 57 -- -- -- -- Calibration

9446 345547099302701 28 -- -- -- -- Calibration

9447 345554099313001 24 -- -- -- -- Calibration

9448 345758099345601 47 -- -- -- -- Calibration

9449 345818099413201 24 -- -- -- -- Calibration

9450 350055099204901 52 -- -- -- -- Calibration

9451 350121099232701 75 -- -- -- -- Calibration

9452 350239099265301 68 -- -- -- -- Calibration

9453 350411099274101 67 -- -- -- -- Calibration

9454 350457099254201 71 -- -- -- -- Calibration

9455 350457099271701 -- -- -- -- -- Calibration

9456 350516099243901 -- -- -- -- -- Calibration

9457 350516099282801 82 -- -- -- -- Calibration

9458 350523099303501 72 -- -- -- -- Calibration

9459 350529099255801 70 -- -- -- -- Calibration

9460 350615099242301 49 -- -- -- -- Calibration

9461 350641099274901 -- -- -- -- -- Calibration

9462 350701099302701 113 -- -- -- -- Calibration

9502 344637099152801 -- -- -- -- -- Calibration

9533 343820098592501 55 -- -- -- -- Calibration

9534 343846099000501 40 -- -- -- -- Calibration

9535 343903098580001 45 -- -- -- -- Calibration

9536 343913098564801 48 -- -- -- -- Calibration

9537 343913098592601 49 -- -- -- -- Calibration

9538 344005098591001 44 -- -- -- -- Calibration
100 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

9539 344149098582301 03N-17W-27 DCC 1 34.696044 -98.973492 Kiowa 3/27/1979 present 

(2015)

1,351.8

9540 344210098593501 03N-17W-28 CA 1 34.700344 -98.992775 Kiowa 1/28/1976 present 

(2015)

1,353.7

9542 344637099085401 04N-19W-36 ACC 1 34.777009 -99.148692 Kiowa 3/24/1981 1/16/1996 1,398.3

9543 344745099083001 04N-19W-25 AAA 1 34.797353 -99.141792 Kiowa 3/13/1979 present 

(2015)

1,408.9

9544 344821099082201 04N-18W-19 BCC 1 34.804831 -99.141456 Kiowa 3/13/1979 3/22/1999 1,405.1

9545 345659099162001 06N-20W-35 DAA 1 34.950294 -99.272633 Kiowa 1/1/1977 present 

(2015)

1,561.7

9546 345732099181801 06N-20W-27 CCC 1 34.958947 -99.305360 Kiowa 1/1/1977 3/22/1995 1,578.9

9547 345751099185801 06N-20W-28 CAA 1 34.964224 -99.316472 Kiowa 3/8/1979 3/11/1996 1,570.4

9548 345818099193001 06N-20W-29 AAA 1 34.971724 -99.325361 Kiowa 3/27/1979 2/4/2003 1,572.7

9549 345824099165901 06N-20W-23 CDC 1 34.972561 -99.285403 Kiowa 1/1/1977 present 

(2015)

1,591.1

9550 345824099185001 06N-20W-21 DCC 2 35.004878 -99.315158 Kiowa 1/1/1977 3/25/2010 1,587.5

9551 345831099191401 06N-20W-21 CCA 1 34.976347 -99.320603 Kiowa 1/1/1977 2/5/2003 1,580.2

9552 345844099193001 06N-20W-20 DAA 1 34.978946 -99.325361 Kiowa 1/1/1977 2/4/2003 1,577.6

9553 345857099193001 06N-20W-20 ADA 2 34.983828 -99.325422 Kiowa 3/8/1977 present 

(2015)

1,582.4

Water-table-altitude observation wells (U.S. Geological Survey, 2015a); Land-surface elevations from U.S. Geological Survey (2015b)

-- 351125099414301 08N-24W-02 DDD 1 35.190330 -99.695653 Beckham 3/3/1952 1/8/1985 1,917.1

-- 350806099302701 08N-22W-27 DCB 1 35.135053 -99.507868 Beckham 4/8/1980 1,732.2

-- 352525099543501 11N-26W-13 CCC 1 35.423661 -99.910109 Roger 

Mills

11/5/1980 2,164.4

-- 351646099515801 09N-25W-05 D 1 35.279496 -99.866493 Beckham 2/18/1981 1,960.3

-- 352433099550501 11N-26W-23 DDB 1 35.409217 -99.918442 Beckham 8/23/1981 2,156.1

-- 350809099304701 08N-22W-27 C 1 35.135887 -99.513424 Beckham 8/31/1981 1,738.5

-- 351518099535301 09N-26W-13 ADD 1 35.255052 -99.898438 Beckham 10/23/1981 2,017.0

-- 345348099292601 05N-22W-23 ABCC 1 34.897281 -99.493422 Greer 5/15/1986 10/13/1987 1,590.6

-- 343819099060001 02N-18W-16 CDC 1 34.638517 -99.100017 Kiowa 9/10/2003 1,312.9

-- 343851099055401 02N-18W-16 BDA 1 34.647383 -99.098317 Jackson 9/10/2003 1,314.4

-- 352035099570501 10N-26W-16 ACD 1 35.343125 -99.951464 Beckham 12/5/2012 2,048.8

-- 352100099593201 10N-26W-07 CDD 1 35.350089 -99.992344 Beckham 12/5/2012 2,102.4

-- 351438099513101 09N-25W-21 BCB 1 35.243983 -99.858708 Beckham 12/6/2012 2,034.2

-- 351453099502901 09N-25W-16 DDD 1 35.248236 -99.841428 Beckham 12/6/2012 2,030.9

-- 351534099563201 09N-26W-15 BAC 1 35.259503 -99.942417 Beckham 12/6/2012 2,000.1

-- 351545099522001 09N-25W-08 CCD 1 35.262664 -99.872258 Beckham 12/6/2012 2,012.3

-- 351639099472301 09N-25W-01 DDD 1 35.277656 -99.789989 Beckham 12/6/2012 1,946.1

-- 351232099424901 09N-24W-34 DAD 1 35.208953 -99.713631 Beckham 12/7/2012 1,932.1
Table 1 101

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

9539 344149098582301 61 -- -- -- -- Calibration

9540 344210098593501 40 -- -- -- -- Calibration

9542 344637099085401 -- -- -- -- -- Calibration

9543 344745099083001 31 -- -- -- -- Calibration

9544 344821099082201 23 -- -- -- -- Calibration

9545 345659099162001 -- -- -- -- -- Calibration

9546 345732099181801 38 -- -- -- -- Calibration

9547 345751099185801 57 -- -- -- -- Calibration

9548 345818099193001 62 -- -- -- -- Calibration

9549 345824099165901 38 -- -- -- -- Calibration

9550 345824099185001 59 -- -- -- -- Calibration

9551 345831099191401 66 -- -- -- -- Calibration

9552 345844099193001 64 -- -- -- -- Calibration

9553 345857099193001 68 -- -- -- -- Calibration

Water-table-altitude observation wells (U.S. Geological Survey, 2015a); Land-surface elevations from U.S. Geological Survey (2015b)

-- 351125099414301 29 -- -- -- -- Calibration

-- 350806099302701 30 -- -- -- -- Calibration

-- 352525099543501 89.5 -- -- -- -- Calibration

-- 351646099515801 40 -- -- -- -- Calibration

-- 352433099550501 215 -- -- -- -- Calibration

-- 350809099304701 56 -- -- -- -- Calibration

-- 351518099535301 70 -- -- -- -- Calibration

-- 345348099292601 50 -- -- -- -- Calibration

-- 343819099060001 19.88 -- -- -- -- Calibration

-- 343851099055401 17.5 -- -- -- -- Calibration

-- 352035099570501 -- -- -- -- -- Calibration

-- 352100099593201 65 -- -- -- -- Calibration

-- 351438099513101 220 -- -- -- -- Calibration

-- 351453099502901 150 -- -- -- -- Calibration

-- 351534099563201 150 -- -- -- -- Calibration

-- 351545099522001 173 -- -- -- -- Calibration

-- 351639099472301 100 -- -- -- -- Calibration

-- 351232099424901 110 -- -- -- -- Calibration
102 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

-- 351327099363701 09N-23W-26 CBB 1 35.224406 -99.610497 Beckham 12/7/2012 1,870.9

-- 350201099244001 07N-21W-34 CBC 1 35.033611 -99.411139 Greer 12/11/2012 1,650.9

-- 350244099281601 07N-22W-25 DCD 1 35.045678 -99.471278 Greer 12/11/2012 1,710.8

-- 350541099275501 07N-21W-07 BCC 1 35.094931 -99.465492 Greer 12/11/2012 1,759.3

-- 350701099302301 08N-22W-34 DCD 1 35.117100 -99.506450 Beckham 12/11/2012 1,781.3

-- 345737099343801 06N-23W-25 DCA 1 34.960497 -99.577417 Greer 12/12/2012 1,619.7

-- 351120099325101 08N-22W-08 BAB 1 35.189100 -99.547739 Beckham 12/17/2012 1,765.4

-- 351213099304801 08N-22W-03 BAB 1 35.203875 -99.513478 Beckham 12/17/2012 1,800.4

-- 351402099304001 09N-22W-22 DCD 1 35.234078 -99.511275 Beckham 12/17/2012 1,837.7

-- 350010099220001 06N-21W-12 DCD 1 35.002953 -99.366808 Greer 12/18/2012 1,678.0

-- 350029099212001 06N-20W-07 CAB 1 35.008317 -99.355772 Greer 12/18/2012 1,670.6

-- 350051099214001 06N-21W-12 AAA 1 35.014203 -99.361208 Greer 12/18/2012 1,662.7

-- 350214099213701 07N-21W-36 ADD 1 35.037356 -99.360406 Greer 12/18/2012 1,663.1

-- 350238099234401 07N-21W-27 DDD 1 35.044142 -99.395794 Greer 12/18/2012 1,628.5

-- 350412099234301 07N-21W-22 AAD 1 35.070189 -99.395450 Greer 12/18/2012 1,701.6

-- 350846099300701 08N-22W-22 DDD 1 35.146281 -99.502092 Beckham 12/18/2012 1,697.6

-- 350921099342001 08N-23W-24 ADA 1 35.155956 -99.572406 Beckham 12/18/2012 1,711.7

-- 345541099164901 05N-20W-11 ABB 1 34.928217 -99.280411 Kiowa 12/19/2012 1,571.6

-- 345729099182401 06N-20W-27 CCC 2 34.958097 -99.306928 Kiowa 12/19/2012 1,577.4

-- 345811099193101 06N-20W-29 AAD 1 34.969992 -99.325297 Kiowa 12/19/2012 1,573.3

-- 350332099203301 07N-20W-20 CCC 1 35.058936 -99.342739 Kiowa 12/19/2012 1,622.5

-- 350337099210401 07N-20W-19 DCC 1 35.060294 -99.351219 Kiowa 12/19/2012 1,613.9

-- 350356099204801 07N-20W-19 DAB 1 35.065689 -99.346842 Kiowa 12/19/2012 1,620.7

-- 345451099155801 05N-20W-13 BAB 1 34.914267 -99.266247 Kiowa 12/20/2012 1,530.7

-- 344843099095701 04N-19W-14 DCD 1 34.812125 -99.165892 Jackson 1/7/2013 1,437.5

-- 344845099121101 04N-19W-16 DCC 1 34.812525 -99.203142 Jackson 1/7/2013 1,509.7

-- 345032099110801 04N-19W-03 CDD 1 34.842233 -99.185778 Jackson 1/7/2013 1,471.5

-- 345054099111801 04N-19W-03 CAB 1 34.848569 -99.188369 Jackson 1/7/2013 1,430.7

-- 344220099154801 03N-20W-25 BCB 1 34.705689 -99.263383 Jackson 1/8/2013 1,411.5

-- 344327099172701 03N-20W-22 BAA 1 34.724206 -99.291000 Jackson 1/8/2013 1,453.3

-- 344636099180901 04N-20W-33 ADC 1 34.776669 -99.302522 Jackson 1/8/2013 1,530.4

-- 344650099144801 04N-20W-36 AAD 1 34.780661 -99.246892 Jackson 1/8/2013 1,650.4

-- 344838099173001 04N-20W-22 BAA 1 34.810808 -99.291836 Jackson 1/8/2013 1,556.8

-- 343840099011201 02N-17W-18 DAA 1 34.644536 -99.020244 Kiowa 1/9/2013 1,369.9

-- 343910099041501 02N-18W-11 CCC 1 34.652836 -99.070872 Jackson 1/9/2013 1,399.0

-- 344054099045301 03N-18W-34 CDD 1 34.681694 -99.081556 Jackson 1/9/2013 1,349.8

-- 344152099021001 03N-18W-25 DDA 1 34.697925 -99.036108 Kiowa 1/9/2013 1,359.7

-- 351806099442501 10N-24W-33 ACA 1 35.301775 -99.740531 Beckham 1/10/2013 1,936.5

-- 351932099430401 10N-24W-22 DAA 1 35.325736 -99.717928 Beckham 1/10/2013 2,010.2
Table 1 103

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

-- 351327099363701 145 -- -- -- -- Calibration

-- 350201099244001 40 -- -- -- -- Calibration

-- 350244099281601 47 -- -- -- -- Calibration

-- 350541099275501 72 -- -- -- -- Calibration

-- 350701099302301 127 -- -- -- -- Calibration

-- 345737099343801 60 -- -- -- -- Calibration

-- 351120099325101 50 -- -- -- -- Calibration

-- 351213099304801 56 -- -- -- -- Calibration

-- 351402099304001 65 -- -- -- -- Calibration

-- 350010099220001 67 -- -- -- -- Calibration

-- 350029099212001 81 -- -- -- -- Calibration

-- 350051099214001 67 -- -- -- -- Calibration

-- 350214099213701 39 -- -- -- -- Calibration

-- 350238099234401 30 -- -- -- -- Calibration

-- 350412099234301 57 -- -- -- -- Calibration

-- 350846099300701 50 -- -- -- -- Calibration

-- 350921099342001 40 -- -- -- -- Calibration

-- 345541099164901 53.5 -- -- -- -- Calibration

-- 345729099182401 39.4 -- -- -- -- Calibration

-- 345811099193101 -- -- -- -- -- Calibration

-- 350332099203301 65 -- -- -- -- Calibration

-- 350337099210401 33 -- -- -- -- Calibration

-- 350356099204801 16.5 -- -- -- -- Calibration

-- 345451099155801 29.5 -- -- -- -- Calibration

-- 344843099095701 30 -- -- -- -- Calibration

-- 344845099121101 54.28 -- -- -- -- Calibration

-- 345032099110801 33.5 -- -- -- -- Calibration

-- 345054099111801 25 -- -- -- -- Calibration

-- 344220099154801 43.2 -- -- -- -- Calibration

-- 344327099172701 44.5 -- -- -- -- Calibration

-- 344636099180901 -- -- -- -- -- Calibration

-- 344650099144801 40 -- -- -- -- Calibration

-- 344838099173001 72 -- -- -- -- Calibration

-- 343840099011201 22.9 -- -- -- -- Calibration

-- 343910099041501 32.6 -- -- -- -- Calibration

-- 344054099045301 21 -- -- -- -- Calibration

-- 344152099021001 15.9 -- -- -- -- Calibration

-- 351806099442501 -- -- -- -- -- Calibration

-- 351932099430401 37.1 -- -- -- -- Calibration
104 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

-- 344321099155401 03N-20W-23 AAD 1 34.722664 -99.265144 Jackson 1/16/2013 1,454.5

-- 344512099155301 03N-20W-11 AAA 1 34.753414 -99.264967 Jackson 1/16/2013 1,590.8

-- 344550099170601 03N-20W-03 ADC 1 34.763994 -99.285161 Jackson 1/16/2013 1,537.2

-- 344756099154801 04N-20W-24 CCC 1 34.798928 -99.263528 Jackson 1/16/2013 1,677.0

-- 344912099081001 04N-18W-18 BDC 1 34.820011 -99.136289 Kiowa 1/16/2013 1,410.6

-- 345013099073001 04N-18W-07 ADA 1 34.837200 -99.125219 Kiowa 1/16/2013 1,423.3

-- 343923099062601 02N-18W-08 DAD 1 34.656511 -99.105592 Kiowa 1/17/2013 1,331.2

-- 343934099042101 02N-18W-10 DAA 1 34.659456 -99.072736 Kiowa 1/17/2013 1,336.6

-- 343934099044401 02N-18W-10 DBB 1 34.659697 -99.079031 Kiowa 1/17/2013 1,334.9

-- 345819099075301 06N-18W-19 DDD 1 34.972092 -99.131547 Kiowa 1/17/2013 1,492.3

-- 350755099283201 08N-22W-25 CDD 1 NFRR 02 35.132094 -99.475564 Beckham 4/16/2013 1/15/2015 1,732.2

-- 351521099522901 09N-25W-17 BCC NFRR 01 35.255967 -99.874842 Beckham 4/16/2013 1/15/2015 2,022.8

Historical water-table-altitude observation wells (U.S. Geological Survey, 2015a)

10 351125099414301 08N-24W-02 DDD 1 35.190330 -99.695653 Beckham 3/3/1952 1/8/1985 --

1 351636099375001 09N-23W-04 DDD 1 35.276718 -99.630930 Beckham 2/27/1952 8/28/1957 --

53 351619099384501 09N-23W-09 BCB 1 35.271996 -99.646208 Beckham 6/24/1953 5/17/1967 --

40 351727099492501 09N-25W-03 AAA 1 35.290885 -99.823992 Beckham 12/3/1951 8/25/1959 --

35 (9107) 351402099533501 09N-25W-19 CCC 1 35.233941 -99.893438 Beckham 11/15/1951 2/14/1973 --

32 (9106) 351400099533501 09N-25W-31 BCB 1 35.233386 -99.893438 Beckham 11/15/1951 8/19/1986 --

27 351306099564601 09N-25W-34 BBB 1 35.218386 -99.946495 Beckham 8/29/1951 10/8/1969 --

49 (9119) 351617099585201 09N-26W-08 BCB 1 35.271441 -99.981497 Beckham 11/6/1951 12/29/1970 --

47 351306099515501 09N-26W-33 BBB 1 35.218385 -99.865659 Beckham 11/7/1951 12/29/1970 --

33 351215099552001 09N-26W-36 CDC 1 35.204219 -99.922605 Beckham 11/8/1951 6/26/1962 --

Synoptic streamflow measurement station (U.S. Geological Survey, 2015a)

-- 07301300 North Fork Red River near 

Shamrock, TX

35.264216 -100.241786 Wheeler 3/11/2013 --

-- 07301315 North Fork Red River near 

Texola, OK

35.294497 -99.990109 Beckham 3/11/2013 --

-- 07301410 Sweetwater Creek near Kelton, 

TX

35.473104 -100.120950 Wheeler 3/11/2013 --

-- 07301420 Sweetwater Creek near 

Sweetwater, OK

35.422272 -99.969277 Beckham 3/11/2013 --

-- 07301425 Sweetwater Creek near Texas 

Line, OK

35.318663 -99.964831 Beckham 3/11/2013 --

-- 07301450 North Fork Red River near 

Erick, OK

35.300051 -99.875383 Beckham 3/13/2013 --

-- 073014505 Buffalo Creek near Prentiss, 

OK

35.384431 -99.828039 Beckham 3/13/2013 --

-- 07301452 Starvation Creek near Prentiss, 

OK

35.323662 -99.758713 Beckham 3/13/2013 --
Table 1 105

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

-- 344321099155401 73 -- -- -- -- Calibration

-- 344512099155301 73.75 -- -- -- -- Calibration

-- 344550099170601 48.4 -- -- -- -- Calibration

-- 344756099154801 76 -- -- -- -- Calibration

-- 344912099081001 22 -- -- -- -- Calibration

-- 345013099073001 34.2 -- -- -- -- Calibration

-- 343923099062601 24 -- -- -- -- Calibration

-- 343934099042101 21 -- -- -- -- Calibration

-- 343934099044401 20.2 -- -- -- -- Calibration

-- 345819099075301 20.5 -- -- -- -- Calibration

-- 350755099283201 75.4 -- -- -- -- Calibration

-- 351521099522901 117 -- -- -- -- Calibration

Historical water-table-altitude observation wells (U.S. Geological Survey, 2015a)

10 351125099414301 29 -- -- -- -- --

1 351636099375001 33.4 -- -- -- -- --

53 351619099384501 23.7 -- -- -- -- --

40 351727099492501 40 -- -- -- -- --

35 (9107) 351402099533501 36 -- -- -- -- --

32 (9106) 351400099533501 34.8 -- -- -- -- --

27 351306099564601 78.6 -- -- -- -- --

49 (9119) 351617099585201 62.7 -- -- -- -- --

47 351306099515501 32.8 -- -- -- -- --

33 351215099552001 26.9 -- -- -- -- --

Synoptic streamflow measurement station (U.S. Geological Survey, 2015a)

-- 07301300 -- -- -- -- -- Streambed seepage

-- 07301315 -- -- -- -- -- Streambed seepage

-- 07301410 -- -- -- -- -- Streambed seepage

-- 07301420 -- -- -- -- -- Streambed seepage

-- 07301425 -- -- -- -- -- Streambed seepage

-- 07301450 -- -- -- -- -- Streambed seepage

-- 073014505 -- -- -- -- -- Streambed seepage

-- 07301452 -- -- -- -- -- Streambed seepage
106 Hydrogeology and Simulated Groundwater Flow and Availability in the North Fork Red River Aquifer, Southwest Okla.

Table 1. Selected data-collection stations in and near the North Fork Red River aquifer study area, southwest Oklahoma.—Continued

[NAVD 88, North American Vertical Datum of 1988; >, greater than; SFR, Streamflow-Routing package; LAK, Lake package; WTF, water-table fluctuation 

method; SWB, Soil-Water Balance; m/d/y, month/day/year; --, not applicable or unknown]

Map name1

(figs. 1–2)

Station 

identifier Station name

Latitude

(decimal 

degrees)

Longitude

(decimal 

degrees)

County

Period of record (may 

contain gaps) or single 

measurement date 

(m/d/y)

Landsurface 

altitude

(feet 

above 

NAVD 88) Begin End

-- 07301475 Long Creek at Sayre, OK 35.291369 -99.667100 Beckham 3/11/2013 --

-- 07301481 North Fork Red River near 

Sayre, OK

35.284773 -99.622041 Beckham 3/11/2013 --

-- 07301489 Timber Creek near Sayre, OK 35.291411 -99.581731 Beckham 3/11/2013 --

-- 07301500 North Fork Red River near 

Carter, OK

35.168108 -99.507313 Beckham 3/11/2013 --

-- 07301950 North Fork Red River blw 

Lake Ck nr Lake Creek, OK

35.053111 -99.371196 Greer 3/12/2013 --

-- 07302000 North Fork Red River near 

Granite, OK

34.973391 -99.333694 Kiowa 3/12/2013 --

-- 07303000 North Fork Red River blw 

Altus Dam nr Lugert, OK

34.889505 -99.307028 Greer 3/12/2013 --

-- 07303400 Elm Fork of North Fork Red 

River near Carl, OK

35.011720 -99.903714 Harmon 3/12/2013 --

-- 07303490 Elm Fork of North Fork Red 

River nr Bloomington OK

34.941731 -99.572319 Greer 3/12/2013 --

-- 07303493 Haystack Creek near 

Bloomington, OK

35.002361 -99.584050 Greer 3/12/2013 --

-- 07303500 Elm Fork of North Fork Red 

River nr Mangum, OK

34.926725 -99.500367 Greer 3/12/2013 --

-- 07303900 Elm Fork of North Fork Red 

River near Granite, OK

34.888600 -99.378869 Greer 3/12/2013 --

-- 07304000 North Fork Red River near 

Lugert, OK

34.865833 -99.310556 Kiowa 3/12/2013 --

-- 07304030 North Fork Red River near 

Warrenn, OK

34.826311 -99.229681 Jackson 3/13/2013 --

-- 07304480 Elk Creek at Hobart, OK 34.986731 -99.117489 Kiowa 3/12/2013 --

-- 07304600 Elk Creek near Roosevelt, OK 34.832039 -99.124661 Kiowa 3/13/2013 --

-- 07304800 North Fork Red River at SH 19 

near Warren, OK

34.783100 -99.165339 Jackson 3/13/2013 --

-- 07305000 North Fork Red River near 

Headrick, OK

34.638127 -99.103691 Tillman 3/12/2013 --

-- 07305500 West Otter Creek at Snyder Lk 

nr Mt Park, OK

34.733956 -98.986465 Kiowa 3/12/2013 --

-- 07307010 Otter Creek near Snyder, OK 34.637849 -98.998688 Kiowa 3/12/2013 --

1

Only sites discussed in this report are labeled on figures 1 and 2.
Table 1 107

Map name1

(figs. 1–2)

Station 

identifier

Well 

or hole 

depth

(feet)

Drainage area

(square miles) Regulated (> 20 percent of 

contributing drainage area 

behind large dams)

Use in numerical 

groundwater-flow 

Total model Contributing

Noncontributing 

-- 07301475 -- -- -- -- -- Streambed seepage

-- 07301481 -- -- -- -- -- Streambed seepage

-- 07301489 -- -- -- -- -- Streambed seepage

-- 07301500 -- -- -- -- -- Streambed seepage

-- 07301950 -- -- -- -- -- Streambed seepage

-- 07302000 -- -- -- -- -- Streambed seepage

-- 07303000 -- -- -- -- -- Streambed seepage

-- 07303400 -- -- -- -- -- Streambed seepage

-- 07303490 -- -- -- -- -- Streambed seepage

-- 07303493 -- -- -- -- -- Streambed seepage

-- 07303500 -- -- -- -- -- Streambed seepage

-- 07303900 -- -- -- -- -- Streambed seepage

-- 07304000 -- -- -- -- -- Streambed seepage

-- 07304030 -- -- -- -- -- Streambed seepage

-- 07304480 -- -- -- -- -- Streambed seepage

-- 07304600 -- -- -- -- -- Streambed seepage

-- 07304800 -- -- -- -- -- Streambed seepage

-- 07305000 -- -- -- -- -- Streambed seepage

-- 07305500 -- -- -- -- -- Streambed seepage

-- 07307010 -- -- -- -- -- Streambed seepage
For more information about this publication, contact

Director, Oklahoma Water Science Center

U.S. Geological Survey

202 NW 66th

Oklahoma City, OK 73116

For additional information visit 

https://www.usgs.gov/centers/ok-water/

Publishing support provided by

Lafayette Publishing Service Center
 
Smith and others—Hydrogeology and Simulated Groundwater Flow and Availability, Southwest Okla.—SIR 2017–5098 

ISSN 2328-031X (print)

ISSN 2328-0328 (online)

https://doi.org/10.3133/sir20175098