Analytical Study of Ogallala Aquifer in Randall County, Texas · ground-water resources, Randall...

TEXAS DEPARTMENT OF WATER RESOURCES

REPORT 250

ANALYTICAL STUDY OF THE OGALLALA AQUIFER IN RANDALL COUNTY, TEXAS

Projections of Saturated Thickness, Volume of Water in Storage,

Pumpage Rates, Pumping Lifts, and Well Yields

By

Ann E. Bell and Shelly Morrison

July 1980

TEXAS DEPARTMENT OF WATER RESOURCES

Harvey Davis, Executive Director

TEXAS WATER DEVELOPMENT BOARD

Louis A. Beecherl Jr., ChairmanGeorge W. McCleskeyGlen E. Roney

John H. Garrett, Vice ChairmanW. O. BankstonLonnie A. "Bo" Pilgrim

TEXAS WATER COMMISSION

Felix McDonald, Chairman Dorsey B. Hardeman, CommissionerJoe R. Carroll. Commissioner

Authorization for use or reproduction of any original material containedin this publicationl i.e., not obtained from other sources, is freely granted. TheDepartment would appreciate acknowledgement.

Published and distributedby the

Texas Department of Water ResourcesPost Office Box 13087Austin, Texas 78711

ii

TABLE OF CONTENTS

CONCLUSIONS

INTRODUCTION

PURPOSE AND SCOPE OF STUDY

NATURE OF THE OGALLALA AQUIFER.

General Geology .

Storage Properties

Natural Recharge and Irrigation Recirculation

PROCEDURES USED TO OBTAIN PROJECTIONS

Hydrologic Data Base . .

Projecting the Depletion of Saturated Thickness

Mapping Saturated Thickness, and CalculatingVolume of Water in Storage

Calculating Pumpage

Calculating Pumping Lifts.

Well-Yield Estimates. .

DISTINCTION BETWEEN PROJECTIONS AND PREDICTIONS.

TABLES AND MAPS PRESENTINGRESULTS OF THE STUDY

SATURATED THICKNESS AND VOLUME OF WATER IN THE OGALLALA AQUIFER

Table of Volume of Water in Storage Corresponding to

Mapped Saturated-Thickness Intervals, 1975.

Map Showing Estimated Saturated Thickness, 1975


Mapped Saturated-Thickness Intervals, 1980. . .

iii

Page

2

3

3

3

4

4

4

5

7

7

8

9

9

11

12

13

14

TABLE OF CONTENTS-Continued

Map Showing Projected Saturated Thickness, 1980


Mapped Saturated-Thickness Intervals, 1990.


Table of Volume of Water in Storage Corresponding toMapped Saturated-Thickness Intervals, 2000.


Table of Volume of Water in Storage Corresponding toMapped Saturated-Thickness Intervals, 2010 .


Table of Volume of Water in Storage Corresponding toMapped Saturated-Thickness Intervals, 2020.


POTENTIAL WELL YIELD OF THE OGALLALA AQUIFER.

Map Showing Estimated Potential Yield, 1975

Map Showing Projected Potential Yield, 1980





PUMPING LIFTS IN THE OGALLALA AQUIFER

Table of Surface Area Corresponding to MappedPumping-Lift Intervals, 1975 .

Map Showing Estimated Pumping Lifts, 1975

Table of Surface Area Corresponding to MappedPumping-Lift Intervals, 1980 .

Map Showins Projected Pumping Lifts, 1980

Table of Surface Area Corresponding to MappedPumping-Lift Intervals, 1990 _ _

Map Showing Projected Pumping Lifts, 1990

iv

Page

15

16

17

18

19

20

21

22

23

25

27

28

29

30

31

32

33

34

35

36

37

38

39


Table of Surface Area Corresponding to Mapped

Pumping-Lift Intervals, 2000 _


Table of Surface Area Corresponding to Mapped

Pumping-Lift Intervals, 2010 .

Map Showing Projected Pumping Lifts, 2010.

Table of Surface Area Corresponding to MappedPumping-Lift Intervals, 2020 _


PUMPAGE FROM THE OGALLALA AQUIFER _

Table of Pumpage Corresponding to Mapped Decline-Rate

Intervals, 1975

Map Showing Estimated Rates of Water-Level Decline, 1975


Intervals, 1980

Map Showing Projected Rates of Water-Level Decline, 1980.


Intervals, 1990



Intervals, 2000

Map Showing Projected Rates of Water-Level Decline, 2000_

Table of Pumpage Corresponding to Mapped Decline-RateIntervals, 2010


Tables of Pumpage Corresponding to Mapped Decline-RateIntervals, 2020


ACKNOWLEDGEMENTS_

STAFF INVOLVEMENT _

v

Page

40

41

42

43

44

45

47

48

49

50

51

52

53

54

55

56

57

58

59

60

60

METRIC CONVERSIONS TABLE

SELECTED REFERENCES . .


vi

Page

60

61

ANALYTICAL STUDY OF THE OGALLALA

AQUIFER IN RANDALL COUNTY, TEXAS

Projections of Saturated Thickness, Volume of Water in Storage,

Pumpage Rates, Pumping Lifts, and Well Yields

CONCLUSIONS

The Ogallala aquifer in Randall County containedapproximately 3.8 million acre-feet (4.7 km 3 ) of water

in 1975. Historical pumpage has exceeded 85,000acre-feet (0.1 km 3

) annually, which is approximatelyfour times the rate of natural recharge to the aquifer inthe county. This overdraft is expected to continue,ultimately resulting in reduced well yields, reducedacreage irrigated, and reduced agricultural production.

There is a very uneven distribution of groundwater in the county. Some areas have ampleground-water resources to support current usage through1990; whereas, in other areas of the county, groundwater is currently in short supply.

To obtain maximum benefits from the remainingground-water resources, Randall County water usersshould implement all possible conservation measures sothat the remaining ground-water supply is used in themost prudent manner possible and with the least amountof waste.

INTRODUCTION

Randall County is situated in the Southern HighPlains of Texas. Canyon, the county seat, is locatedapproximately 15 miles (24 km) south of Amarillo. Thecounty has a total population of approximately 63,500and contains an area of. 914 square miles (2,367 km 2 ),

of which approximately 840 square miles (2,176 km 2 )

lies north and west of a prominent escarpment whichforms Palo Duro Canyon and the eastern boundary ofthe Texas High Plains. This report deals with that area ofthe county above the escarpment which is underlain bythe Ogallala Formation.

Randall County has a total farm income of over$60 million annually (Texas Almanac and StateIndustrial Guide 1978·79). Leading crops in the countyare wheat, grain sorghums, corn, hay, and sugar beets.

Numerous agribusinesses! including custom livestockfeeding, and sale of irrigation equipment supplies, feedand seed, and fertilizer, also make significantcontributions to the total county income.

Ground water is extremely important to theeconomy of the county inasmuch as most of the cropsare irrigated with ground water. Additionally, the waterused by rural residents, municipalities, and localindustries is mostly ground water.

The principal source of fresh ground water in thecounty is the Ogallala aquifer. During the past threedecades, the withdrawal of ground water has greatly

, "', '-,'-~>

Location of Randall County, and Extent of theOgallala Aquifer in Texas

exceeded the natural recharge to the aquifer. If thisoverdraft continues, the aquifer ultimately will bedepleted to the point that is may not be economicallyfeasible to produce water for irrigation.

This is one of numerous planned county studiescovering the declining ground-water resource of theOgallala aquifer in the High Plains of Texas. The reportcontains maps, charts, and tabulations which reflectestimates of the volume of water in storage in theOgallala aquifer in Randall County and the projecteddepletion of this water supply by decade periodsthrough the year 2020. The report also containsestimates of pumpage, pumping lifts, and other datarelated to current and future water use in the county.However, the report does not attempt to project thatportion of the volume of water in underground storagewhich may be ultimately recoverable.

PURPOSE AND SCOPE OF STUDY

This study resulted from an immediate need forinformation to illustrate to the High Plains water usersthat the ground-water supply is being depleted. It ishoped that this study will help persuade the water usersto implement all possible conservation measures, so thatthe remaining ground-water supply will be used in themost prudent manner possible and with the least amol;'ntof waste.

study is included. A complete set of tabulations andillustrations resulting from this study is presented at theend of the report.

The illustrations were prepared to answer fourquestions believed to be of prime importance to theRandall County landowners and water users. Thesequestions, and methods by which a set of answers can beobtained from the illustrations, are as follows:

1. Question: How much water is in storageunder any given tract of land in the countyand what is expected to happen to this waterin the future?

Answer: First, determine the approximatelocation of the tract on the most current(1975) map of saturated thickness. Read thevalue of the contour line at this location (ifmidway between two contour lines, take anaverage of the two). This thickness value canthen be converted to the approximatevolume of water in storage, in acre-feet persurface acre, by multiplying it by thecoefficient of storage of 0.15, or 15 percent.To obtain estimates of what can be expectedin the future, the same procedure can befollowed by using the maps which illustrateprojected saturated thickness in the years1980,1990,2000,2010, and 2020.

The study was also conducted to provideinformation to local, State, and federal officials for theiruse in implementing plans to alleviate the water-shortageproblem in the High Plains of Texas.

These immediate needs for current informationhave resulted in a concerted effort by the TexasDepartment of Water Resources to utilize high-speedcomputers to conduct evaluation and projection studiesof ground-water resources. The results of one of thesecomputer studies is contained in this report.

2. Question: What can be expected to happento well yields if the saturated thicknessdiminishes as illustrated by the maps?

Answer: Well yields are expected to declineas the aquifer thins; therefore, a map ofestimated well yields has been prepared foreach year of the study. The landowner needonly find the approximate location of hisproperty on the well-yield map that appliesto the year in question and read thewell-yield estimates directly from the map.

This report does not represent a detailedground-water study of the county; rather, the report wasprepared using only those data which were readilyavailable in the files of the Texas Department of WaterResources. Information provided for 1975 is consideredreliable; however, the projections of future conditionsshould be used only as a guide to reasonableexpectations.

This study represents a new approach by theDepartment in making and presenting appraisals ofground-water resources. Consequently, a detailedexplanation of the methods and assumptions used in the

- 2-

3. Question: With energy cost increas ing,pumping lifts (pumping levels) arebecoming more and more important.What are the estimates of currentpumping I iIt s and what are theyexpected to be in the future?

Answer: Contour maps depicting estimatedpumping lifts have been prepared for eachyear of the study. These maps are contouredin feet below land surface. The landownerneed only find the approximate location of

his property on the map that applies to theyear in question to read the pumping-liftestimates.

4. Question: If an all-out effort is made toconserve ground-water resources, how canlandowners and water users determine howthey are doing compared to the projectionsin the study?

Answer: Using the maps that show rates ofwater-level declines, the landowners andwater users can determine what the changesin water levels are in their area and whatthey are projected to be in the future. Thiscan be accomplished by finding theapproximate location of their property onthe map pertaining to the year in questionand by reading the estimates of water-levelchanges which are recorded in feet. Todetermine how he is doing from year toyear, the landowner or water user can makemeasurements of depth to water in his ownwells or obtain copies of measurementsmade by the Department or theground-water district for his area. Thesemeasurements can then be compared to theprojected values on the map nearest to theyear of interest to obtain an estimate of theeffectiveness of the conservation efforts.

NATURE OF THE OGALLALA AQUIFER

Because thorough understanding of the Ogallalaaquifer is not necessary for the water user, the followingdiscussion of aquifer geology and hydrology is rathergeneraL Readers interested in pursuing the subject inmore detail may do so from the numerous reports whichhave been published on the Ogallala. Most of thesepublications are included in the list Q.f selectedreferences of this report.

General Geology

Fresh ground water in Randall County is obtainedprincipally from the Ogallala Formation of Pliocene age.Water in the Ogallala Formation is unconfined and iscontained in the pore spaces of unconsolidated or partlyconsolidated sediments.

The Ogallala Formation principally consists ofinterfingering bodies of fine to coarse sand, gravel, silt,and clay-material eroded from the Rocky Mountainswhich was carried southeastward and deposited by

- 3-

streams. The earliest sediments, mainly gravel and coarsesand, filled the valleys cut in the pre-Ogallala surface.Pebbles and cobbles of quartz, quartzite, and chert aretypical of these early sediments. After filling the valleys,deposition continued until the entire area that is nowthe Texas High Plains was covered by sediments fromthe shifting streams.

The upper part of the formation contains severalhard, caliche-cemented, erosionally resistant beds calledthe "caprock." A wind-blown cover of fine silt, sand,and soil overlies the caprock.

The Ogallala deposits overlie rocks of Triassic age.These rocks, principally shale, serve as a nearlyimpermeable floor for the aquifer. On a broad scale, theerosional surface at the top of the Triassic rocks dipsgently (about 10 feet per mile (2 m/km]) toward thesoutheast, similar to the slope of the land suriace. Ingeneral, however, this pre-Ogallala surface had greaterrelief than the present land surface. Low hills and widevalleys which contain deep, narrow stream channels aretypical features of the Triassic erosional surface_ Becausethe Ogallala was deposited on top of this irregularsurface, the formation is very thin in some areas andvery thick in others. Often this contrast occurs inrelatively short distances.

The Canadian River has cut deeply through theOgallala Formation in the northern part of the TexasHigh Plains area. The valley effectively separates theformation geographically into two units having littlehydraulic interconnection. Erosion has also removed theOgallala from much of its former extent to the east, andto the west in New Mexico. As a result, the SouthernHigh Plains, although relatively flat, stands in high reliefand is hydraulically independent of adjacent areas. Forthis reason, coupled with the scarcity of local rainfall,water that is being withdrawn from the aquifer cannotbe replaced quickly by natural recharge and is in effectbeing mined.

Storage Properties

The coefficient of storage of an aquifer is definedas the volume of water released from or taken intostorage per unit surface area of the aquifer per unitchange in the component of head normal to that surface.In water-table aquifers such as the Ogallala, thecoefficient of storage is nearly equal to the specificyield, which is defined as the quantity of water that aformation will yield under the force of gravity, if it isfirst saturated and then allowed to drain, the quantity ofwater being expressed as a percentage of the volume ofthe material drained.

Natural Recharge and Irrigation Recirculation

Recharge is the addition of water to an aquifer byeither natural or artificial means. Natural recharge resultschiefly from infiltration of precipitation. The Ogallalaaquifer in Randall County receives natural recharge byprecipitation that falls within the county and inadjoining areas.

A coefficient of storage of 15 percent has beenselected for use in this study based on past studies andthe results of numerous aquifer tests published in TexasWater Development Board Report 98 (Myers, 1969).The following chart shows the volumes of watercorresponding to various amounts of aquifer saturatedthickness, based on a storage coefficient of 15 percent.These are the approximate amounts of water that woulddrain from the aquifer material by gravity flow if theentire saturated thickness could be drained.

SATURATEDTHICKNESS

(feet)

255075

100'50200250300400500

VOLUME OF WATERIN STORAGE(acre·feet, per

surface acre)

3.757.50

11.2515.0022.5030.0037.5045.0060.0075.00

of fields, which eliminates compacted zones in the soil(locally called "hard pans"), and the plowing of playalake bottoms and sides; bench leveling, contour farming,and terracing; maintaining a generally higher soilmoisture condition by application of irrigation waterprior to large rains; and increasing the humus level in theroot zone by plowing under a large amount of foliagefrom crops grown under irrigation.

Obtaining a reliable estimate of the presentrecharge rate is further complicated by the considerationwhich must be given to irrigation recirculation. Asubstantial portion of the water pumped from theOgallala for irrigation percolates back to the aquifer.This does not constitute an additional supply of water,but reduces the net depletion of the aquifer. As withnatural recharge, many factors are involved in makingestimates of recirculation. Some of these factors are therate, amount, and type of irrigation application; the soiltype and the infiltration rate of the soil profile in theroot zone; the amount of moisture in the soil prior tothe irrigation application; the type of crop being grown,its root development, and its moisture extractionpattern; and the climatic conditions during andfollowing the irrigation application. Tentative estimatesof the actual amounts of recharge and irrigationrecirculation in Randall County will be found in asubsequent section on "Calculating Pumpage."

PROCEDURES USED TOOBTAIN PROJECTIONS

The amount and rate of natural recharge fromprecipitation depend on the amount, distribution, andintensity of the precipitation; the amount of moisture inthe soil when the rain or snowmelt begins; and thetemperature, vegetative cover, and permeability of thematerials at the site of infiltration. Because of the widevariations in these factors, it is difficult to estimate theamount of natural recharge to the ground-waterreservoir. Estimates of annual natural recharge to theOgallala aquifer made by Barnes and others (1949,p.26-27) indicate only a fraction of an inch. Theis(1937, p. 546·568) suggested less than half an inch, andHavens (1966, p. F1), in a study of the Ogallala in NewMexico, indicated about 0.8 inch (2 em) per year.

The authors of this report believe that rechargefrom precipitation may be more than these earlierestimates, due to changes in the soil and land surfacethat have accompanied large-scale irrigation developmentin the county. Some of the farming practices which arebelieved to have altered the recharge rate are: clearingthe land of deep-rooted native vegetation; deep plowing

·4·

Hydrologic Data Base

The Texas Department of Water Resources and theHigh Plains Underground Water Conservation DistrictNo.1 cooperatively maintain a network of water levelobservation wells in Randall County_ Records from thesewells provided the principal data base used in this study.This data base was supplemented in some areas withrecords from water well drillers' logs collected by boththe District and the Department.

The data base included: (1) measurements of thedepth to water below land surface, which have beenmade annually in the wells in the observation network;(2) the dates these measurements were made; and (3) thedepth from land surface to the base of the Ogallalaaquifer (In many cases, this was identical to the welldepth). To facilitate automatic data processing withmodern, high-speed computers, the data base alsoincluded a unique number for each well and thegeographical coordinates of each well location.

Wells chosen from the data base for use inobtaining projections of future conditions were those inwhich depth to the base of the aquifer could bedetermined or estimated, and those needed to providespaced data coverage in the county. Locations of thewells that were selected and used for control are shownon the various maps in this report.

Projecting the Depletionof Saturated Thickness

3.

in each well as of 1966 (the middle year).Each group inoluded records of all wells in a20·foot (6.1-meter) range of saturatedthickness. (Ranges are shown in thetabulation below.)

The average decline in water level wascalculated for each year for each well group,and these decline values were adjusted toremove the effects of each year's deviationfrom long-term average precipitation.

From the foregoing procedure, the followingdepletion schedule was developed (no depletion wasallowed for areas with 10 feet or less of saturatedthickness) :

4. The average annual decline in water level forthe total period (1960-72) was calculated foreach well group, incorporating theadjustments for departure from averageprecipitation.

Based on this depletion schedule, a computerprogram was written to calculate future saturatedthickness at individual well sites. The following problemis presented to show the computational procedures used.

The water·use patterns between 1960 and 1972 asreflected in the changes in water levels in wells measuredin the High Plains of Texas were used as the principaldata source for developing an aquifer depletion schedule.The depletion schedule generally reflects averageprecipitation and precipitation distribution in the areafor the duration of the study period. Additionally, indeveloping and applying the depletion schedule,adjustments through time were made to reflect theeffects of depletion of the aquifer on its ability to yieldwater. That is, as the aquifer's saturated thicknessdecreases, its ability to yield water to wells is reduced,the well yields decline, less water is pumped, and thereresults a lessened rate of further aquifer depletion.

The aquifer's hydraulics are such that if a wellpenetrates the total saturated section and the pump issized to produce the maximum the aquifer will yield, thewell yield will decline at a disproportionately greaterrate than the reduction in saturated thickness. Actually,the remaining well yield expressed as a percentage offormer yield will be only about half of the remainingsaturated thickness expressed as a percentage of formerthickness. For example, a well with 60 feet (18.3 m) ofsaturated section and a maximum yield of 900 gallonsper minute (56.81/51 will probably yield only 225gallons per minute (14.2 lIs) when the saturated sectionis reduced to 30 feet (9.1 mI.

The depletion schedule for Randall andsurrounding counties was developed in the followingmanner:

RANGE OFSATURATED THICKNESS

(feet)

o to 1010 to 2020 to 4040 to 6060 to 8080 to 100

100t0120120 to 140140 to 160160to180180 to 200200 to 220220 to 240240 to 260260 to 280

AVERAGE ANNUALWATER· LEVEL

DECLlNE,1960-72(feet)

0.00.40.85

1.471.601.802.072.562.502.473.042.972.873.494.05

Problem: A well has a saturated thickness of110 feet in 1975 and one wants to project whatthe saturated thickness will be in this well forevery year to the year 2020.

The beginning saturatedthickness is 110 feet in 1975.

1.

2.

The records for all water level observationwells for the years 1960 through 1972 inArmstrong, Carson, Donley, Gray, Oldham,Potter, Randall, and Wheeler Counties wereseparated from the master file. Thesecounties have similar soil types, croppingpatterns, depths to water, saturatedthickness, and climatic conditions.

These well records were then sorted intogroups according to the saturated thickness

- 5-

Factors: 1.

2. The average2.07 feet perwith saturatedto 120 feet.

decline rate isyear for wellssections of 100

3.

4.

The average decline rate is1.80 feet per year for wells withsaturated sections of 80 to100 feet.

The average decline rate is1.60 feet per year for wells withsat u ra ted sections of 60 to80 feet.

6.

7.

The average decline rate is 0.85foot per year for wells withsaturated sections of 20 to40 feet.

The average decline rate is0.40 foot per year for wells withsaturated sections of 10 to20 feet.

5. The average decline rate is1.47 feet per year for wells withsaturated sections of 40 to60 feet.

8. The time interval is 1975through 2020.

The projected saturated thicknesses in the subjectwell are calculated and shown in the following table:

YEAR

1975197619771978197919801981198219831984198519861987'98819891990199119921993199419951996199719981999200020012002200320042005200620072008200920102011201220132014201520162017201820192020

SATURATED THICKNESS,BEGINNING-OF YEAR

(feet)

110.00107.93105.86103.79101. 72

99.6597.8596.0594.2592.4590.6588.8587.0585.2583.4581.6579.8578.2576.6575.0573.4571.8570.2568.6567.0565.4563.8562.2560.6559.0557.5856.1154.6453.1751.7050.2348.7647.2945.8244.3542.8841.4139.9439.0938.2437.39

AVERAGEDECLINE RATE

(feet)

2.072.072.072.072.071.801.801.801.801.801.801.801.801.801.801.801.601.601.601.601.601.601.601.601.601.601.601.601.601.471.471.471.471.471.471.471.471.471.471.471.471.47

.85

.85

.85

.85

SATURATED THICKNESS,END OF YEAR

(feet)

107.93105.86103.79101. 72

99.6597.8596.0594.2592.4590.6588.8587.0585.2583.4581.6579.8578.2576.6575.0573.4571.8570.2568.6567.0565.4563.8562.2560.6559.0557.5856.1154.6453.1751. 7050.2348.7647.2945.8244.3542.8841.4139.9439.0938.2437.3936.54

Similar computations were made for each ofthe selected data-control wells in Randall County,and the saturated-thickness values for 1975, 1980,

·6·

1990, 2000, 2010, and 2020 were extracted fromthis data set for use in further calculations andmapping.

Mapping Saturated Thickness, andCalculating Volume of Water in Storage

To obtain estimates of the volume of water instorage in the Ogallala aquifer, an electronic digitalcomputer was used to construct maps which reflect

the saturated thickness of the aquifer for thoseyears included in the study. These maps were thenrefined by the computer to reflect the number ofacres corresponding to each range of saturated

thickness. The number of acres for each range wasmultiplied by the saturated thickness in feet for

that range and then by the coefficient of storage(0.15 or 15 percent), to yield an estimate of thevolume of water in storage in each

saturated-thickness range. Totaling these volumesproduced an estimate of the volume of water in

storage in the county. The current (1975) andprojected volume estimates are shown in thefollowing graph:

~ .. 0

Acre-Feel! '0 Yecr• >0

Hj 1975 3.782.000

! 2 01980 3,515,000

2 0 ~ 1990 2,737.000i 2000 2,091,000~ '0 I 0 ~; 2010 1,636,000

i 00 00 2020 1,301,000......,~ l " e

"w0:?!?' ....'" .J ,0

I:stlmated Volume of Water in Storage

Preparing a data base and writing thenecessary programs for the computer to use inconstructing the saturated-thickness maps and inmaking the necessary calculations is time consuming;however, once the data base is prepared andprograms written, the computer can perform in afew hours calculations that would have requiredmany years of manual effort_

A generalized description of the methodology usedin mapping and in computing water volume follows: Abase map with a scale of 1 inch equals 2 miles

(1: 125,000) was selected to prepare data for computerprocessing_ All data points (observation wells) were

plotted on these base maps by hand and assignedidentifying numbers. A machine called a digitizer wasthen used to translate these mapped location data (welllocations, county boundaries, etc.) into informationprocessible by the computer. To accomplish this, alatitude and longitude coordinate was recorded on eachbase map as a central reference point, and all data pointsand county boundaries were then digitized; that is,measurements were made by the digitizer to referencethese data points and boundaries to the initial latitudeand longitude coordinate. Then the digitized

- 7-

information was processed by the computer and themaps were re-created by a computer-driven plotter. Thecomputer-plotted image maps were ultimately checkedagainst the hand-constructed maps to verify that thedata were plotted accurately.

The assignment of a unique number to each datapoint (observation well) on the base maps made itpossible to machine process the data related to thesepoints and to plot these data back on the maps at theproper location.

To compute the volume of water in storage, thecomputer was instructed to subdivide the county intosquares measuring approximately 0.5 mile (0.8 km). The

known saturated-thickness values obtained from the datapoints were filled into the squares in which the datapoints were located. Based on these known values, thecomputer filled in a weighted-average value for eachremaining square, taking into consideration all knownvalues within a radius of 7 miles (11 km). After this stepwas completed, the computer then counted the numbersof squares having equal values, thus obtaining theapproximate area in square miles (later converted toacres) corresponding to each range of saturatedthickness. As previously stated, the number of acres ineach 25-foot (7.6-meter) range of saturated thicknesswas multiplied by the corresponding saturated-thickness

value and the storage coefficient (0.15 or 15 percent) toobtain the approximate volume of water in acre-feet inthat saturated-thickness range.

Although the calculations were made by thecomputer from information stored in its image field, the

data in the image field were printed out in the form ofcontoured saturated-thickness maps, which arereproduced in this report. Facing eachsaturated-thickness map in the report is a corresponding

tabulation of the approximate volume of water instorage.

Calculating Pumpage

Estimates of current pumpage were obtained inthis study by calculating the storage capacity of thedewatered section of the Ogallala aquifer as reflected inchanges in the annual depth-to-water measurementsmade in the water level observation wells. Factors fornatural recharge and irrigation recirculation were thenadded to these volumetric figures to obtain morerealistic pumpage estimates.

The step-by-step procedure involved in makingpumpage estimates is similar to the procedures usedin calculating the estimates of volume of water in

Year Acre-Feet

These amounts were added to the previouslycalculated storage capacity of the dewatered section toobtain estimates for current (1975) and future pumpage.The following graph shows the current and projectedestimates of pumpage:

storage; therefore, a more general explanationfollows.

Change in water level (decline) maps for theaquifer were made by the computer for the yearsconsidered. From these maps, the volume ofdesaturated material was multiplied by the numberof acres corresponding to each 0.25·foot(.076-meter) range of decline and then multipliedby the storage coefficient of the aquifer (0.15 or15 percent), which resulted in an estimate of thevolume of water taken from storage for eachdecline range. Estimates for natural recharge andirrigation recirculation were added to these values toobtain estimates of pumpage.

1975

19801990

2000

2010

2020

Estimated Pumpage

130,000

124,000

104,00086,000

66,000

55,000

An attempt was made to obtain a reliable estimateof the natural recharge and recirculation for use in thisstudy. This involved obtaining an estimate of the amountof water required by each of the major crops grown inthe area. These values, generally referred to as "duty ofwater," were obtained from Texas AgriculturalExperiment Stations located in the High Plains area. Theduty of water figure for each major crop was multipliedby the number of crop acres, and the resulting numberswere added together to yield an estimate of the totalcrop water demand.

The amount of precipitation which fell just priorto and during the growing season was subtracted fromthe total water demand estimate. The differencebetween these values should equal that amount whichwould have been supplied by irrigation, which will bereferred to as irrigation makeup water.

The volume figure represented by the dewateredsection was then compared to the volume of waterwhich should have been supplied to crops by irrigationmakeup water. In all tests, the volume of waterrepresented by the depletion of the aquifer wasconsiderably less than the makeup water estimate. Thisdifference was attributed to irrigation recirculation andnatural recharge.

Various combinations of estimates for naturalrecharge and recirculation were added to the volumerepresented by aquifer depletion, in an attempt toobtain comparable values with the makeup waterestimated for the test years. One-half inch (1.3 em) peryear of natural recharge added to the volumerepresented by the depletion of the aquifer, and thenadding 10 percent of this for recirculation, most nearlyequaled the makeup water estimated in the largestnumber of instances in Randall County and in adjoiningcounties with similar conditions.

- 8-

Calculating Pumping Lifts

The pumping lilt (pumping level) is the depth

from land surface to the water level in a pumping well; itis equal to the depth of the static water level plus thedrawdown due to pumping. The amount of pumping liftlargely determines the amount of energy required toproduce the water, and thus strongly affects thepumping costs.

In calculating pumping lifts, procedures were usedthat are similar to those used in making estimates of thevol ume of water in storage and the estimates ofpumpage. Again, the computer and original data basewere used as previously described.

In making estimates of pumping lifts, it wasassumed (1) that the yield of each pumping well is 900gallons per minute (56.8 lis) except as limited by thecapacity of the aquifer (this conforms with the historicaltrend of equipping new wells with 8-inch[20-centimeter) or smaller pumps), (2) that the specificwell yield is 15 gallons per minute per foot of drawdown13.1 [lis] 1m), and (3) that once the well yield equals thecapacity of the aquifer, the well will continue to beproduced at a rate near the capacity of the aquifer untilpumping lifts are within 10 feet (3 m) of the base of theaquifer. After that time, it is assumed that the pumpinglift will remain constant because of greatly diminishedwell yields. It. should be noted that this la-foot(3-meter) minimum is somewhat arbitrarily chosen, asone cannot predict accurately the minimum saturatedthickness that will be feasible for producing irrigationwater under future economic conditions.

The above assumptions restrict the drawdown inwells to a maximum of 60 feet (18.3 m); that is, themaximum well yield of 900 gallons per minute (56.8 lis)

divided by specific well yield of 15 gallons per minuteper foot (3.1 [l/sJlm) equals 60 feet (18.3 m) ofmaximum drawdown.

Based on the above assumptions, pumping liftswere calculated separately for each of the selecteddata<ontrol wells in the county. The factors involvedwere the historical and projected saturated-thicknessvalues, the historical and projected static water levels,and the drawdown value assigned to the Randall Countyarea.

wells. As an example, in areas where the saturatedportion of the formation is comprised of thick beds ofcoarse and well-sorted grains of sand, the well yieldsprobably will exceed the estimates shown on the maps.In other localized areas, the saturated portion of theformation may be comprised principally of thick beds ofsilt and clay which can be expected to restrict well yieldsto less than those shown on the maps.

The following can be used as a general guide inRandall County in estimating well yields based onsaturated thickness:

The maps presented in this report areintended for use as general guidelines only and arenot recommended for use in determining wateravailability when buying and selling specific tractsof land. Inasmuch as the availability of groundwater constitutes a large portion of the price of landbought and sold in this area, it is recommended that aqualified ground-water hydrologist be consulted to makeappraisals of ground-water conditions when suchtransactions are contemplated.

In all areas where the aquifer's saturated thicknesswas 70 feet (21.3 m) or greater (areas where a well,pumped at full capacity, would be drawn down 60 feet[18.3 ml to yield 900 gallons per minute [56.8I/sl)'the computer was instructed to add 60 feet(18.3 m}-the drawdown-to the static water level todetermine pumping lift. For a well with a saturatedthickness of less than 70 feet (21.3 m), the pumping liftwas calculated by subtracting 10 feet (3 m) from thedepth of the well (base of the aquifer). Thesecalculations were made for each year of record to bereported (1975, 1980, 1990,2000,2010, and 20201 foreach well. The pumping-lift values were stored in thecomputer and printed out in the form of contour maps.Additionally, the surface area corresponding to eachinterval between the mapped contours was calculatedand printed out in tabular form.

Well-Yield Estimates

SATURATED THICKNESSlfeet}

Less than 2020 to 3030 to 4040 to 6060 to 80

More than 80

WELL YIELD(gallons per minute)

Less than 100100to 250250 to 500500 to 800800 to 1,000

More than 1,000

Estimates of the rate, in gallons per minute, atwhich the Ogallala aquifer should be capable of yieldingwater to wells in various areas of the county arepresented on maps for each year of record reported(1975, 1980, 1990, 2000, 2010, and 2020). Thesewell-yield estimates are based on capabilities of theaquifer to yield water to irrigation wells of prevailingconstruction as reflected by the very large number ofaquifer tests which have been conducted in varioussaturated-thic!<ness intervals in the Texas High Plains.The estimates are adjusted to reflect the expecteddecreases in well yields through time due to the reducedsaturated thickness as depletion of the aquiferprogresses.

The well-yield estimates are subject to deviationscaused by localized geological conditions. The Ogallala isnot a homogeneous formation; that is, the silt, clay,sand, and gravel which generally comprise the formationvary from place to place in thickness of layers, layeringposition, and grain·size sorting. The physicalcomposition of the formation material can drasticallyaffect the ability of the formation to yield water to

·9·

DISTINCTION BETWEEN PROJECTIONSAND PREDICTIONS

The actions of the Randall County water user willdetermine whether the projections of this study come topass, as the rate of depletion of the ground-waterresource is determined by the rate of water use_ Theauthors have not made predictions of what will occur,but have furnished projections based on past trends andpresently available information.

There are many unpredictable factors which caninfluence the future rates of withdrawal of ground waterfrom the Ogallala aquifer for irrigation farming. Thesefactors include: (1) the amounts and distribution ofprecipitation which will be received in the area in thefuture; (2) federal crop acreage controls or the lack ofthese; (3) the price and demand for food and fibergrown in the area; (4) the cost and availability of energyto produce water from the aquifer; (5) farm labor costand availability of farm labor; (6) results of continuingresearch that seeks to develop more frugalwater-application methods for irrigation, crops having

less water demand, and methods for inducing clouds toyield more water as rain; and (7) most important, thedegree to which feasible soil and water conservationmeasures are employed by the High Plains irrigator. Any

·10 -

of these factors could appreciably influence the rate ofuse of ground water in the future; however, theprojections in this study provide a reasonable set ofgeneral expectations on the further depletion of theaquifer.

SATURATED THICKNESS AND VOLUME OF

WATER IN THE OGALLALA AQUIFER

MAPPED SATURATED·THICKNESS INTERVAL

(feet)

0- 2525- 5050- 7575-100

100-125125-150

TOTAL

1975

Volume of Water in Storage Correspondingto Mapped Saturated-Thickness Intervals

(Coefficient of Storage: 15 percent)

SURFACE AREA(acres)

111,542240,832112,50449,74319,546

5,475

539,642

- 12-

VOLUME OFWATER IN STORAGE

(acre-feet I

333,7341,349,8631,016,652

642,106325,427113,811

3,781,593

IIL __

EXPLANATION

•

•

•

••

. . ~• ·-/"'--';+-----50-------· C---- ---- ---- ------ ----- '"

""

•Well used for control

--150---line showing approximate saturated

thickness of the Ogallala aquifer, in feel.

Interval is 25 feet (7.62m)

O;._.....__l'-.....__I'--z-i'i;;, iiiiiii10 Miles

1975

i

"'-I

Estimated Saturated Thickness

. 13·


(feet)

0- 2525~ 5050- 7575-100

100-125

TOTAL

1980



SURFACE AREA(acres)

128.994235,638110,882

50,76513.363

539,642

. 14·


(acre-feetl

356,1721,286,4681,005,961

649,827216,929

3,515,357

•

••

. =1· .._ -./"_\,-=-=~... 50_ __::::"... !'C.50"-l

•

,- "- - _._._.ARUD Ft

• So,_

••

•

fi;\'25-/ \' .' ,

"S •'\

•

~.

•

•

I!~

Ii

EXPlANA TlON

•Well u~ed for control

--/50--'~-_""-"""_"-~""'i;._"iiiiiiiiiiii,:,l0MleJ

-~-

Line showing approximate saturated


Interval is 25 feel (7.62m)

1980Projected Saturated Thickness

. 15 .

MAPPED SATURATEDTHICKNESS INTERVAL

(feet)

0- 2525- 5050- 7575-100

TOTAL

1990



SURFACE AREA(acres)

221,701218,850

76,15122,940

539,642

·16·


(acre-feet)

593,1431,158,026

694,807290,987

2,736,963

o

o

5

,.

o

~I. • •

______0 .!- L ~ ---'

6 4

°:1<;

°°

:55 ,0

0 •0

0,

"° f~--•2S c:..~ ,

~L""ocrc ~

0

0

0

<:-.-, 0

0

0

~--- ---

EXPlANA TlON


--!SO--line showing approximate saturated



1990Proiected Saturated Thickness

- 17 -


(feet)

0- 2525- 5050- 7S75-100

TOTAL

2000

Volume of Water in Storage Correspondingto Mapped Saturated-Thickness Intervall


SURFACE AREAlacres)

319,628174,41442,355

3,245

539,642

. 18·


(acre-feet)

774,683903.847379,677

38,737

2,096,944

o

o

-((go-, 1

o>

:>"" ;1

o

o

.:;: .of---~~--_J

o

o

_--\..1.- ==O-===::::::2_5~O CJ

o

o

o

o

o

o

o

o

o

L _

i, 0

I~ ~

Jo

EXPLANATION

•Well used for control ----.... , M .. "'---150--

line showing approximate soturated

thickness of the Ogallolo aquifer, in feet.


2000Projected Soturoted Thickness

- 19 -

MAPPED SATURATEDTHICKNESS INTERVAL

(feet)

0-2525-5050-75

TOTAL

2010



SURFACE AREA(acres)

406,433116.255

16,954

539,642

·20·


(acre-feet)

907,835586,781141,470

1.636,086

, .•

•

•

•• •• I

-- -------------'

--L" ~MAR;ClO - t\ ~~-.,-----125. r ~~ ,tliLL~ I

•lS

•

••

••, •, .

-,

•••

•25

CANYO,,< ~-L:a,. 6 •Q

•

• • •

I • • CPI •,. •

I.• • Relph •

I•

• •i ,

•I •• •L __~~ •------------------ -- -- --

25p (~-- .

!Q! •I!i

EXPlANA nON


--/50--

O;,_.~"I_:il""."''ioiii'''....l5ioiii .:.l..0No I..

line showing approximate saturated

thickness of the Ogallala aquifer, in feet.



- 21 -


(feet)

0-2525-5050-75

TOTAL

2020

Volume of Water in Storage Corresponding

to Mapped Saturated-Thickness Intervals


SURFACE AREA(acres)

467.45671,676

5'0

539,642

·22·


(acre-feet)

952,227350,743

3,981

1.306.951

oo

o--------'

oo

o

-.o

I 0

iiIIiL _

25)----\01 -lis)50

0 0

0

00

o ;>'\;

0

00

M .<fJ0

0

~ 0"

EXPlANA liON

•Well used lor control

--/50--line showing approximate saturated


Intervol is 25 feet j7.62m)

O;'_""I~_;l_....._~"""i5 .....:1:0 M:Jas

y"l-

j


- 23 -

POTENTIAL WELL YIELD OF THE

OGALLALA AQUIFER

•

---------,

!.1

•,

•

•

• I~

-~. ~_____' _-",~",,---_.-.L2:'J

EXPLANATION

Potential well yields, in gallons per minute

less than 100 0 500-800

CJ 100-250 0 800-1000:':'.'.:

0 250-500 0 more than 1000

-;.O!""1Oiii0l"'""i1Oiiil'""!i'i;;;;; iiil10 Milu~ __ 77

i-;:::.:::;1-

~

1975Estimated Patential Yield

- 27 -

•

• 1• I. ._. --.1

EXPLANATION


0 leu than 100 0 500-800

0 100-250 bid 800-1000

0 250-500 0 more thon 1000

0:......_ ........;' .;1;0 Miles~ ,--

1980Projected Potentiol Yield

- 28-

EXPLANATlON


less thon 100 0 500·BOO

0 100·250 L2J BOO·lOOO

0 250·500 CJ more thon 1000

1990Projected Potential Yield

·29·

~-,,"-

j

CANYON ~"...zb

•

••

••• ••

•

•

EXPLANATION

Potential well yields, in gollons per minute

c::::::J less thon 100 0 500-800

0 100-250 IT] 800-1000--

0 250-500 0 more thon 1000

O~~.~'I_~_""liOi....."';; iiilO Mde~

O;.,,-.z'....~...........;;. oioI6, Kilomn...

-=-"'

I+_-.J

T-i"oi-

1


- 30-

EXPLANATION

• •• •

•


D less than 100 0 500-800

D 100-250 0 800-1000

D 250-500 0 more thon 1000

-i"J

I


. 31 .

•••,

•

EXPLANATION

•

•

•

• •

•

AMARILLO

••~_==---__.-.-J


0 less thon 100 0 500-800

0 100-250 0 800-1000

0 250-500 0 more thon 1000

-""-


- 32-

PUMPING LIFTS IN THE OGALLALA AOUIFER

MAPPEDPUMPING·L1FT

INTERVAL(feet)

25- 5050- 7575-100

100-125125-150150-175175-200200-225225-250250-275275-300

TOTAL

1975

Surface Area Corresponding to MappedPumping-Lift Intervals

SURFACE AREA(acres)

25,91527,53630,86835,95337,93178,425

102,84889,11559.81538.78812,448

539,642

·34·

••---~-'6':

""

,-/50 LillS) _L _

-------,---~ I

---

11""1I

RL...O 4.i • • :... : 275

U~ ,li":' •11" ~•

250.~

I

f•!<i• • ,

20 0

EXPlANATlON


---200---line showing approximate

pumping lift, in feel.

Interval is 25 feet (7.62ml

1975Estimated Pumping Lifts

- 35 -

MAPPEDPUMPING-LIFT

INTERVAL(feet)

25- 5050- 7575-100

100-125125-150150-175175-200200-225225-250250-275275-300300-325

TOTAL

1980

Surface Area Corresponding to MappedPumping·Lift Intervals

SURFACE AREA(acres)

14,04917,90219,96129,41339,67180,078

105,59988,34553,85052,46336,604

1,707

539,642

- 36-

•••

-yCAf.tl

Palo OIJroIStene PQ!"Kj

I•!

EXPLANATION


--200--line showing approximate

pumping lilt, in feel.

Intervol is 25 leet (7.62m)

o~

1980Projected Pumping Lifts

. 37 •

,,

10 M .. ~ I'o!-

I

MAPPEDPUMPING-LIFT

INTERVAL(feet)

25- 5050- 7575-100

100-125125-150150-175175-200200-225225-250250-275275-300300-325

TOTAL

1990


SURFACE AREA(acres)

14,04917,55820,13228,89938,67377,316

105,80288,82650,54541,41242,79613,634

539,642

- 38-

225 7 •G)

150

'-rCh

EXPlANA TlON




Inlervol is 25 feel (7.62m)

°..................""51- ..°. i¥ iel

- =--= --~-


·39·

MAPPEDPUMPING-LIFT

INTERVAL(feet)

25- 5050- 7575-100

100-125125-150150-175175-200200-225225-250250-275275-300300-325325-350

TOTAL

2000


SURFACE AREA(acres)

14,04917,55820,13528.89938,67177,002

105,46688,97847,72236,99242,10621.390

67'

539,642

-40 -

EXPLANATION



pumping lifl, in feel.

Interval is 25 feet {7.62m}

115

~-:':=2 __

O~...~....._-i':,, ~10 Ioi'. U~


- 41 -

•

MAPPEDPUMPING-LIFT

INTERVAL(teet)

25- 5050- 7575-100

100-125125-150150-175175-200200-225225-250250-275275-300300-325325-350

TOTAL

2010


SURFACE AREA(acres)

14,04917,55820,13228,89938,67477,002

105,46688,64447,03035,21438,92126,201

1,852

539,642

- 42 -

EXPLANATION




Interval is 25 feel (7.62m)

/75.

.~:~_ 7__ ·


·43 -

•

MAPPEDPUMPING-LIFT

INTERVAL(feet)

25- 5050~ 7575-100

100-125125-150150-175175-200200-225225-250250-275275-300300-325325-350

TO"rAL

2020


SURFACE AREA(acres)

14,04917,55820,13228,89938,67477,002

105,46688,64447,03035,21438,75026,201

2.023

539,642

- 44-

EXPLANATION


--200--Line showing approximole

pumping lift, in feet.


•


l"J-

I

PUMPAGE FROM THE OGALLALA AOUIFER

1975

Pumpage Corresponding to MappedDecline-Rate Intervals

MAPPED DECLINE·RATE INTERVAL

(feet)

0.00-0.25.25- .50.50- .75.75-1.00

1.00-1.501.50-2.002.00-3.003.00-4.00

TOTAL

SURFACE AREA(acres)

121,34952,45650,74942,45497,31777,29368,54328,296

538,457

STORAGE CAPACITYOF DEWATEREO

SECTION(acre-feet)

1,3702,9504,7195,524

18,00420,17024,52318.515

95,775

- 48-

ESTIMATED PUMPAGE RATE,INCLUDING NATURAL

RECHARGE ANDIRRIGATION RECIRCULATION

(acre-feet per year)

7,0695,6497,5178,022

24,26525,72930,11721,664

130,032

)5

•

•

IIL._._.

EXPLANATION


--U5--line showing approximate rate of decline

in water level, in feet per year.

Interval is variable

O~-=~"'_.-'__=="""'i. ..:il0 />II lu

1975

if'1-

l

Estimated Rates of Water-Level Decline

- 49·

1980


MAPPED DECLlNERATE INTERVAL

{feetl

0.00-0.25.25- .50.50- .75.75-1.00

1.00-1.501.50-2.002.00-3.00

TOTAL

SURFACE AREA(acres)

17,63845,46556,959

122,740173,554100,257

21,844

538,457

STORAGE CAPACITYOF OEWATERED

SECTION(acre-feet)

4042,6865,337

16,22732,54025,452

7,219

89,865

·50 -




1,2525,0388,481

23,47543,74832,592

8,942

123,528

•

25. .__-L5~_-L~L

•

•

'-":;

~~f)I '"l/IL _

EXPLANATION


--/25--line showing approximate role of decline

in waler level, in feel per year.

O~~""__I""'''i__I'''''''''i' -.,;jI)O Miles

v-~-


1980Projected Rates of Water-Level Decline

- 51 -

1990

Pumpage Corresponding to MappedDecline·Rate Intervals

MAPPED DECLINERATE INTERVAL

(feet)

0.00-0.25.25- .50.50- .75.75-1.00

1.00-1.501.50-2.002.00-3.00

TOTAL

SURFACE AREA(acres)

26,32896,603

103,709117,181128,596

64,3192,221

538,957

STORAGE CAPACITYOF DEWATERED

SECTION(acre-feet)

6265,6189,754

15,16824,01916,056

678

71,919

- 52-




1,89510,60815,47922,05632,31520,610

848

103,811

1.00

, ~I. . .!.-- _._._~L:_._l0~

. ,•

•

I .10

IiL,:::5~~_fii~5~_

SOl lIS

EXPlANATlON


---1.25--line showing approximate role of decline

in waler level. in feel per yeor_

1-f'.i-

~Intervol is variable

1990Projected Rates of Water-level Decline

- 53 -

2000

Pumpage Corresponding to Mapped

Decline-Rate Intervals


Ifeet)

0.00-0.25.25- .50.50- .75.75-1.00

1.00-1.501.50-2.00

TOTAL

SURFACE AREA(acres)

54,017150,162106,582101,24490,08527,316

529,396


SECTION(acre·feet I

9838,8979,853

13,12416,6966,625

56,178

- 54-

ESTIMATED PUMPAGE RATE.INCLUDING NATURAL



3,55516,66815,72319,07722,494

8,539

86,056

•

I •I

I II ,.~25> .

IL__._.

•

•

•

•

___......-t---;;:_._--~

EXPLANAnON


--us--line showing approximate rale of decline



O~OiI!"."iiiii~~~ioo; ..iIO Kilo",.I ...JI"'Rj

2000

y-f::::!-

j

Projected Rates of Water-Level Decline

- 55 -

2010



(feed

0.00-0.25.25- .50.50- .75.75-1.00

1.00-1.501.50-2.00

TOTAL

SURFACE AREA(acres)

147,067157,779

98,98763.62248,163

4,610

520,228

STDRAGE CAPACITYDF DEWATERED

SECTION(acre-feet)

1,7009,1699,1758,1728,8551,094

38,165

- 56-

ESTIMATED PUMPAGE RATE.INCLUDING NATURAL


(acre-feet per yearl

8,61017,31614,62911,906, 1,948

1,415

65,824

. . \----- .~_.!- __~.5~_~.~

."0

EXPLANATION

•Well used lor (onlrol

\._""'I~_~_""'I__~~"""i':.. :J Nt .5

--1.25--line showing approximate role of decline

in waler level, in feet per year.



- 57 -

2020

Pumpage Corresponding to Mapped

Decline·Rate Intervals


(feet)

0.00-0.25.25- .50.50- .75.75-1.00

1.00-1.501.50-2.00

TOTAL

SURFACE AREA(acres)

231,820142,59567,65252,19222,850

342

517,451


SECTION(acre·feet)

3,1987,9426,2536,6544,102

78

28,227

- 58-



lacre-feet per year)

14,14215,272

9,9799,7115,560

102

54,766

•

I~

-J-c. ~--, .75_50

••

•

F

•

•-- ------- --- ----'

•

•---- --4----~-

t 25

• V ?

••

• 'l:,> •

IIL _

EXPlANAnON

•Well used for confrol

--1_25--line showing approximate rote of decline


~,"=",",".""_""'._IOOiil_.,;'Iiio ';;O /'lII" u

!V

-f'J-

I

Intervol is variable


- 59 -

ACKNOWLEDGEMENTS

Special appreciation is expressed to the Randall

County landowners and water users for allowing theirwells to be measured by Department and Water Districtpersonnel. This study could not have been accomplishedwithout their cooperation and the records obtained fromtheir wells.

Special thanks are also expressed to the staff ofthe High Plains Underground Water ConservationDistrict No.1, Mr. A. Wayne Wyatt, manager, forproviding records and consultation during the study.

Additionally, appreciation is expressed to severalindividuals for consultation and for review and commenton the methodology and techniques employed in thisstudy: Mr. Frank A. Rayner, former general manager ofthe High Plains Underground Water ConservationDistrict No.1; Dr. Donald Reddell, associate professorof Engineering, Texas A&M University; Mr. Leon New,irrigation specialist, Texas Agriculture Extension Service,Lubbock, Texas; Mr. Shelby Newman, superintendent,Texas Agricultural Experiment Station, Stephenville,Texas; Dr. C. C. Reeves, Jr., professor of Geosciences,Texas Tech University; and Dr. James Osborn, formerchairman of the Department of Agricultural Economics,Texas Tech University.

STAFF INVOLVEMENT

This report is one of a series of county reportsbeing published under the title "Analytical Study of theOgallala Aquifer." Former staff member A. WayneWyatt was instrumental in initiating the study andcoauthored a number of the previously published reportsof this series.

The Randall County report was prepared underthe supervision of Bernard B. Baker, head of the GroundWater Data Unit in the Texas Department of WaterResources' Data Collection and Evaluation Section,Dr. Tommy R. Knowles, chief. Numerous staff membersof this Section assisted the authors in assembling andevaluating data and information. Overall technical

·60·

superVIsion of the Ogallala study is exercised by C. R.Baskin, director, Data and Engineering Services Division.The Department's Information Systems and ServicesOffice, David L. Ferguson, director, provided automateddata processing and computational services, andprepared the manuscript copy of tabular and graphicaldisplays.

METRIC CONVERSIONS TABLE

For those readers interested in using theInternational System (SI) of Units, the metricequivalents of English units of measurement have beengiven in parenthesis in the text. The English units used intables of this report may be converted to metric units bythe following conversion factors:

MULTIPLYENGLISH TO OBTAIN

UNITS BY SI UNITS

inches 2.540 centimeters (em)

'eo, .3048 met~s 1m)

miles 1.609 kilometers (km)

square miles 2.590 square kilometersIkm:l)

gallons 3.785 liters (I)

gallons per .06309 liters per secondminute (lIs)

gallons per .207 liters per secondminute per meterper foot ([l/sl/m)

acres .4047 square hectometersIhm 1 )

acres .004047 square kilometersIkm:l)

acre-feet 1,233. cubic meters 1m3 }

acre-feet 1.233 X 10-6 cubic kilometers(km 3 )

million 1.233 cubic kilometersacre-feet (km l )

SELECTED REFERENCES

Alexander, W. H., Jr., 1961, Geology and ground-waterresources of the Northern High Plains of Texas,progress report no. 1: Texas Board Water EngineersBull. 6109, 47 p.

Alexander, W. H., Jr., Broadhurst, W. L., and White,W. N., 1943, Progress report on ground water in theHigh Plains in Texas: Texas Board Water Engineersduplicated rept., 22 p.

Baker, C. L., 1915, Geology and underground waters ofthe northern Llano Estacada: Univ. Texas Bull. 57,225 p.

Baker, E. T., Jr., Long, A. T., Jr., Reeves, R. D_, andWood, L. A" 1963, Reconnaissance investigation ofthe ground-water resources of the Red River, SulphurRiver, and Cypress Creek basins, Texas: Texas WaterComm_ Bull. 6306, 137 p.

Barnes, J. R" and others, , 949, Geology and groundwater in the irrigated region of the Southern HighPlains of Texas, progress report no. 7: Texas BoardWater Engineers duplicated rept., 51 p.

Bell, A. E., and Morrison, S., 1977, Analytical study ofthe Ogallala aquifer in Hockley County,Texas-projections of saturated thickness, volume ofwater in storage, pumpage rates, pumping lifts, andwell yields: Texas Dept. Water Resources Rept. 214,63 p.

Bell, A. E., and Sechrist, A. W., 1970, Playas-SouthernHigh Plains of Texas: Playa Lake Symposium,

ICASALS, Texas Tech Univ., Lubbock, Texas, Oct.1970, Proc., p. 35-39.

Brand, J. P., 1953, Cretaceous of Llano Estacada ofTexas: Univ. Texas, Bur. Ecan. Geology Rept. ofInv. 20, 59 p.

Broadhurst, W. L., Sundstrom, R. W., and Weaver, D. E.,1949, Public water supplies in western Texas: TexasBoard Water Engineers duplicated rept., 277 p.

__1951, Public water supplies in western Texas: U.S.Geol. Survey Water-Supply Paper 1106, 168 p_

Cronin, J. G., 1961, A summary of the occurrence anddevelopment of ground water ir) the Southern HighPlains of Texas: Texas Board Water Engineers Bull.6107,110p.

__1969, Ground water in the Ogallala Formationin the Southern High Plains of Texas and

- 61 -

New Mexico: U.S. Geo!' Survey Hydro!. Inv. AtlasHA-330, 9 p.

Cronin, J. G., Follett, C. R., Shafer, G_ H., and Rettman,P. L., 1963, Reconnaissance investigation of theground-water resources of the Brazos River basin,Texas: Texas Water Comm. Bull. 6310, 163 p.

Cronin, J. G., and Wells, L. C., 1960, Geology andground-water resources of Hale County, Texas: TexasBoard Water Engineers Bull. 6010, 146 p.

Dallas Morning News, 1977, Texas Almanac and StateIndustrial Guide 1978-79: A. H. Bela Corp., 704 p.

Evans, G. L., and Meade, G. E., 1945, Quaternary of theTexas High Plains in Contributions to geology, 1944:Univ. Texas Pub_ 4401, p_ 485-507.

Fenneman, N. M., 1931, Physiography of the westernUnited States: New York, McGraw-Hili Book Co.,534 p.

Fink, B. E., 1963, Ground-water geology of Triassicdeposits, northern part of the Southern High Plains ofTexas: High Plains Underground Water ConservationDist. No.1, Rept_ 163,79 p.

Frye, J. C., 1970, The Ogallala Formation-a review:Ogallala Aquifer Symposium, Texas Tech Univ.,Lubbock, Texas, 1970, Proc., p. 5-14.

Frye, J. C., and Leonard, A. B., 1957, Studies ofCenozoic geology along eastern margin of Texas HighPlains, Armstrong to Howard Counties: Univ. Texas,

Bur. Econ. Geology Rept. of Inv. 32, 62 p.

Gammon, S. W., and Muse, W. R., 1966, Water-level datafrom observation wells in the Southern High Plains ofTexas: Texas Water Devel. Board Rept. 21, 537 p.

Gard, Chris, 1958, Ground-water conditions in CarsonCounty, Texas: Texas Board Water Engineers Bull.5802, 120 p.

Gillett, P. T., and Janca, I. G., 1965, Inventory of Texasirrigation, 1958 and 1964: Texas Water Comm. Bull.6515,317p.

Gould, C. N., 1906, The geology and water resources ofthe eastern portion of the Panhandle of Texas: U.S.Geol. Survey Water-Supply Paper 154, 64 p.

Gould, C. N., 1907, The geology and water resources ofthe western portion of the Panhandle of Texas: U.S.Geol. Survey Water-Supply Paper 191,70 p.

Grubb, H. W., 1966, Importance of irrigation water tothe economy of the Texas High Plains: Texas WaterDevel. Board Rept. 11, 53 p.

Haragan, D. R., 1970, An investigation of clouds andprecipitation for the Texas High Plains: Texas WaterDevel. Board Rept. 111, 125 p.

Havens, J. S., 1966, Recharge studies on the High Plainsin Northern Lea County, New Mexico: U.S. Geo!.Survey Water-Supply Paper 1819-F, 52 p.

Hughes, W. F., and Harman, W. L, 1969, Projectedeconomic life of water resources, Subdivision no. 1,High Plains underground water reservoir: Texas A&MUniv. Tech. Mon ..6, 82 p.

Lang, J. W., and Twichell, Trigg, 1945, Water resourcesof the Lubbock district, Texas: Texas Board WaterEngineers duplicated rept., 168 p.

Leggat, E. R., 1952, Geology and ground-waterresources of Lynn County, Texas: Texas Board WaterEngineers Bull. 5207,76 p.

__ 1954a, Summary of ground-water development inthe Southern High Plains, Texas: Texas Board WaterEngineers Bull. 5402,21 p.

__1954b, Ground-water development in theSouthern High Plains of Texas, 1953: Texas BoardWater Engineers Bull. 5410, 7 p.

__1957, Geology and ground-water resources ofLamb County, Texas: Texas Board Water EngineersBull. 5704, 187 p.

Long, A. T., Jr., 1961, Geology and ground-waterresources of Carson County and part of Gray County,Texas, progress report no. 1: Texas Board WaterEngineers Bull. 6102, 45 p.

Luckey, R. R., and Holstra, W. E., 1974, Digital modelof the Ogallala aquifer of the northern part of theNorthern High Plains of Colorado: Colorado WaterConservation Board, Colorado Water Resources Circ.No. 24, 22 p.

McAdoo, G. D., Leggat, E. R., and Long, A. T., 1964,Geology and ground-water resources of CarsonCounty and part of Gray County, Texas, progressreport no. 2: Texas Water Comm. Bull. 6402, 30 p.

- 62-

Moulder, E. A., and Frazor, D. R., 1957,Artificial-recharge experiments at McDonald wellfield, Amarillo, Texas: Texas Board Water EngineersBull. 5701,34 p.

Myers, B. N., 1969, Compilation of results of aquifertests in Texas: Texas Water Devel. Board Rept. 98,537 p.

New, Leon, 1968, High Plains irrigation survey: TexasA&M Univ. Ext. Service duplicated rept., 14 p.

__ 1969, High Plains irrigation survey: Texas A&MUniv. Ext. Service duplicated rept., 14 p.

__1970, High Plains irrigation survey: Texas A&MUniv. Ext. Service duplicated rept., 10 p.

__ 1971, High Plains irrigation survey: Texas A&MUniv. Ext. Service duplicated rept., 16 p.




North Plains Ground Water Conservation District No.2,1966, Geology and ground-water resources of theNorth Plains Ground Water Conservation DistrictNo.2: North Plains Ground Water ConservationDistrict No.2, Progress rept. No.2, 49 p.

__ 1970, Geology and ground-water resources of theNorth Plains Ground Water Conservation District:North Plains Ground Water Conservation DistrictNo.2, Progress rept. No.3, 35 p.

__1973, Geology and ground-water resources ofLipscomb County, Texas: North Plains Ground WaterConservation District No.2, 31 p.

Osborn, J. E., Harris, T. R., and Owens, T. R_, 1974,Impact of ground water and petroleum on theeconomy of the Texas High Plains: Texas Tech Univ.,Dept. Agr. Econ., 87 p.

Rayner, F. A., 1965, The ground-water supplies of theSouthern High Plains of Texas: Proc. 3rd West TexasWater Coni., Texas Tech Call., p. 20-42.

__1973, Taking a new look at the demise of theOgallala aquifer: Testimony presented to West Texas

Citizens Advisory Council on Water Resources publichearing, Lubbock, Texas, October 3,1973,16 p.

Rettman, P. L., and Leggat, E. R., 1966, Ground·waterresources of Gains County, Texas: Texas Water Devel.Board Rept. 15, 186 p.

Schwiesow, W. F., 1965, Playa lake use and modificationin the High Plains, in Studies of playa lakes in theHigh Plains of Texas: Texas Water Devel. BoardRept. 10, p. 1·8.

Sherrill, D. W., 1958, High Plains irrigation survey:Texas A&M Call. Ext. Service duplicated rept., lOp.

1959, High Plains irrigation survey: Texas A&MCoiL Ext. Service duplicated rept., 10 p.

Smith, J. T., 1973, Ground-water resources of Motleyand northeastern Floyd Counties, Texas: Texas WaterDevel. Board Rept. 165,8 p.

Swann, T., 1974, Texas High Plains facts: Lubbock.Water, Inc., lOp.

Texas Board Water Engineers, 1960, Reconnaissanceinvestigation of the ground-water resources of theCanadian River basin, Texas: Texas Board WaterEngineers Bull. 6016, 33 p.

Texas Water Development Board, 1971, Inventories ofirrigation in Texas, 1958, 1964, and 1969: TexasWater Devel. Board Rept. 127, 232 p.

Theis, C. V., 1937, Amount of ground-water recharge inthe Southern High Plains: Am. Geophys. UnionTrans., 18th Ann. Mtg., p. 564·568.

Thurmond, R. V., 1951, High Plains irrigation survey:Texas A&M Coil. Ext. Service duplicated rept., 4 p.

White, W. N., Broadhurst, W. L., and Lang, J. W., 1946,Ground water in the High Plains of Texas: U.S. Geol.Survey Water·Supply Paper 889·F, p. 381-420.

Wyatt, A. W., 1968, Progress report no. 1, A generaldiscussion accompanied by hydrological mapspertaining to the ground-water resources in the SouthPIa ins Underground Water Conservation DistrictNo.4: South Plains Underground Water ConservationDistrict No.4, 24 p.

__1975, TWDB High Plains study shows 340 millionacre-feet of water in 45-county area, in Water forTexas: Texas Water Devel. Board pub., V. 5, no. 1and 2, p. 20·22.

Wyatt, A. W., and others, 1970, Water-level data fromobservation wells in the Southern High Plains ofTexas, 1965·70: Texas Water Devel. Board Rept. 121,361 p.

__ 1971, Water-level data from observation wells inthe Northern Panhandle of Texas: Texas Water Devel.Board Rept. 137,263 p.

Wyatt, A. W., Bell, A. E., and Morrison, S., 1976,Analytical study of the Ogallala aquifer in HaleCounty, Texas-projections of saturated thickness,volume of water in ston:ge, pumpage rates, pumpinglifts, and well yi-elds: Texas Water Deve1. Board Rept.200,63 p.

__ 1976, Analytical study of the Ogallala aquifer inLamb County, Texas-projections of saturatedthickness, volume of water in storage, pumpage rates,pumping lifts, and well yields: Texas Water Devel.Board Rept. 204, 63 p.

__ 1976, Analytical study of the Ogallala aquifer inParmer County, Texas-projections of saturatedthickness, volume of water in storage, pumpage rates,pumping lifts, and well yields: Texas Water Devel.80ard Rept. 205, 63 p.

__1976, Analytical study of the Ogallala aquifer inCastro County, Texas-projections of saturatedthickness, volume of water in storage, pumpage rates,pumping lifts, and well yields: Texas Water Devel.Board Rept. 206, 63 p.

__1976, Analytical study of the Ogallala aquifer inBailey County, Texas-projections of saturatedthickness, volume of water in storage, pumpage rates,pumping lifts, and well yields: Texas Water Devel.Board Rept. 207, 63 p.

__1976, Analytical study of the Ogallala aquifer inCrosby County, Texas-projections of saturatedthickness, volume of water in storage, pumpage rates,pumping lifts, and well yields: Texas Water Devel.Board Rept. 209, 63 p.

__1976, Analytical study of the Ogallala aquifer inFloyd Cou nty, Texas-projections of saturatedthickness, volume of water in storage, pumpage rates,pumping lifts and well yields: Texas Water Devel.Board Rept. 211, 63 p.

__1977, Analytical study of the Ogallala aquifer inBriscoe County, Texas-projections of saturatedthickness, volume of water in storage, pumpage rates,pumping lifts, and well yields: Texas Water Devel.Board Rept. 212, 63 p.

·63·

Wyatt, A. W., Bell, A. E., and Morrison, S., 1977,Analytical study of the Ogallala aquifer in DeafSmith County, Texas-projections of saturated

- 64-

thickness, volume of water in storage, pumpagerates. pumping lifts, and well yields: Texas WaterDevel. Board Rept. 213, 63 p.

Analytical Study of Ogallala Aquifer in Randall County, Texas · ground-water resources, Randall...

Documents

Transcript of Analytical Study of Ogallala Aquifer in Randall County, Texas · ground-water resources, Randall...