Records of Ground-Water Recharge and Discharge for the Edwards Aquifer in the San Antonio Area, Texas, 1934-77
Bulletin 37 Edwards Underground Water District San Antonio, Texas
Prepared in Cooperation with the U. S. Geological Survey and the Texas Department of Water Resources CONTENTS Page
Abstract 4
Introduction 5
Precipitation •• 8
Ground-water recharge .• 8
Water levels and ground-water storage. . 11
Ground-water discharge . 11 References • 17
-2- ILLUSTRATIONS Page Figure 1. Map showing hydrologic features in the San
Antonio area . . . • 6 2. Map showing drainage basins and data-collection
sites in the San Antonio area .• 7 3. Graph showing accumulated recharge and discharge,
1934-77 ...... 15
TABLES
Table 1. Annual and long-term average precipitation at
selected stations, 1974-77 ...... 9 2. Calculated annual recharge to the Edwards aquifer
by basin, 1934-77 •... 10
' 3. Annual high and low water levels in selected observation wells in the Edwards aquifer,
1974-77. 12 4. Calculated annual discharge from the Edwards aquifer, by county, 1934-77 .... 13 5. Calculated discharge from the Edwards aquifer
by county and by water use, 1977 ...... 16
-3- RECORDS OF GROUND-WATER RECHARGE AND • DISCHARGE FOR THE EDWARDS AQUIFER IN·THE SAN ANTONIO AREA, TEXAS, 1934-77
Compiled by R. W. Maclay and R. A. Rappmund U.S. Geological Survey
ABSTRACT
The average annual ground-water recharge to the Edwards aquifer in the San Antonio area, Texas, from 1934 through 1977 was about 589,200 acre-feet. A maximum annual recharge of 1,711,200 acre-feet occurred in 1958, and a minimum annual recharge of 43,700 acre-feet occurred in 1956.
A maximum annual discharge of 960,900 acre-feet occurred in 1977, and
a minimum annual discharge of 388,800 acre-feet occurred in 1955. The maximum annual discharge by wells was 406,800 acre-feet in 1971.
-4- INTRODUCTION e Compilation of the records of ground-water recharge and discharge for the Edwards aquifer in the San Antonio area, Texas, is part of a continu- ing investigation by the U.S. Geological Survey in cooperation with the
City Water Board of San Antonio, the Edwards Underground Water District, and the Texas Department of Water Resources.
The calculations of annual recharge are based on data collected from a network of stream-gaging stations and on assumptions that relate the run-
off characteristics of gaged areas to ungaged areas. The basic approach (Puente, 1978) is a water-balance equation in which recharge within a stream basin is the difference between measured streamflow above and below the infiltration area of the aquifer, plus the estimated runoff within the . infiltration area •
Annual discharge is compiled from: (1) Data collected by the Texas Department of Water Resources on pumpage for municipal, military, and indus- trial use; (2) calculations of pumpage for irrigation as determined from records of power consumption and irrigated acreage; and (3) U.S. Geological
Survey records of springflow at points of discharge.
The hydrologic features in the San Antonio area are shown on figure 1, and the drainage basins and data-collection sites are shown on figure 2.
Previous reports on recharge and discharge for the Edwards aquifer are given in the list of references.
-5- BLAN CO 100°30' 100• 99°30' 99° 98°30' SUTTON K_IMBLE_T-7----- r KERR ·
/ ~04
EXPLANATION 0 Nueces-llestNuecesRiverrechargebasin Frio-Ory1"ri0Riverrech11rgebasln •e S11b!nalRiverrechargeho,.in 0 Area between Sabinal River bns In and Med 1.na River bnsin ModinaRiverrechargebnsin • Area between Me
BASIN 30UNDARY
SUBBASINOIVIOE
Location of key observation well
CJ U>tGAGEO AREAS A Leona River B Blanco Creek c LittleBlancoandUoltonCreeks D RancheroCreek E ParkersandliveOakCreeks 100°30' 100° 99°30' 99° 98°30' F Between Hondo Creek and Medina River basin G Sink, Purgatory, and Alligator Creeks '====::::i'o====':ro===:::::i30 MILE S STREAM-GAGING STATIONS NO. STA. NO. NAME l. 08190500 West Nu eces fdver near Brackettville. Tex. 2. 08190000 lrnecesRiveratlaguna,Tex. 3. 06 192000 NuecesRiverbelawUvald.:',Tex. 4. 06196000 Ory Frio River near Reagan Wells, Tex. 5. 08195000 FrioRiveratConcan , Tex. 6. 08197500 frio River bel ow Ory Frio River near Uvalde, Tex. 7. 06198000 SabinalRivernear Sabinal, Tex. 8. 08198500 SabinalRiveratSabinal , Tex. 9. 08201500 SecoCreek atMillerRanchnearUtopfa,Tex. 10. 08202700 Seco Creek at Rowe Ranch near O'H.u:is , Tex. 11. 08200000 Hondo Creek near Tarpley , Tex . 12. 08200700 Hondo Creek at King Wat~rhole near Hondo, Tell. . '). 08179000 Med ina River near Pipe Creek, Tex. 14. 08179100 Red BluffCreek nearPipeCreek,Tex. 15. !l8178700 Salado Creek (upper station) at San Antonio, Tex. 16. ;)8183900 CiboloCreeknearBoerne,Tex. 17. 08185000 CiboloCreekatSelma,Tex. 18. 08169000 Comal River at New Braunfels, Tex. 19. 08167000 Guadalupe River at Comfort, Tex. <:O. 08167600 Rebecca Cre .. ~ near Spring eranch, Tex. 2i. 08167500 Guadalupe Riv,.,. near Spriri'} Brcmch, Tex. 22. 08166800 GuadalupeRivcr a tSattle<",Tex. 23. 08168500 Guadalupe Rive r above ::omal River at New Braunfels, Tex. 24. 08171000 Blanco River at Wimberley, Tex. 2s. o817':JGo ::o. OB1724CC ~i1~mn~~e:l~tr LgAn~~£~ '1 e~:x • Base from U.S. Geological Survey State base map, 1: 500,000
FIGURE 2.-Drainage basins and data-collection sites in the San Antonio area -7- ... 100°30' ·!00" SUTTON ______L___ EDWARDS
/
...
EXPLANATION ~· i ------~- [[[Il] INFILTRATION AREA OF THE EDWARDS AQUIFER
i DRAINAGE DI VIDE 100"30' 100° 99° 30' ... 98°30' "BAD-WATER LINE" (D OWNDIP LIMIT OF EDWARDS PLATEAU FRESHWATER) (Catchment area) 0c===:::' ':i:0====2I0====30 MILE S
GULF COASTAL PLAIN (Artesian are a)
TE XAS
Diagramatic cross section LOCATI ON MAP
Bau from U.S. GeolOQicol Survey State base map , L 500, 000 FIGURE 1.-Hydrologic features in the San Antonio area Note: Large-format versions of the original plates are on the following pages.
98° BLANCO 100°30' 100° 99°30' 99° 98°30' ______..L__ 9 -r---SUTTON i:1_M_BL_E -7------~-~-----=:-=::::::ir--~"----z_o_, , EDWARDS ' KERR I --....___~"" I r I / I ~04
EXPLANATION 0 Nueces-West Nue es River recharge bas i n 0 Fr io-Dry Prio River rech.1rg:e bas in e Sab i nal Ri ve r recharge basin Area between Suhi nal River basin and Me d ina River has i n I •e Ned i na River rec ha q;e bas in I Area between Medina River and Cibolo Cree k LLJ I • Cibo lo and Dry Ct)mal Creek recharge hns i n ~ IK$-~- •0 Guadalup Ri ver recharge bas in 0 Blanco River r echarge basin 1 ~ ~ PRECIPITATlcii1 STATION
STREAM-GAGING STATION } 98° BASIN SOUNDARY
- ··- SUBBASIN DIVIDE x Location of key observation well
' LJ UNGAGED AREAS I A Leona River ,~ B Blanco Creek () ------~- c Little Blanco and llolton C·reeks ' D Ranchern Creek I E Parkers and Live Oak Creek s 100°30' 100° 99°30' 99° 98°30' F Between Hondo Creek and Medina River basin G Sink, Purgatory, and Alligator Creeks oi======Io r:======::::20C:=:=:=:==:i3 0 MILE s STREAM-GAGING STATIONS NO. STA. NO. NAME 1. 08190500 West Nueces Fd ver near Br FIGURE 2.-Drainage basins and data-collection sites in the San Antonio area -7- BLANCO 98° 100°30' . JOO" 99° 30' 99° 98°30' -r---SUTTON ______l__ ~l_M_BL_E_7-~--~-~-..J,.,_...... -::::=:-=::::::t~~~~~~-...... , EDWARDS ' KERR I --.-~-"" I I I I I I I '~- 98° } I EXPLANATION -.{'-.0-?."' I .0 ,~ \.,~L c:,"' ------~- ---~ ~ -- INFILTRATION AREA OF THE EDWARDS AQUIFER ' \ I -··- DRAINAGE DIVIDE 100°30' 100° 99°30' 99• 98°30' -- "BAD-WATER LINE 11 (DOWNDIP LIMIT OF EDWARDS PLATEAU FRESHWATER) (Catchment area) oi:======'i:o======2IO::======::::i3 0 MILE s l BALCONES FAULT ZONE (Infiltration area) r GULF COASTAL PLAIN (Artesian area) TEXAS ~TUDY L__/ AREA Diagramatic cross section LOCATION MAP Base from U.S. Geolo9ical Survey State base map, I : 500, 000 FIGURE 1.-Hydrologic features in the San Antonio area