Floods in Central Texas, 

August 1-4, 1978

.S. GEOLOC?! G AI, « 'im V E Y, P R O t KS SI 0 N A ^ PAPER

Bjeporfprepared faintly hj? the" U*& Geologi

the Nati&nafe Oceanic ancLAfniosphevic Ad^i^tra
Floods in Central Texas, 

August 1-4, 1978

By E. E. SCHROEDER and B. C. MASSEY, U.S. Geological Survey, and 

EDWIN H. CHIN, National Weather Service, National Oceanic and Atmospheric 

Administration

U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1332

Report prepared jointly by the U.S. Geological Survey 

and the National Oceanic and Atmospheric Administration

UNITED STATESGOVERNMENTPRINTINGOFFICE, WASHINGTON : 1987
DEPARTMENT OF THE INTERIOR 

DONALD PAUL HODEL, Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

Library of Congress Cataloging in Publication Data

Schroeder, E. E.

Floods in central Texas, August 1-4, 1978. 

(Geological Survey professional paper ; 1332)

"Report prepared jointly by the U.S. Geological Survey and the National Oceanic and Atmospheric 

Administration." 

Bibliography: p. 

Supt. of Docs, no.: I 19.16:1332

1. Floods-Texas. I. Massey, B.C. II. Chin, Edwin H. III. Geological Survey (U.S.) IV. United States. 

National Oceanic and Atmospheric Administration V. Title. VI. Series. 

GB1399.4.T4S35 1985 551.48'9'09764 84-600154

For sale by the

Books and Open-File Reports Section

U.S. Geological Survey

Federal Center

Box 25425 

Denver, CO 80225
CONTENTS

Page

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

Introduction ........................................................... 1

Meteorological settings and precipitation distribution ........................... 1

Description of the floods ................................................. 20

Nueces River basin .................................................. 20

Guadalupe River basin ............................................... 23

Medina River basin .............................................. 23

Colorado River basin ................................................. 29

Pedernales River ................................................ 29

Llano River .................................................... 30

Brazos River basin ...................................................... 30

Magnitude and frequency of the floods ...................................... 34

Flood damage.......................................................... 37

Summary . ........................................................... 38

Selected references ...................................................... 39

ILLUSTRATIONS

Page 

FIGURE 1. Map showing location of streamflow-data sites ....................................................... 2

2. Map showing Medina and vicinity in south-central Texas ............................................... 3

3. Map showing track of Amelia .................................................................... 4

4. Maps showing surface weather at 0600 c.s.t., July 30-August 4, 1978 ..................................... 5

5. Maps showing 500-mb analysis at 0600 c.s.t., July 30-August 4, 1978 ..................................... 9

6. Graph showing evolution of 1000-mb dewpoint temperature at Corpus Christi, San Antonio, and Abilene from

July 31 to August 4, 1978.................................................................... 12

7. Maps showing evolution of precipitable water from surface to 500-mb at 0600 c.s.t., July 31 to August 4, 1978 ..... 13

8. Maps showing 850-mb temperature and 24-h trajectory valid at 0600 c.s.t., August 1 and 2, 1978 ............... 14

9. Map showing 700-mb, 12-hour net vertical displacement and K Index valid at 1800 c.s.t., July 31, 1978. .......... 15

10. Map showing isohyetal analysis for south-central Texas, August 2-3, 1978 ................................. 16

11. GOES infrared imagery, August 2 and 3, 1978 ....................................................... 17

12. Graphs showing mass rainfall curves at selected rain gages, August 1-4, 1978 .............................. 20

13. Maps showing isohyetal analyses for storms centered near Medina and Albany ............................. 24

14. Graphs showing depth-area duration analysis for storms centered near Medina and Albany .................... 26

15. Discharge hydrograph of Guadalupe River at Comfort for August 1-6, 1978 ................................ 27

16. Discharge hydrograph of Guadalupe River near Spring Branch for August 1-6, 1978 ......................... 27

17. Discharge hydrographs of Medina River near Pipe Creek for August 2-7, 1978, and Beaver Creek near Mason for

August 2-5, 1978 .......................................................................... 28

18. Log-Pearson Type III frequency curve for Medina River near Pipe Creek .................................. 29

19. Photograph showing cypress tree uprooted by floodwaters on the Medina River ............................. 29

20. Photograph showing Medina River near Pipe Creek, before, during, and after the flood ....................... 30

21. Discharge hydrographs of North Fork Hubbard Creek near Albany for August 3-6, 1978, and Hubbard Creek

below Albany for August 2-7, 1978 ............................................................ 31

22. Discharge hydrograph of Clear Fork Brazos River at Fort Griffin for August 3-7, 1978 ....................... 32

23. Discharge hydrograph of Clear Fork Brazos River at Eliasville for August 4-12, 1978......................... 32

24. Discharge hydrographs of Millers Creek near Munday for August 4-7, 1978, and California Creek near Stamford

for August 3-6, 1978 ....................................................................... 36

25. Photograph showing inundation of State Highway 173 and the Medina River bridge at Bandera ................ 36

26. Photograph showing State Highway 290 flooded by Spring Creek near Fredericksburg........................ 37

27. Photograph showing aerial view of the Brazos River in flood at Graham ................................... 38

III
IV CONTENTS

TABLES

Page

TABLE 1. Comparison of maximum storm rainfalls with that of historical storms over central Texas in the summer season ..... 19

2. Comparison between storm rainfalls and 100-year amounts .............................................. 19

3. Comparison of extreme point rainfalls in the United States and the world ................................... 19

4. Summary of flood stages and discharges............................................................. 21

5. Locations of discontinued stream-gaging stations and miscellaneous discharge-measurement sites ................ 25

6. Data for gaging station 08167000 Guadalupe River at Comfort ........................................... 26

7. Data for gaging station 08167500 Guadalupe River near Spring Branch .................................... 27

8. Data for gaging station 08179000 Medina River near Pipe Creek .......................................... 28

9. Data for gaging station 08150800 Beaver Creek near Mason ............................................. 31

10. Data for gaging station 08086150 North Fork Hubbard Creek near Albany .................................. 32

11. Data for gaging station 08086212 Hubbard Creek below Albany .......................................... 33

12. Data for gaging station 08085500 Clear Fork Brazos River at Fort Griffin................................... 33

13. Data for gaging station 08087300 Clear Fork Brazos River at Eliasville..................................... 34

14. Data for gaging station 08082700 Millers Creek near Munday ............................................ 35

15. Data for gaging station 08084800 California Creek near Stamford ......................................... 35

GLOSSARY

Acre-foot (acre-ft). The volume of water required to cover 1 acreto a 

depth of 1 foot. It equals 43,560 cubic feet, 325,851 gallons, or 

1,233 cubic meters.

Contents. The volume of water in a reservoir or lake. Content is 

computed on the basis of a level pool or reservoir backwater 

profile and does not include bank storage.

Convection cloud. A cloud which owes its vertical development, 

and possibly its origin, to convection.

Cubic foot per second (ft3/s). A rate of discharge. One cubic foot 

per second is equal to the discharge of a stream of rectangular 

cross section, 1 foot wide and 1 foot deep, flowing at an average 

velocity of 1 foot per second. It equals 28.32 liters per second 

or 0.02832 cubic meters per second.

Cubic foot per second per square mile [(ft3/s)/mi2]. The average 

number of cubic feet per second flowing from each square mile 

of area drained by a stream, assuming that the runoff is distributed uniformly in time and area. One cubic foot per second per 

square mile is equivalent to 0.01093 cubic meter per second per 

square kilometer.

Dew point (or dew temperature). The temperature to which a 

given parcel of air must be cooled at constant pressure and 

constant water-vapor content in order for saturation to occur.

Drainage area of a stream at a specific location. The contributing 

area of a stream, measured in a horizontal plane, bounded by 

topographic divides. Drainage area is given in square miles. 

One square mile is equivalent to 2.590 square kilometers.

Flash flood. A local and sudden flood which usually follows brief 

heavy precipitation.

Flood. Any high streamflow that overtops natural or artificial 

banks of a stream and overflows onto land not usually underwater and causes or threatens damage.

Flood peak. The highest value of the stage or discharge attained 

by a flood.

Flood profile. A graph of the elevation of water surface of a 

river in flood, plotted as ordinate, against distance, plotted 

as abscissa.

Flood stage. The approximate elevation of the stream when overbank-flooding begins.

Front. The interface or transition zone between two airmasses of 

different density.

Gaging station. A particular site on a stream, canal, lake, or 

reservoir where systematic observations of gage height or discharge are obtained.

Isohyetal map. A map showing lateral distribution of precipitation and drawn as contours of equal rainfall depths.

Jet stream. High-velocity strong winds concentrated within a 

narrow stream high in the atmosphere.

Mean sea level. The annual mean sea level is the average of 

hourly heights of the tide from a calendar year of tidal record. 

This is referenced to the National Geodetic Vertical Datum 

of 1929.

Millibar (mb). A unit of pressure equal to 1,000 dynes per square 

centimeter.

National Geodetic Vertical Datum (NGVD). Formerly called Sea 

Level Datum of 1929. A geodetic datum derived from a general 

adjustment of the first order level nets of both the United 

States and Canada. In the adjustment, sea levels from selected 

tide stations in both countries were held as fixed. The year 

indicates the time of the last general adjustment. This datum 

should not be confused with mean sea level.

N-year precipitation (rain). A precipitation amount which can be 

expected to occur, on the average, once every AT years.

Precipitable water. The total atmospheric water vapor contained 

a vertical column of unit cross-sectional area extending from the 

surface up to a specified pressure level, usually 500 mb.

Rawinsonde. A radiosonde tracked by a radio direction-finding 

device to determine the winds aloft.

Recurrence interval. As applied to flood events, recurrence interval is the average number of years within which a given flood 

peak will be exceeded once.

Ridge. An elongated area of high atmospheric pressure.

Time of day expressed in 24-hour time. For example, 12:30 a.m. 

is 0030 hours, 1:00 p.m. is 1300 hours.

Unit discharge. The average number of cubic feet of water flowing 

per second from each square mile of area drained, assuming that 

the runoff is distributed uniformly in time and area.

Vorticity. A vector measure of local rotation in a fluid flow, 

defined mathematically as the curl of the velocity vector. In 

meteorology, vorticity usually refers to the vertical component 

of the vector.
CONTENTS

CONVERSION OF INCH-POUND UNITS TO 

INTERNATIONAL SYSTEM OF UNITS (SI)

[Most units of measure used in this report are inch-pound units. The following factors may be used to convert inch-pound 

units to the International System of Units (SI).]

Multiply

acre-foot (acre-ft)

cubic foot per second (ft3/s)

cubic foot per second

per square mile [(ft3/s)/mi2 ]

degrees Fahrenheit (°F)

foot (ft)

inch (in)

knot (kn)

mile (mi)

mile per hour (mph)

millibar (mb)

nautical mile (nmi)

square mile (mi2 )

By

1,233

0.02832

0.01093

5/9(F-32)

.3048

25.4

1.85

1.609

1.609

0.1

1.85

2.590

To obtain

cubic meter

cubic meter per second

cubic meter per second

per square kilometer

degrees Celsius (°C)

meter

millimeter

kilometer per hour

kilometer

kilometer per hour

kilopascal (kPa)

kilometer

square kilometer

FLOODS IN CENTRAL TEXAS, 

AUGUST 1-4, 1978

By E.E. SCHROEDER and B.C. MASSEY, U.S. GEOLOGICAL SURVEY,

and EDWIN H. CHIN, NATIONAL WEATHER SERVICE, NATIONAL OCEANIC 

and ATMOSPHERIC ADMINISTRATION

ABSTRACT

Catastrophic floods caused by record rainfall occurred in central Texas 

during August 1-4, 1978. Torrential rain initiated by the remnants of 

tropical storm Amelia fell over south-central Texas during August 1-3, and 

very intense rain due to the interaction between the cold front and maritime 

air mass fell over north-central Texas on August 3-4. Rainfall of more than 

48 inches near Medina in south-central Texas established a new United 

States record of extreme point rainfall for a 72-hour period.

Major flooding occurred on the Medina and Guadalupe Rivers. Severe 

to minor flooding occurred on the Brazos, Llano, Pedernales, and Nueces 

Rivers. Floods with recurrence intervals in excess of 100 years and recordsetting peak discharges were observed at several streamflow stations.

Thirty three lives were lost and total damages reportedly exceeded $110 

million.

INTRODUCTION

Catastrophic floods caused by intense rainfall occurred 

in central Texas during Aug. 1-4,1978. The rain was initiated 

by remnants of tropical storm Amelia but was compounded 

by other meteorological factors. Torrential rain fell over 

the hill country area of south-central Texas during Aug. 

1-3, and over the big country area of north-central Texas 

during Aug. 3-4. A maximum rainfall of more than 48 in. at 

a location 11 mi northwest of Medina (29°49'N. 99°15'W.) 

set a new extreme point rainfall record for a 72-hour period 

in the United States. A map of central Texas is shown in 

figure 1, and a map of Medina and vicinity (expanded scale) 

is shown in figure 2.

Major flooding occurred on the Medina River and its 

tributaries above Medina Lake and on the Guadalupe River 

and its tributaries above Canyon Lake. Moderate to severe 

flooding occurred on tributaries of the Nueces River, on 

Clear Fork Brazos River and its tributaries, and on the 

Llano and Pedernales Rivers, which are tributaries of the 

Colorado River. Peak discharges at several streamflow stations exceeded the historic peaks. The highest unit discharge observed was 3,010 ftVs/mi2 from the 14.1-mi2 

drainage area of Spring Creek, which is a tributary of 

the Pedernales River.

Much of the extraordinary runoff was in the form of flash 

flooding. About half of the town of Medina was damaged.

and many buildings in the city of Bandera farther downstream 

on the Medina River also were damaged. Medina Lake had 

4 ft of flow over the spillway at maximum stage. In northcentral Texas, 6 ft of water inundated the town of Albany on 

a tributary of Clear Fork Brazos River, forcing people to 

seek safety on roofs and trees. Floodwater opened gaps in 

the earthen dam of Albany Reservoir and overtopped the 

spillway at Lake Throckmorton. A total of 33 people lost 

their lives due to the floods. Property damages were estimated 

at $110 million.

This report presents the meteorlogical situations and the 

precipitation distributions that caused the floods and a 

description of the floods by basins with peak stages and 

discharges and flood-frequency estimates. Detailed dischargehydrograph data, including historic maxima are presented 

in tabular form for 10 gaging stations. These should be of 

considerable value in assessing the risks involved in developing 

the flood plains of streams in the affected area.

This report was prepared jointly by the U.S. Geological 

Survey and the National Oceanic and Atmospheric 

Administration and in cooperation with the State of Texas 

and other agencies.

METEOROLOGICAL SETTINGS AND 

PRECIPITATION DISTRIBUTION

The disturbance that developed into tropical storm Amelia 

originated off the African coast as a tropical wave on July 

19, 1978. It remained a weak system without much deep 

convection until it reached the central Caribbean Sea on 

July 26. On July 29, as the wave moved off the Yucatan 

Peninsula into the southwestern Gulf of Mexico, convection 

increased and the cloud mass took on a circular appearance 

on satelite pictures. By Sunday moniing, July 30, the disturbance 

had turned toward the northwest and the cloud band structure 

had appeared. The track of Amelia is shown in figure 3, and 

surface analysis for the period July 30-August 4 is shown in 

figures 4A-F. All time mentioned in this report refers to 

central standard time (c.s.t.) unless stated otherwise. The 

surface analysis at 0600 July 30 (fig. 4A) indicated very flat

1
101

FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

99° 98° 97'

Base from US. Geological Survey 

1-1,000,000. Compiled in 1962 

Edited in 1965

100 MILES

EXPLANATION

DATA-COLLECTION SITENumber corresponds to that 

in table 1 and in the report 

text

COUNTIES DESIGNATED AS 

FLOOD-DISASTER AREAS

BASIN DIVIDES

T

2* 

0 ZOO Ml

34-. - - 5 5 

--\\

IT" / 2

^---11 Si. - p

LES IT

^REPORT AREA

L/» ' . ,..

\l~ 

lt~-'~-\

\\--J-

*'l&*»

-1 '

0 20 40 60 80 100 KILOMETERS

FIGURE 1. Location of streamflow-data sites.
METEOROLOGICAL SETTINGS AND PRECIPITATION DISTRIBUTION

99°00'

KERR COUNTY _ 

BANDERA COUNTY

29°45' 

0 5 10 15 KILOMETERS 

FIGURE 2. Medina and vicinity in south-central Texas.

pressure gradient over Texas, with the coastal stations of 

Corpus Christi and Brownsville having light easterly winds 

with overcast sky. The low pressure center, which was to 

develop into Amelia, was centered in the western Gulf of 

Mexico at 23.5°N. 95°W. The corresponding 500-mb analysis 

(fig. 5A) showed a flat contour gradient with very light 

southeasterly winds of about 10 kn (knots) over the eastern 

two-thirds of Texas. A very weak low center was situated 

over north-central Mexico.

During the day of July 30, the low pressure center that 

was to develop into Amelia continued on a north-northwestward 

track at 10 mph. Before crossing the Texas coast north of 

Brownsville during the evening of July 30, this system 

reached tropical storm intensity, with winds in excess of 45 

kn. The estimate of storm intensity was based on data obtained 

by reconnaissance flights through the storm. By 2200 July 

30, Amelia was 40 mi north of Brownsville. During the 

night, Amelia continued on a northwesterly track and by 

0600 Monday, July 31, was about 50 mi west by north of

Corpus Christi at approximately 28.0°N. 97.8°W. The pressure 

gradient along the southwest Texas coast from near Brownsville 

to just east of Corpus Christi tightened during this period 

indicating a stronger onshore flow of warm moist air from 

the Gulf of Mexico. During July 31, the storm continued to 

drift northwestward while its circulation continued to weaken. 

The surface center of circulation could be traced inland to 

the west of San Antonio during the night of July 31-August 

1, after which it was no longer identifiable. After the low was 

filled, the surface analysis at 0600 Tuesday, August 1 (fig. 

4C) indicated continued onshore southeasterly flow and 

strong moisture advection. For example, with the wind 

southerly or southeasterly at Corpus Christi and vicinity on 

July 31 and August 1, warm maritime air with a mixing 

ratio of 22.5 grams of water vapor per kilogram of dry air 

near the surface was moving into south-central Texas. This 

predominantly southeasterly circulation pattern persisted 

throughout the life of the storm systems as can be seen from 

surface maps at 0600 August 2-4 (figs. 4D-F).
FLOODS IN CENTRAL TEXAS, AUGUST 1-4,1978

105° 100° 95° 90°

25'

20°

250 500 MILES

250 500 KILOMETERS

EXPLANATION 

1 ^^ ^^~ Development of tropical wave stage

'fc 'fc % Dissipation of tropical wave stage

^^^^" " "^ Tropical storm stage

0 29A July 18, 1978, 6 a.m.

0 30P July 30, 1978, 6p.m.

FIGURE 3. Track of Amelia.

FIGURE 4(facing page). Surface weather at 0600 c.s.t. A, July 30, 1978; B, July 31, 1978.
METEOROLOGICAL SETTINGS AND PRECIPITATION DISTRIBUTION

120° 115° 110° 105° 100° 95° 90° 85° 80° 75°

30°

20°

135° 130° 125° 120° 115° 110° 105° 100° 95° 90° 85° 80° 75

50°

45°

40°

35°

30°

25°

20°

EXPLANATION

Cold front v * <r Stationary front 

Warm front 08 Isobars. 08 stands for 1008 millibars,

12 stands for 1012 millibars

B JULY 31, 1978 

H Center of high pressure 

L Center of low pressure
FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

135° 130° 125° 120° 115° 110° 105° 100° 95° 90° 85°

20°

135° 130° 125° 120° 115° 110° 105° 100° 95°

C AUGUST 1, 1978

85° BD° 75°

50°

45°

20°

D AUGUST 2, 1978 

FIGURE 4. Surface weather at 0600 c.s.t. C, August 1, 1978; D, August 2, 1978.
METEOROLOGICAL SETTINGS AND PRECIPITATION DISTRIBUTION

135° 130° 125° 120° 115° 110° 105° 100° 95° 90° 85° 80° 75°

20°

135° 130° 125° 120° 115° 110° 105° 100° 95° 90° 85° 80° 75°

45'

40°

30°

20°

F AUGUST 4, 1978

FIGURE 4. Surface weather at 0600 c.s.t. E, August 3, 1978; F, August 4, 1978.
8 FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

The evolution of the 500-mb circulation pattern from 

July 30-Augiist 4 is shown in figures 5A-F. It was characterized 

by flat contour gradient and very light southerly wind 

during the entire storm period. It was not until the morning 

of August 4 that the winds picked up over central Texas. At 

0600 August 1 a vorticity center (fig. 5C, marked with X) 

with the central value greater than 8x10 's ' was located over 

northern Mexico just south of Del Rio, Texas. This vorticity 

center later migrated northward through the hill country 

and was over north-central Texas by the morning of August 

3 (not shown). This vorticity center, combined with the 

remnants of Amelia and strong northward flow of moisture, 

all played a role in the extreme precipitation.

The evolution of dewpoint temperatures at Corpus Christi, 

San Antonio, and Abilene from July 31 to August 4, adjusted 

to 1,000-mb level for easy comparison, is shown in figure 6. 

A common measure of moisture used in many hydrometeorological studies is the persisting 12-hour 1,000-mb dewpoint. 

The surface dewpoints at observing stations are reduced to 

1,000 mb adjusting the observed values at the moist adiabatic 

lapse rate. The persisting 12-hour 1,000-mb dewpoint then 

is the value that has been equaled or exceeded for a time 

interval of 12 consecutive hours. Studies have been conducted 

to determine smoothed regional and monthly values of this 

measurement of moisture (Environmental Science Services 

Administration, 1968). These values for Texas in late July 

and early August vary from just over 78°F (degrees Fahrenheit) 

near the coast to 58°F at Abilene. At Corpus Christi from 

the early afternoon of July 31 to midday of August 4, the 

dewpoint temperature was within a few degrees of this 

climatological extreme. In fact, the previous record was just 

slightly exceeded during the night of July 31-August 1 

when the dewpoint temperature stayed at 79°F. At San 

Antonio and Abilene, the departures from the climatological 

extremes were slightly greater than at Corpus Christi. At 

San Antonio it was about 6°F below. Early in the period the 

dewpoint at Abilene was considerably below the extremes. 

It continued to increase as the moist air moved northward, 

and by the evening of August 3, was within about 9°F of the 

climatological extremes.

General comparison can also be made between dewpoint 

temperatures in figure 6 and the August mean dewpoint 

temperatures, also adjusted to 1,000 mb, which was 74°F at 

Corpus Christi, 70°F at San Antonio, and 67°F at Abilene 

(Environmental Science Services Administration, 1968). The 

observed dewpoints were considerably higher than the climatic 

values at Corpus Christi from the evening of July 31 through 

the morning of August 4 and also at Abilene from the 

afternoon of August 2 through the morning of August 4. 

This high moisture content was not limited to the surface 

level. The evolution of precipitable water from the surface 

to 500 mb in Texas and vicinity is shown in figure 7. High 

precipitable water content of 1.50 in. or more already covered 

coastal and southern Texas by the morning of July 31. By

the morning of August 1, the southeastern two-thirds of 

Texas had precipitable water in excess of 1.50 in. By 0600 

August 2, the area with precipitable water greater than 1.50 

in. covered central Texas, while there was a reduction of 

precipitable water in other regions.

The rawinsonde station closest to the precipitation center 

in the north-central Texas region of the big country is 

located at Stephenville, approximately 75 mi east-southeast 

of Albany. The sounding at 0600 August 2 (at Stephenville) 

had total precipitable water of 1.72 in. from the surface to 

500 mb. Precipitable water climatic statistics for Stephenville 

were not available for comparison. The nearest station with 

statistics available is at Fort Worth, 60 mi northeast of Stephenville. 

At Fort Worth, the mean monthly precipitable water for 

August was 1.41 in. with standard deviation of 0.30 in.

Temperature and trajectories at 850 mb for 0600 August 1 

and August 2 are shown in figures 8A-B. For example, an 

air parcel arriving at 850 mb near Fort Worth during the 

morning of August 1 originated over the Gulf of Mexico 

about 40 mi east of Corpus Christi 24 h earlier. By inference, 

an air parcel arriving at 850 mb over the vicinity of Medina 

would have originated over a Gulf region further south. 

Both figures show that warm advection was prevalent and 

Gulf air was continuously being brought into central Texas.

The rawinsonde station near Victoria, Texas, is located 

upstream and to the southeast of the precipitation center of 

the hill country storm. Total precipitable water from the 

surface to 500 mb at Victoria was 1.97 in. at 0600 on both July 

31 and August 1. For comparison, the corresponding mean 

August precipitable water at Victoria was 1.46 in. with standard 

deviation of 0.27 in. (Lott, 1976). The observed mean of 

semimonthly maxima of precipitable waters at 0600 for the 

last half of July was 1.83 in. with standard deviation of 0.18 

in. and for the first half of August was 1.82 in. with standard 

deviation of 0.17 in. (Ho and Riedel, 1979). These climatic 

statistics, however, should be viewed with some caution 

because they were derived from a data sample of 7 years of 

data at Victoria (July 1966-December 1972) combined with 

21 years of data at San Antonio (January 1946-June 1966). 

The maximum observed value for the period of record for 

the last half of July was 2.10 in. observed on July 22, 1972, 

and for August it was 2.26 in. observed on August 4, 1966. 

The observed precipitable water thus exceeds the average 

maximum values and were within 15 percent of the highest 

observed. Surface wind was southeasterly at 10 kn and 

the 500-mb wind over Victoria was southeasterly at 20 

kn at 0600 both days. There is no doubt that very moist 

maritime air brought in by the prevailing southeasterly 

flow through midtroposphere was in place prior to the 

outbreak of the storm over the hill country during the 

night of July 31-August 1.

FIGURE 5(facing page). 500-mb analysis at 0600 c.s.t. A, July 30, 

1978; B, July 31, 1978.
METEOROLOGICAL SETTINGS AND PRECIPITATION DISTRIBUTION

150° 140° 130° 120° 110° 100° 90° 80C 70° 60° 50°

20°

150° 140° 130° 120° 110° 100° 90°

A JULY 30, 1978

60° 50°

20°

EXPLANATION B JULY 31, 1978

L Center of low pressure 5 7 6 Height contours in decameters. 576 stands for 5760 meters

H Center of high pressure ~15 Isotherms in degrees Celsius. 15 stands for 15° C 

The heavy dashed line encloses X, a vorticity center with corticity greater than 8 X 10~5 sec." 1
10 FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

150° 140° 130° 120° 110" 100° 90° 80° 70° 60° 50°

20'''

C AUGUST 1, 1978

60° 50°

D AUGUST 2, 1978 

FIGURE 5. 500-mb analysis at 0600 c.s.t. C, August 1, 1978; D, August 2, 1978.
METEOROLOGICAL SETTINGS AND PRECIPITATION DISTRIBUTION

150° 140° !30° 120° 110° 100° 90° 80° 70° BOC 50°

11

150° 140° 130° 120° 110" 100° 90° 80° 70°

F AUGUST 4, 1978 

FIGURE 5. 500-mb analysis at 0600 c.s.t. E, August 3, 1978; F, August 4, 1978.
12 FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

85

80

75

70

Corpus Christ!

80 iiiiiir 

San Antonio

70

65

60

75

70

65

60

55

i I i I

0 6 12 18 0 6 12 18 0 6 12 18 0 6 12 18 0 6 12 18 0 CDT 

July 31 Aug 1 234

FIGURE 6. Evolution of 1000-mb dewpoint temperature at Corpus Christi, 

San Antonio, and Abilene from July 31 to August 4, 1978.

Synoptic scale rising (sinking) motion provides an environment 

favorable (unfavorable) to the development of mesoscale 

convective systems. Floods resulting from convective storms 

that produce heavy rainfall are most unlikely to occur in an 

environment of strong synoptic scale subsidence and sinking 

motion. This is an example of the control exerted by the 

synoptic scale on smaller scale events. The 12-hour net 

vertical displacement for air parcels reaching 700 mb at 

0600 and 1800 was positive (upward) over central Texas 

during July 31-August 5. The only brief interlude was 12 

hours ending at 0600 August 2, when the net vertical displacement 

was downward over north-central Texas. This was at a time 

before there was significant weather over north-central Texas. 

This subsidence field in effect prevented moist low-level air 

from rising, thus building up the potential for intense convective 

activity later on. The net vertical displacement (north-central 

Texas) reverted to positive again after the morning of August 

2 and prior to the storm outbreak in Albany and vicinity. 

This rising motion persisted and intensified during the 

evening of August 3 and throughout the morning of August 

4.

The stability prognosis indicated a K Index greater than 

32 over the hill country during the morning of July 31, 

increasing to more than 40 in the evening. The K Index is a

measure of the air-mass moisture content and static stability, 

and is given by:

K=(T850-T500)+Td ,850-(T700-Td ,700)

where T and Td are temperature and dew point, respectively, 

in degrees Celsius; and the subscripts denote pressure level, 

in millibars. The larger the K Index of the air mass, the 

more unstable the air mass is. In general, a K Index greater 

than 35 is associated with numerous thunderstorms; an 

index smaller than 20 with no thunderstorms.

The 12-hour net vertical displacement of an air parcel 

arriving at 700-mb level over southeastern Texas in the 

evening of July 31 was 20 mb. This corresponded to a 

synoptic scale rising motion of 0.5+ cm/sec (centimeter per 

second). By itself, this was a moderate rising motion, but it 

was a relative maximum. Figure 9 shows these two parameters 

at 1800 July 31, just prior to the first rain event over the hill 

country. By Tuesday morning, the vorticity center formerly 

over Mexico had crossed the Texas border. The moisture 

envelope also reached as far north as the Balcones Escarpment, 

which runs from the Del Rio area to San Antonio and 

northeastward to Austin. This is an uplift zone where surface 

elevation rises some 800 ft in about 10 mi and marks the 

beginning of the rough terrain that froms the Edwards 

Plateau.

With the meteorological factors so favorable, convective 

storms developed and rain began to fall during the night of 

[uly 31-August 1 over the eastern part of the hill country 

through the San Antonio area. The rain continued during 

the morning, spreading northwestward. Total rainfall amounted 

to 4-5 in. which primed the area where much heavier rain 

would fall later. The Manatt Ranch, about 11 mi northwest 

of Medina on the upper tributary of Little Rocky Creek, 

which is tributary to the Medina River, had 5 in. during this 

first burst. The city of Kerrville, 18 mi north-by-east from 

Medina, received 6 in. during this initial rain.

Convective activity over the hill country diminished sharply 

during the afternoon of Tuesday, August 1. By Tuesday 

evening, however, convection intensified over southern Texas 

and slowly spread northward toward the hill country. By 

2200, the first light rainfall moved into the Medina and 

Guadalupe River watersheds. Satellite pictures revealed 

that the large area of convection in south-central Texas had 

diminished partially in late evening. But by midnight Tuesday, 

new cells had developed within the decaying area, about 

40-50 mi west of San Antonio. These new cells grew rapidly 

in size and intensity and moved very slowly through Bandera, 

Kerr, Gillespie, and Kendall Counties, producing torrential 

rain in the early morning hours of Wednesday, August 2. 

The rains diminished later in the morning, but Manatt 

Ranch received over 31 in. of rain during this second major 

rainfall burst. The city of Medina received more than 24 in. 

Headwater regions of the Guadalupe River centered around 

Kerrville received over 11 in.
METEOROLOGICAL SETTINGS AND PRECIPITATION DISTRIBUTION 13

July 31 August 1

August 2 August 3 August 4 

FIGURE 7. Evolution of precipitable water from surface to 500-mb at 0600 c.s.t.. July 31 to August 4, 1978.

Rain continued during much of Wednesday at a slightly 

reduced rate and over a more northern region north and 

northwest of the upper Guadalupe and Medina basins, but 

by about 1900, scattered convective showers started further 

south in northwestern Bandera County. Around 2230, satellite 

IR (infrared) imagery showed that the cells started to intensify 

and expand rapidly, spreading northeastward over central 

Kerr County, western Gillespie and southeastern Mason 

Counties. The precipitation center, with rainfall exceeding 

20 in., was located in west-central Gillespie County. Rainfall 

was heaviest from just prior to midnight to the early morning 

of Thursday, August 3. Manatt Ranch was again in the path 

of the storm and had an additional 12 in. of rain during this 

third and last major rain burst over the hill country. Therefore, 

in 3 days ending August 3, the Manatt Ranch had a total 

rainfall of more than 48 in. This set a new United States 

record for extreme point rainfall in 72 hours although most 

of the rain at the Manatt Ranch fell within 52 hours. Hunt 

10W recorded 7.5 in. during this burst, while nearby Ingram 

received nearly 16 in. Medina, which recorded 24 in. of rain 

the previous night, had only 0.6 in. during the night of

August 2-3, revealing the northward progression of the 

storms. The areal rainfall distribution of the second major 

burst during August 2 and the third major burst during 

August 3 over the hill country is shown in figure 10.

The National Weather Service operates an S-band WSR-57 

weather radar at Hondo, about 45 mi south-southeast from 

the maximum precipitation area centered in a grid square 

30 nmi on a side (900 nmi2 ) enclosing the Manatt Ranch. 

The accumulated rainfall from 1830 August 1 to 0730 August 

2, conservatively estimated from radar Video Integrator 

Processor (VIP) levels for this grid square, was about 11 in. 

The same conservative estimate from 1850 August 2 to 0530 

August 3 was about 20 in. (Moore and Smith, 1979). This 

suggested that areal average rainfall was much heavier on 

the second night than on the first night. A more detailed 

analysis as represented by figure 10, indicated that the 

center (periphery) of the maximum storm rainfall was indeed 

over the ranch on the first (second) night, with a major 

portion of area of heaviest rain outside (inside) of the grid 

square on the first (second) night. This may partly explain 

the apparent difference between the time of maximum point
14 FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

EXPLANATION B AUGUST 2, 1978 

 25 850-mb temperature, in degrees Celsius | I-H*" 24-hour trajectories, in 6-hour increments

FIGURE 8. 850-mb temperature and 24-h trajectory valid at 0600 c.s.t. A, August 1, 1978; B, August 2, 1978.
METEOROLOGICAL SETTINGS AND PRECIPITATION DISTRIBUTION 15

oEXPLANATION

 0 Net vertical displacement of air parcels, in mb/12-hours

12 12 K index, in degrees Celsius (°Q 

FIGURE 9. 700-mb, 12-hour net vertical displacement and K Index valid al 1800 c.s.t., July 31, 1978.

rainfall at Manatt Ranch (31 in. the night of August 1-2) and 

the time of maximum areal rainfall estimated by radar (the 

night of August 2-3).

The prevailing south or southeasterly flow over the Gulf 

Coast and central Texas persisted through August 4. By the 

morning of August 1, the warm maritime air mass was 

advancing into north-central Texas. A further increase in 

dewpoint occurred at Abilene during August 2-3 (fig. 6), 

indicating strong local moisture convergence. An area of 

strong vorticity (>8xlOV) was now situated over northcentral Texas. The surface analysis showed that a cold front, 

which earlier had extended from Idaho and Colorado, through 

Kansas eastwards, had now passed the panhandle area. Ahead 

of this front, a trough formed briefly and the pressure 

dropped noticeably along the trough. By 2111 August 3, the 

cold front had reached north-central Texas and briefly became 

stationary, but started to move southward again as a cold 

front by the early morning of August 4.

Strong convection due to the interaction between this 

front-trough system and the maritime air mass coming from 

the south produced heavy rain in Haskell, Throckmorton, 

and Shackelford Counties in the big country (north-central 

Texas) beginning during the early morning of August 3. 

Rain was most intense during the evening and night of 

August 3-4. Major portions of these three counties received 

amounts greater than 10 in. in 2 days. Some areas of Shackelford 

County had more than 25 in., with a maximum of 32.5 in. 3 

mi west of Albany.

Albany is a ranch town of 2,000 people situated on the 

north bank of a tributary to the Brazos River. Shackelford 

County, like most of the big country that surrounds Abilene, 

is considerably flatter and drier than the hill country. It is 

mostly an area of wide open space devoted to large-scale 

farming and ranching. The terrain is not particularly hilly, 

elevations range from 1,300 to 1,900 ft above NGVD. Moist 

tropical air masses occasionally penetrate this deep into
16 FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

99°

?"*K I MnfB L E?l X

0 10 20 30 40 KILOMETERS

EXPLANATION

Total rainfall, in inches, August 2

 Total rainfall, in inches, Augusts 

* Manatt Ranch

FIGURE 10. Isohyetal analysis for south-central Texas, August 2-3, 1978.

Texas, but excessive rainfall and flash flooding are somewhat 

less common and usually less severe than in the hill country 

or coastal region.

The NOAA Geostationary Operational Environmental 

Satellite (GOES) is constantly looking at the earth's cloud 

pattern from 22,500 mi in space in an earth synchronous 

orbit. The GOES image was very valuable during this 

meteorological event to reveal that high-level outflow persisted 

even after the surface low had vanished. However, quantitative 

precipitation estimates using the Schofield-Oliver technique 

(Schofield and Oliver, 1977) were found to be considerably 

lower than the observed amount. The original technique 

was designed for short-lived isolated thunderstorms with 

large updrafts and rapidly expanding anvils. Long-lived, 

slow-moving large-area thunderstorm systems such as those

that occurred over the Texas hill country during August 

2-3 or over the Texas big country during August 3-4, are 

associated with strong, steady-state updrafts and outflows. 

The subsidence outside the rainshaft causes the anvil to 

erode at its outer edge as fast as new cloud material arrives 

at the tops of the storm. Heavy rain could fall continuously 

without any visible sign of anvil expansion. Also a slowmoving thunderstorm cluster could remain in the same 

area for 3 or more hours, as did the thunderstorm systems 

that yielded torrential rain over the hill country during 

August 1-3 and over the big country during August 3-4.

As a result, large areas become greatly saturated and 

there is no longer any dry air entrainment into the sides of 

individual updrafts in the center of the cluster. Entrainment 

of dry air not only reduces the moisture content of the
METEOROLOGICAL SETTINGS AND PRECIPITATION DISTRIBUTION 17

FIGURE 11. GOES infrared imagery. A, 0100 c.s.t., August 2, 1978; B, 0200 c.s.t., August 2, 1978; C, 1930 c.s.t,, August 3, 1978; D,

2030 c.s.t., August 3, 1978.

rising column but also tends to produce a lapse rate of 

temperature for the saturated parcel greater than the saturated 

adiabatic lapse rate to reduce the buoyancy forces and inhibit 

further cumulus growth. Without this inhibitive factor, convective 

cells in the central part of a storm system would be able to 

produce much more rain than isolated thunderstorms.

Schofield and Oliver (1980) proposed an improved rainfall 

estimation procedure based mainly on the experience of 

applying rainfall estimation technique to the storms over 

central Texas under discussion. Using satellite IR imagery 

and taking into account the saturated environment factor, 

they estimated a rainfall of 11.05 in. at 4.5 mi northwest of
18 FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

Medina during the 6^ hours ending 0400 August 2. However, this still represented an underestimate of about 4.5 

in. The reason for the difference is that by its nature, 

GOES IR rainfall estimation is approximately an 80-km2 

(square kilometer) areal average, while surface observation 

can be a point maximum.

Klazura (1971) measured drop-size distributions in warm 

cumuli over southeast Texas. He confirmed the expectation 

that the higher the cloud builds, the broader the dropletsize spectrum and the larger the concentration of large 

drops; this in turn leads to a highly efficient collisioncoalescence process for rain formation. The enhanced GOES 

IR images at 0100 and 0200 August 2 and again at 1930 and 

2030 August 3 are shown in figures 11A-D. These were time 

periods when each storm had rapid development. The growth 

of the cumulonimubus towers was evident. At 2030 August 3 

the storm over north-central Texas had a cloudtop temperature 

of -80°C (degrees Celsius), which translated to a cloudtop 

height exceeding 55,000 ft. Comparable heights were reached 

by cloud towers associated with the hill country storm. The 

radar summary issued by the National Weather Service 

indicated that an echo top of 40,000 ft was observed over the 

hill country at 0530 August 4. The existence of high cloud 

tops and high echo tops suggested high precipitation efficiencies. 

The difference in cloud heights between those reported by 

radar summary and those sensed by satellite radiometer in 

this instance is, of course, due mainly to the difference in 

time of observation. However, even if observation time is 

the same for the same cloud, radar summary usually reports 

a lower height than that reported by satellite observation. 

This is because radar detects lai ge precipitation-size particles 

such as rain drops or graupels but cannot detect much 

smaller, supercooled cloud droplets and small ice crystals 

near the cloud top where temperatures are sensed by satellite 

IR radiometer.

The disastrous Texas floods of August 1-4, could be recognized 

as the result of two separate major storms of different origin 

and distinguishable time and geographical context but with 

some shared features. The presence of very moist maritime 

air that originated in the Gulf of Mexico and the presence of 

positive vorticity advection preceded the outbreak of both 

storms. In the case of the storm of August 1-3 over the hill 

country, moist Gulf air mass initially was brought into 

south-central Texas by the cyclonic circulation of the remnant 

of tropical storm Amelia. Considerable rain fell over the 

Texas Coastal Plains and over part of the hill country during 

the night of July 31-August 1. The very unstable atmospheric 

structure with high K Index remained over south-central 

Texas as well as the continuation of warm air advection after 

filling of Amelia. There was an established pattern throughout 

the duration of the storm that convective activity would 

subside during the day but would reinvigorate as evening 

approached. During the nights of both August 1-2 and 

August 2-3, thunderstorms developed over the southern

part of the hill country. Satellite IR pictures showed that as 

the cells grew, merged, and then slowly moved northward 

against the Balcones Escarpment, orographic lifting enhanced 

the release of convective instability thus increasing rainfall 

intensity. Major contributions to rainfall for the hill country 

storm were observed on these two nights.

The storm of August 3-4 over the big country resulted 

from the interaction of a cold front with the maritime air 

mass that penetrated deeply into north-central Texas. This 

deep penetration of maritime air was the result of the persistent 

southeasterly flow field through a deep layer for at least 2 

days prior to the storm outbreak over Albany and vicinity 

during the early morning hours of August 3. Orography 

was not a factor for the August 3-4 storm; rainfall covered a 

larger area than that of the hill country storm. The major 

contribution of the storm rainfall was in a single major 

rainburst during the night of August 3-4.

Selected mass rainfall curves at locations near each precipitation 

center are shown in figure 12. Rainfall curves for Hunt 10W 

and Stamford 2 were derived from recording gages, other 

curves were constructed from bucket survey data with limited 

time resolution. It is clear, however, that the rainfall rates 

were intense. For example at the northern center, a total 

amount of 32.5 in. fell at Albany 3W, but 23 in. of the total 

fell during an 8-hour period ending at 0200 August 4. 

Lsohyetal analyses of the storm centered near Medina is 

shown in figure 13A and for the storm centered near Albany 

in figure 13B.

Preliminary depth-area-duration analysis of the hill country 

storm with a maximum centered near Medina is shown in 

figure 14A and for the big country storm with a maximum 

centered near Albany is shown in figure 14B. A comparison 

with the areal rainfall of historic storms with those that 

occurred during the summer of 1978 over central Texas 

(Shipe and Riedel, 1976) is given in table 1.

It is evident from the depth-area-duration analyses that 

the storms of August 1978 were indeed extraordinary. Rainfall 

in the Medina storm established summer season records 

over 100-mi2 areas for durations of 6, 12, and 48 hours and 

over 200-mi2 areas for durations of 6 and 12 hours. The 

Albany storm was characterized by a record-setting 24-hour 

rainfall over 100-mi2 and 200-mi2 areas. It should be noted, 

however, that the period of comparison in table 1 covers 

June to August only; the September 8-10, 1921, storm 

centered in Thrall, Texas, for example, was not included. 

Comparisons between the extreme point rainfalls in these 

recent storms and corresponding 100-year return period 

amounts (Hershfield, 1961; Miller, 1964) are shown in 

table 2. The rare intensity of the storms is apparent.

Comparisons between the maximum at Manatt Ranch 

with the most extreme point rains known in the United 

States for 6- to 72-hour durations are shown in table 3. The 

last line lists the world record rains for 1, 2, and 3 days 

observed at Cilaos, La Reunion, an island east of Madagascar
METEOROLOGICAL SETTINGS AND PRECIPITATION DISTRIBUTION 19

TABLE 1. Comparison of maximum storm rainfalls with that of historical storms over central Texas in

the summer season.

Area Duration 

(mi2) (hours)

1

*

100 6 

12 

24 

48

100 6 

12 

24 

48

,000 6 

12 

24 

48

Greatest on record 

(central Texas)

In. Date

12.7 (June 27-July 4, 1936) 

16.5 (June 28-30, 1940) 

25.8 (June 30-July 2, 1S32) 

30.0 (June 27-July 1, 1899)

12.2 (June 27-July 4, 1936) 

15.6 (June 28-30, 1940) 

23.8 (June 30-July 2, 1934) 

29.5 (June 27-July 1, 1899)

10.9 (June 27-July 4, 1936) 

12.3 (June 27-July 4, 1936) 

21.1 (June 27-July 1, 1899) 

27.1 (June 27-July 1, 1899)

Depth (in.)

Medina center Albany center 

(Aug. 1-3, 1978) (Aug. 2-4, 1978)

15.4* 8.7 

20.0* 16.0 

24.0 27.3* 

31.6* 30.0

13.8* 8.2 

17.7* 15.0 

21.5 25.5* 

28.5 28.1

9.1 6.4 

12.0 11.5 

15.0 19.6 

20.3 21.7

Denotes record- sett ing event in the summer season.

TABLE 2. Comparison between storm rainfalls and 1 00- yr amounts

Location

Medina 11NW

Location

Albany 3W

100-year Storm 

24-hour rain 24-hour rain 

(in.) (in.)

9.05 30* 

(ending 0600 

Aug. 2, 1978)

100-year Storm 

24-hour rain 24-hour rain 

(in.) (in.)

8.8 29.05 

(Aug. 4, 1978)

100-year Storm 

3-day rain 3-day rain 

(in.) (in.)

11.4 >48 

(52 hours 

Aug. 1-3, 1978)

100-year Storm 

2-day rain 2-day rain 

(in.) (in.)

10.0 30.25 

(48 hours 

Aug. 3-4, 1978)

* Approximate.

TABLE 3. Comparison of extreme point rainfalls in the United States and the world.

Storm

Smethport, Pa. (July 17-18, 1942)

Thrall, Tex. (Sept. 8-10, 1921)

Yankeetown, Fla. (Sept. 3-7, 1950)

Manatt Ranch (Aug. 1-3, 1978)

Cilaos, La Reunion (Mar. 15-18, 1952)

Duration (hours)

6 12 18 24 

Amount (in.

+30.8 34.3

36.4 38.2

38.7

73.62

48 72

39.7

43.1

98.42

45.2

>48 (52 

hours)

127.56
20 FLOODS IN CENTRAL TEXAS, AUGUST 1-4,1978

50

40

30

20

10

i i i r

Hunt 10 W 

(30°03' N, 99°31'E)

 14"3

Medina 3W

f

Medina 8N

i | i i i | i r

Medina 11 NW

' 48"+

(Manatt 

Ranch) _

0 i I/ I I I i I i I i i i 

0 12 18 0 6 12 18 0 612180 6 12 18 0 6 12 18 0 6 12 18 0 6 12 18 0 6 12 18 0 612180 6 12 18 0 6 12 18 0 6 12 18

^ Aug 1 3 Aug 1 3 Aug 1 3 Aug 1

40

30

20

10

"I I I | I I I | I I r 

Albany 7NW

Stramford 2 

(32°57' N, 

99°48' E)

Albany 1 N

Albany 3W 

32".5

0 6 12 18 0 6 12 18 0 6 1218 0 6 12 18 0 6 12 18 0 6 12 180 6 12 18 0 6 12 18 0 6 12 18 0 6 12 18 0 6 12 18 0 6 12 180 

Aug 234 Aug 234 Aug 234 Aug 234

FIGURE 12. Mass rainfall curves at selected rain gages, August 1-4, 1978.

in the Indian Ocean, where elevations rise to 10,000 ft in 

10-15 mi from the shore (Paulhus, 1965).

Rainfall extremes set the very lowest limit to estimates of 

probable maximum precipitation (PMP). The record of 

more than 48 in. observed during August 1-3, 1978, 11 mi 

northwest of Medina in the hill country reached 95 percent 

of the all-season probable maximum precipitation (PMP) 

for 72 hours and 10 mi2 at that location (Schreiiier and 

Riedel, 1978) and will constitute important input in future 

PMP studies.

DESCRIPTION OF THE FLOODS

Flooding to some degree occurred in an area of approximately 

25,000 mi2 in parts of the Nueces, Guadalupe, Colorado, 

and Brazos River basins. A summary of flood stages and

discharges for selected sites is given in table 4; the locations 

of the sites are shown in figure 1. The locations of discontinued 

streamgaging stations and miscellaneous discharge-measurement 

sites are given in table 5.

NUECES RIVER BASIN

During the early part of the storm on August 1, substantial 

rain fell on the headwaters of the Sabinal River, Hondo 

Creek, and Seco Creek in the Nueces River basin. The 

greatest 24-hour amount recorded by the National Weather 

Service in this basin was at Vanderpool in Bandera County, 

where a total of 11.53 in. fell in the 24-hour period ending at 

0700 August 2. Sharp rises occurred on many streams, but 

flooding was minor.
DESCRIPTION OF THE FLOODS 

TABLE 4. Summary of flood stages and discharges

21

Map

number

1

2 

3

4

5

6

7

8

9

10 

11

12 

13

14

IS 

16

17

18

19

20 

21

22 

23

24 

25 

26

27

28

29

30

31 

32

33

34 

35 

36

37

38

HRD 

station

number

08082SOO

0808. 700 

08082800

08082900

08083240

0808324S

08083300

08083400

08083420

08083470 

08083500

08084000 

08084500

08084800

08085300 

08085500

08086050

080861SO

08086212

08086290 

08086400

08086500 

08087300

08038000 

08088300 

08088400

08088450 

08088SOO

08089000 

08092600

08098290 

08099000

08099100

08099300 

08099400 

08109SOO

08114000

08116650

Stream and place of 

determination

BRAZOS RIVER BASIN

Brazos River at Seymour

Millers Creek near Munday

Millers Creek Reservoir near 

Bomarton

North Elm Creek near 

Throckmorton 3/

Clear Fork Brazos River at 

Hawley

Mulberry Creek near Hawley

Elm Creek near Abilene

Little Eln Creek near Abilene

Cat Claw Creek at Abilene

Cedar Creek at Abilene

Fort Phantom Hill Reservoir 

near Nugent

Nugent 

Lake Stamford near Haskell

California Creek near Stamford

Humphries Draw near Haskell 3/

Fort Griffin

Deep Creek at Horan 3/

North Fork Hubbard Creek near 

Albany

Hubbard Creek below Albany

Big Sandy Creek above 

Breckenridge

Hubbard Creek Reservoir near 

Breckenridge

Itubbard Creek near Breckenridge

Eliasville

Brazos River at South Bend

Lake Graham near Graham

Big Cedar Creek near Ivan

Possum Kingdom Reservoir near 

Graford

Brazos River near Palo Pinto

Brazos River at Whitney Dam 

near Whitney

Brazes River near Highbank 

Leon Reservoir near Ranger

Leon River near De Leon

Sabana River near De Leon 

Proctor Lake near Proctor

Brazos River near College 

Station

Brazos River at Richmond

Brazos River near Rosharon

Contributing drainage area 

(mi 2 )

5,972

104 

240

3.58

1,416

205

133

39.1

13.0

119

470

2,199 

368

478

3.51

228

39.3

613

280 

1,085

1,039 

5,697

13,107 

24.2 

221

97.0 

14,030

14,245 

16,950

20,870 

259

479

264 

1,259 

30,033

35,441

35,773

Period 

of 

known 

floods

1906-78

1883-1978 

1974

1966

1915

1932

1963

1903

1970

1970 

1940

1876 

1953

1897

1966 

1876

1888

1940

1966

1949 

1962

1925 

1877

1876 

1900 

19S8

1964 

1941

1876 

1853

1909 

1955

1908

1890 

1963

1852

1884

Maximum flood 

previously known

Date

Sept. 28, 195S

June 1.5, 1930 

June 3, 1977

Apr. 30, 1966

1932

1957

Sept. 18, 1974

1913

Sept. 18, 1974

Sept. 18, 1974 

May 25, 1957

1876 

Sept. 9-10, 1962

June 10, 1962

Aug. 5, 1971 

Sept. 1900

June 6, 1961

June 10, 1940 

July 18, 1953

Jan. 21, 1968

May 16, 1949 

July 20, 19S3 

Apr. 29, 1957

Feb. 3, 1975

July 20, 1953

Sept. 1900 

May 1. 1957

1876 

Sept. 1955 

Apr. 30, 1970

July 8, 1968 

Oct. 5, 1941

1876 

May 9, 1922

Dec. 1913 

June 13, 1967

May 1908

May 1908 

Jan. 26, 1968

Dec. 10, 1913

Dec. 11, 1913

Stage 

(feet)

23.00

>18.0 

,309.89

26.28

I/

16.0

18.68

15.0

6.41

12.54 

58.7

30.0 

1,416.6

29.6

19.41 

38.0

25.6

21.0

25.10

24.6 

1,183.61

34.2 

35.0

36.2 

IS.. 2 

1,077.77

22.39 

1,001.0

§/ 

45.0

42.0 

1,382.2

19.3.

24.0 

1,174.84

51.2

56.4

Discharge 

(ftVs)

71,200

I/ 

1/3,440

1,350

I/

I/

4,570

!/

1,200

4,670 

2/89,910

I/ 

2/74,100

If

1,840 

I/

I/

I/

27,200

If

2/327,200

I/ 

If

y 

If

2/61,120

9,590 

2/743,700

11

y

y 

2/5/40.640

I/

I/ 

2/137,500

I/

If

Maximum during 

August 1978 flood

Date 

(1978)

Aug. 5

Aug. 4 

Aug. 6

Aug. 4

Aug. 4

Aug. 4

Aug. 3

Aug. 3

Aug. 3

Aug. 3 

Aug. 6-10

Aug. 4 

Aug. 5

Aug. 4

Aug. 4 

Aug. 4

"

Aug. 4

Aug. 4

Aug. 4 

Aug. 5

Aug. 5 

Aug. 6

Aug. 6 

Aug. 5 

Aug. 5

Aug. 5 

Aug. 12

Aug. 8 

Aug. 10

Aug. 13 

Aug. 6-8

Aug. 4

Aug. 4 

Aug. 4-7 

Aug. 18

Aug. 20

Aug. 21

Stage 

(feet)

14.20

17.53 

1.335.30

30.6

14.64

13.98

13.26

9.50

6.60

11.93 

48.4

9.97 

1,422.18

31.00

19.36 

38.88

21.80

23.3

41.41

21.86 

1,188.06

30.66 

37.04

41.50 

.78 

1.067.61

4.11 

999.69

22.93 

12.81

5.90 

1.369.80

2.47

8.80 

1,154.48

6.90

13.29

Discharge 

CftVs)

28,200

34,600 

2/34 ,480

5,000

2,540

1,770

1,830

1,340

1,310

3,830 

2/50.370

2,840 

2/103,600

40,000

1,830 

149,000

13,000

103,000

330,000

5,140 

-'401,500

14,600 

68,000

78,100 

1.6 

2/36,090

3.0 

2/564,800

54,500 

5/5.710

4.000 

2/20,000

17

617 

2/31.170 

1/4.120

3,850

3.270

Recurrence 

^nterval 

(years)

>100

>100

-

--

--

-

-

MOO

10 

 100

10

>100

>100

--

MOO

25

--

"

"

--

--

"

See footnotes at end of table.
22 FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978 

TABLE 4. Summary of flood stages and discharges Continued

Map

number

39

40

41

42

43

44 

45

46

47

48

49

50

51

52

S3

54

55

56

57

58 

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

WRD 

station

number

08126500

08127000

08136500

08136700

08138000

08140600

08140700 

08140800

08141000

08141500

08143000

08143500

08143600

08144500

08144800

08144900

08145000

08146000

08147000

08148000

08148500

08150000

08150700

08150800

08151500

08152000

08152800

08153100

081S3SOO

08154500

08165300

08165500

08166000

..

08166300

08167000

08167500

Stream and place of 

determination

COLORADO RIVER BASIN

Colorado River at Bal linger

Elm Creek at Bal linger

Concho River at Paint Rock

Colorado River near Stacy

Colorado River at Winchell

Lake Clyde near Clyde

Jim Ned Creek near Coleman

Hords Creek Lake near Valera

Itords Creek near Valera

Lake Brownwood near Brown wood

Pecan Bayou at Brownwood

Pecan Bayou near Mull in

San Saba River at Menard

Brady Creek near Eden

Brady

Brady Creek at Brady

San Saba River at San Saba

Colorado River near San Saba

Lake Buchanan near Burnet

Bear Creek at Interstate Highway 10 near Junction 10/

North Llano River near

Junction 3/

Llano River near Junction

Llano River near Mason

Beaver Creek near Mason

Llano River at Llano

Sandy Creek near Kingsland

Spring Creek near Fredericksburg 3/

Cane Branch at Stonewall 3/

Pedernales River near Johnson

City

Lake Travis near Austin

GUADALUPE RIVER BASIN

North Fork Guadalupe River near

Hunt

Guadalupe River at Hunt

Johnson Creek near Ingram

Turtle Creek at State Highway

16 near Kerrville 10/

Turtle Creek tributary near

Kerrville 3/

Guadalupe River at Comfort

Guadalupe River near Spring

Branch

Contributing drainage area 

fmi'l

5,240

471

5,132

11,160

11,700

37.9

532 

333

48

S3

1.535

1,614

2,034

1,151

97

513

575

3,042

17,720

18,370

155 

914

1,874

3.280

218

4,233

327

15.2

1.37

947

25,250

168

288

114

26.5

.46

838

1,315

Period 

of 

known 

floods

1882

1904

18S3

1882

1882

1970

1900 

1961

1948

1900

1933

1900

1967

1880

1884

1963

1882

1899

1878

1937

1936 

1875

1875

1875

1963

1879

1881

1967

"

1859

1940

1900

1900

1852

_

1848

1859

Maximum flood 

previously known

Date

1884

Aug. 1906

Oct. 13, 1957

Sept. 17, 1936

Sept. 18, 1936

Sept. 19, 1936

May 28, 1975

1908 

May 6, 1969

May 1, 1956

July 3. 1932

May 2, 1956

July 3, 1932

Jan. 23, 1968

June 6, 1899

July 1938

Sept. 24, 1971

July 23, 1938

July 23, 1938

July 23, 1938

Jan. 24, 1968

Sept. 16, 1936 

Sept. 16, 1936

June 14, 1935

June 14, 1935

May 16, 1965

June 14, 1935

Sept. 11, 1952

Aug. 28, 1974

--

Sept. 11, 1952

May 18, 1957

July 1, 1932

July 2, 1932

July 2, 1932

_

_

July 1869

1869

Stage 

(feet)

36.0

5/14.50

14.20

43.4

64.59

62.20

1,873.4 

26.5

9.08

1,906.86

23.0

1,431.4

--

29.26

23.3

15.8

1,747.7

29.1

39.3

63.2

1,020.8

29.2

43.3

-

13.58

41.5

34.2

8.42

"

42.5

707.4

37.3

36.6

35.0

..

..

40.3

53.0

Discharge 

(ftVs)

I/

I/

50,000

301,000

356,000

I/

2/6,370

I/

5,020

2/12,790

i/

2/192,300

2/235,000

13,700

I/

I/

 ~ 40 ,880

86,000

203,000

224,000

2/1,010.000

31,300 

94,800

319,000

 /388.000

23,200

380,000

163,000

7,530

-

441,000

2/1,770,000

140.000

206,000

138,000

..

_

I/

I/

Maximum during 

August 1978 flood

Date 

(1978)

Aug. 3

Aug. 3

Aug. 3

Aug. 4

Aug. 5

Aug. 4

Aug. 4 

Aug. 4

Aug. 5

Aug. 3

Aug. 16-24,

29, 30

Aug. 4

Aug. 3

Aug. 2

Aug. 3

Aug. 3

Aug. 2

Aug. 3

Aug. 4

Aug. 8

/Vug. 3 

Aug. 2

Aug. 2

/Vug. 3

Aug. 3

Aug. 3

Aug. 2

Aug. 3

Aug. 3

Aug. 3

Aug. 4

Aug. 3

Aug. 2

Aug. 3

Aug. 2

_

Aug. 2

Aug. 3

Stage 

(feet)

23.95

9.17

19.11

22.50

31.88

1.875.50 

24.90

5.77

1,887.90

11.06

1.424.4

1.05

6.50

17.36

1.3

1.738.12

8.31

28.38

22.59

1.011.94

23.50

22.14

,21.35

24.00

25.61

8.89

17.0

"

24.9

662.9

26.8

23.5

21.4

_

11.2

40.9

45.25

Discharge 

(ftVs)

16,600

23,400

12,700

35,700

29,600

1/7,420 

16,200

1,830

2/3.570

2,360

2/138,500

47

1,690

35,400

2.1

 21 ,570

536

27,000

28,100

2/814 ,700

81,000 

64,800

76,700

92,500

66,900

139,000

3,610

42,500

<10

127,000

2/868,200

39,300

62,900

73,900

32,700

605

240,000

158.000

Recurrence 

interval 

(years)

-

15

--

"

«

-

--

--

-

"

25

--

--

-

10

--

-

>100

15

"

>100

-

25

--

10

60

..

_

>100

>100

See footnotes at end of table.
DESCRIPTION OF THE FLOODS 

TABLE 4. Summary of flood stages and discharges Continued

23

Map

number

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

KRD 

station 

number

08167600

08167700

08167800

..

08178900

08179000

08179100

08179500

08180500

08180800

08181500

08183900

08195000

08196000

08198000

08200000

08201500

Stream and place of 

determination

Rebecca Creek near Spring

Branch

Canyon Lake near New Braunfels

Cuadalupe River at Sattler

North Prong Medina River near

Medina 10/

Bandera Creek tributary near

Bandera 3/

Medina River near Pipe Creek

Red Bluff Creek near Pipe Creek

Medina Lake near San Antonio

Medina River near Rio Medina 3/

Medina River near Somerset

Medina River at San Antonio

Cibolo Creek near Boerne

NUECES RIVER BASIN

Frio River at Concan

Dry Frio River near Reagan

Wells

Sibinal River near Sabinal

Hondo Creek near Tarpley

Seco Creek at Miller Ranch near

Utopia

Contributing drainage area 

(mi 2 )

10.9

1,432

1,436

67.5

.27

474

56.3

634

650

967

1,317

68.4

405

117

206

86.2

43.1

Period 

of 

known 

floods

1885

1962

1962

1932

_

1880

1905

1913

1922

1890

1939

1892

1869

1875

1892

1907

1901

Maximum flood 

previously known

Date

Sept. 1952

Apr. 22, 1977

Feb. 11. 1975

July 1. 1932

..

1919

Sept. 27, 1964

Sept. 16. 1919

July IS. 1973

July 17, 1973

July 17, 1973

Sept. 27, 1964

July 1, 1932

1880

July 2, 1932

June 17, 1958

June 17, 1958

Stage 

(feet)

25.5

917.96

8.18

_

..

43.0

22.64

1,078.0

23.2

29.39

43.59

19.15

34.44

33.0

33.0

28.2

16.4

Discharge 

(ftVs)

t/

2/460.400

H/5,390

40,200

..

 / 115,000

46.900

2/288,000

28,600

30,500

31,900

36,400

162,000

I/

y

69,800

52,600

Maximum during 

August 1978 flood

Date 

(1978)

Aug. 1

Aug. 4

Aug. 5

Aug. 2

Aug. 2

Aug. 2

Aug. 2

Aug. 2

Aug. 2

Aug. 4

Aug. 4

Aug. 2

Aug. 2

Aug. 1

Aug. 2

Aug. 2

Aug. 2

Stage 

(feet)

2.06

H/930.61

8.31

_

10.9

49.6

3.7

1.076.67

20.0

22.35

29.95

3.65

6.9

5.23

19.43

13.10

8.40

Discharge 

(ftVs)

1.5

2/588,400

5.850

123,000

120

281,000

160

-'281.000

20,100

12,800

1.030

462

3,350

1,500

23,200

13,200

10,600

Recurrence 

interval 

(years)

_

--

..

>100

-

-

"

"

«

"

-

..

--

"

_

y Discharge not determined.

21 Contents in acre-feet.

3/ Discontinued site, see table 2.

4_/ The maximum stage since 1915 occurred in 1932 and the second highest

stage occurred in 1959, 2,510 feet. 

S_/ The maximum stage occurred in 1876 and was several feet higher than

flood of June 16, 1930, 30 feet, 95,600 ft 3 /s. 

6_/ Stage and discharge data at site 08093100. 

7/ At site 6.5 miles downstream.

GUADALUPE RIVER BASIN

The drainage area of the Guadalupe River above Canyon 

Lake received the first of the heavy rainfall during the 

night of August 1 and the morning of August 2. The storm 

cell, which was centered just west of Kerrville in Kerr County, 

produced rainfall amounts that resulted in severe flooding 

on the Guadalupe River and all of its local tributaries. On 

August 2, the flood crest on the Guadalupe River at Comfort 

(site 75, fig. 1) exceeded by 0.6 ft the previously known 

maximum, which occurred in July 1869. When the crest 

reached the Spring Branch gaging station (site 76) on August 

3, the peak discharge had attentuated from 240,000 ftVs 

at Comfort to 160,000 ftVs at Spring Branch. Secondary 

peaks occurred at both stations. A discharge hydrograph 

for Guadalupe River at Comfort is shown in figure 15, and 

data are presented in table 6. A discharge hydrograph for 

Guadalupe River near Spring Branch is shown in figure 16, 

and data are presented in table 7.

Canyon Lake contained all of the flood runoff from the 

Guadalupe River basin above the dam, so no damage occurred

8_/ Backwater from Colorado River.

57 Prior to completion of Lake Brownwood.

107 Miscellaneous site, see table 2.

ll/ At site 17 miles downstream.

12/ Elevation at 2400 hours.

13/ Maximum since closure of Canyon Dam on July 21, 1962. 

14/ From rating extended above 32,000 ftVs on basis of 

	slope-area measurement of 64,000 ftVs.

below Canyon Lake. The contents of Canyon Lake increased 

from 362,200 acre-ft at 2400 August 1 to 588,400 acre-ft at 

2400 August 4. This was the maximum storage since closure 

of the dam on July 21, 1962.

MEDINA RIVER BASIN

A second cell of the storm that caused flooding in the 

Guadalupe River basin was centered near Medina in Bandera 

County where the North Prong and the West Prong of the 

Medina River join. The official total rainfall near the storm's 

center was in excess of 48 in., which resulted in a catastrophic 

flood on the headwaters of the Medina River. A peak discharge 

of 123,000 ftVs from a drainage area of 67.5 mi2 was recorded 

at a miscellaneous site (site 80) on the North Prong Medina 

River about 10 mi upstream from Medina. The maximum 

flood discharge probably occurred a short distance downstream 

from the confluence of the North Prong and West Prong of 

Medina River.
99°30°

30° 15' 

EXPLANATION

sohyet showing precipitation in inches 

Isohyet showing precipitation in inches 

Maximum rainfall 48"+ 

Recording rain gauge

29° 30'

FIGURE 13. Isohyetal analyses for storm centered near: A, Medina; B, Albany.
DESCRIPTION OF THE FLOODS 

TABLE 5. Locations of discontinued stream-gaging stations and miscellaneous discharge-measurement sites

25

Map 

number

Station 

number Name and location

BRAZOS RIVER BASIN

4 08082900 North Elm Creek near Throckmorton. Lat 33'10'SO", long 99°22'05, Throckmorton County, 

Hydrologic Unit 12060101, at culvert on State Highway 24, and 11.3 miles (18.2 kilometers) west of Throckmorton.

15- 0808S300 Humphries Draw near Haskell. Lat 33°10'40", long 99'34'30", Haskell County, Hydrologic Unit 12060101, at culvert on State Highway 24, and 9.3 miles (15.0 kilometers) 

east of Haskell.

17 08086050 Deep Creek at Moran. Lat 32'33'33", long 99 0 10'11", Shackelford County, Hydrologic

Unit 12060105, at downstream side of bridge on U.S. Highway 380, 0.8 mile (1.3 kilometer) north of Moran, and 10.8 miles (17.4 kilometers) upstream from Hubbard Creek.

COLORADO RIVER BASIN

59 Bear Creek at Interstate Highway 10 near Junction. Lat 30°31'57", long 99°50'11", 

Kinble County, Hydrologic Unit 12090202, 1.3 miles (2.1 kilometers) upstream from 

Interstate Highway 10, 1.5 miles (2.4 kilometers) upstream from mouth, and 3.4 miles 

(5.5 kilometers) west of Junction.

60 08148500 North Llano River near Junction. Lat 30°31'06", long 99°48'39", Kimble County, Hydrologic Unit 12090202, 1,000 feet (305 meters) upstream from remains of old Wilson Dam, 

2.1 miles (3.4 kilometers) northwest of Junction, and 4 miles (6 kilometers) upstream 

from confluence with South Llano River.

66 08152800 Spring Creek near Fredericksburg. Lat 30°18'10", long 99°03 T 20", Gillespie County,

Hydrologi 1: Unit 12090206, downstream side of bridge on U.S. Highway 290, and 11 miles 

(18 kilometers) west of Fredericksburg.

67 08153100 Cane Branch at Stonewall. Lat 30°14'07", long 98°39'2rf , Gillespie County, Hydrologic 

Unit 12090206, at culvert on U.S. Highway 290 at Stonewall, and 0.6 mile (1.0 kilometer) upstream from Pedernales River.

GUADALUPE RIVER BASIN

73 Turtle Creek at State Highway 16 near Kerrville. Lat 29°57M1", long 99°12'35", Kerr 

County, Hydrologic Unit 12100201, 0.1 mile (0.2 kilometer) upstream from Lambs Creek, 

at State Highway 16 and 9.0 miles (14.5 kilometers) southwest of Kerrville.

74 08166300 Turtle Creek tributary near Kerrville. Lat 29°58 I 11", long 99°11'02", Kerr County,

Hydrologic Unit 12100201, at culvert on Farm Road 2771, and 5.9 miles (9.5 kilometers) 

south of Kerrville.

80 North Prong Medina River near Medina. Lat 29°51'49", long 99°22'18", Bandera County, 

Hydrologic Unit 12100302, 0.5 mile (0.8 kilometer) upstream from Lima School, and 12.0 

miles (19.3 kilometers) upstream from mouth.

81 08178900 Bandera Creek tributary near Bandera. Lat 29°50 I 51", long 99°06'12", Bandera County, 

Hydrologic Unit 12100302, at culvert on Farm Road 689, and 10 miles (16 kilometers) 

north of Bandera.

85 08180500 Medina River near Rio Medina. Lat 29°29'53", long 98°54'16", Medina County, Hydrologic Unit 12100302, on left bank 233 feet (71 meters) upstream from bridge at Haby's 

crossing, 4.2 miles (6.8 kilometers) northwest of Rio Medina, and 10.4 miles (16.7 

kilometers) upstream from San Geronimo Creek.
26 FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

TABLE 6. Data for gaging station 08167000 Guadalupe River at Comfort 

[Gage height, in feet, and discharge, in cubic feet per second, at indicated time, 1978]

Date

Aug. 1

Aug. 2

Hour

- 0900

1500

1600

1700

1800

1900

2400

- 0300

0400

0500

OGOO

0700

0800

0900

Gage 

height

4.10

4.14

4.36

6.12

8.25

9.85

11.26

11.74

13.24

15.85

22.97

30.98

37.55

40.90

Discharge

50

56

103

1,040

1,990

2,760

3,580

3,960

5,710

10,700

36,000

99,500

183,000

240,000

Date Hour

Aug. 2 - 1000

1100

1200

1500

1800

2100

2400

Aug. 3 - 0300

0500

OCOO

0700

0800

0900

1100

Gage 

height

38.82

36.07

34.19

30.89

26.23

21.36

17.58

15.20

19.38

30.76

33.98

35.08

34.87

33.00

Discharge

203,000

161,000

137,000

98,600

56,400

28,000

14,600

9,260

20,100

97,200

134,000

148,000

145,000

122,000

Date

Aug. 3

Aug. 4

Aug. 5

Aug. 6

Hour

- 1400

1600

1800

2100

2400

- 0600

1200

2400

- 1200

2400

- 1200

2400

Gage 

height

27.83

23.67

19.87

16.45

14.52

12.31

10.88

9.00

8.00

7.49

7.18

7.04

Discharge

69,200

39,900

21,700

12,000

7,870

4,520

3,330

2,340

1,770

1,450

1,260

1,170

Period

Highest mean discharge, in cubic feet per second,

for the indicated number of consecutive days

1 3 7

August 1978 

1940 to July 1978-

74,200

27,300

44,400

13,700

19,800

6,840

10,000

A NEAR MEDINA, AUGUST 1-3

1218 24 48 HOURS

1000

100

10

B NEAR ALBANY, AUGUST 2-4 

18 2448 HOURS

10 15 20 25 30 35 40 0 10 15 20 25

MAXIMUM AVERAGE DEPTH OF RAINFALL, IN INCHES 

FIGURE 14. Depth-area duration analysis for storm centered near: A, Medina; B, Albany.
DESCRIPTION OF THE FLOODS 27

TABLE 7. Data for gaging station 08167500 Guadalupe River near Spring Branch 

[Gage height, in feet, and discharge, in cubic feet per second, at indicated time, 1978]

Date

Aug. 1

Aug. 2

Hour

- 0300

1200

2100

- 0300

0600

1000

1100

1200

MOO

1600

1800

2000

2200

Gage 

height

2.20

2.37

2.55

2.57

2.77

3.07

3.90

5.10

6.60

8.25

10.95

17.70

25.30

Discharge

40

64

95

99

144

232

611

1,290

2,320

3,580

6,050

14,4Cu

27,600

Date Hour

Aug. 2 - 2400

Aug. 3 - 0100

0200

0300

0400

0800

1200

1900

2000

2200

2400

Aug. 4-0100

Gage 

heirjht

34.00

37.00

42.00

45.25

44.40

38.00

32.70

25.60

28.00

32.60

37.00

39.20

Discharge

54,400

94,500

130,000

HO, 000

152,000

96,100

50,000

30,100

37,000

58,100

88,300

106,000

Date Hour

Aug. 4 - 0200

0300

0800

1200

1600

2000

2400

Aug. 5 - 0400

1200

2400

Aug. 6 - 1200

2400

Gage 

height

40.60

39.40

32.30

27.80

21.40

14.00

11.00

9.40

8.00

6.90

5.87

5.85

Discharge

118,000

108,000

56,300

36,400

21,300

10,400

6,920

5,340

4,100

3,240

2,420

2,400

Period

Highest mean discharge, in cubic feet per second,

for the indicated number of consecutive days 

1 3 7

August 1978-------

1923 to July 1978-

76,500

66,100

43,200

32,700

20,100

14,900

240

210 

co 180 

150 

120 

08167000 Guadalupe River at 

Comfort, Texas (drainage area 

838 square miles) 1978

FIGURE 15. Discharge hydrograph of Guadalupe River near Comfort ior August 1-6, 1978.

160

140

120

100

80

60

40

20

08167500 Guadalupe River near 

Spring Branch, Texas (drainage 

area 1315 square miles) 1978

12345 6 

AUGUST

FIGURE 16. Discharge hydrograph of Guadalupe River near Spring 

Branch for August 1-6. 1978.
28 FLOODS IN CENTRAL TEXAS, AUGUST 1-4,1978

TABLE 8. Data for gaging station 08179000 Medina River near Pipe Creek 

[Gage height, in feet, and discharge, in cubic feet per second, at indicated time, 1978]

Date

Aug. 1

Aug. 2

Hour

- 0600

1200

1900

2400

- 0300

0400

0500

0700

0800

0900

1000

1100

Gage 

height

3.88

3.96

3.96

4.22

4.20

7.10

8.20

9.75

11.65

27.95

43.60

49.60

Discharge

16

26

26

60

57

1,060

1,810

3,230

5.3GO

39,000

119,000

281 ,000

Date Hour

Aug. 2-1200

1300

1400

1600

1900

2400

Aug. 3 - 0200

0300

0400

0500

1200

1800

Gage 

height

45.00

38.70

33.20

25.20

18.40

15.55

15.00

20.70

23.00

21.20

15.80

13.40

Discharge

160,000

95,100

64,200

36,100

19,800

14,300

13,300

24,900

30,400

26,000

14,700

10,600

Date

Aug.

Aug.

Aug.

Aug.

Aug.

3

4

5

6

7

Hour

- 2400

- 1200

2400

- 1200

2400

- 1200

2400

- 1200

2400

Gage 

height

10.70

8.60

7.80

7.15

6.65

6.15

5.80

5.45

5.20

Discharge

6,710

4,260

3,450

2,840

2,410

2,000

1,720

1,460

1,260

Period

Highest mean discharge, in cubic feet per second,

for the indicated number of consecutive daye 

1 3 7

August 1978-------

1924 to July 1978-

41,700

23,000

20,100

15,000

9,640

7,900

350

300

o 

$250

EC 

LJJ

£200

gioo 

o

Q

50 -

08179000 Medina River near Pipe 

Creek Texas, 

(drainage area 474 

square miles)

70

60

50

40

30

20

10

08150800 Beaver 

Creek near Mason, 

Texas (drainage area 

218 square miles)

4 5 

AUGUST

3 4 

AUGUST

FIGURE 17. Discharge hydrographs of Medina River near Pipe Creek for August 2-7, 1978, and Beaver Creek near Mason for August 2-5, 1978.
DESCRIPTION OF THE FLOODS 29

400,000

l-v O

CO lO

in CM CM _ d d

100,000

' 10,000

1000

100

Station data (1923-78) plotted as recommended by Water Resources Council (1977) 

guidelines (Bulletin 1 7A)

o o

o o

CM in

RECURRENCE INTERVAL IN YEARS

FIGURE 18. Log-Pearson Type III frequency curve for Medina River 

near Pipe Creek.

The flood crest reached the stream-gaging station Medina 

River near Pipe Creek (site 82) on August 2, and exceeded 

by more than 6 ft the previously known maximum stage 

since 1880, which occurred in 1919. The peak discharge was 

281,000 ftVs. A discharge hydropgraph for this station is 

shown in figure 17, and data are presented in table 8. An 

analysis of the annual peak-flow data for this site shows that 

a discharge of 281,000 ftVs has a recurrence interval greatly 

in excess of 100 years (fig. 18). Red Bluff Creek (site 83), 

which flows into the Medina River just below the Pipe 

Creek gaging station, received very little runoff and had a 

peak discharge of only 160 ftVs on August 2.

Medina Lake near San Antonio (site 84) reached a stage of 

1,076.67 ft, with 4 ft of flow over the spillway at the maximum 

stage. Storage in Medina Lake increased from 188,200 acreft at 0800 August 1 to 281,000 acre-ft at 1900 August 2.

One of the most striking indications of the severity of the 

flood was the destruction of massive cypress trees that lined 

the low-water banks of the Guadalupe and Medina Rivers 

and many of the tributaries. These trees ranged in size up to 

6 ft in diameter, and the larger trees were estimated to be as 

much as 600years old (oral commun., David Riskin, Botanist, 

Texas Parks and Wildlife Department, September 1978). 

Entire stands of these picturesque trees were either uprooted 

or snapped off and floated downstream. Hundreds were left 

scattered along the flood plains (fig. 19) or lodged in huge 

piles of debris along the channel banks and beneath the 

highway bridges. Many of the trees that were not uprooted 

were left partially down and stripped of their bark and 

foliage (fig. 20).

In this area of central Texas, older trees develop an extensive 

system of large lateral roots because tap roots cannot penetrate 

the limestone bedrock beneath the shallow topsoil. When 

the receeding floodwaters became too shallow to maintain 

free flotation of the uprooted trees, the lateral roots carved 

distinctive ruts in the soil as the trees were moved along the 

flood plain. These straight narrow ruts defined the direction 

of flow.

COLORADO RIVER BASIN

PEDERNALES RIVER

Heavy rainfall was not as widespread in the Colorado 

River basin as in the Guadalupe and Medina River basins. 

The highest unit runoff observed during this storm occurred 

on Spring Creek, which is tributary to the Pedernales River. 

Spring Creek, a short distance upstream from the station 

Spring Creek near Fredericksburg (site 66), had a peak 

discharge of 42,500 ftVs from a 14.1-mi2 drainage area. The

FIGURE 19. Cypress tree uprooted bv floodwaters on the Medina River.
30 FLOODS IN CENTRAL TEXAS, AUGUST 1-4,1978

FIGURE 20. Medina River near Pipe Creek, before, during, and after

the flood.

unit discharge was 3,010 ftVs/mi2, which is equivalent to 

4.67 in. of runoff per hour at the time of the peak. Overbank 

flooding occurred on the Pedernales River upstream from 

the gaging station near Johnson City (site 68), but the flood 

crest was 17.6 ft lower than the crest of the September 1952 

flood.

LLANO RIVER

Rainfall in the Llano River basin generally was 5 in. or 

less except in several small areas near Junction. The peak 

discharge on Bear Creek (site 59), which is tributary to the 

North Llano River just northwest of Junction, was 81,000 

ft3 /s from a drainage area of 155 mi2 . The floodwaters on 

Bear Creek inundated Interstate Highway 10, which was 

closed for several hours. At the gaging station on Beaver 

Creek near Mason (site 63), another tributary to the Llano 

River, the recorded peak stage of 24.00 ft was over 10 ft 

higher than the previous maximum in 1965, and the peak 

flow rate was 66,900 ft3 /s. The discharge hydrograph for 

Beaver Creek near Mason is shown in figure 17, and data 

are presented in table 9.

BRAZOS RIVER BASIN

On August 3, a new storm developed in the Brazos River 

basin. During the 24-hour period ending at 0700 August 4, a 

total of 29.05 in. of rain was recorded by the National Weather 

Service at Albany in Shackelford County. Record-breaking 

floods occurred on the Clear Fork Brazos River and on 

Hubbard Creek and other tributaries of the Clear Fork 

Brazos River. A peak discharge of 103,000 ft3/s from a drainage 

area of 39.3 mi2 was recorded at North Fork Hubbard Creek 

near Albany (site 18) on August 4. The unit discharge of 

2,620 ft3 /s/mi2 was one of the highest ever recorded in 

Texas for a drainage area of this size. The streamflow station 

Hubbard Creek below Albany (site 19) had a peak discharge 

of 330,000 ftVs from a drainage area of 613 mi2 . Discharge 

hydrographs for North Fork Hubbard Creek near Albany 

and Hubbard Creek below Albany are shown in figure 21, 

and data are presented in tables 10 and 11, respectively.

The contents of Hubbard Creek Reservoir near Breckenridge 

(site 21) increased from 185,800 acre-ft at 2400 August 2 to a 

maximum of 401,500 acre-ft at 0800 August 5. The reservoir 

effectively contained the floodwaters from the Hubbard 

Creek basin although it was not designed for flood control. 

Sufficient storage capacity was available in the reservoir to 

contain the flood wave with only moderate releases, which 

prevented more serious flooding downstream on the Clear 

Fork Brazos River. The streamflow station Hubbard Creek 

near Breckenridge (site 22), downstream from the reservoir 

and about 11 mi upstream from the Clear Fork Brazos 

River, had a peak discharge of only 14,600 ftVs.
DISCHARGE, IN THOUSANDS OF CUBIC FEET PER SECOND

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32 FLOODS IN CENTRAL TEXAS, AUGUST 1-4,1978

TABLE 10. Data for gaging station 08086150 North Fork Hubbard Creek near Albany 

[Gage height, in feet, and discharge, in cubic feet per second, at indicated time, 1978]

Date Hour Discharge Date Hour Discharge Date Hour Discharge

Aug. 3 - 1100

1300

1400

1600

1800

1900

2000

2100

2200

2300

1.95

2.74

2.93

2.98

3.18

6.60

12.00

19.60

22.70

23.05

0.00

9.2

25

31

58

1,360

4,780

10,100

48,600

70,200

Aug. 3 - 2400

Aug. 4 - 0100

0200

0300

0400

0500

0600

0700

0800

22.80

22.55

23.30

22.70

21.20

21.10

22.30

21.50

16.00

53,600

42,000

103,000

48,600

13,000

12,800

30,700

13,600

7,460

Aug. 4 - 1000

1100

1200

1300

1800

2400

Aug. 5 - 0600

1200

2400

11.00

7.20

5.40

4.50

3.73

3.38

3.24

3.13

3.01

4,080

1,670

816

456

207

115

82

63

42

Period

Highest mean discharge, in cubic feet per second,

for the indicated number of consecutive days 

1 3 7

August 1978 

1964 to July 1978 

13,100

1,570

6,640 

754

2,860 

361

150

08085500 Clear Fork 

Brazos River at Fort Griffin, 

Texas (drainage area 3988 

square miles)

FIGURE 22. Discharge hydrograph of Clear Fork Brazos River at Fort 

Griffin for August 3-7, 1978.

go 80

< o

in LU

O 01

I 01

60

It 40

. UJ 

01 LL.

5 5 20

W u_

Q O

08087300 Clear Fork Brazo River 

at Eliasville, Texas (drainage area 

5697 square miles)

789 

AUGUST

10 11 12

FIGURE 23. Discharge hydrograph of Clear Fork Brazos River at Eliasville for August 4-12, 1978.

Serious flooding developed on the Clear Fork Brazos 

River as a result of heavy runoff from tributaries upstream 

from Hubbard Creek. California Creek near Stamford (site 

14), which has a drainage area of 478 mi2 , had a peak discharge 

of 40,000 ftVs. The gaging station on the Clear Fork Brazos 

River at Fork Griffin (site 16) recorded a peak discharge of 

149,000 ftVs, and the stage exceeded the previously known 

maximum stage by 0.88 ft. When the flood crest reached the 

gaging station at Eliasville (site 23), 13.2 mi upstream from 

the main stem of the Brazos River, the peak discharge had 

attentuated to 68,000 ftVs. A discharge hydrograph for Clear 

Fork Brazos River at Fort Griffin is shown in figure 22, and 

data are presented in table 12. A discharge hydrograph for 

Clear Fork Brazos River at Eliasville is shown in figure 23, 

and data are presented in table 13.
BRAZOS RIVER BASIN 33

TABLE 11. Data for gaging station 08086212 Hubbard Creek below Albany 

[Gage height, in feet, and discharge, in cubic feet per second, at indicated time, 1978]

Date

Aug. 3

Aug. 4

Hour

- 0400

0600

1200

1300

1500

1800

2100

2200

2300

2400

- 0100

0200

Gage 

height

3.31

3.81

4.04

7.37

8.13

9.74

12.72

18.01

23.88

30.17

35.79

38.29

Discharge

0.00

3.8

6.9

681

1,020

1,980

3,760

7,890

15,300

26,300

56,700

118,000

Date Hour

Aug. 4 - 0300

0400

0430

0500

0600

0700

0730

0800

1000

1200

1500

1800

2400

Gage 

height

39.89

41.41

41.15

40.29

40.33

40.19

40.39

40.01

38.11

35.72

32.44

29.94

27.67

Discharge

189,000

330,000

300,000

218,000

221,000

210,000

226,000

196,000

112,000

56,000

33,700

25,900

21,600

Date Hour

Aug. 5 - 0600

0800

1000

1200

1800

2400

Aug. 6 - 1200

2400

Aug. 7-1200

2400

Gage 

height

23.30

18,00

11.40

9.40

7.80

7.19

6.52

6.04

5.65

5.40

Discharge

14,400

7,920

2,970

1,840

942

657

391

250

164

122

Period

Highest mean discharge, in cubic feet per second, 

for the indicated number of consecutive days

3 7

August 1978 - 

1967 to July 1978-

94,700

20,100

34,400

14,600

14,800

6,670

TABLE 12. Data for gaging station 08085500 Clear Fork Brazos River at Fort Griffin 

[Gage height, in feet, and discharge, in cubic feet per second, at indicated time, 1978]

Date Hour hg^t

Aug.

Aug.

3 - 2100

2200

2300

2400

4 - 0100

0500

0800

1200

1500

1.54

6.28

19.20

25.20

28.81

35.66

36.56

35.58

36.32

Discharge

0

1,360

13,900

16,900

20,800

43,200

57,000

39,500

52,000

Date Hour

Aug. 4 - 1700

1900

2100

2400

Aug. 5 - 0400

1200

2400

Aug. 6-1200

Gage 

height

38.10

38.81

38.88

38.76

38.18

36.75

34.40

32.80

Discharge

108,000

142,000

149,000

141,000

107,000

59,600

28,600

20,800

Date

Aug.

Aug.

Aug.

Aug.

6

7

8

9

Hour

- 2400

- 1200

2400

- 1200

2400

- 1200

2400

Gage 

height

28.05

21.55

16.15

13.17

11.48

10.18

9.19

Discharge

10,400

7,340

5,160

4,040

3,360

2,850

2,500

Period

Highest mean discharge, in cubic feet per second,

for the indicated number of consecutive days 

1 3 7

August 1978 

1925 to July 1978-

72,800

30,800

53,500

24,000

25,400

15,300
34 FLOODS IN CENTRAL TEXAS, AUGUST 1-4, 1978

TABLE 13. Data for gaging station 08087300 Clear Fork Brazos River at Eliasville 

[Gage height, in feet, and discharge, in cubic feet per second, at indicated time, 1978]

Date

Aug. 4 -

Aug. 5 -

Hour

0030

0500

0600

0700

0900

1000

1100

1200

1400

1900

2400

0600

1200

Gage 

height

7.56

7.84

7.98

8.25

8.72

9.10

10.25

11.29

12.40

16.90

24.19

31.70

35.44

Discharge

0.04

.93

4.3

29

132

289

1,160

2,920

4,570

8,650

15,600

30,200

47,100

Date

Aug. 5 -

Aug. 6 -

Aug. 7 -

Aug. 8 -

Hour

1800

2400

0100

0200

0600

1200

1800

2400

1200

2400

1200

Gage 

height

36.63

36.98

37.04

36.93

36.71

36.08

35.48

34.92

34.05

33.24

32.10

Discharge

61,900

67,100

68,000

66,300

63,100

54,500

47,400

43,300

37,600

34,800

31,300

Date

Aug. 8 -

Aug. 9 -

Aug. 10-

Aug. 11-

Aug. 12-

Hour

2400

1200

2400

1200

2400

1200

2400

0400

1200

2400

Gage 

height

30.51

27.83

24.53

22.01

20.37

18.22

15.20

12.28

11.23

10.83

Discharge

27,500

21 ,900

16,100

12,700

11,300

9,630

7,310

4,420

2,820

2,040

Period

Highest mean discharge, in cubia feet per second,

for the indicated number of consecutive days 

1 3 7

August 1978 

1917 to July 1978-

55,200

32,400

46,400

23,200

30,700

16,600

Some tributaries to the Brazos River upstream from the 

Clear Fork Brazos River also experienced high rates of runoff. Millers Creek near Munday (site 2), which has a drainage 

area of 104 mi2 , had a peak discharge of 34,600 ftVs. Discharge hydrographs for Millers Creek near Munday and 

California Creek near Stamford are shown in figure 24, and 

data are presented in tables 14 and 15, respectively.

The stream flow gaging station on the Brazos River near 

South Bend (site 24), 1.8 mi downstream from the Clear 

Fork Brazos River, has a peak discharge of 78,100 ftVs. 

Although this discharge was exceeded by a flood that occurred 

in May 1941, the peak stage (41.5 ft) was the greatest to occur 

since at least 1876. Because of changes in the stage-discharge 

relationship, the peak stage of the August 1978 flood exceeded 

that of May 1941 by about 14 ft.

Major flooding occurred along the Brazos River from 

South Bend to Possum Kingdom Reservoir. Possum Kingdom 

Reservoir was 6.6 ft below the normal pool level before the 

heavy runoff began. Releases from the reservoir by the 

Brazos River Authority, in anticipation of the approaching 

flood wave, reduced the crest of the flood and effectively 

prevented a more serious flood from occurring downstream.

Flood damages in the Brazos River basin downstream from 

Possum Kingdom Reservoir were minimal. Flooding did 

not occur on the Brazos River downstream from Lake Whitney, 

where sufficient storage capacity was available to contain 

the floodwaters.

MAGNITUDE AND FREQUENCY OF THE FLOODS

The relationship of flood-peak magnitude to the probability 

of occurrence, or recurrence interval, generally is referred 

to as a flood-frequency relation. The probability of occurrence 

is the percent chance of a given flood magnitude being 

exceeded in any 1 year. The recurrence interval, which is 

the reciprocal of the probability of occurrence multiplied 

by 100, is the average number of years between exceedances. 

It is emphasized that the recurrence interval is an average 

interval and that the occurrence of floods is assumed to be 

random in time; no schedule of regularity is implied. The 

occurrence of a flood having a 50-year recurrence interval 

(2-percent chance of occurrence) is no guarantee, therefore, 

that a flood of equal or greater magnitude will not occur the 

following year, or even the following week.
MAGNITUDE AND FREQUENCY OF THE FLOODS

TABLE 14. Data for gaging station 08082700 Millers Creek near Munday 

[Gage height, in feet, and discharge, in cubic feet per second, at indicated time, 1978]

35

Date

Aug. 4

Hour

- 0300

0400

0500

0600

0800

0900

1000

1100

1200

1300

Gage 

height

0.52

.52

1.01

2.76

3.96

5.84

8.45

10.94

13.86

17.07

Discharge

0

1.0

2.0

32

82

216

372

555

2,080

25,700

Date Hour

Aug. 4 - 1400

1500

1600

1800

2200

2400

Aug. 5 - 0600

1200

1800

Gage 

height

17.53

17.34

17.05

16.32

15.58

15.40

14.95

14.18

13.52

Discharge

34,600

30,600

25,400

15,600

8,910

7,690

5,280

2,750

1,530

Date

Aug. 5

Aug. 6

Aug. 7

Hour

- 2400

- 0600

1200

1800

2400

- 0600

1800

2400

Gage 

height

12.63

11.27

8.35

4.49

3.08

2.53

1.99

1.78

Discharge

790

589

366

114

42

25

13

9.9

Period

Highest mean discharge, in cubic feet per second,

for the -indicated number of consecutive daye 

1 3 7

August 1978 

1964 to July 1978 

8

70/1

 073 & t <J

4,160 

802

1.790 

376

TABLE 15. Data for gaging station 08084800 California Creek near Stamford 

[Gage height, in feet, and discharge, in cubic feet per second, at indicated time, 1978]

Date

Aug. 3

Hour

- 1000

1100

1200

1400

1600

1800

2000

2200

2400

Gage 

height

6.38

6.67

7.38

8.40

10.33

13.14

16.31

24.38

27.90

Discharge

0.44

6.3

44

107

270

600

1,190

4,260

9,670

Date Hour

Aug. 4 - 0200

0400

0600

0700

0800

1200

1500

2000

2400

Gage 

height

29.25

30.20

30.94

31.00

30.92

30.07

29.34

28.14

27.17

Discharge

15,700

24,800

38,600

40,000

38,200

23,000

16,400

10,500

7,550

Date Hour

Aug. 5 - 0600

0900

1200

1500

2000

2400

Aug. 6 - 0400

0800

1200

2400

Gage 

height

24.82

21.00

15.20

12.25

10.13

9.38

8.37

7.73

7.33

7.30

Discharge

4,640

2.500

941

485

251

185

105

64

40

38

Period

Highest mean discharge, in cubic feet per seconds

for the indicated number of consecutive days 

1 3 7

August 1978 

1963 to July 1978-

20,400

5.820

7,860

4,950

3,380

3,040
36 FLOODS IN CENTRAL TEXAS, AUGUST 1-4,1978

40

0 30

W Q

H o. 20

cc y

< m

53 10

08082700 Millers Creek 

near Munday, Texas (drainage 

area 104 square miles)

56 

AUGUST

08084800 California Creek 

near Stamford, Texas (drainage 

area 478 square miles)

45 

AUGUST

FIGURE 24. Discharge hydrographs of Millers Creek near Munday for August 4-7, 1978, and California Creek near

Stamford for August 3-6, 1978.

FIGURE 25. Inundation of State Highway 173 and the Medina River bridge at Bandera.
FLOOD DAMAGE 37

FIGURE 26. State Highway 290 flooded by Spring Creek near Fredericksburg.

Recurrence intervals of peak discharges on the Clear 

Fork Brazos River, Guadalupe River above Canyon Lake, 

and Medina River above Medina Lake were greater than 

100 years. The peak discharge for Spring Creek near 

Fredericksburg (site 66) was 3.8 times the magnitude of the 

100-year regional flood. Flood-frequency data are presented 

in table 4 for all stations in the flood area that experienced 

floods with frequencies of 10 years of more.

FLOOD DAMAGE

Seventeen counties in central Texas sustained widespread 

damages from the floods associated with tropical storm 

Amelia (National Oceanic and Atmospheric Administration, 

1978). Eight of these counties (Bandera, Kendall, and Kerr 

Counties in south-central Texas, and Haskell, Shackelford, 

Stephens, Throckmorton, and Young Counties in northcentral Texas) were declared flood-disaster areas by the 

Federal government. Ironically, Bandera, Kendall, and Kerr 

Counties had been declared drought-disaster areas prior to 

the floods.

In Bandera, Kendall, and Kerr Counties, 25 people were 

drowned, about 150 people were injured, and property 

damages were estimated to be at least 50 million dollars. 

About 175 homes were destroyed or damaged. Public utilities

were disrupted in much of the area and many roadways and 

bridges were heavily damaged. The bridge on State Highway 

173 over the Medina River at Bandera, which was designed 

to withstand the 50-year flood, was inundated by 18 ft of 

water (fig. 25). The damage to livestock and crops, to farm 

and ranch facilities, and to farm and pasture lands was 

extremely heavy.

Much damage was sustained in Gillespie and Kimble 

Counties in south-central Texas. Two people were drowned 

when Spring Creek inundated the bridge on State Highway 

290 west of Fredericksburg (fig. 26). Many roadways, bridges, 

and farm and ranch lands were extensively damaged.

In Haskell, Shackelford, Stephens, Throckmorton, and 

Young Counties in the Brazos River basin in north-central 

Texas, the flood damage was comparable to the damage in 

south-central Texas. Six people were drowned, four were 

injured, and property damages were estimated to be at least 

$62 million. About 750 homes and 75 businesses were destroyed 

or damaged (fig. 27), and the damages to livestock, crops, 

and farm and ranch lands were extremely severe. In Haskell 

County alone, these damages were estimated to be about $30 

million.

In the total area affected by the storm, 33 people were 

drowned and 154 were injured. Property damages were 

estimated to be more than $110 million.
38 FLOODS IN CENTRAL TEXAS, AUGUST 1-4,1978

L

"=!*,

FIGURE 27. Aerial view of the Brazos River in flood at Graham.

SUMMARY

The catastrophic floods in central Texas during August 

1-4, 1978, were the result of two separate major storms of 

different origin and distinguishable time and geographical 

context but with some shared features. The presence of very 

moist maritime air that originated in the Gulf of Mexico 

and the presence of positive vorticity advection preceded 

the outbreak of both storms. In the case of the storm of 

August 1-3 over the hill country of south-central Texas, 

moist Gulf air initially was brought into the area by the 

cyclonic circulation of the remnant of tropical storm Amelia. 

The storm of August 3-4 over the upper Brazos River basin 

in north-central Texas resulted from the interaction of a 

cold front with the maritime air mass that penetrated deeply 

into north-central Texas.

Major flooding of the hill country in south-central Texas 

occurred on the Medina River and its tributaries above the 

Medina Lake and on the Guadalupe River and its tributaries 

above Canyon Lake. Moderate to severe flooding occurred 

on tributaries of the Nueces River, on Clear Fork Brazos 

River and its tributaries, and on the Llano and Pedernales 

Rivers, which are tributaries of the Colorado River. Peak 

discharges at several streamflow stations exceeded the historic 

peaks. The highest unit discharge observed was 3,010 ftVs/mi2 

from the 14.1-mi2 drainage area of Spring Creek, which is a 

tributary of the Perdanales River. In the upper Brazos 

River basin in north-central Texas, 6 ft of water inundated 

the town of Albany on a tributary of Clear Fork Brazos 

River. Floodwater opened gaps in the earthen dam of Albany 

Reservoir and overtopped the spillway at Lake Throckmorton.

Thirty-three lives were lost and total damages reportedly 

exceeded $110 million.
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& U.S. GOVERNMENT PRINTING OFFICE: 1986 773-047/46,028 REGION NO. 8