Lake Brownwood Watershed - Texas State Soil and Water ...

Late Twentieth Century Vegetation Descriptions
Descriptions of the vegetation in the Lake Brownwood watershed from the late 1900s did not fail to mention
mesquite as a prevalent component of every community as it even had invaded the bottomland riparian zone for the first
time. Other invasive woody species found in the bottomlands included saltcedar (Tamarix sp.), willow (Salix sp.), and
eastern red cedar (Juniperus virginiana) (Scifres, 1980; LBJ School of Public Affairs, 1978).
Both the Edwards Plateau and Rolling Plains regions were generally described at the time as a mesquite-shortgrass
savannah with varying densities of woody species. Important components of the shrub stratum included oaks, junipers and
species of Acacia and Mimosa (LBJ School of Public Affairs, 1978). The native tall- and midgrasses had given way to
stands of Texas wintergrass, threeawns, short gramas, buffalograss, curly mesquite, tobosa (Hilaria mutica), dropseeds
(Sporobolus spp.) and hooded windmillgrass (Chloris cucullata) (Scifres, 1980).
The Western Cross Timbers still supported post oak and blackjack oak woodlands; however, this community had
an almost impenetrable understory of yaupon (Ilex vomitoria), winged elm (Ulmus alata), common persimmon (Diospyros
virginiana), and other spiny brush species as well as numerous low-growing shrubs and vines. Willow baccharis
(Baccharis salicina) was a common invader in the post oak savannahs in this region as well (Scifres, 1980).
The region continued to be predominantly locked in agricultural land uses through the end of the twentieth century
with vast ranching operations and a number of smaller farms. By the end of the twentieth century, the predominant crops
grown in the region were sorghum, cotton, and wheat (Scifres, 1980).
HYDROLOGICAL HISTORY
Temperature and precipitation data were obtained from the National Climatic Data Center for three cooperative
stations at Albany (410120), Balinger (410493), and Brownwood (411138), which are located north, southwest and
southeast of the study area, respectively (Figure 3-2). Due to their similarity, simple averaging of the data from these
stations was used to estimate temperatures and precipitation for the entire watershed. Table 3-2 presents a summary of the
mean monthly and mean annual temperatures and precipitation for the station and watershed. Except for a record drought
in the 1950s, meteorological data indicate that temperature precipitation patterns in the Lake Brownwood watershed has
been rather stable for the past century. The average annual temperature in the watershed is approximately 64.4° F, and the
average annual rainfall is approximately 25.9 inches. Data from the Texas Water Development Board (TWDB) indicate that
the average annual gross evaporation in the watershed is approximately 67.3 inches.
The U.S. Geological Survey (USGS) has operated gauges at four stream sites in the Lake Brownwood watershed and one
on Pecan Bayou several miles downstream of Lake Brownwood (Figure 3-2): The locations of the gauges are shown on
Figure 3-2 and their periods of records are as follows.
08143500 - Pecan Bayou at Brownwood, Texas (1923-1983)
08140700 - Pecan Bayou near Cross Cut, Texas (1968-1978)
08140800 - Jim Ned Creek near Coleman, Texas (1965-1980)
08142000 - Hords Creek near Coleman, Texas (1940-1970)
08141500 - Hords Creek near Valera, Texas (1947-1990)
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