Chapter 2 Regional Summaries - Texas Water Development Board

POPULATION AND WATER DEMANDS
Approximately 8 percent of the state’s 2010 population resided in the Brazos G Region. Between 2010 and 2060,
the region’s population is projected to increase 76 percent (Table G.1). By 2060, the total water demands for the
region are projected to increase 43 percent (Table G.1). Municipal water use makes up the largest share of these
demands in all decades and is projected to increase by 75 percent (Table G.1). Manufacturing and steam-electric
power generation demands are also projected to grow by 61 percent and 90 percent, respectively (Table G.1).
Irrigation water demand, however, declines 10 percent by 2060 because of projected reductions in irrigated land
and technological advances in irrigation techniques (Table G.1, Figure G.2).
EXISTING WATER SUPPLIES
The Brazos G Region has a large number of surface water and groundwater supply sources, with over threefourths
of the existing water supply in the region associated with surface water (Table G.1). The principal surface
water sources are the Brazos River, its tributaries, and the 40 major reservoirs throughout the region. There are
six major aquifers in the region: the Seymour and Edwards-Trinity (Plateau) aquifers in the western portion of
the region, the Trinity and Edwards (Balcones Fault Zone) aquifers in the central portion, and the Carrizo-Wilcox
and Gulf Coast aquifers in the eastern portion. Although the surface water portion of total supply is expected to
increase slightly over time due to increased return-flows, by 2060 the total water supply is projected to decline
a little more than 1 percent (Table G.1, Figure G.2). This projected decline in groundwater supply is due to a
greater emphasis on sustainable use of groundwater resources in the region.
NEEDS
Although on a region-wide basis it might appear that the Brazos G Region has enough water supply to meet
demands through 2040, with only small deficits in 2050 and 2060, the total water supply volume is not accessible
to all water users throughout the region (Table G.1). Consequently, in the event of drought, Region G would be
projected to have a total water supply need of 131,489 acre-feet in 2010 (Table G.1). Irrigation accounts for nearly
half of those needs at 59,571 acre-feet. By 2060, overall water needs are expected to increase to 390,732 acre-feet,
with almost half of this need associated with municipal users (Table G.1, Figure G.2).
RECOMMENDED WATER MANAGEMENT STRATEGIES AND COST
The Brazos G Planning Group recommended a variety of water management strategies that would provide more
water than is required to meet future needs (Figures G.3 and G.4). In all, the strategies would provide 587,084
acre-feet of additional water supply by the year 2060 at a total capital cost of $3.2 billion (Appendix A). Some
of this water could be made available to other regions with needs. Because there were no economically feasible
strategies identified to meet their needs, six counties in the region have unmet irrigation needs (ranging from
49,973 acre-feet in 2010 to 33,932 acre-feet by 2060). Some mining needs go unmet in each decade (ranging from
1,800 acre-feet in 2010 to 2,567 acre-feet in 2060) due to a lack of feasible strategies. Some municipal (Abilene,
Round Rock, and Cedar Park) needs (totaling 2,196 acre-feet) and some steam-electric needs (36,086 acre-feet)
would be unmet in case of drought in 2010 because infrastructure is not yet in place to access the supply.
70
Chapter 2: brazos G region summary
WAT E R FOR TEXAS 2012 STATE WATER PLAN