HYDROGEOLOGY: THE DEMAND FOR WATER
Comal County, for example is antici- pated to grow its population by 50,000 people, or more than 35 percent, to nearly 195,000 people. The popula- tion and employment growth in the area will require major growth in the accompanying utility services (water, power, refuse collection, phone, etc.). In this paper we will address how such growth will require infrastruc- ture projects to provide the additional water needed. The debate is how we are going to manage a growth in wa- ter consumption of between 50 and 100 billion gallons of water by 2030 and where is it going to come from, be it surface water, treated water, out-of- area imported water, groundwater or most likely all the above. If the growth in supply is to be from groundwater it will come most likely from the Carrizo- Wilcox aquifer system, the Trinity aquifer system or other more localized aquifer systems.
To illustrate the size of the chal- lenge, in the southern end of the cor- ridor, the San Antonio Water System (SAWS) today is working on the Vista Ridge Project to produce water from the Carrizo-Wilcox aquifer and bring down 16.3 billion gallons of water per year through a 142 mile long pipeline from Burleson County in the NE to Bexar County in the SW (see Figure 1). On the other end of the corridor to the north lies Austin in Travis County. It principally gets its water from Lake Austin and Lake Travis which are dammed reservoirs on the Colorado
Figure 1. Map of the San Antonio to Austin Corridor (The Silicon Valley of Texas) showing major aquifers, water suppliers, counties, and other significant features.
River. The City of Austin and other communities operate treatment plants to process the stored water in Lake Aus- tin and Lake Travis used by industry and residents. Aus- tin operates the Davis and Ullrich treatment plants on Lake Austin and the Handcox Water Treatment Plant on Lake Travis (Figure 1). The major growth areas between Austin
and Georgetown (particularly Williamson County, including Round Rock) also have opportunities to develop large-scale regional groundwater projects from the Carrizo-Wilcox aqui- fer in Bastrop, Lee and Milam Counties.
Suburban Water Supplies
Figure 2 illustrates the distribution of the types of new water sources as proposed by the 2016 regional water plan compiled by the South-Central Texas Regional Water Planning Group (SCTRWPG) including the City of San Antonio. New surface water sources and new groundwater sources are expected to comprise 17 percent and 16 percent of the total new water resources in the region by 2070, or about 134,000 and 126,000 acre-feet per year, respectively (1). High-growth areas include significant portions of northern Bexar, Kendall, Comal, Guadalupe, Hays and Caldwell counties. The 2016 SCTRWPG (Region L) plan (1) reports that municipal water demands will more than double in each of Caldwell, Comal, Guadalupe and Kendall counties from 2020 to 2070, while Bexar County municipal demands will increase from about 299,000 to approximately 443,300 acre-feet per year during the same period.
Figure 2. Distribution of the Types of New Water Sources as Proposed by the 2016 Regional Water Plan Compiled by the South-
Central Texas Regional Water Planning Group (SCTRWPG).
The Hill Country area outside of San Antonio is not favor- ably situated for additional reservoir construction and res- ervoirs currently require decades for permit approvals and construction. Therefore, the suburban high-growth areas are and will continue to be more dependent on groundwater
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64
