My project deals with the depleting availability of water both globally and locally. I wanted to ask what the main causes of water scarcity would be here in San Antonio? (increasing population, over expansion?)and Aside from the controversies concerning the Edwards Aquifer in the media are there any other major signs of water scarcity?
San Antonio rests atop 3 major ecosystems - the Blackland Prairie, the Edwards Plateau and the Coastal Plains. Each of these systems have varying characteristics among and within them. One of the basic characteristics that drives the nature of an eco-system is rainfall. San Antonio is a semi-arid community that averages approximately 32 inches of precipitation each year. While this is significantly less than the rainy eastern parts of the state, we enjoy many times the average rainfall of west Texas and parts of the very arid Western United States. Thus, weather and rainfall patterns are one of the biggest factors in determining water availability. Other factors of scarcity, in general, include increasing water demands (population, commercial and agricultural uses), diminishing supplies due to over allocation (or use) or contamination, lack of planning/funding to meet future needs, and regulatory reductions.
For San Antonio, we have taken steps to protect the water quality of our primary source of water through stringent land use control measures. San Antonio has actively increased its water efficiency thru conservation to stretch the sources we have, invested in a $125 million recycling project to use our treated waste water for non-drinking purposes while still protecting the environmental needs of the San Antonio River, constructed an approx $200 million system to store Edwards water in the Carrizo aquifer in South Bexar County to meet summer peak needs (Aquifer Storage and Recovery Project) and has contracts in place to meet our expected needs for 50-80 years. We have also participated in regional and state water planning which has projected needs for the next fify years and supplies available to meet them. The projects to secure the needs of a growing population include a variety of groundwater and surface water projects as well as continued research into desalination of brackish groundwater and/or seawater sources. All of these projects are intended to meet our needs through a repeat of the Drought of Record (1950's drought which had the least rainfall and most impact since rainfall and other data has been recorded).
I would say then, that we have projected our needs, protected our existing sources and are stretching them as far as they can go, developing additional supplies in a diverse portfolio of projects and have committed to funding these new sources through the City Council approved Water Supply Fee. The biggest factors leading to possible scarcity, then, for our community/region may be a shift from long-term planning which seeks to meet our short, mid and long-range needs and rainfall conditions "worse" than the drought of record conditions.
For more information on water planning, you may want to review our webpage (www.saws.org). The Texas Water Development Board also has oodles of info about the state water plan and conditions around the state. If you can find it on the web, the Global Trends 2015 report published by the federal government provides some insight into anticipated global conditions through the next 10 years or so.
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