The 'sole source:' A history of San Antonio, south central Texas, and the Edwards Aquifer, 1890s-1990s

This study examines South Central Texas's past knowledge of, belief about, and interaction with its sole source of water, the Edwards Aquifer (San Antonio Region). Built in a semi-arid climate, San Antonio remains the largest city in the United States relying on a sole source of water. San Antonians and other South Central Texans interact with the Edwards under the influence of three myths: (a) the natural world exists in an unending abundance, (b) social progress comes from economic growth, and (c) technology will cure any human-caused problem. These myths inhibit decision-making for the common good in the region and have done so since the first interaction of European-Americans with the Edwards began in the late nineteenth century. Rapid population growth, combined with steadily increasing use of water for modern conveniences and intensive agriculture, taxed the capability of the aquifer to provide water endlessly. Most immigrants to the area brought experience and beliefs about water use from water-rich areas to this drier region. After the shock of the Great Drought in the 1950s made the populace aware of potential limits on water use, the region moved toward minimal cooperation with the creation of the Edwards Underground Water District. Mixed messages from local and regional agencies and self-identification with groups dependent upon use of the sole water source created long-standing conflicts among the region's population. In the late twentieth century, the Edwards became a pivot for fights between reservoir proponents and aquifer protectionists, spring users and city dwellers, agriculturalists and suburbanites, river authorities and municipalities, and, finally, environmentalists and government agencies. Throughout the squabbling, all cities but San Antonio moved towards supplementing their water source. Proposed alternatives to mining the aquifer included interbasin transfers, springs augmentation, water marketing, endangered species relocation, aquifer storage and retrieval, reservoir building and sharing, and conservation. However, only the threat of federal intervention in the region, prompted first by creation of the Sole Source Amendment to the Safe Drinking Water Act and then the use of the Endangered Species Act in federal court, pushed the quarreling constituents toward tentative cooperation as the twentieth century closed.