The Evolution of Texas' Aquifers: A History of Aquifer Designations and Boundaries

R. E. Mace, D. B. Coker, and W. F. Mullican, III
Texas Water Development Board, Austin, Texas 

Aquifers are a critically important water resource to the state of Texas. Since the 1950s, the Texas Water Development Board and its predecessor agencies have published maps and reports on the State’s aquifers as part of its charge to plan or coordinate planning for use of Texas’ water resources. Interestingly, the ensemble and resolution of aquifers recognized by the Board has changed over the years. Maps published in 1952 show only nine named aquifers, while the latest maps include a total of 30 named aquifers. Additionally, the mapped extent of these aquifers has changed considerably over time. For the most part, the addition, subtraction, or refinement of aquifers on the Board’s maps is made with staff recommendation and Board approval, the most recent change being the addition of the Yegua-Jackson aquifer to the list in the 2002 State Water Plan.

The Board is not the only State agency that develops and keeps aquifer maps. Groundwater availability modeling, other Board conducted or supported studies, and external studies show that additional changes are warranted. These changes include updating the aquifer boundary of the Edwards (Balcones Fault Zone) aquifer so as to reflect new information on the position of the bad water line and adjusting of the boundaries of the Seymour, Edwards-Trinity (Plateau), Bone Spring-Victorio Peak, Igneous, and Marathon aquifers. The Board will also consider adding new aquifers to the list, such as the Diablo Plateau and Austin Chalk aquifers.

AAPG Search and Discovery Article #90032©2004 GCAGS 54th Annual Convention, San Antonio, Texas, October 10-12, 2004