THE USE OF GROUNDWATER AVAILABILITY MODELS IN TEXAS IN THE ESTABLISHMENT OF DESIRED FUTURE CONDITIONS

In 2002, the Texas Water Development Board delineated 16 “groundwater management areas” in Texas as required by to Senate Bill 2 passed by the Texas Legislature in 2001. As required by House Bill 1763, passed by the Texas Legislature in 2005, groundwater conservation districts in each groundwater management area are required to adopt desired future conditions for relevant aquifers within the groundwater management area to the Texas Water Development Board by September 1, 2010. A desired future condition is essentially a management goal that defines the philosophy and policy of groundwater management in a defined area. More specifically, a desired future condition is the desired, quantified condition of a relevant aquifer (such as groundwater level, groundwater storage volume, or spring flow) at a specified time or times in the future. The process is termed “joint planning” because the groundwater conservation districts within a groundwater management area must work together to establish these goals in such a manner that they are physically possible.

Once desired future conditions are adopted and submitted to the Texas Water Development Board, staff develops estimates of pumping that would achieve the desired future condition. These total pumping estimates to achieve the desired future condition are developed based on groundwater models (including Groundwater Availability Models), water budget analyses, and district-provided data. Details of the development of the total pumping number are specific to the area. One of the key factors in the use of groundwater models in the development of the total pumping number is the usefulness and accuracy of groundwater models of the area.

This talk will summarize how the groundwater models were used in assisting the groundwater conservation districts in establishing their desired future conditions under a wide range of management philosophies and hydrogeologic settings.