Groundwater Management Area Process

Legislation passed in 2005 (House Bill 1763) established a framework for regional collaboration among local groundwater conservation district managers on shared aquifers.  Most groundwater districts are organized by county, and thus are able to manage only a portion of an aquifer. Districts managing the same aquifer must now coordinate with neighboring districts within their Groundwater Management Area (GMA) on issues such as management goals and groundwater availability determinations. The state is currently divided into 16 groundwater management areas.

Groundwater management areas of Texas Map courtesy of TWDB

Groundwater management areas of Texas
Map courtesy of TWDB

What are Desired Future Conditions?

Groundwater conservation districts within each Groundwater Management Area are required to define “Desired Future Conditions” for the groundwater resources within the Groundwater Management Area.  A Desired Future Condition (DFC) is a quantifiable future groundwater condition. These conditions, called metrics, can be a particular groundwater level, a level of water quality, a volume of spring flows or other condition. The chosen conditions serve as management goals and define how an aquifer will look in the future.

What is modeled available groundwater?

Based on the chosen Desired Future Condition, the Texas Water Development Board determines how much groundwater is available (now termed “modeled available groundwater” and was originally  termed “managed available groundwater”) for withdrawal. These volumes in turn become the permitting targets for the groundwater districts and will be used in the state’s regional water planning process. This process is a key way for communities to maintain local and regional control of their groundwater.

What is the timeline?

Groundwater Management Areas submitted their Desired Future Conditions to the Texas Water Development Board in 2010. Texas Water Development Board then inputted the Desired Future Conditions for each Groundwater Management Area into the Groundwater Availability Models to determine the Modeled Available Groundwater (MAG) for each region. Groundwater Conservation Districts use the results of this analysis to update their management plans. Texas statute requires submission of updated plans, and updated Desired Future Conditions, to the Texas Water Development Board at least once every five years.

How do Desired Future Conditions relate to surface water use?

Some Desired Future Conditions clearly recognize the interconnectivity between ground and surface water; others do not. Groundwater Management Area 7, where groundwater flows feeds springs critical to preserving the flow of the Nueces, Frio, and Llano and San Saba rivers, has a Desired Future Conditions based on preserving spring flow. Unfortunately, Groundwater Management Area 9, where groundwater feeds springs of the Guadalupe and Blanco River, has adopted a Desired Future Condition that ignores the groundwater/surface water interaction with these rivers, as well as recharge to the Edwards Aquifer.

Regardless of whether a Desired Future Condition explicitly acknowledges surface water connections, many rivers will cease to flow consistently if groundwater is pumped too rapidly as a result of inadequately protective Desired Future Conditions and management plans.