Drought Plan for Western Hays County

Summary by Jack Hollon, for HTGCD

Drought, like any challenge or crisis, heightens awareness. A dry time such as the present is thus a good time to take stock of our water resources, look at consumption habits or patterns, and decide if changes are needed to insure adequate water for the future. When we are close to an “edge” of this sort, our senses sharpen. The question of survival improves our attention; priorities become clearer.

Our local groundwater conservation district, HTGCD, takes this opportunity to summarize the drought plan we have been working on and get it before the public. On Aug. 7, at 8:30am, the Board will hold a public hearing on the Draft Plan at Woodcreek’s City Hall, on Champions Circle.

We first note that such a plan, required by law, is always a work in progress. As our knowledge of the aquifer increases, through data gathering and research, and what we take from it tends to grow, elements of the Plan such as drought stages, with their trigger criteria and expected responses, will be modified to improve the Plan – make it better fit our unique situation.

The draft now before the Board calls for year-round conservation, with a May-through-Sept. “Conservation Period” when certain voluntary conservation measures would be publicized and encouraged. This comprises “Stage 1,” our default condition when water is relatively abundant.

In dry times when special measures are needed, the monitored parameters (rainfall patterns, stream flows, water levels at certain wells) will be used to “trigger” or initiate a drought stage commensurate with conditions. The Plan defines three possible drought stages: Moderate Drought (Stage 2), Severe Drought (Stage 3), and Extreme Drought (Stage 4). In addition, a Stage 5 “Water Emergency” is available to the Board when all or part of the District faces a condition deemed “...a state of disaster due to drought conditions or other unforeseen events that could cause imminent health or safety risks to the public.” For each of these stages, the Plan recommends or requires conservation measures to be taken.

In the beginning, we propose to use the Standardized Precipitation Index (SPI), for the past 6 or 9 months, averaged between the South Central and Edwards Plateau Regions, or the stream flow on the Blanco River (USGS gage at Wimberley) as our primary triggers.

The flow of the Blanco has been recorded over the past 80+ years, so there is a rich data base there. In addition, we note that except after large rainfalls, the flow of area streams like the Blanco is a direct discharge from the surrounding aquifers. This discharge to streams is correlated fairly well with aquifer storage and water levels, both in our area and to our west, the area that tends to supply the Trinity Aquifer with underground flows toward the southeast.

The SPI is a statistical tool that compares recent rainfall, say for the past nine months, with rainfall over similar periods in the past 100 years or so. After transforming that data, the index will indicate the number of “standard deviations” the recent period varies from “normal.” This number can then be used as a trigger to initiate the appropriate stage, using reasonable time delays.

The Board will have flexibility in choosing between these triggers, or using them both. This is recommended, since droughts vary enormously in their special characteristics and histories. Each drought follows a unique course over time. The addition of water level data as a trigger is expected to follow soon, as that data base is rapidly reaching a state of reliability that will make it useful for these purposes.

The Draft Plan can be accessed on line at “www.haysgroundwater.com” the District’s website, or by calling the office at 512-858-9253. Comments and suggestions are welcomed, either in writing or at the hearing mentioned above. The Board is expected to adopt a revised plan that comes out of this process later in August.

In the meantime, we encourage innovation and sharing of water conservation measures for the home or business. As we are seeing in the energy transition, with its much higher fuel prices, people are finding all sorts of ways to cope and live reasonably well while using less. A drought plan, to be successful, relies on individual initiative and responsibility. Each of us can have the satisfaction of making a contribution.

Jack Holly represents Wimberley on the board of directors of the Hays Trinity Groundwater Conservation District.