Clearwater Underground Water Conservation District General Manager, Dirk Aaron, is concerned about the Trinity Aquifer and the considerable drawdown being experienced in three significant regions of Bell County. Those rural areas that count on the Middle (Hensell) Trinity Aquifer as their sole source of household water are the River Ridge Ranch Development, Hidden Springs Development, and the Stillman Valley Community that includes parts of Youngsport.
District staff completed the quarterly static water level measurements of monitor wells this past month and has found some very disturbing facts relative to the Trinity Aquifer. Aaron said, “Couple these disturbing drawdowns of the Trinity Aquifer and the fact that we are moving into the driest season of the year, confirms the need for rural well owners to take action and stop their excessive use of groundwater for extreme landscapes. Keep in mind the Trinity Aquifer does not have a recharge zone that could quickly replenish the aquifer and that area of recharge is farther to the west and northwest of Bell County than most people realize. We know most regions of Texas, because of the epic drought, have not received enough rainfall in the last three years to replenish the aquifer. When adequate rainfall returns, it will be years before that rainfall makes its way to the Middle Trinity Aquifer. Currently, Clearwater has registered over 1946 domestic wells in the Trinity Aquifer, and a majority of these wells are the sole source water for most parts of West and Southwest portions of Bell County.
Aaron confirmed that the Upper (Glen Rose) Trinity layer of the aquifer is experiencing an average of 2.98 feet per year drop in water levels, based on multiple readings over the last six years. In the Middle (Hensell) Trinity layer we are seeing an average of 5.90 feet per year drop in water levels over the same six years. In the Lower (Hosston) Trinity we are seeing an average of 7.31 feet per year drop in water levels in the past six years. Aaron described these numbers as expected yet not alarming as we view the County as a whole, “But when we focus our analysis on specific rural areas that well drillers and well owners are expressing concern, the situation becomes more disconcerting and alarming.”
Aaron stated, “We focused our efforts and analysis in those specific areas that depend solely on the Middle Trinity Aquifer. This is the layer that is most affordable to drill a new well ($25,000.00 or more) as compared to the Lower Trinity, which is much deeper and costly to produce from. In doing so, we found much greater drawdowns in those rural ranchette subdivisions such as the River Ridge Ranch, south of Killeen on the Lampasas River.” Aaron stressed that facts speak for themselves and the 13.35 feet/year of drawdown over the last six years, which is 80 feet of water level drop in the River Ridge Ranch (compared to the District wide 5.90 feet/year) is more than alarming. Lowering an existing well can cost as much as $5,000.00 and that may not be an option. Because the structure of the Trinity in this 1,000 acre plus subdivision is not that prolific, we see 70 registered exempt wells (domestic use) struggling to provide needed water to these homeowners. We encourage all new owners constructing homes to also look at drilling to the Lower Trinity by conducting research and feasibility of spending additional money before drilling to the Lower Trinity.
Aaron also stated, “We also focused our analysis on the Hidden Springs Ranchette Subdivision, Southwest of Salado off of SH 2843 toward Florence. This subdivision has more than 130 registered Exempt Middle Trinity wells on the 1500 acre tract known as Hidden Springs. The monitor wells in and around that area are also expressing extreme drawdowns of 10.73 feet/year over the last six years, meaning we see a total of 65 feet of water level drop. This kind of loss is a result of the large concentration of wells and excess domestic use, both inside and outside purposes.”
These draw-down averages bring to light the Board’s concern that it is a challenge to keep drawdown in these rural subdivisions within the desired future condition (DFC) expressed in Clearwater UWCD’s Management Plan. When the District developed the DFC for the Middle Trinity layer of the Aquifer the goal for was to contain the drawdown at no more than 5.72 feet average per year or 286 feet over 50 years. This process is mandated by Chapter 36 “Texas Water Code”, and requires Texas Water Development Board to set the managed available groundwater for each major aquifer accordingly.
Measured drawdown of the static water levels is a key method of measuring the long term availability of water in an aquifer. Static water level is the elevation or level of the water table in a well when the pump is not operating or termed resting. This can be expressed in feet below land surface. Reports are frequent that well drillers are returning to wells drilled less than four years ago and to lower the pump. This is a result of wells being drilled and equipped with submersible pumps that are set typically 100 feet or more below the static water level. However when drawdown exceeds the depth of the pump then problems occur demanding the pump be lowered, but often we see the pump needs to be replaced because of damage due to pumping air. Lowering the pump can only be an option for so long. The thickness of the Middle Trinity varies depending on the location of the well as does its specific capacity. Most of the rural well owners know that the exempt well limits by Clearwater UWCD are 17 gpm, but often we see Middle Trinity wells producing as little as 2 to 3 gallons per minute. Using this limited resource for extreme landscape purposes is not in the best interest of a rural homeowner whose financial investment of a home and acreage is dependent on a sole source of water from the Middle Trinity.
Aaron stressed, “Research shows that the average family of three uses 6,000 to 10,000 gallons per month (indoors) but our current estimates show that home owners with large expansive landscape on 2 acre tracts or larger typically use in excess of 30,000 gallons per for both indoor and outdoor use. This kind of excess will not last for long and could destroy the value of one’s investment. The “property right” to drill and produce groundwater for domestic use is sacred in Texas, but with that right come the responsibility to protect and conserve your valued asset, and that is “water.”
Clearwater UWCD does recognize that many factors contribute to drawdown and that the unmanaged groundwater use in Williamson County is definitely contributing to the problem in Bell County and Burnet County. Clearwater UWCD also stands on the need for conservation and encourages all private and permitted well owners that reducing our use of groundwater now by as much as 20% is achievable.