1 Different aquifers recharge, or fill back up with water, at different rates. Many Texas aquifers contain “fossil water” — the water has taken thousands of years to accumulate and could take a comparable amount of time to refill after being depleted. In many cases, the current rates of groundwater withdrawal are not sustainable in the long run because we are using the water faster than it is naturally replenishing.
- For example, all of Texas’ Hill Country aquifers, except for the Edwards Aquifer, are being depleted faster than they can recharge.
- Some Texas cities have already been forced to lessen their reliance on groundwater because they have been depleting aquifers faster than the water levels can recharge. This does not bode well for groundwater’s usefulness as a water source in the future, unless a more sustainable approach is adopted.
2 Rapid urbanization is expected to continue in the future. This typically leads to an increase in hard, paved surfaces that don’t allow water to seep into the ground and recharge aquifers. If aquifer recharge declines in the future and groundwater mining rates don’t slow accordingly, communities will quickly deplete their groundwater resources.
3 Subsidence caused by groundwater pumping is already a big issue across parts of the Houston region, where land has sunk by as much as 12 to 13 feet. If too much water is pumped from the ground in areas vulnerable to subsidence, we can expect to see more land sink and become vulnerable to flooding.
4 As water becomes scarcer, we can expect more legal issues to arise related to Texas’ complicated groundwater laws. The following areas will likely lead to conflict and uncertainty:
- Because Groundwater Conservation Districts (GCDs) manage such small areas, multiple GCDs often manage the same aquifer. This leads to inconsistency in an aquifer’s regulations and withdrawal limitations.
- Although GCDs seek to regulate groundwater pumping to protect aquifer levels, poor funding and a fear of lawsuits based on recent court rulings seriously limit a GCD’s ability to do so effectively. Because landowners own the water underneath their properties, GCDs can be forced to pay landowners if they “unreasonably limit” the landowner’s right to pump, even if this is done to protect overall groundwater levels. These conflicts could lead to lawsuits and liability for damages, which could be financially ruinous to GCDs.
- GCDs can only regulate large groundwater withdrawals; generally, wells that produce less than 25,000 gallons per day are exempt from regulation. (A lot of groundwater pumping for oil and gas development is also exempt, regardless of amount.) There is heightened concern about over-pumping in areas like the Central Texas Hill Country, where there are large numbers of smaller, exempt wells.
- Various areas in Texas are not managed by a GCD at all, and so groundwater is solely regulated by the rule of capture.
5 In situations where groundwater is withdrawn from rural areas and then imported into cities to support their larger populations, this can potentially lead to rural-urban tension and conflicts.
6 One way to potentially use groundwater as a reliable water source in the future is through the concept of conjunctive use. This approach involves mainly relying on surface water during wet periods, and shifting to a greater groundwater reliance as things get drier. Reduced surface water pumping in dry periods protects river flow when surface supplies are low, and reduced groundwater pumping in wetter times allows for aquifer recharge. In theory, communities could continue to switch back and forth, informed by climate conditions and water availability, to protect each water source when it is most vulnerable.