Best Bets for Texas Water

Groundwater withdrawal

More than 55 percent of Texas’ water supply comes from beneath its surface. This water, called groundwater, generally moves slowly through the Earth’s rocks and soil; the below-ground areas where it collects are called aquifers.

Groundwater is an important water source for homes, businesses and industries in some Texas cities, including San Antonio, El Paso, Houston and Amarillo, and many smaller towns.

Approx. 80 percent of Texas’ groundwater use goes to irrigate crops.

Texas groundwater law 101

Texas groundwater law is complicated, but it primarily relies on the rule of capture, which says that landowners have the right to capture any water that exists below their property. This also means that a landowner’s neighbor has the same right, even if their groundwater usage pulls water away from another landowner’s property.

Groundwater conservation districts, which exist across much of Texas, are tasked with the difficult job of managing groundwater levels in a way that protects the rights of all property owners when some owners seek to pump very large amounts.

Other important concepts:

  1. There are 16 different Groundwater Management Areas in Texas that create “desired future conditions,” or goals for what the future of groundwater in an area will look like. These desired conditions can focus on goals like maintaining springflow levels, or limiting aquifer level declines to a specific amount.
  2. Based on these goals, the Texas Water Development Board determines how much groundwater can be pumped in an area to meet the desired future conditions (these proposals are called “managed available groundwater”).
  3. Many areas across Texas have local (covering individual counties) or regional (covering multiple counties) Groundwater Conservation Districts (GCDs), which are responsible for making sure the desired future conditions are met. GCDs have the power to modify the rule of capture to varying degrees, though they can only regulate large groundwater withdrawals. These regulatory districts are tasked with the difficult job of balancing property owner rights and groundwater pumping so that aquifers don’t suffer from overexploitation.

Groundwater withdrawal report card
Environment
This strategy is promising on some fronts, but there are some real concerns.

Using groundwater can lessen the pressure on surface water supplies, but over-pumping leads to numerous environmental concerns, including less groundwater flowing into rivers and streams via springs.

True costs
This strategy is promising on some fronts, but there are some real concerns.

Groundwater withdrawal can be less expensive than some other water supply strategies, but if done irresponsibly, it can have huge ecological and societal costs, especially in rural areas.

Long-term viability
This strategy is promising on some fronts, but there are some real concerns.

Groundwater must be used carefully and in moderation so that aquifers aren’t depleted faster than they can recharge. Current efforts to market and pump large volumes of groundwater are increasing the likelihood of this threat.

Groundwater withdrawal grade breakdown
Environmental impacts
Positive
  • If communities were to switch between using surface water and groundwater in a way that is sensitive to the conditions of each water source and allows each time to replenish, this intermittent groundwater withdrawal (also known as conjunctive use) could help relieve pressure on surface water sources, especially during dry times, without depleting groundwater supplies.
  • Withdrawing groundwater in careful moderation may help communities to avoid constructing reservoirs and inflicting related adverse impacts on the environment, such as inundating croplands, pasture and forest.
Negative
  • Pumping too much groundwater can lead to subsidence, or sinking land, in some areas of the state (this is a big issue in the Houston-Galveston region, where it contributes to flooding. Parts of West Texas are also at high risk). Subsidence occurs because groundwater is a natural part of the below-ground landscape, and helps to hold the ground up; without it, underground layers contract and the land’s surface falls inward. Subsidence likely is largely irreversible.
  • Many Texas rivers get a portion of their water flow from springs and seeps (small openings), which form where groundwater rises to the surface. Pumping too much groundwater can rob rivers of the fresh water they need to sustain healthy fish, wildlife and bays. This is a big problem during drought, when rivers receive very little water from rain and runoff and often depend on groundwater contributions to keep them flowing.
  • Groundwater pumping can be energy-intensive, especially as water levels in aquifers get lower and lower.
  • Springs are important habitats for unique wildlife, including lots of threatened and endangered species. Overpumping can harm these already-struggling species.
If aquifers are overpumped and can't supply our rivers with their base flow, then all of the users downstream are deprived of that water. ... All the fish and wildlife would suffer ... and further downstream there are cities that rely on surface water for their municipal drinking water needs.
True costs

1 Groundwater withdrawal costs vary greatly depending on the aquifer’s geology, water depth, how far the groundwater will be transported, and whether the water has naturally-occurring contaminants. All pumping systems will require maintenance in the long term.

2 In some areas of the state, such as the Houston-Galveston region, groundwater withdrawal-related subsidence can worsen the reach and impacts of flooding.

3 If groundwater is not carefully withdrawn and aquifers are depleted, this can lead to habitat loss and can deprive surface water of needed spring flows. These ecological costs lead to societal costs in the forms of habitat loss, and limited commercial and recreational opportunities on rivers, streams and bays.

4 The deeper the water level, the more expensive it is to withdraw the water. This means that over time as water is withdrawn and water levels sink, pumping water from the same area becomes more expensive. In some cases, it can become prohibitively so, especially for individual homeowners and small farmers.

Long-term viability

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.

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