As the Texas population grows, there is an increasing demand for groundwater as more water wells are drilled.
Lakes and rivers are also sources of drinking water. A newer issue is data centers and their thirst for water used to cool the operation of computers.
As cities spread out, vegetation is removed and replaced with paved surfaces. This increases runoff of water into storm drains that would normally percolate into the soil and recharge groundwater resources.
The current Texas water plan projects water supply will decrease about 18% by 2070.
Texans will vote in November on a proposition to fund water infrastructure projects over the next two decades.
Larry French, senior fellow for water policy at the Texas Public Policy Foundation, said population is the main driver for water demand.
"Let's face it, East Texas is water-rich, Central Texas is water-challenged, and West Texas is water-scarce. Rule of capture is the law of the land for groundwater. And that's basically, if you're a landowner, you own the water beneath your land and you have a right to pump as much water as you can get. Basically, that's the rule of capture unaltered. There are restrictions; you're not allowed just to pump it out and waste it."
Even in water-rich East Texas there's a battle right now over potential plans to pump a lot of water and transport it to other parts of the state for water needs there. Many locals fear it will deplete their wells.
"I usually say when it comes to water, there's at least two things to remember. One is that water is heavy, and so that means it's expensive to move because if you're having to pump it uphill, it takes a lot of electricity and energy to do that. And water is also personal. You can't live without water. People, particularly in rural areas, the water that's under their land, is critical for them."
French said conservation efforts are essential moving forward like reducing water lost through leaky pipes. He said in Austin, it's estimated that there are about 9 billion gallons lost in faulty pipes per year.
He said a future water source is brackish groundwater, which is saltier than freshwater, and is less costly to treat than seawater. However, seawater will be important along the Texas Gulf Coast.
