Texas’ population growth is expected to strain the state’s water supply over the coming decades.

As its population continues to rise, Texas is tasked to provide enough water for its people. The biggest single proposed solution for this potential water shortage is using more surface water, including 23 new reservoirs, according to the State Water Plan. Surface water currently accounts for about half of the state’s existing water supply.

According to the water plan, the Texas population is projected to increase by more than 70% over what has been forecasted, from 29.7 million people in 2020 to nearly 51.5 million in 2070.

By 2070, water demand is expected to increase by 9% to 19.2 million acre-feet during a severe drought, up from 17.7 million acre-feet in 2020. An acre-foot is enough water to cover an acre of land with one foot of water.

Over the same period, the state’s water supply is expected to fall 18% — leaving Texas about 5-to-7 million acre-feet short of water during a statewide record drought, when water supplies are lowest and demands are highest.

That’s more water than the maximum capacities of East Texas’ Lake Livingston, South Texas’ Amistad Reservoir, and Austin’s Lake Travis combined.

Naturally, the counties with the fastest population growth are seeing the highest water demands. Over the next five decades, demand for water is expected to increase drastically.

An analysis from the Water Development Board estimates that a severe drought could cause $153 billion in economic damages to the state annually by 2070 if new water supply strategies are not implemented.

“Until this state gets serious and has a sense of urgency, we will be woefully deficient [in water] in the future,” said State Senator Charles Perry (R-Lubbock) during an interim Senate hearing on water.

Referencing the time span of the State Water Plan, he said, “Pockets of this state don’t have until 2070.”

As more severe droughts occur along with population growth, some water experts are advocating for alternatives to building additional reservoirs, such as seawater desalination, rainwater harvesting, and wastewater reuse.

“Dams don’t make water,” said Samuel Sandoval Solís, a professor in water resources at the University of California Davis who has studied the Rio Grande Basin. “If it doesn’t rain, as suspected, we are going to have monuments to stupidity built with taxpayer dollars.”

This summer, Texas experienced its hottest July on record, fueling the state’s worst drought in a decade.

Water levels in reservoirs across the state fell drastically, prompting hundreds of mandatory water restrictions.

In August, reservoirs along the Rio Grande saw their lowest levels in decades. The Amistad Reservoir dropped to 30% capacity — its lowest level since 1998 — while Falcon Lake dropped to 9% capacity — its lowest level in two decades.

By late October, state reservoirs had fallen to an average of 67% capacity, down from 80% a year earlier, according to state data.

Not everyone has such a pessimistic perspective on the future of the state’s water provisions, however.

Todd Danielson, the vice president of engineering for Texas Water Utilities, said, “If we are able to build the reservoirs, to do the aquifer storage and recovery, to change the way that we use water, we will be able to provide water for the long term and to continue this great growth that Texas is seeing.”