The world will face “insurmountable” water crises in less than three decades, researchers said Tuesday, if it does not move away from water-intensive power production.

A clash of competing necessities — drinking water and energy demand — will cause widespread drought unless action is taken soon, researchers from Denmark’s Aarhus University, Vermont Law School and the U.S.-funded Center for Naval Analyses Corporation said in the reports.

“There will be no water by 2040 if we keep doing what we’re doing today,” researcher Benjamin Sovacool, director of the Center for Energy Technology at Aarhus University said in a press release on two new reports released Tuesday.

Globally, there has been a three-fold population increase in the past century and a six-fold increase in water consumption, the report said. If trends in population and energy use continue, it could leave a 40 percent gap between water supply and demand by the year 2030.

In most countries, including the United States, energy production is the biggest source of water consumption — even larger than agriculture, researchers said. In 2005, 41 percent of all freshwater consumed in the U.S. was for thermoelectric cooling, according to the study.

Power plants produce excess heat, requiring cooling cycles that use water. Only wind and solar voltaic energy production require minimal water.

“If we keep doing business as usual, we are facing an insurmountable water shortage — even if water was free, because it’s not a matter of the price,” Sovacool said.

Researchers said nuclear power and coal — the most “thirsty” power sources — should be eventually replaced with more efficient methods, especially renewable sources like wind and solar, the report said.

“Electricity generation from thermoelectric power plants is inextricably linked to water resources at nearly all stages in the power production cycle, yet this critical constraint has been largely overlooked in policy and planning,” the report said.

Researchers said they chose Texas as an important case study because its population is predicted to grow from 25 million to 55 million by 2050, which will increase the competition for water and electricity.

The state, which is also prone to drought, gets 33 percent of its power from coal, 10 percent from nuclear and 48 percent from natural gas, according to the study. During the summer of 2011, Texas experienced the worst drought in state history.

One of the main reasons residents did not experience blackouts that summer was Texas’ wind energy production, the researchers said. At least 10 percent of the state’s energy needs were provided by wind that summer, up to 18 percent on some days — making it an important alternative to nuclear, coal and natural gas.

Texas, which produces more wind energy than any other state, hit a record high in March 2014 with 37 percent of its electricity being produced by wind, the report said. That was largely thanks to a new transmission line and advanced weather forecasting.

Growing water scarcity “means that we’ll have to decide where we spend our water in the future. Do we want to spend it on keeping the power plants going or as drinking water? We don’t have enough water to do both,” Sovacool said in the release.