Water shortages are plaguing countries around the globe, and the need for solutions creates strong opportunities for long-term investments.

The water industry has traditionally been an under-invested sector, say Anisha Sircar and Aovon Ashraf in a recent Bloomberg News article, but that’s starting to change. Investors are becoming more informed about the needs and possibilities for investing, they say.

The United Nations estimates that 2.1 billion people around the world lack access to safely managed drinking water. Meanwhile, the S&P Global Water Index, a basket of 50 water-related businesses around the world, has risen 24% this year to record levels, outperforming a 20% rise in the S&P 500,” they explain.

Companies that improve power plants’ water efficiency and technologies for industrial processes, buildings and general infrastructure all offer investment potential.

“Investors are increasingly moving into clean technology,” the article says. “In the ETF market, the First Trust Water ETF took in nearly $34 million in September this year, the most since November 2016. The Invesco S&P Global Water Index ETF had a $42 million inflow earlier this month, while the Invesco Water Resources ETF has absorbed almost $26 million over the last four months.”

Water quality and water availability are increasingly important issues that will drive global investments and geopolitics for years ahead.