Scarce freshwater is a growing problem.

The source of life may cover 70% of our planet, but freshwater only accounts for 3% – and two-thirds of that is locked up in glaciers.

Severe water stress affects approximately three billion people worldwide, two-thirds of whom happen to reside in Brazil, Russia, India, and China (BRIC) – nations that are transitioning to developed economies.

But we don't want to have a Waterworld situation on our hands (that didn't work out well for anyone).

Instead, investors should look for companies that are being smart with their water usage.

Freshwater Drying Up

In many of the BRIC countries, people are rapidly depleting groundwater aquifers, which accounts for that one-third of the freshwater used globally. This is putting in excess of two billion people at risk of losing their water supply.

Such aquifers are critical to agriculture around the globe, too, since they provide half of the irrigation water used.

The United States isn't immune to this scarcity either, as evidenced by California's severe drought.

Jay Famiglietti used satellite data to show that Sacramento and San Joaquin river basins have seen losses of about 15 cubic kilometers of water annually, reported the Financial Times. Groundwater pumping in the state's agriculturally important Central Valley has been responsible for more than half of the losses.

If the trend continues, the consequences could be dire.

But it's not just people or the agriculture industry that's affected by water's growing scarcity. It's becoming a problem for many corporations, as well. Thus many have worked to improve their water efficiency

According to a report in the Financial Times, since 2011 alone corporations have spent in excess of $84 billion to improve the way they obtain, manage, and use water.

For example, Coca-Cola (KO) and its bottlers have spent nearly $2 billion since 2003 on reducing water use and improving water quality wherever the company has operations.