Other water-themed ETFs include Guggenheim S&P Global Water Index (NYSEArca: CGW), First Trust ISE Water (NYSEArca: FIW) and PowerShares Global Water (NYSEArca: PIO).

“Our planet’s growing population is always going to need clean water and, even in developed countries, many water systems have aging infrastructure that needs updating. More than a handful of water-related companies had strong performances over the past year,” Selena Maranjian at the Motley Fool writes. “Demand for clean water isn’t going away anytime soon.”

Bank of America Merrill Lynch strategists recently turned bullish on water stocks. They cited the “global water crisis,” Barron’s reports. A billion people lack access to clean water, the firm writes. “[W]ater is undergoing pressure both on the supply and demand side.”

PowerShares Water Resources