As droughts worsen across the world, investors are turning up the heat on companies wasting water and trying to pick winners from a sparse crowd of specialist listed companies looking to address the problem.

From Kenya to California and nearly half of Europe, a shortage of fresh water has grabbed the attention of policymakers and given millions of citizens a fresh window into the stressed state of the planet.

Against that backdrop, a group of investors managing nearly $10 trillion on August 16 said they planned to step up efforts to pressure boards to better manage the critical resource and could vote against directors of laggard firms.