Calgary Herald: Water scarcity means big growth for companies that purify, transport and distribute the world’s most essential resource, but a global recession that has halted new projects and put off price increases means water investors will have to wait for the boom years. Water, cheap and indispensable, has long been prized as a stable investment in both good and bad times. But as the population grows, urbanization tightens access to clean water and climate change promises more droughts, …