“Coping with Water Scarcity” is the theme of this year’s World Water Day, promoted by the United Nations. The link:

World Water Day
The UN’s Water Portal can be a valuable resource.

“UN-Water’s work encompasses all aspects of freshwater and sanitation. Over the years, agencies within the United Nations have developed specific expertise on an array of themes within this wide remit.” The thematic index provides access to specialist resources on many water topics, linkable from the “UN-Water” page.

Via UNESCO, there are many water issues with numerous, world-wide links:
http://www.unesco.org/water/waterlinks/WaterIssues/