From the website:
This is the first time in human history that most of the world’s population live in cities: 3.3 billion people …and the urban landscape continues to grow.
38% of the growth is represented by expanding slums, while the city populations are increasing faster than city infrastructure can adapt.
The objective of World Water Day 2011 is to focus international attention on the impact of rapid urban population growth, industrialization and uncertainties caused by climate change, conflicts and natural disasters on urban water systems.
This year [the] theme [is], Water for cities: responding to the urban challenge, aims to spotlight and encourage governments, organizations, communities, and individuals to actively engage in addressing the defy of urban water management.
Here’s the link to the WWD 2011 event at Colorado State University.