Improving water security with blue, green, and gray water

Agriculture is one of the most insatiable consumers of dwindling water resources around the world. And food production will need to increase by about 70% over the next 35 years to meet the needs of a growing population. Crops aren't creating the only demands; agriculture will face competition for water from cities, industries, and recreation.

With limited water and the increasing number of people depending on it, water security is tenuous. But integrated water management plans using "blue," "green," and "gray" water can increase water security. What do these colors mean and why are these waters vital?