Blue – little water scarcity, Red – physical water scarcity, Peach – approaching water scarcity, Orange – economic water scarcity

Last year, the IWMI (International Water Management Institute) undertook the largest survey of global freshwater resources. The results were startling, even to the panel of hydrologists familiar with the issue. Of chief concern is the expected population rise, 8 billion worldwide by 2025. The five year study shows significant water issues in many developing areas, especially China and India. For example, in India, water tables have been dropping by 6 meters per year.

The authors call for dramatic changes in water management policy. Top priorities are more efficient irrigation and wastewater reuse. Agricultural accounts for 70% of freshwater usage worldwide. Even though conservation in cities is useful, a typical city person uses 150 liters / day. It takes about 2,000 liters to produce food for one person/ day. Most of the recommended changes are focused on water productivity, including cheap irrigation systems.

It should be noted many of the recommendations may have negative environmental impacts (e.g. increased dam usage).

Takeaway: The issue is much more urgent than I thought even in parts of the US. Investment in conservation and productivity is important first step.