Their population has doubled, economic development has proceeded rapidly in some countries but lagged in others, income disparities have increased, demand for water has grown rapidly in response to the heavy development of coastal areas, urbanisation has accelerated and agriculture (which alone accounts for more than 70% of total water consumption) has expanded even more. These trends have increased pressure on both surface and groundwater resources, leading to environmental degradation, increased pollution and other sustainability challenges. The region faces equally great institutional challenges, particularly the difficulty of balancing a tradition of low, fixed prices with massive infrastructure investment needs, and the perennial difficulty of balancing competing demands from residential, industrial and agricultural users.