Water pollution and water shortages pose the most serious problems. They cause health ailments, damage agriculture, jam up hydroelectric dams, interfere with manufacturing and limit urbanization. As aquifers dry up, soil erodes, turning an area the size of Connecticut to desert every year. The resulting dust storms add to the country’s already horrendous air pollution. Beijing’s preferred solution to the problem is a massive south-to-north river diversion project. Odds are, that will make matters worse, draining water from already overtaxed southern supplies.