CATHERINE CALLAWAY, CNN ANCHOR: More and more strip malls and subdivisions are dotting America's landscape. Some environmental groups say that this kind of development is having a negative impact on the nation's water supplies. Elaine Quijano explains.</s>ELAINE QUIJANO, CNN CORRESPONDENT (voice-over): In the concrete canyons of America's cities and suburbs, some say sprawl is draining away critical groundwater in areas already hit hard by drought.</s>JOHN BAILEY, SMART GROWTH AMERICA: We pave over natural area and rain comes down, it can't soak back into the ground.</s>QUIJANO: John Bailey works for Smart Growth America, one of three environmental groups that studied 18 metropolitan areas nationwide. (on camera): The report found that in those areas, including Washington, D.C., Atlanta and Boston, paved surfaces and storm drains are channeling billions of gallons of water, some of it polluted, directly into rivers and streams.</s>BAILEY: With ground water aquifer infiltration what we're getting is that clean drinking water, and what happens when it goes off of paved surfaces, it is oftentimes warmer and it's more polluted.</s>QUIJANO (voice-over): One example: Georgia's Lake Allatoona (ph), a reservoir that supplies drinking water to half a million people in the Atlanta region. Now the U.S. Environmental Protection Agency warns the lake could become too contaminated to supply drinking water in 10 years, partly because of leaky septic tanks and street runoff. But some home builders say they're aware of those concerns.</s>MARK FITZGERALD, GREATER ATLANTA HOME BUILDERS ASSOCIATION: What we need is sort of a private partner -- private/public partnership that allows us to look at the various alternatives about how we protect our water resources.</s>QUIJANO: Still, environmentalists say by curbing sprawl and protecting more open spaces, like wetlands, communities should be able to tap into clean water for years to come. Elaine Quijano, CNN, Washington.
Urban Sprawl May Threaten Water Supplies