Sprawling land development, characterized by strip malls, parking lots and roads, may not only be polluting our water but also reducing the amount available, according to a recent report.
A report released by American Rivers, the Natural Resources Defense Council and Smart Growth America, reports that paved over land is sending billions of gallons of water into streams and rivers as polluted runoff, rather than into the soil to replenish groundwater. "Paving the Way to Water Shortages: How Sprawl Aggravates Drought" investigated what happens to water supplies when natural areas are replaced by roads, parking lots and buildings.
The report estimates that in Atlanta, the nation's most rapidly sprawling metropolitan area, recent sprawl development sends an additional 57 billion to 133 billion gallons of polluted runoff into streams and rivers each year. This water would have otherwise filtered through the soil to recharge aquifers and provide underground flows to rivers, streams and lakes. The study also reviews the nation's next 17 most land-consuming metro areas.
The actual impact on the public's water use varies from city to city. On average, 40 percent of Americans get their water directly from underground sources. In addition, groundwater supplies 50 percent of the water in the rivers and lakes.
Not everyone agrees with the study's conclusions. Gary Garczynski, president of the National Association of Homebuilders, said, "The report does not consider many important variables that affect water supply, including water management issues."
For example, some of the urban areas cited in the study, such as Atlanta and Fort Worth, Texas, mostly rely on surface water for their urban supply, according to Garczynski. Both areas have networks of reservoirs that retain runoff from heavy rains.
However, counties across metro Atlanta already have started buying land to combat problems. In June, Douglas County bought 800 acres around the Dog River. The $5.6 million purchase is designed to protect the county's reservoir. Protecting land around waterways prevents shoreline erosion; therefore, the county will have less silt to dredge. Filtering sediment to make water drinkable can cost millions.
Two years ago, the Douglasville-Douglas County Water and Sewer Authority paid $1.4 million to dredge the Dog River of 80,000 cubic yards of silt. The county no longer uses Bear Creek as a reservoir because it contains too much silt.
The study suggests directing growth to communities where people already live. Known as "smart growth," the plan usually entails integrated planning incentives and infrastructure investments to revitalize existing communities.
While Garczynski agrees that many communities should consider adopting sensible, smart growth policies, he points out that developed land covers just three percent of America's land area.
While America always has been the land of the great pioneer, it might make some sense to take care of what already has been established.
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