The Environmental Blight of Urban Sprawl

The rapidly expanding urbanization of these areas, without thought to long-term environmental destruction, results in blocked wildlife migration, air pollution in forests, and runoff water pollution in surrounding streams, lakes and estuaries. The proliferation of impenetrable surfaces like cement, asphalt, and roofing materials in high-density residential developments causes much higher-velocity rain runoff, vastly increasing rates of pollution, erosion and flooding. In addition, the lack of runoff directed naturally towards soil and streams alters levels of groundwater and area water tables, obliterating stream flows and damaging water-dwelling habitat.  The level of runoff imperviousness in a common suburban development that combines half-acre residential lots and a smaller (strip mall) sized shopping center may measure seventy-five to ninety-five-percent imperviousness, which triples the levels at which several species of fish typically begin to disappear.

The rapidly declining rate of a huge variety of animals and plants seems to coincide with the shrinkage, fragmentation, or disappearance of wild habitat, as urban development expands further away from cities. According to National Resources Defense Council policy analyst Jutka Terris, “As of mid-1997, the U.S. Fish and Wildlife Service reported that 1,082 species of plants and animals were listed as threatened and endangered, with another 119 proposed for listing.” Some species now considered at risk include the Florida panther, or mountain lion, and Arizona’s sonoran pronghorn, pygmy owl, and the brown-and-white flecked raptor. California risks the loss of its rare gnatcatcher bird, kangaroo rat, redleg frog, and Pacific pond turtle, among others. The growing popularity of all-terrain vehicle excursions in desert areas of states like California and Arizona crushes vegetation, pollutes creeks and washes, and often kills many small animals and nested birds’ eggs.

Unfortunately, the list goes on and on. The result of this trend is known as the ‘generalization of habitat,’ and allows only those animal species hardy enough to survive on what grows in our gardens and sits in our garbage cans. In addition, the fragmentation of wild habitats caused by further-encroaching suburbia can result in the eventual genetic mutation to, or total loss of, complete generations of some species. The continuing losses ensuing from uncontrolled urban sprawl endanger our planet’s remaining natural habitat, but it is certainly not too late to reverse this trend through better laws, incentives, and responsible land use stewardship. An increase in municipalities’ utilization of land-planning tools like zoning regulations, differential tax rates and developmental rights also help to maintain existing farmlands and greenbelt areas, and further restrict the environmental damage of sprawl. “…An interdependence between healthy ecosystems and community well-being” is recommended by Carnegie Mello University Professor Michael P. Johnson, who feels this expectation depends on the principal of stewardship fostered in citizen-empowered communities willing to learn about and monitor upcoming urban development.

Fortunately, a number of U.S. and European cities are now integrating urban planning that adheres to ‘smart growth’ standards, including more compact, pedestrian and mass transit-friendly neighborhoods which minimize degradation of surrounding wilderness. Smart growth planning can reduce traffic and its associated pollutants as well, since doubling average neighborhood density results in a decreased per-household vehicle use of twenty to forty- percent, and like-reduced auto emissions. These higher densities can also drastically reduce the increase in water runoff normally associated with urban sprawl. A New Jersey study found that the result of directing urban growth into better-planned areas with higher average density rates could reduce storm water runoff by as much as forty-percent. The bottom line: We can create and implement workable planning solutions that reduce the alarming rate of denigration that urban sprawl is heaping upon our remaining wilderness. If the force of law is required to enable and sustain this stewardship role by states and municipalities, then so be it.