In other states like Tennessee, the legislature acted before the election to put new laws in place. There are a number of important intersects. The basic job of restoring the Chesapeake involves reducing nutrient loadings, namely nitrogen and phosphorous. And urban sprawl makes that job harder in a number of ways. First, it causes the permanent and unnecessarily extensive loss of forests to development, highways and even agriculture displaced by development.
Forests are our most efficient absorber of nutrients by far.
Although forests currently cover 60 percent of the drainage area of the Bay, they deliver only 17 percent of the nitrogen and a mere 3 percent of the phosphorous to the Bay. Once they are removed, the forests are nearly impossible to replace, and the uses that take their place generate and pass through much higher levels of nutrients. Second, nearly a quarter of the nitrogen entering the Chesapeake comes from the air, and about half of that is from automobiles. Those automobiles are concentrated in the developing areas of the watershed close to the Bay, where they do the most damage. Even though we have made great progress as a nation in reducing the pollution produced from individual autos, urban sprawl has meant that the number of vehicle miles traveled in the Chesapeake region has gone up at a rate four times greater than population growth.