Sprawl is dirtying streams and posing threat to U.S. drinking water
Storm-water runoff threatens nearly every urban and suburban stream in the U.S., with serious implications for the country’s drinking water. Used to be rain fell largely onto meadows, forests, and fields, where it was absorbed by plants or filtered into the underground water table, eventually percolating up to replenish streams. It was a fab system for everything involved: wee stream critters, bank-side plants, and people craving potable water. But today, rain encounters ever-growing expanses of roof and pavement, courses through gutters and conduits, and heads toward streams with erosive speed, washing away plants and animals and depositing loads of trash and pollutants. Without nature’s slow filtering, dirtier streams are flowing into the rivers that supply many with drinking water, increasing the costs of water treatment. Activists, scientists, and officials nationwide are turning to stream restoration and low-impact development plans like green roofs in an effort to improve stream health.