Even a little pavement does a lot to impact aquatic life in cities, USGS finds

A new study from the U-S Geological Survey finds that urban development may have a deeper impact on aquatic life than previously understood. KPCC's Molly Peterson reports.

What scientists mean when they talk about urban development is pavement. Driveways, parking lots, sidewalks: when a watershed gets developed, concrete and asphalt follows. Water flows fast over these surfaces, and picks up whatever's on them, including fertilizers, insecticides, and other threats to aquatic life. Biologists working for the geological survey found that even a little bit of development is very destructive to aquatic insects and fish. Pavement over 10 percent of a watershed can cut the population of insects and fish by up to a third. That can severely disrupt the food web. Managing streams and surface runoff is the state's responsibility. California and some local agencies, as well as nonprofits, are all looking into green infrastructure: that means more streets with gravel or surfaces where water can percolate down instead of running off.