There is a small organization in southeastern Pennsylvania that has devoted its entire 47-year existence to studying fresh water, becoming perhaps the most respected scientific institution in a field critical to us all. Recently, the Environmental Protection Agency asked the Stroud Water Research Center’s scientists to help clarify the Clean Water Act’s “Definition of the Waters of the United States” to ensure their continued protection. Here is the clarification: “The scientific literature clearly demonstrates that streams, regardless of their size or how frequently they flow, strongly influence how downstream waters function. Streams supply most of the water in rivers, transport sediment and organic matter, provide habitat for many species, and take up or change nutrients that could otherwise impair downstream waters.”
This sentence is enormously important and little understood. It says that small, and even intermittent, streams are the source of most clean water and their protection is critical to the entire system. Small streams supply larger rivers with up to 70% of their flow, provide food and habitat for humans and other species, and filter pollutants out of the water itself. The economic benefit of these services is almost incalculable.
So what’s the problem? Well, these are the streams that coal companies blow off mountaintops, that loggers dry up when they clear cut, that frackers contaminate in pursuit of gas, that developers fill in. These are powerful forces, for whom science is just another gun to hire and this careful, comprehensive study just one more nail in EPA’s coffin.