It may sound strange, but in large quantities, warm water is a type of pollution. It holds less oxygen than cold water and often favors invasive species over natives. That’s why wastewater facilities are usually required to cool their discharge before releasing it into local rivers and lakes.

PhotoBut chillers require enormous amounts of electricity and are expensive. So Bruce Roll, Director of Watershed Management for Clean Water Services in Oregon, says his facility received a permit to plant trees and other vegetation along the Tualatin River instead. The trees will shade and cool the water naturally. But they will also store carbon, filter runoff from farms and cities, and provide erosion control.

Roll: “And then over time you get Mother Nature coming back, bringing back keystone organisms like beavers and the herons and wood ducks and all this other wildlife that comes along as the ecosytems are restored through natural vegetation.”

Working with farmers, ranchers, and other landowners in the area, Clean Water Services has planted trees and helped restore more than sixty-five miles of the Tualatin River basin.

Reporting credit: ChavoBart Digital Media.
Photo: Tualatin River after large woody debris was installed (Source: Tualatin River Watershed Council).

More Resources
Clean Water Services
Clean Water Services 2012-2013 Annual Report
Clean Water Services project brochure

Topics: Species & Ecosystems