Yale Students and Faculty Comparing Management Approaches to Protecting Surface Drinking Water
Tracy Stanton on March 17, 2010 3 Comments
I was fortunate to tag along on Monday with a group of graduate students and faculty from the Yale School of Forestry and Environmental Studies as they toured the Cedar River Watershed, which is located high up in the Cascade Mountains and provides a portion of the drinking water to the city of Seattle and other communities in the greater Seattle metro area. Seattle is one of four (the others are in MA, CT and NY) drinking water systems under intense study by the group, part of a course designed to analyze the different ways that water managers choose to meet drinking water standards; be that with an "engineered" approach of a concrete/steel filtration plant or a "natural" approach utilizing the forested/grassland/wetland areas to filter. Regardless of the approach chosen to protect water quality, few managers have developed a formal decision-making method for comparing the costs and benefits of a forested watershed vs a filtration plant for meeting drinking water standards.
Natural water filtration through forested land, wetlands and grasslands is a valuable ecosystem service provided, mostly free of charge, to the beneficiaries of clean drinking water (that's you and me and anyone who turns on the tap). But managing the forests or any ecosystem for the continued provision of clean, and affordable drinking water, is not a cost-free endeavor. Municipalities, such as Seattle, invest millions of dollars in the provision of clean drinking water.
Ultimately, this group aims to develop a real tool to aid water managers in deciding which approach makes more sense. Or maybe it's a combination. We'll keep tabs on what is developed and be sure to share the outcome. Meanwhile, here's a link to the two faculty members leading the course: http://environment.yale.edu/profile/gentry/teaching; http://environment.yale.edu/profile/ashton.
Good study. You may find it interesting to read about the Nestle-Vittel project and how Vittel mineral water was preserved by working with those in the watershed producing agricultural goods. They learned several things - one being that is it expensive to pay people to manage their land in a manner that is not supported by the economy. What I learned was that we need to have a shared economic approach, so that the economy and its participants pay for what it gets.
The cost of preserving land that filters water is almost always less expensive per unit of pollution than the cost of building treatment facilities. But until the states take unit cost into consideration when prioritizing projects for funding, Clean Water and Drinking Water State Revolving Funds will continue to devote 97% of their low-interest loans and grants to construction.
This may be true when taken into context of a rural setting, such as Seattle's rural Cedar River Watershed. I question however this assertion in highly developed areas, where the cost of preserving land is high compared to the benefits received of the amount of water filtered/infiltrated. In many urban watersheds there is not even a supply of land which can be preserved hence there is no "going back." I think the economics are quite different when one begins with a landscape that is predominantly hardscape.