The science is clear: protecting forests makes for clean water.
Still, additional research is needed as the conservation community seeks a better understanding of how the extent, type, and location of protected forests impact water quality.
With funding from the William Penn Foundation, the Open Space Institute (OSI) is conducting a three-year study to measure the connection between land protection and clean water that will help guide its work in protecting the Delaware River watershed. The study will consider a range of topics, including how much of a watershed needs to be forested to keep water clean; how the uses of unprotected land affect water quality; and the role of forest protection in avoiding future degradation of streams and waterways.
The OSI assessment will be informed by scientific literature review; consultation with scientists and data modelers; and assessment of programs that fund forest conservation to maintain water quality outside of the Delaware Basin.
“Everyone has the goal of clean water, but different strategies are relevant in different places. Our goal is to develop a better understanding of the role of land protection in protecting and achieving clean water,” explained OSI Conservation Research Director, Abigail Weinberg. “With limited dollars to spend on land protection throughout the conservation field, OSI is examining data and lessons learned in order to target land protection for clean water. This will inform our spending in and around the Delaware.”
And according to Weinberg, with municipalities and counties across the east protecting or restoring land for water quality, there’s no shortage of programs to investigate. Some illuminating insights are emerging.
A Recipe for Clean Water
A review of the literature found broad agreement that if 70 to 90 percent of a watershed is forested, streams are likely to retain good water quality, pointing to a clear role for land protection. Yet even with protected forest covering a large portion of the watershed, findings show that the land use of the non-forested areas is also critically important. Clean water and healthy streams remain at risk if high intensity agriculture covers more than 10 to 30 percent of a watershed or if impervious surfaces like pavements and buildings cover as little as three percent.
These findings point to the value of focusing land protection in watersheds where there is still some significant forest land, along with a number of other land use factors. In fact, forest protection mixed with smart land use and planning may be the best approach for maintaining clean water. But are these the only places where land protection is a relevant tool? What about in less forested landscapes where development and agriculture have more of an impact?