Some of the biggest cities in the world know the importance of protecting their water. New York City, Seattle and Vancouver are prime examples of large populations that rely on surface-fed water. In fact in British Columbia, over 85% of drinking water is surface fed from creeks and streams. Our forests are the best filter available. Not only do intact forests clean water, but they protect slopes from run-off, land and mudslides. This has never been more clear than the recent flooding disasters in Grand Forks and most recently in the lower mainland of Vancouver’s Fraser Valley.
https://www.wri.org/insights/forests-near-or-far-can-protect-water-cities