Protecting watersheds has benefits for water quality, flood control, recreation, hunting, and the landscape.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 recommends protecting watersheds with respect to depletion and degradation of their forest cover and from other harmful upstream activities.
A 1997 economic analysis of the New York water supply calculated that improved filtration would cost US $6-8 billion, whereas the same could be achieved by spending $1.5 billion on protecting the watershed. As a result of the report, an agreement was signed that included spending $350 million on land acquisition within the New York watershed.