Forests play an essential role in regulating freshwater flows and maintaining water quality. Both the quantity and quality of water available for domestic, agricultural, industrial and recreational purposes are influenced by the existence and health of forests.

FAO has been actively conducting work in the fields of forest hydrology, watershed management and sustainable mountain development since the late 1970's. Several departments work in collaboration to support projects, events, and technical publications.

Today, the Forests and Water Programme is responsible for carrying out all activities of FAO's Forestry Department that are related to forests and water, as well as watershed management. The main activities of the Forests and Water Programme include supporting the formulation and implementation of field projects, participating in and organizing international events, collaborating with international networks and processes and producing literature in four main thematic areas namely, forest hydrology, watershed management, upstream/downstream linkages and sustainable mountain development.