By 2025, 1.8 billion people will be living in regions with absolute water scarcity and two-thirds of the world’s population may experience water-stress conditions. Forests capture and store water and can play an important role in providing drinking water for millions of people in the world’s mega-cities. Forests reduce the effects of floods, prevent soil erosion, regulate the water table and assure a high quality water supply for people, industry and agriculture. Forests are in most cases an optimal land cover for catchments supplying drinking water. Forest watersheds supply a high proportion of water for domestic, agricultural, industrial and ecological needs. Forests and trees contribute to the reduction of water-related risks such as landslides, local floods and droughts and help prevent desertification and salinization.
Today, at least one third of the world’s biggest cities, such as New York, Singapore, Jakarta, Rio de Janeiro, Bogotá, Madrid and Cape Town draw a significant portion of their drinking-water from forested areas. If properly utilized, forest catchment areas can provide at least a partial solution for municipalities needing more or cleaner water.
It is well known that water used by forests can be influenced and reduced by prudent forest planning and management practices such as the planting of appropriate tree species. Countries are stepping up policy and project activities to increase forest areas for the protection of soil and water.
Eight percent of the world’s forests have soil and water conservation as their primary objective. While every hectare of forests make a huge contribution to regulating water cycles, around 330 million hectares of the world’s forests are designated for soil and water conservation, avalanche control, sand dune stabilization, desertification control or coastal protection. This area increased by 59 million hectares between 1990 and 2010.
Example of FAO project in forest management is the "Fouta Djallon Highlands (FDH) Integrated Natural Resources Management Project" in West Africa. This ten-year project, supported by the Global Environment Facility and jointly implemented by FAO, UNEP and the African Union, involves eight countries (Gambia, Guinea, Guinea Bissau, Mali, Mauritania, Niger, Senegal, and Sierra Leone).
The Fouta Djallon Highlands are the point of origin of a number of international water courses, notably the Gambia, Niger and Senegal rivers. Shifting agriculture and tree felling for charcoal production led to heavy deforestation and depleted water resources in the area. In order to improve local livelihoods and water resources, the project aims to ensure the conservation and sustainable management of natural resources through the restoration of forest cover.