Reservoirs and forests can be good neighbours.
Many of the reservoirs built between 1890 and 1940 were surrounded by new forests, because it was thought that human or agricultural use of gathering grounds would cause pollution. These fears are obsolete. It was also thought that trees would retain water and increase the total volume held in the catchment. This theory was proved wrong by an extensive instrumentation and monitoring exercise in the Plynlimon catchment (Natural Environment Research Council 1976). It is now known that trees consume water and, if they are coniferous, increase the acidity of reservoirs. Afforestation has therefore ceased to be a component of reservoir schemes. From an amenity and multipleï¾use point of view this is regrettable. A study of the Lake Vrynwy reservoirï¾forestry project concluded that: 'The combination of visual interest provided by farm, forest and water undertaking attracts more than 100,000 people to the valley each year'. The Vrynwy estate 'carries several rural industries under one control, has a productive forest with a full spread of age classes earning net income every year, and supports a contented and still developing rural community' (Newton & Rivers 1982). It is an example deserving emulation.