Forest hydrology


Forest river in flood

This research programme is concerned with improving our understanding of these effects so that forestry not only protects, but where possible enhances the freshwater environment.

Forests and the way that they are managed can have profound effects on water. Well designed and managed forests help to protect water and the wide range of flora and fauna that depend on this important habitat. In contrast, poor planning and management can contribute to water shortages, local flooding and water pollution, including increased acidification, siltation and nutrient enrichment.

Research objectives

The overall objective of the research programme is to improve our understanding of the effects of forests on water to ensure that future benefits can be secured and any negative effects minimised. Specific objectives include:

  • Conducting research into the effects of forests and forestry management on the quality and quantity of water
  • Evaluating the impact of floodplain woodland on flood and base flows
  • Assessing the interactions between riparian woodland and the freshwater environment
  • Investigating the long-term effects of forestry on surface water acidification
  • Assessing the effectiveness of best management practices at protecting the freshwater environment.

Funders and partners

Forestry Commission logo
This research is primarily funded by the Forestry Commission Protecting soil and water resources programme.

Much of the research is undertaken in partnerships with other research institutes, regulatory bodies and universities, at both national and European levels. Strong links are also maintained with end users through the provision of expert advice and involvement in key stakeholder groups. Current funders and collaborators/partners include:

  • Department of Environment, Food and Rural Affairs (Defra)
  • Environment Agency
  • Scottish Environmental Protection Agency
  • English Nature
  • Scottish Water
  • United Utilities
  • Freshwater Fisheries Laboratories
  • Centre for Ecology & Hydrology
  • Newcastle University
  • Edinburgh University
  • Cardiff University
  • Southampton University
  • European Union (collaborators from Sweden, France, Italy, Austria, Estonia and Spain).

Forestry Commission policy

The protection of the water environment is a key element of sustainable forestry. This research programme directly supports the Forestry Commission policy of achieving sustainable forest management.


UK research on forests and water began in the 1960s. Effort initially focused on assessing the effects of the rapid expansion of upland conifer afforestation that was occurring at that time. The main concerns centred on whether afforestation would reduce water supplies significantly and dry up streams. These issues were replaced during the 1980’s by increasing fears over the potential of forestry to degrade water quality. Research addressed aspects such as the effects of forestry on stream water acidification, the pollution of rural water supplies, siltation in watercourses and nutrient enrichment of lochs.

In the 1990s, the emphasis shifted to the development and assessment of best management practice following the introduction of the Forestry Commission’s Forests & Water Guidelines in 1988. Recent work is more orientated to lowland woodlands and evaluating how forestry can help to tackle wider problems of diffuse pollution and flooding. The work of the research programme is reviewed at five-yearly intervals.


Tom Nisbet