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Everyday Surfing: Forests and Flooding

by Martin Hollingham Co-ordinator, MSc Water Resources, University of Wales Bangor.


A search for ‘Forests and Flooding’ will lead to disappointingly few sites dedicated to this topic. The webpages you’ll find are typically a single page describing the link between forests and reduction in runoff and are usually part of a larger web site concerned with catchment management or environmental protection. Most of these are watershed groups in the US and Canada.

The Whyfiles, University of Wisconsin ( is typical of these and explores the links between land use change and flooding, and also links to the US forest roads guidance document which details the best methods of road construction to prevent runoff. Some of the others are: the NBC4 page on Chesapeake Bay which points out the important role of forests in the watershed (; the Television Trust for the Environment’s campaign page to protect forests, in Malaysia (; and the wilderness societies campaign page to stop logging in Melbourne’ water catchment. (

There are also numerous single page articles detailing current or summarizing past research, such as this summary of a hydrological experiment at the USFS Fernow Experimental Forest in north-central West Virginia ( All the units are American but at least this webpage includes some results.

An example of a more general paper is ‘Forests and Water’ from The Overstory web page (

Details of how the effects of operations can have impacts on drinking water quality  through increased runoff,  are given in the U.S. Department of Agriculture, Forest Service, Southern Research Station’s pdf document, ‘Drinking water from forests and grasslands’ (

 A more useful reference though is the UN press’ ‘Forests Climate and Hydrology’  ( publication which although not out of print, is difficult to obtain, but gives useful summaries of research exploring  the links between forests, hydrology and climate, Chapter 5 is particularly relevant with respect to flooding.

While the above pages are interesting in themselves the are no websites specifically dedicated to Forests and Flooding and articles have to be retrieved from the  search engines of relevant research agencies such as CEH (, DFID (, USEPA. ( websites.  Very little seems available from the Forestry Commission website , however reference to flooding is made in this pdf document  on a management plan for the  Glen Urquhart forest.$FILE/urquhart.pdf.

The nearest subject area to Forests and Flooding is Catchment/Watershed Management or Land Use and Hydrology/Water Resources. Some of the more famous Catchment experiments are online, the Coweeta hydrological laboratory, run by the US Forest Service can be found at, while a brief summary of research at the UK equivalent at Plynlimon can be found at

The FAO Land-water linkages site ( ) is a useful site for those wishing to apply catchment management principles. Here you can find: to what extent different land use systems and practices affect hydrological regime and water quality; and methods to value the resulting benefits and costs. There are also links to some FAO publications which deal with soils, irrigation and catchment management, which are available free online unlike their hardcopy counterparts.

Other sites containing relevant reports are: the Land Use and Water Resources Research Journal, which is available free online, while it is a relatively young journal there are some articles on flooding. (; the Centre for Land use and water resources research (; and The Forest Conservation Portal (


There are numerous pages that point to the benefits of forests on water resources, the methods of quantifying these, and the need for participatory catchment management projects. Such a site  as the  European Tropical Forest Research Network which has a page on how to value forests for their hydrological services; hydropower in Costa Rica is used as an example ( Also for more detail on how to include the benefits of reduced flooding in your annual report, look at  the Forest Trends ‘Developing markets for water services from forests’ ( While not overly concerned with flooding this pdf document details methods of assessing the benefits of forests on water resources, such as watershed protection, biodiversity conservation, and carbon storage.


With all this talk of forests influencing hydrology its easy to forget that forests can also be affected by hydrology and can suffer from flood damage. The north eastern US Forestry Service web pages contains webpage on the effects of flooding on trees. ( )


Some forests may also need seasonal flooding. The Barmah- Millewa forest is such is affected by changes in the river regime caused by the Hume Dam in the Murray Darling watershed. The Hume Dam is used for irrigation and this has the effect of prolonging summer flows in the forest.  The water management plan is detailed in

If  after all that surfing you feel that you now know enough about forests, flooding and watersheds, why not get a certificate! Join the US EPA watershed academy, which runs an online course in watershed management. As well as watershed ecology and pollution there is a section on forestry and methods of watershed management including community participation (


Copyright © Martin Hollingham