Water Stewardship Information Sources

Citation Wilford, D.J., M.E. Sakals, W.W. Grainger, T.H. Millard, and T.R. Giles. 2009. Managing forested watersheds for hydrogeomorphic risks on fans. B.C. Min. For. Range, For. Sci. Prog., Victoria, B.C. Land Manag. Handb. 61.
Organization FLNRO
URL https://www.for.gov.bc.ca/hfd/pubs/Docs/Lmh/Lmh61.htm
Abstract/Description or Keywords Fans are linked to their watersheds by hydrogeomorphic processes - floods, debris floods, and debris flows. These processes move water, sediment, and debris from the hillslopes of a watershed through channels to the fan. Fans in British Columbia are often the site of residential developments, and transportation and utility corridors, as well as high-value habitat for fish and high-productivity growing sites for forests. Collectively, these features are termed "elements-at-risk" because they may be vulnerable to watershed-generated hydrogeomorphic processes that issue onto the fan. These processes may be natural or result from land use activities, and can cause the partial or total loss of some or all of the elements on the fan.

In British Columbia, forest harvesting and road building is associated with increased hydrogeomorphic hazards. The downstream effects of these forestry activities in source areas may be far-reaching and extend beyond the scope of conventional siteoriented planning. A five-step approach is presented to assist land managers undertake risk analyses and assessments that place their proposed developments within the watershed-fan system. The five steps are: 1) identify fans and delineate watersheds; 2) identify elements-at-risk on fans; 3) investigate fan processes; 4) investigate watershed processes; and 5) analyze risks and develop plans. This scheme is applicable to forested watersheds throughout British Columbia.

Keywords: Watershed management, alluvial fans, risk analysis, forest management planning, hydrogeomorphic processes.
Information Type report
Regional Watershed Province
Sub-watershed if known
Aquifer #
Comments
Project status complete
Contact Name Dave Wilford
Contact Email [email protected]