BC Hydro operates and maintains an extensive network of hydroelectric transmission lines across British
Columbia (BC Hydro 2010a) that spans vast areas of vegetated landscape. BC Hydro implements an Integrated
Vegetation Management Program (IVMP) (BC Hydro 2010b), which is critical in mitigating the risk of power interruption resulting from line contact with adjacent vegetation. Manual and mechanical vegetation treatments (such as hand slashing, mowing, and mulching) are used as vegetation control measures as part of the IVMP. These operations result in an accumulation of woody debris, which may alter the risk of fire in the hydro rights-of-way (ROWs). BC Hydro recognizes fuel loading as a factor in determining vegetation management cycles for various vegetation types in ROWs. Increasing the frequency of ROW maintenance prevents excessive growth in target species and reduces the deposits of debris produced in maintenance operations. Mulching treatments in hydro ROWs are costly and create, at least in the short-term, an increased environmental disturbance. Vegetation management programs attempt to balance their cost and environmental effects with the positive outcomes of reduced fuel loading and consequent fire risk in ROWs. Other considerations in vegetation management include the proximity of combustible fuels and legislation under the British Columbia Wildfire Act (British Columbia 2005). This legislation requires a utility transmission operation adjacent to forest land or grass land to “maintain the site in a manner that prevents any fire from spreading from the site.”
FPInnovations is interested in evaluating wildland fuel conditions in mulched fuel along linear corridors to assess quantity and combustibility of fuels, and quantify the potential fire spread and ignition probability. In May 2012, we studied BC Hydro ROWs and wildland fuel environments at a number of sites in Northern and Southern Interior BC to evaluate the accumulation of woody debris (specifically mulch) resulting from ROW maintenance operations.