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In August 2004, the French Fire burned more than 13,000 acres of wildlands west of the city of Redding in northern California. The burned lands are administered by federal agencies (Bureau of Land Management-Redding District, National Park Service - Whiskeytown National Recreation Area), along with significant private holdings in and around the community of French Gulch. A National Interagency Burned Area Emergency Response (BAER) team assessed the burned area and oversaw initiation of a variety of Emergency Stabilization (ES) treatments including rehabilitation of suppression damage, timber salvage, hillslope treatments, invasive weed control, and stabilization of damaged cultural resources.
The burned area encompasses a portion of the upper Clear Creek watershed, a major tributary of Whiskeytown Reservoir, which supplies drinking water to several communities, agricultural irrigation water to the Sacramento Valley, and habitat for federally threatened and endangered species. An earlier cooperative study between the National Park Service and University of Montana found toxic levels of trace elements and heavy metals in water and sediments of tributaries feeding Whiskeytown Reservoir had “bioaccumulated” in fish, amphibians, and other aquatic life. The origin of these materials were abandoned hard rock mines and processing facilities, a large number of which are found within the burned area, and it was speculated that the increased runoff and sediment load following the French Fire might result in even greater concentrations.
Using Burned Area Rehabilitation (BAR) funds and in-kind contributions, the National Park Service again partnered with the University of Montana and United States Geological Survey (USGS) to further explore the relationship between trace elements and heavy metals and post-fire conditions in and downstream of the French Fire. Sampling began in October 2004, and continued throughout 2005. Preliminary results suggest variations in the concentrations of metals over the sampling period; for example, mercury levels increased following the fire, but declined by June 2005, while arsenic levels showed the opposite trend. Additional samples remain to be processed, and a second year of BAR funding has been requested in 2006 to better define long-term fluctuations and identify potential mitigation and remediation measures.
The results of this study are of great interest throughout those extensive areas of the western United States where mining occurred historically and wildland fires burn today. Rural and urban population growth has increased reliance on surface waters for domestic and other uses, and clean water is a critical component of overall ecosystem health. Understanding the response of these materials in post-fire conditions will better position land managers to take appropriate management responses following wildland fires.
Contact: Jennifer Gibson, Ecologist
Phone: (530) 242-3457 |
