Rocky Creek Post-Wildfire Debris Flooding in Big Sur
The 2016 Soberanes Fire was one of the costliest fires in US history and spanned across 200 square miles in Monterey County. The following winter, back-to-back storms targeted the burn area and dropped 10 inches of rain in a couple of days, unleashing an unprecedented amount of runoff. The burn area allowed for debris torrents and flows in Rocky Creek resulting from erosion due to the loss of vegetation, reductions in infiltration, and soil water repellency along the Palo Colorado Watershed. The debris flows on Rocky Creek ultimately caused several roadway failures due to scouring and creek overtopping.
The design team responded following the storms to assess the damage and come up with a long-term repair at the site. Conventional construction methods are limited, so the design team prepared a practical design that would allow smaller haul trucks and materials to be transported up the road.
This presentation is a first-hand account of the post-wildfire flooding assessments that took place along Palo Colorado Road in January and February of 2017. Key points will be presented on the site constraints and the process that an agency must go through for federal funding approval following a disaster declaration.
Alex Yescas, PE, CFM, ENV SP
Water Resources Sector Lead
HDR, Inc., San Diego, CA