A groundbreaking ceremony for the Randall Road Debris Basin was held on May 4th in Montecito, Santa Barbara County. The Randall Road Debris Basin is a new 8-acre basin to be constructed along San Ysidro Creek in an area that saw severe debris deposition and resulted in the loss of life and property after the catastrophic debris flow that ensued after the 2018 Thomas Fire. WRECO worked with the Santa Barbara County Flood Control and Water Conservation District to design the basin to capture large debris-like boulders and tree trunks, and reduce water elevation and velocity for large storm events while maintaining a natural sedimentation transport process during smaller storm events. The project was initially proposed by a resident to improve safety in the area and to lessen the chance of future devastation from recurring debris flows. The project was able to progress to construction in 3 years thanks to the remarkable support from the community and the tireless work of the District and WRECO design team.
The design maintains the current San Ysidro Creek up to a 5-year storm event water surface elevation to support and maintain fish passage and stream functions for smaller storm events. Beyond that 5-year elevation, the basin expands into a large floodplain area that will reduce velocities and water surface elevations for larger storm events and provide volume to capture large debris elements. Debris racks within the basin and at the downstream culvert will assist in the capture of large boulders and woody debris. A memorial will be included at the northern end of the basin as well as a pedestrian trail along the roadway to have the potential to connect to a larger network of trails in the future.
The estimated project cost of $15.5 million to $17.5 million is funded by Federal Emergency Management Agency ($13.5 million) and local flood control money. The cost included acquiring six private properties on Randall Road and one on East Valley Road. Construction of the project is expected to finish by the end of the year.
WRECO also worked on the Gobernador debris basin outlet control structure in Santa Barbara County and is executing the San Ysidro debris basin improvement project upstream of the debris basin on Randall Road.