Monday, September 12, 2011

San Antonio Creek Flooding Study


Report titled: DEBRIS PRODUCTION AND FLOOD HAZARD EVALUATION FOR PLANNING, SAN ANTONIO CREEK WATERSHED, VENTURA COUNTY, CALIFORNIA 


From the executive summary:  San Antonio Creek drains approximately 50 square miles in the Ventura River Basin in western Ventura County, California. Recurring floods along San Antonio Creek and its tributaries, including Lion, Reeves, and Thacher Creeks, have resulted in millions of dollars in damages in Upper Ojai and Ojai Valleys, and in the canyon downstream. The Ventura County Watershed Protection District (VCWPD), in partnership with the Natural Resources Conservation Service (NRCS) and Ventura County Resource Conservation District, developed an approximated floodplain map as part of ongoing efforts to reduce flood-related damages to agricultural and rural residential properties. 



This information will be used to identify alternatives for protecting agricultural and rural residential properties that have potential for flooding during a 100-year storm event. 




This project was presented at the August meeting of the Ventura River Watershed Council. The study used computer models to analyze the effects of sediment (debris) flows delivered from the mountains into the Ojai Valley.  The entire valley is geologically made up of 'alluvium' eroded from the steep mountains over tens of thousands of years.  Traditional flood control uses debris basins and concrete channels to trap sediment and flush water off the land, often having negative effects on downstream property.  The study stopped short of making any recommendations, but should be considered as we move forward with watershed planning.


An overview poster of the study can be dowloaded here: