Author(s): A. Jake Gusman; Martin J. Tea; Daniela Todesco; Mark Bandurraga
Linked Author(s): Martin Teal, P.E., P.H., D.WRE
Keywords: No Keywords
Abstract: Increasing water discharge to account for a high concentration of sediment in the flow is known as bulking, and its applicability depends on the type of sediment-laden flow expected in a watershed. Based on sediment concentration, sediment/water flow ranges from normal streamflow to hyperconcentrated flow to debris or mud flows. The Ventura County Watershed Protection District currently uses a simplified method for estimating bulking factors for debris-prone watersheds. The purpose of this study was to investigate bulking methods used by various agencies, perform a literature review, and begin developing a recommended procedure for estimating bulking factors in Ventura County. Bulking factors for five Ventura County watersheds were computed by distributing the calculated debris yield throughout the clear water hydrograph. For each watershed, bulking factors were computed for the 10-, 50-, and100-year recurrence interval events. The computed bulking factors were then compared to the agency bulking curves. Preliminary results for five Ventura County watersheds indicate that the County's current bulking factor curve may overestimate bulking factors. A new bulking factor curve for Ventura County is currently under development, and will incorporate the results from additional watersheds throughout the County.
Year: 2009