PACE conducted a two-dimensional numerical modeling study to determine the 100-year flooding extents on the Oxnard floodplain located in Ventura County, California. The study examined the three sub-watersheds developed by the Ventura County Watershed Protection District including Hueneme Drain, “J” Street Drain, and Rice/Industrial Drain, separately. The goals of the study were 1) to estimate the locations and extents of flooding on the Oxnard floodplain, including acreage of inundation and 2) determine the discharges at the floodplain outflow. A FLO-2D numerical model was developed for each of the three sub-watersheds, the boundaries of which closely follow those used in Ventura County’s VCRat model. The model grid was assembled using FLO-2D’s GDS software and established by importing DTM data provided by Ventura County into the GDS. Model parameters were then imported into the GDS. Following collection and importation, data was area averaged on a grid cell by grid cell basis. Hydrology for all simulations is the County’s design 100-year, 24-hour rainfall, Zone B, and was provided by the County’s hydrology branch.