The purpose of this Technical Memorandum is to evaluate the hydrology and hydraulic characteristics of the Santa Paula Creek watershed. The following summarizes the tasks for the hydrology and hydraulic analysis outlined in the grant:

Hydrology Analysis: Evaluate the hydrologic characteristics of the creek during storm events, dry season low flows, and groundwater derived from existing reports by the Army Corps of Engineers (ACOE), Ventura County Watershed Protection District (VCWPD), and other available studies. Collected hydrology information shall be used as much as possible. For channel restoration and flood control analysis, peak discharge shall be estimated for the baseline, annual flow, 2-year, 5-year, 10-year, 25-year, and the 100-year flood events for key concentration points within the watershed and along the channels within the project reach. The level of detail of the analysis shall be done as appropriate for watershed planning level. Future watershed conditions analysis shall be performed as appropriate based on the current land use map.

Hydraulic Analysis: Channel hydraulic characteristics will be determined for both current conditions and proposed channel modifications for each alternative proposed to ensure maintaining of improving the level of flood protection and meeting the goals of the restoration project. The level of analysis shall be done appropriate for watershed planning level. The results of the analysis shall be used as the basis for determining the level of flood protection, analyzing channel stability, estimation of sediment transport of the channels, bank protection and channel stabilization requirements. The hydraulic analysis shall be performed based on the available topographic maps and available FEMA floodplain maps. The hydrology and hydraulic analysis prepared as part of this Technical Memorandum will be combined with the watershed geomorphology and steelhead ecology studies to guide the development of appropriate, long-term engineering solutions for improved fish passage in Santa Paula Creek while maintaining existing water-diversion rights.