Sespe Creek Levee Improvements / Certification

Fillmore, CA

PACE contracted with the Ventura County Watershed Protection District to perform the engineering design to correct hydraulic design deficiencies in the existing Sespe Creek levee system. The 1.1-mile SC-2 portion of the levee system within the City of Fillmore, California, was identified as deficient in providing the required level of flood protection, resulting in the need to raise the top of the embankment along a 1,550-foot portion up to 6 feet. The upgrades met current Federal Emergency Management Agency (FEMA) standards and removed the mapped flood hazards in the residential areas behind the levee.

This engineering design required the following technical analyses to provide the technical basis for the recommended levee rehabilitation design:

• Hydrology
• Hydraulics
• Geomorphology
• Sediment transport
• Geotechnical
• Economic flood damage
• Levee local interior drainage
• Engineering alternatives feasibility

The final engineering and construction design incorporated the best aspects of each of the alternatives analyzed, involving a combination of fill and retaining walls. This project required the first complex Section 408 permit to be completed within the U.S. Army Corps of Engineers (USACE) Los Angeles District.

Key Features:

• Hydrology / hydraulics / sediment transport analyses
• Levee design
• Risk and uncertainty analysis
• FEMA Conditional Letter of Map Revision (CLOMR)
• FEMA floodwall design
• Plans, specifications, and estimates (PS&Es)
• Safety Assurance Review (SAR)
• USACE Section 408 permit processing