Inter-Departmental Correspondence

Department of Public Works



August 26, 2010


September 14, 2010







Honorable Board of Supervisors


James C. Porter, Director of Public Works


Operations and Maintenance Manual for the Levee at San Carlos Airport



Adopt a Resolution:



Adopting the August 2010 Levee Operations and Maintenance Manual for the Levee at San Carlos Airport; and



Authorizing Public Works staff to update and amend the Levee Operations and Maintenance Manual in the future as may be required.



The Federal Emergency Management Agency (FEMA) is updating and digitizing their Flood Insurance Rate Maps (FIRM) for communities in San Mateo County. The new FIRMs will identify areas in the County that do not meet FEMA’s new levee height requirements, which will trigger a mandatory flood insurance requirement for homeowners with federally backed mortgages within those communities.


Redwood Shores is one of the communities that would currently be placed in a flood hazard zone under FEMA’s new criteria. Redwood City (City) has land use authority over the community and is currently working to finish the upgrades and certification of the entire levee system surrounding the Redwood Shores Peninsula, which includes a section of levee at the San Carlos Airport (Airport), prior to FEMA’s deadline in late 2010.


The levee at the Airport is located within Redwood City limits and is also located within the City’s General Improvement District (GID) I-64, which was formed to finance the maintenance of levees within the district. While the County has maintained the levees adjacent the Airport for several decades, the City has funded and constructed all other improvements to the levee system protecting Redwood Shores that are within its city limits and inside its GID I-64.


A small portion of the levee at the Airport is also within the Federal Aviation Administration protected airport safety areas and cannot be raised due to flight safety requirements because of its close proximity to the runway. The Airport will deploy a removable self-activating barrier system on this portion of the levee when storm and tide conditions warrant.



The County has worked cooperatively to assist the City in their construction improvements of the levee at the Airport and has agreed to maintain the improvements once the City has completed the project. FEMA’s levee certification process requires that the agency that is maintaining a levee adopt an Operations and Maintenance (O&M) Manual outlining the procedures for the monitoring, inspection and maintenance of the levee. We have prepared the O&M manual for the levee at the Airport with input from City staff and are also recommending that Public Works staff be authorized to update and amend the Levee O&M Manual in the future as may be required.


County Counsel has reviewed and approved the Resolution as to form.


Adopting the Levee O&M Manual will contribute to the Shared Vision 2025 outcome of a Collaborative Community by assisting the City of Redwood City with the certification of improvements to the levee system surrounding Redwood Shores to avoid the requirement of its residents to pay for flood insurance.



Additional inspection and maintenance costs associated with the adoption and implementation of the Levee O&M Manual are expected to be negligible and will be paid for from the Airport Enterprise Fund.


There is no impact to the County General Fund.