In addition to using FEMA flood maps to regulate flood hazards, the County applies a number of policies and regulations to new development that are intended to avoid, minimize and mitigate the impacts and hazards of construction within flood plains. These include the policies of the General Plan and Local Coastal Program, as well as the County’s zoning and building regulations. The County’s building regulations are consistent with federal and state codes and are updated on a three year cycle that corresponds to the regular updates of the International ICC codes and the California State Building Code.

The process used by San Mateo County to implement the NFIP requires applicants in all FEMA designated flood zones, with the exception of Moderate to Low Risk Areas designated Zone X, to demonstrate compliance with standards for development within these zones. This includes certification that all habitable areas of the project is at least one foot above the base flood elevation, limiting the use of all areas below this elevation to utility purposes constructed with breakaway walls, and installing flood vents within the foundation.

The Elevation Certificate (EC) is a three step process that must be completed before a certificate of occupancy can be issued. The first EC needs to be provided at time of plan check. The next EC must be provided while the project is under construction during the framing inspection. The last EC needs to be provided and approved at time of final inspection or prior to issuance of a Certificate of Occupancy.

In addition to ensuring that the correct benchmark and Vertical Datum is being use, our review of Elevations certificates involves confirmation of the following elevations:

a) Top of Bottom floor (including basement, crawlspace, or enclosure floor)

b) Top of the next higher floor

c) Bottom of the lowest horizontal structural member (V-Zones Only)

d) Attached garage (top of slab)

e) Lowest elevation of machinery or equipment servicing the building.

f) Lowest adjacent (finished) grade next to the building (LAG)

g) Highest adjacent (finished) grade next to the building (HAG)

h) Lowest adjacent grade at the lowest elevation of deck or stairs, including structural support.

For additional regulations applicable to development within a flood hazard area, see Chapter 35.5 Flood Hazard Areas of the Zoning Regulations.