Floodplain Building Requirements

County of Ventura Floodplain Management Ordinance 3841, and amendments thereto, specifies that property owners who wish to develop in the 1% annual chance floodplain (100-year floodplain) must obtain a Floodplain Development Permit from the Public Works Agency prior to the issuance of a Building Permit or a Grading Permit. A Floodplain Development Permit is required to ensure that development is compliant with the County’s Ordinance and the National Flood Insurance Program (NFIP).  Regulating development in floodplains is important not only because it helps prevent potential loss of life and property, it ensures that buildings, fill and other materials do not obstruct flood flows and subsequently cause flooding impacts elsewhere outside of the floodplain.

The definition of “development” is comprehensive:

“Development” is any man-made change to improved or unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations located within the area of the special flood hazard.” It also includes permanent storage of equipment and other materials.

In the unincorporated Ventura County, the latest available digital Flood Insurance Rate Maps (DFIRMs) that have been approved by FEMA are dated January 20, 2010. To see if your property has been mapped in a floodplain by FEMA, please click here.  You may also view the DFIRMs at the Public Works Agency counter located on the 3rd floor of the Hall of Administration in the Government Center, 800 S. Victoria Ave, Ventura, CA, during normal business hours, Monday through Friday.

It is equally important to be aware that development proposed in proximity (i.e., within the creek bed, banks,  overflow area) to a “red line watercourse/ channel” will require a Watercourse Permit from the Ventura County Watershed Protection District prior to the issuance of a Floodplain Development Permit, Grading Permit, or a Building Permit. Also, if development is proposed within a District easement or other property interest, an Encroachment Permit must be obtained from the District prior to the issuance of a Floodplain Development Permit, Grading Permit, or a Building Permit.

Development that is proposed in proximity to a Federal  or State of California “blue line” watercourse may also require permits from the U.S. Army Corps of Engineers http://www.usace.army.mil/Pages/default.aspx ,  U.S. Fish and Wildlife Service http://www.fws.gov, California Department of Fish and Game https://www.wildlife.ca.gov/Conservation/Mammals/Bighorn-Sheep/Sierra-Nevada , California Coastal Commission http://www.coastal.ca.gov,  and other Federal and State agencies. If required, these permits need to be issued prior to the issuance of a Floodplain Development Permit, Floodplain Clearance, Grading Permit, or a Building Permit.

The purpose of this requirement is to help assure that coordination occurs between various levels of government on projects impacting floodplains. Permit applicants are not well served if they are allowed to proceed with a project only to have work delayed or stopped later by a Federal or State agency because they have not obtained all the proper permits.

More Information:

Design Guidelines for Flood Damage Reduction FEMA 15


Elevated Residential Structures FEMA 54


Engineering Principles and Practices of Retrofitting Floodprone.. FEMA 259


Above the Flood: Elevating Your Floodprone House FEMA 347


Protecting Building Utilities from Flood Damage FEMA 348


Openings in Foundation Walls FEMA Technical Bulletin – 1


Flood Damage-Resistant Material Requirements FEMA Technical Bulletin- 2


Floodproofing Non-Residential Structures FEMA 102, Technical Bulletin -3


Elevator Installation, Technical Bulletin -4


Free-of-Obstruction Requirements, Technical Bulletin -5


Below-Grade Parking Requirements FEMA Technical Bulletin -6


Wet Floodproofing Requirements FEMA Technical Bulletin -7


Corrosion Protection for MEtal Connectors in Coastal Areas -8


Design & Construction Guidance for Breakaway Walls Below Elevated Coastal Buildings -9


Ensuring that Structures Built on Fill in or Near Special Flood…FEMA TB 10


Crawlspace Construction for Buildings Located in Special Flood…FEMA TB 11