City of Concord, California

Flood Zone

FEMA Issuance of Digital Flood Insurance Rate Maps (DFIRMs), June 16, 2009

Upcoming changes in the Federal Emergency Management Agency's (FEMA's) designation of flood-prone areas include the addition of Special Flood Hazard Areas (SFHAs), or floodplains, along the northern portion of the Walnut Creek channel in Concord.  Property owners in flood-prone areas who have federally back mortgages will be required to have flood insurancewhen the maps become final, on June 16, 2009.   If flood insurance is purchased before the new maps are finalized, the insurance rate will be calculated at the current lower (non-flood prone area) rates, which is a significant savings.  Renters may also purchase flood insurance if they wish.

Outreach Materials
 • Letter to Affected Property Owners and Occupants
 • Letter to Property Owners and Occupants in buffer area

Flood Insurance and FEMA's Grandfathering Rule
 • FEMA Fact Sheet - Map Modernization and the Grandfathering Rule
 • FEMA Fact Sheet - Saving on Flood Insurance-Grandfather Rule
 • FEMA - Grandfather Rule
 • Preferred Risk Policy (PRP) Eligibility Extension

Levee Systems and the National Flood Insurance Program
 • FEMA - Contra Costa County Levee Status Map
 • FEMA Fact Sheet - Overview of NFIP and Levee Systems
 • FEMA Fact Sheet - Living with Levee Systems - Information for Property Owners
 • FEMA Fact Sheet - FAQs for Levee Systems

Additional Information
 • FEMA Fact Sheet - Levees and Flood Insurance for Insurance Industry Professionals
 • FEMA Fact Sheet - Levees and Flood Insurance for Mortgage Lenders
 • FEMA - Acronyms and Abbreviations used with Levee Systems
 • FEMA - Glossary used with Levee Systems
 • Local Hazard Mitigation Plan

Procedure and Guidelines

Article II Chapter 34

Flood Insurance Program
Section 34-31

The Federal National Flood Insurance Act of 1968 allows persons in flood plain areas of a community to purchase flood insurance at reduced rates. In order for such rates to be available within a community, the community must make provision for regulating development and land uses in accordance with applicable Federal requirements. The purpose and intent of this chapter is to identify special hazard areas in the City of Concord which are prone to flooding and to impose requirements on development and uses within such areas in accordance with applicable Federal requirements.


  • Base Flood- a flood which has a one percent chance of being equaled or exceeded in any given year (also called the "100-year flood").
  • Flood Boundary and Floodway Map (FBFM) - official map on which the Federal Emergency Management Agency or Federal Administration has delineated both the areas of special flood hazards and the floodway.
  • Flood Insurance Rate Map (FIRM) - official map on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the community.
  • Flood Insurance Study - official report provided by the Federal Insurance Administration that includes flood profiles, the flood insurance rate map, the flood boundary and floodway map, and the water surface elevation of the base flood.
  • Floodplain or Floodprone Areas- any land area susceptible to being inundated by water from any source
  • Floodproof or Floodproofing- any combination of structural and nonstructural additions, changes or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents.
  • Floodway- the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot. Also referred to as "regulatory floodway."
  • Floodway Encroachment Lines- the lines marking the limits of floodways on federal, state and local floodplain maps.
  • Floodway Fringe- area of the floodplain on either side of the "regulatory floodway" where encroachment may be permitted.
  • Highest Adjacent Grade- the highest natural elevation of the ground surface prior to construction next to the proposed walls of structure.
  • Lowest Floor - the lowest floor of the lowest enclosed area, including basement. An unfinished or flood-resistant enclosure, usable solely for parking of vehicles, building access or storage in an area other than a basement area is not considered a building's lowest floor, provided that such enclosure is not built so as to render the structure in violation of the applicable non-elevation design requirements. (Note: This definition allows attached garages to be built at grade. Below-grade garages are not allowed as they are considered to be basements.)
  • Special Flood Hazard Area (SFHA)- an area having special flood, mudslide (i.e. mudflow), or flood-related erosion hazards, and shown on an FHBM or FIRM as zone A, AO, A1-A30, AE, A99, AH, E, M, V1-V30, VE or V.
  • Watercourse- a lake, river, creek, stream, wash, arroyo, channel or other topographic feature on or over which waters flow at least periodically. "Watercourse" includes specifically designated areas in which substantial flood damage may occur.

Certifications and/or Forms

The Elevation Certificate is an important administrative tool of the National Flood Insurance Program (NFIP). It is to be used to provide elevation information necessary to ensure compliance with community floodplain management ordinances, to determine the proper insurance premium rate, and to support a request for a Letter of Map Amendment or Revision (LOMA or LOMR-F)

Certification of the elevation of the lowest floor, floodproofed elevation or elevation of the structure's lowest horizontal member is required at that point where the footings are set and slab poured. Failure to submit the elevation certification shall be cause to issue a stop work order for the project. As-built plans certifying the elevation of the lowest adjacent grade are also required

If fill is used to elevate a structure above the base flood elevation, the permit holder may wish to apply for a letter of map amendment or Revision (LOMA or LOMR).

Applicant may obtain a Flood Zone Verification form, from the Engineering section located at the permit center, which will reference information regarding the Flood Zone for the parcel in question (i.e. zone type, community panel number).

A Flood Plain Permit shall be obtained before construction or development begins on property within any of the special flood hazard areas.

Standards of Construction

Refer to the City of Concord's Municipal Code - Section 34-34

Violations; Penalties

Section 34-38

It shall be unlawful for any person, firm, or corporation to construct, locate, extend, convert, or alter any structure or land without full compliance with the terms of the City of Concord 's Municipal Code and all other applicable regulations.

The application for the permit shall include the following information:

  1. Proposed elevation in relation to mean sea level, of the lowest floor (including basement) of all structures; in Flood Hazard Zone AO elevation of existing grade and proposed elevation of lowest floor of all structures.
  2. Proposed elevation in relation to mean sea level to which any structure will be flood-proofed.
  3. Certification by a registered professional engineer or architect that the flood-proofing methods for any nonresidential structure meet the flood-proofing criteria.
  4. Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.
  5. The site plan shall clearly show the location of the project, all proposed structures, property lines, right of way, and set back distances. The floodplain boundary, stream channel, and floodway boundary if applicable shall be shown.
  6. Such other information as the City may require.

The City shall review all permit applications to determine the following:

  1. That all requirements of this chapter have been satisfied.
  2. That the site indicated in the permit is reasonably safe from flooding.
  3. Whether the proposed development adversely affects the flood-carrying capacity of the special flood hazard area. For purposes of this chapter, adversely affected means that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will increase the water surface elevation of the base flood more than one (1) foot at any point.
  4. With respect to applications involving five (5) or more parcels, that the flood discharge exiting the development after construction is equal to, or less than, the flood discharge at the location prior to development.

The Ordinance prohibits the issuance of a building permit for a building within a Special Flood Hazard Area (SFHA) without first obtaining a SFHA permit. Engineering division will determine if a proposed building lies within a flood hazard area. If it does, the following procedure applies:

  1. Engineering division will provide the permit applicant with a SFHA permit application form.
  2. Engineering division will review the application for completeness and compliance with ordinance requirements. When appropriate, specific requirements will be noted on the permit.
  3. Engineering division will approve, conditionally approve, or deny the permit application. Building division will be informed of Engineering division's decision via the normal building permit plan check process.
  4. Building division to inspect construction for conformance with ordinance requirements (flood proofing, required elevation certificate).
  5. Engineering will file all applications in SFHA file along with pertinent information.
  6. Building division will submit to Engineering pertinent records such as documentation inspections and elevation certificates for filing.
  7. Engineering division will initiate enforcement proceedings for any ordinance violations.
  8. For development permits such as subdivisions of use permits, Engineering division will notify the developer of the ordinance requirements through the project conditions of approval.


Flood Zone Verification (fax over to the Engineering section)
Flood Plain Permit
Article II, Chapter 34 - Section 34

City of Concord CA