Description: Sec. 26-56-005. - Purpose.The dataset represents the F1 - Floodway Combining District, as specified in Sonoma County Code Zoning Regulations Chapter 26.Purpose: to provide land use regulations for properties situated in floodways, to safeguard against the effects of bank erosion, channel shifts, increased runoff or other threats to life and property and to implement the provisions of the general plan public safety element. The application of this district shall be based upon data from the Federal Emergency Management Agency. Additional more detailed engineering analysis of flooding, erosion or other conditions may be necessary so as to prevent property damage and safeguard the health, safety and general welfare of people.(Ord. No. 4643, 1993.)Sec. 26-56-010. - Location and boundaries.(a)The F1 district shall be applied to properties which lie within the floodway as shown on the most recent FEMA maps and accompanying report. The boundaries of the floodway as indicated on the zoning maps should be considered approximate.(b)The provisions of this article may be waived by the decision-making body where it is demonstrated through engineering analysis, field determinations or other appropriate data, that the precise floodway boundary differs from that shown on the FEMA maps, and provided further, that FEMA approval and sign-off is first secured. No use shall be approved within the floodway that will significantly increase the flood hazard or significantly affect the carrying or storage capacity of the floodway.(Ord. No. 4643, 1993.)Sec. 26-56-020. - Uses within floodway.All uses allowed within the base district with which this district is combined shall be permitted subject to the provisions of Section 26-56-030, except that no new permanent structure nor structure intended for human occupancy shall be permitted within the floodway.(Ord. No. 4643, 1993.)Sec. 26-56-030. - Development standards for floodways.The decision-making body shall be guided by the following standards in administering the FW district:(a)The placement and type of materials used in bank stabilization shall be complementary to surrounding development and natural conditions and shall not be depreciative of surrounding property values.(b)Where, in the opinion of the planning director or other decision-making body, topographic data, engineering studies or other studies are needed to determine the effects of bank erosion on a proposed structure or the effect of the structure, including bank stabilization activities, on the floodway and natural vegetation, the applicant may be required to submit such data.(c)Within the Laguna de Santa Rosa, a "zero net fill" policy shall be enforced whereby no fill shall be permitted to be placed in the Laguna unless an engineering analysis demonstrates that no reduction in flood storage capacity would result from the placement of fill. For purposes of this article, the "Laguna" shall be defined as the Laguna de Santa Rosa and tributaries thereto which are within designated floodways on the most recent FEMA maps.(d)Temporary structures such as floating docks and moorage facilities may require issuance of a use permit.(e)Except as specifically allowed in this article, no building or structure shall be constructed, erected, moved, converted, altered or enlarged in the floodway, nor shall any other condition be allowed which would tend to cause significant stream channel alteration or adversely affect the carrying or storage capacity of a floodway, or otherwise constitute a threat to life and property. Ordinary maintenance and repair of existing nonconforming structures shall be permitted subject to the provisions of Article 94.(Ord. No. 4643, 1993.)Related Resource:FEMA - HomepageFEMA Map Service CenterFEMA Contact InformationFEMA Map Specialist (877-336-2627) or e-mail, FEMAMapSpecialist@riskmapcds.com
Copyright Text: FEMA Description:
The National Flood Hazard Layer (NFHL) data incorporates all Flood Insurance Rate Map (FIRM) databases published by the Federal Emergency Management Agency (FEMA), and any Letters of Map Revision (LOMRs) that have been issued against those databases since their publication date. It is updated on a monthly basis. The FIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper FIRMs. The FIRM Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The FIRM Database is derived from Flood Insurance Studies (FISs), previously published FIRMs, flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by FEMA. The NFHL is available as State or US Territory data sets. Each State or Territory data set consists of all FIRM Databases and corresponding LOMRs available on the publication date of the data set. The specification for the horizontal control of FIRM Databases is consistent with those required for mapping at a scale of 1:12,000. This file is georeferenced to the Earth's surface using the Geographic Coordinate System (GCS) and North American Datum of 1983.
FEMA Summary:
The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards, " Section 2 (b) (4) of the Flood Disaster Protection Act of 1973. In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. The FIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The FIRM Database serves to archive the information collected during the Flood Risk Project.
FEMA Use Limitations:
The hardcopy FIRM and FIRM Database and the accompanying FIS are the official designation of SFHAs and Base Flood Elevations (BFEs) for the NFIP. For the purposes of the NFIP, changes to the flood risk information published by FEMA may only be performed by FEMA and through the mechanisms established in the NFIP regulations (44 CFR Parts 59-78). These digital data are produced in conjunction with the hardcopy FIRMs and generally match the hardcopy map exactly. Acknowledgement of FEMA would be appreciated in products derived from these data.
Federal Emergency Management Agency
500 C Street, S.W.
Washington, DC 20472
1-877-336-2627
mscservices@riskmapcds.com