Section 113 - Dwelling and Structures Within an Adopted Plan of Flood Control(a) The following definitions apply to this section: (1) Existing Dwelling -- "Existing Dwelling" means a building used for human habitation constructed within a floodway prior to the adoption of the floodway as an authorized flood control project, as a plan of flood control, or as a designated floodway, or as otherwise permitted by the board.(2) Existing Mobile Home -- "Existing Mobile Home" means a mobile home that was positioned within a floodway prior to the adoption of the floodway as an authorized flood control project, as a plan of flood control, or as a designated floodway, or as otherwise permitted by the board.(3) Existing Structure -- "Existing Structure" means a building used for any purpose other than for human habitation constructed within a floodway prior to the adoption of the floodway as an authorized flood control project, as a plan of flood control, or as a designated floodway, or as otherwise permitted by the board.(4) Human Habitation -- "Human Habitation" means an improvement of real property used, or intended to be used, for residential purposes, including but not limited to living, sleeping, cooking, or eating.(5) Seasonal Occupancy -- "Seasonal Occupancy" means to occupy or reside in a dwelling only during the nonflood season.(6) Residential Development -- "Residential Development" means any development or subdivision where a subdivision map is required.(b) Dwellings and structures within an adopted plan of flood control must comply with the following requirements: (1) New dwellings, with the exception of dwellings for seasonal occupancy (nonflood season), are not permitted except as provided in subdivisions (d) and (e) of this section.(2) New dwellings for seasonal occupancy and existing dwellings and structures constructed prior to adoption of the plan of flood control are permitted within the floodway under the following conditions: (A) The dwelling or structure is not abandoned and is maintained in a condition suitable for the approved use;(B) The dwelling or structure does not impede floodflows;(C) The dwelling or structure is properly anchored to prevent flotation during periods of high water;(D) The finished floor level of new dwellings for seasonal occupancy must be a minimum of two (2) feet above the design flood plane or two (2) feet above the 100-year flood elevation, whichever is higher; and(E) New dwellings for seasonal occupancy may not be constructed on a levee section or within ten (10) feet of a levee toe.(3) Any exterior remodeling, modifications, additions, or repairs to the dwelling, or structure, or property which modifies the footprint or consists of replacement of over fifty (50) percent of the structure must have prior approval by the board and meet the following conditions:(A) Any remodeling, modifications, additions, or repairs may not place the dwelling or structure closer to the low water channel of the floodway; and(B) The finished floor of any remodeling, modification, addition, or repair to the dwelling or structure must be a minimum of two (2) feet above the design flood plane or two (2) feet above the 100-year flood elevation, whichever is higher.(4) If a dwelling or structure is damaged, due to any cause, to a cumulative extent of more than fifty (50) percent of its market value within a ten-year period, the dwelling or structure may not be reconstructed or replaced without the approval of the board;(5) If a damaged dwelling or structure is not repaired or replaced, the entire dwelling or structure, including all stored materials, equipment, and debris, must be completely removed within a reasonable period of time, as determined by the board, and the area restored so that there is no interference with the adopted plan of flood control.(6) Structures may be constructed within an adopted plan of flood control provided they conform to the following: (A) Structures may not be constructed on a levee section or within ten (10) feet of a levee toe;(B) Structures must be securely anchored and floodproofed to at least two (2) feet above the 100-year flood elevation or two (2) feet above the design flood plane, whichever is higher. The floodproofing must be consistent with the potential uses of the structure;(C) Structures must be located and oriented to have minimal impact on floodflows; and(D) The number of structures permitted is limited to the minimum reasonably necessary to accomplish an appropriate land use activity.(c) Mobile homes within an adopted plan of flood control must comply with the following requirements: (1) New mobile homes are not permitted unless the mobile homes are located within an existing mobile home park or as provided in subdivisions (d) and (e) of this section;(2) Existing mobile homes, not located within a mobile home park, may remain and the requirements are the same as those for existing dwellings; and(3) Owners of existing mobile homes which are not located within a mobile home park and which are not anchored in place must have an evacuation plan on record with the board; and(4) If flood damage occurs to the mobile home due to failure of the evacuation plan or its execution, the mobile home may not remain or be replaced within the adopted plan of flood control without the approval of the board.(d) Dwellings, structures, and mobile homes are permitted within shallow flooding areas designated as a "zone B" as shown on some designated floodway maps adopted by the board. The board's zone B designation is not to be confused with the Federal Emergency Management Agency's B-zone which relates to a different floodplain identification. In addition to the other standards in this section, the following conditions apply to dwellings, structures, and mobile homes within a designated zone B: (1) The dwelling, structure, or mobile home is not permitted on a levee section or within ten (10) feet of a levee toe;(2) Dwellings, structures, and mobile homes are permitted to within fourteen (14) feet of the top of a streambank provided the streambank is revetted to board standards;(3) Dwellings, structures and mobile homes are not permitted within thirty (30) feet of an unrevetted streambank;(4) The finished floor level of the dwellings and mobile homes must be a minimum of two (2) feet above the design flood plane or two (2) feet above the 100 year flood elevation, whichever is higher;(5) Only the minimum floodway area necessary for the placement of the dwelling, structure, or mobile home shall be used. Generally not more than thirty (30) percent of the flood plain area may be used. Designated floodway maps, however, may be more restrictive;(6) Sufficient area of the floodway must remain clear of the dwelling, mobile home, or structure to preserve the historical orientation of the floodway and to prevent an increase in streamflow stages and velocities.(7) If a dwelling, structure, or mobile home is damaged due to any cause, cumulatively to the extent of more than fifty (50) percent of its market value, the dwelling, structure, or mobile home may not be reconstructed or replaced without the approval of the board.(8) Except for approved mining activities, excavating or grading that would increase the depth of flooding within a zone B and which might interfere with the safe evacuation of the area during flooding is not permitted.(9) New residential developments may be subject to a higher standard than the 100-year event up to and including the Standard Project Flood, (e.g., floor elevations required to be above the Standard Project Flood) or an equivalent rare flood.(e) New dwellings, structures and mobile homes along an unleveed stream shall comply with the following requirements:(1) Dwellings, structures, and mobile homes are permitted to within fourteen (14) feet of the top of the streambank provided the streambank is revetted.(2) Dwellings, structures and mobile homes are not permitted within (30) feet of an unrevetted streambank.(f) Upon abandonment of the permitted dwelling or structure, the property owner shall be responsible for removal of the dwelling or structure and all appurtenant structures, vehicles, equipment, stockpiles of materials, and debris within a reasonable time.Cal. Code Regs. Tit. 23, § 113
1. New section filed 9-30-96; operative 10-30-96 (Register 96, No. 40). Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608, 8609 and 8710, Water Code.
1. New section filed 9-30-96; operative 10-30-96 (Register 96, No. 40).