(A) General standards. In all SFHAs and known flood-prone areas, the following provisions are required.
(1) Manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, use of: over-the-top; or frame ties to ground anchors. This standard shall be in addition to, and consistent with, applicable state requirements for resisting wind forces.
(2) New construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure.
(3) New construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage below the FPG.
(4) New construction and substantial improvements shall be constructed by methods and practices that minimize flood damage.
(5) Electrical, heating, ventilation, plumbing, air conditioning equipment, utility meters, and other service facilities shall be located at/above the FPG or designed so as to prevent water from entering or accumulating within the components below the FPG. Water and sewer pipes, electrical and telephone lines, submersible pumps, and other waterproofed service facilities may be located below the FPG.
(6) New and replacement water supply systems shall be designed to minimize or emanate infiltration of floodwaters into the system.
(7) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.
(8) On-site waste disposal systems shall be located and constructed to avoid impairment to them, or contamination from them, during flooding.
(9) Any alteration, repair, reconstruction, or improvements to a structure that is in compliance with the provisions of this ordinance shall meet the requirements of “new construction” as contained in this subchapter.
(10) Parking lots, driveways, and sidewalks within the SFHA shall be constructed with permeable materials.
(11) Whenever any portion of the SFHA is authorized for use, the volume of space which will be occupied by the authorized fill or structure below the BFE shall be compensated for and balanced by an equivalent volume of excavation taken below the BFE. The excavation volume shall be at least equal to the volume of storage lost (replacement ratio of one to one) due to the fill or structure.
(a) The excavation shall take place in the floodplain and in the same property in which the authorized fill or structure is located.
(b) Under certain circumstances, the excavation may be allowed to take place outside of, but adjacent to, the floodplain provided that the excavated volume will be below the regulatory flood elevation, will be in the same property in which the authorized fill or structure is located, will be accessible to the regulatory floodwater, will not be subject to ponding when not inundated by floodwater, and that it shall not be refilled.
(c) The excavation shall provide for true storage of floodwater but shall not be subject to ponding when not inundated by floodwater.
(d) The fill or structure shall not obstruct a drainage way leading to the floodplain.
(e) The grading around the excavation shall be such that the excavated area is accessible to the regulatory floodwater.
(f) The fill or structure shall be of a material deemed stable enough to remain firm and in place during periods of flooding and shall include provisions to protect adjacent property owners against any increased runoff or drainage resulting from its placement.
(g) Plans depicting the areas to be excavated and filled shall be submitted prior to the actual start of construction or any site work; once site work is complete, but before the actual start of construction, the applicant shall provide to the Floodplain Administrator a certified survey of the excavation and fill sites demonstrating the fill and excavation comply with this subchapter.
(B) Specific standards. In all SFHAs, the following provisions are required.
(1) In addition to the requirements of this chapter, all structures to be located in the SFHA shall be protected from flood damage below the FPG. This building protection requirement applies to the following situations:
(a) Construction or placement of any structure having a floor area greater than 400 square feet;
(b) Addition or improvement made to any existing structure where the cost of the addition or improvement equals or exceeds 50% of the value of the existing structure (excluding the value of the land);
(c) Reconstruction or repairs made to a damaged structure where the costs of restoring the structure to it’s before damaged condition equals or exceeds 50% of the market value of the structure (excluding the value of the land) before damage occurred;
(d) Installing a travel trailer or recreational vehicle on a site for more than 180 days;
(e) Installing a manufactured home on a new site or a new manufactured home on an existing site. This subchapter does not apply to returning the existing manufactured home to the same site it lawfully occupied before it was removed to avoid flood damage;
(f) Reconstruction or repairs made to a repetitive loss structure; and
(g) Addition or improvement made to any existing structure with a previous addition or improvement constructed since the community’s first Floodplain Ordinance.
(2) New construction or substantial improvement of any residential structure (or manufactured home) shall have the lowest floor; including basement, at or above the FPG (two feet above the base flood elevation). Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of floodwaters shall be provided in accordance with the set standards.
(3) New construction or substantial improvement of any commercial, industrial, or non-residential structure (or manufactured home) shall either have the lowest floor, including basement, elevated to or above the FPG (two feet above the base flood elevation) or be floodproofed to or above the FPG. Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of floodwaters shall be provided in accordance with the set standards. Structures located in all “A Zones” may be floodproofed in lieu of being elevated if done in accordance with the following:
(a) A Registered Professional Engineer or Architect shall certify that the structure has been designed so that below the FPG, the structure and attendant utility facilities are watertight and capable of resisting the effects of the regulatory flood. The structure design shall take into account flood velocities, duration, rate of rise, hydrostatic pressures, and impacts from debris or ice. Such certification shall be provided to the official as set forth; and
(b) Floodproofing measures shall be operable without human intervention and without an outside source of electricity.
(4) New construction or substantial improvements of elevated structures shall have the lowest floor at or above the FPG. Elevated structures with fully enclosed areas formed by foundation and other exterior walls below the flood protection grade shall be designed to preclude finished living space and designed to allow for the entry and exit of floodwaters to automatically equalize hydrostatic flood forces on exterior walls. Designs must meet the following minimum criteria:
(a) Provide a minimum of two openings located in a minimum of two exterior walls (having a total net area of not less than one square inch for every one square foot of enclosed area);
(b) The bottom of all openings shall be no more than one foot above the exterior grade or the interior grade immediately beneath each opening, whichever is higher;
(c) Openings may be equipped with screens, louvers, valves, or other coverings or devices; provided they permit the automatic flow of floodwaters in both directions;
(d) Access to the enclosed area shall be the minimum necessary to allow for parking for vehicles (garage door), or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator);
(e) The interior portion of such enclosed area shall not be partitioned or finished into separate rooms;
(f) The interior grade of such enclosed area shall be at an elevation at or higher than the exterior grade;
(g) Openings are to be not less than three inches in any direction in the plane of the wall. This requirement applies to the hole in the wall, excluding any device that may be inserted such as typical foundation air vent device;
(h) Property owners shall be required to execute a flood openings/venting affidavit acknowledging that all openings will be maintained as flood vents, and that the elimination or alteration of the openings in any way will violate the set requirements. Periodic inspections will be conducted by the Floodplain Administrator to ensure compliance. The affidavit shall be recorded in the office of the County Recorder; and
(i) Property owners shall be required to execute and record with the structure’s deed a non-conversion agreement declaring that the area below the lowest floor (where the interior height of the enclosure exceeds six feet) or the detached accessory building shall not be improved, finished or otherwise converted; the community will have the right to inspect the enclosed area. The non-conversion agreement shall be recorded in the office of the County Recorder.
(5) A residential or nonresidential structure may be constructed on a permanent land fill in accordance with the following:
(a) The fill shall be placed in layers no greater than one foot deep before compacting to 95% of the maximum density obtainable with either the Standard or Modified Proctor Test method, which shall be retained in permit file;
(b) The fill shall extend five feet beyond the foundation of the structure before sloping below the BFE;
(c) The fill shall be protected against erosion and scour during flooding by vegetative cover, riprap, or bulkheading. If vegetative cover is used, the slopes shall be no steeper than three horizontal to one vertical;
(d) The fill shall not adversely affect the flow of surface drainage from or onto neighboring properties;
(e) The top of the lowest floor including basements shall be at or above the FPG; and
(f) Fill shall be composed of clean granular or earthen material.
(6) (a) Manufactured homes and recreational vehicles to be installed, or substantially improved, on a site for more than 180 days must meet one of the following requirements.
(b) These requirements apply to all manufactured homes to be placed on a site outside a manufactured home park or subdivision; in a new manufactured home park or subdivision; in an expansion to an existing manufactured home park or subdivision; or in an existing manufactured home park or subdivision on which a manufactured home has incurred “substantial damage” as a result of a flood.
(C) Standards for identified fringe.
(1) If the site is located in an identified fringe, then the Floodplain Administrator may issue the local Floodplain Development Permit provided the provisions contained in this subchapter have been met.
(2) The key provision is that the top of the lowest floor of any new or substantially improved structure shall be at or above the FPG.
(D) Standards for SFHAs without established base flood elevation and/or hoodways/fringes.
(1) Drainage area upstream of the site is greater than one square mile.
(a) If the site is in an identified floodplain where the limits of the floodway and fringe have not yet been determined, and the drainage area upstream of the site is greater than one square mile, the Floodplain Administrator shall require the applicant to forward the application, along with all pertinent plans and specifications, to the State Department of Natural Resources for review and comment.
(b) No action shall be taken by the Floodplain Administrator until either a permit for construction in a floodway permit (including letters of authorization) or a floodplain analysis/regulatory assessment citing the 1% annual chance flood elevation and the recommended flood protection grade has been received from the State Department of Natural Resources.
(c) Once the Floodplain Administrator has received the proper permit for construction in a floodway permit (including letters of authorization) or floodplain analysis/regulatory assessment approving the proposed development, a Floodplain Development Permit may be issued; provided the conditions of the Floodplain Development Permit are not less restrictive than the conditions received from the State Department of Natural Resources, and the provisions of this subchapter have been met.
(2) Drainage area upstream of the site is less than one square mile.
(a) If the site is in an identified floodplain where the limits of the floodway and fringe have not yet been determined and the drainage area upstream of the site is less than one square mile, the Floodplain Administrator shall require the applicant to provide an engineering analysis showing the limits of the floodplain and 1% annual chance flood elevation for the site.
(b) Upon receipt, the Floodplain Administrator may issue the local Floodplain Development Permit; provided the provisions contained in this subchapter have been met.
(3) (a) The total cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the regulatory flood more than 0.14 of one foot, and will not increase flood damages or potential flood damages.
(b) The costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities, such as sewer, gas, electrical, and water systems, and streets and bridges.
(E) Conditions for variances.
(1) Variances shall only be issued when there is:
(a) A showing of good and sufficient cause;
(b) A determination that failure to grant the variance would result in exceptional hardship; and
(c) A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud or victimization of the public, or conflict with existing laws or ordinances.
(2) No variance for a residential use within a floodway, subject to the provisions of this subchapter, may be granted.
(3) Any variance granted in a floodway subject to the provisions of this subchapter will require a permit from the State Department of Natural Resources.
(4) Variances to the provisions for flood hazard reduction may be granted only when a new structure is to be located on a lot of one-half acre or less in size, contiguous to and surrounded by lots with existing structures constructed below the flood protection grade.
(5) Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
(6) Variances may be granted for the reconstruction or restoration of any structure individually listed on the National Register of Historic Places or the State Register of Historic Sites and Structures.
(7) Any applicant to whom a variance is granted shall be given written notice specifying the difference between the flood protection grade and the elevation to which the lowest floor is to be built and stating that the cost of the flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation.
(8) The Floodplain Administrator shall maintain the records of appeal actions and report any variances to the Federal Emergency Management Agency or the State Department of Natural Resources upon request.
(F) Variance notification.
(1) Any applicant to whom a variance is granted that allows the lowest floor of a structure to be built below the flood protection grade shall be given written notice over the signature of a community official that:
(a) The issuance of a variance to construct a structure below the flood protection grade will result in increased premium rates for flood insurance up to amounts as high as $25 for $100 of insurance coverage; and
(b) Such construction below the flood protection grade increases risks to life and property. A copy of the notice shall be recorded by the applicant in the office of the County Recorder and shall be recorded in a manner so that it appears in the chain of title of the affected parcel of land.
(2) The Floodplain Administrator will maintain a record of all variance actions, including justification for their issuance.
(G) Historic structure. Variances may be issued for the repair or rehabilitation of “historic structures” upon a determination that the proposed repair or rehabilitation will not preclude the structure’s continued designation as an “historic structure” and the variance is the minimum to preserve the historic character and design of the structure.
(H) Special conditions. Upon the consideration of the factors and the purposes of this subchapter, the Board of Zoning Appeals may attach such conditions to the granting of variances as it deems necessary to further the purposes of this subchapter.
(Prior Code, § 153.051) (Ord. 2014-5, passed 6-7-2014)