(44 CFR 59.1. 60.3).
A. 
Basis of districts. The various special flood hazard districts shall include the SFHAs. The basis for the delineation of these districts shall be the FIS and the FIRM for Buchanan County prepared by the Federal Emergency Management Agency, Federal Insurance Administration, dated August 19, 1997, [NOTE: If preparing an ordinance amendment for adoption of a new FIRM and FIS, the new effective date should be used here, not the initial FIRM date. Every time a community receives a new FIRM, an ordinance amendment must be adopted to update the FIRM's effective date. This amendment must be adopted and approved by FEMA prior to the effective date of the new FIRM to avoid suspension from the NFIP.] and any subsequent revisions or amendments thereto.
B. 
The Floodplain Administrator may identify and regulate local flood hazard or ponding areas that are not delineated on the FIRM. These areas may be delineated on a "local flood hazard map" using best available topographic data and locally derived information such as flood of record, historic high-water marks, or approximate study methodologies.
C. 
The boundaries of the SFHA districts are established as shown on the FIRM, which is declared to be a part of this chapter and which shall be kept on file at the Buchanan County offices.
(1) 
The Floodway District is in an AE Zone and is delineated, for purposes of this chapter, using the criterion that certain areas within the floodplain must be capable of carrying the waters of the 1% annual chance flood without increasing the water surface elevation of that flood more than one foot at any point. The areas included in this district are specifically defined in Table (see Exhibit A) of the above- referenced FIS and shown on the accompanying FIRM. In addition to the Flood Insurance Rate Maps, all zones, when at a higher elevation, will extent to the 1977/2021/2022 flood elevations as defined in this chapter.
(a) 
The following provisions shall apply within the Floodway District of an AE Zone [44 CFR 60.3(d)]:
[1] 
Within any floodway area, no encroachments, including fill, new construction, substantial improvements, or other development shall be permitted unless it has been demonstrated through hydrologic and hydraulic analysis performed in accordance with standard engineering practice that the proposed encroachment will not result in any increase in flood levels within the community during the occurrence of the base flood discharge. Hydrologic and hydraulic analyses shall be undertaken only by professional engineers or others of demonstrated qualifications, who shall certify that the technical methods used correctly reflect currently accepted technical concepts. Studies, analyses, computations, etc., shall be submitted in sufficient detail to allow a thorough review by the Floodplain Administrator. However, in the cases of the replacement or repair of damaged bridges and/or drain pipes, the standard shall be that such replacement or repair of said bridges and/or drain pipes do not worsen the existing flood levels during the base flood discharge that existed prior to said replacement or repair. Such conclusion that the replacement or repair of bridge and/or drain pipes does not worsen the preexisting flood levels must be supported by the opinion of a professional engineer. Additionally, any structure such as, but not limited to, drain pipes, box culverts, and bridges etc., shall be greater than or equal to cross-sectional area of the drainage channel itself.
[2] 
Development activities which increase the water surface elevation of the base flood may be allowed, provided that the applicant first applies, with the Buchanan County endorsement, for a conditional letter of map revision (CLOMR) and receives the approval of the Federal Emergency Management Agency.
[3] 
All new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Article IV.
[4] 
The placement of manufactured homes (mobile homes) is prohibited, except in an existing manufactured home (mobile home) park or subdivision. A replacement manufactured home may be placed on a lot in an existing manufactured home park or subdivision, provided the anchoring, elevation, and encroachment standards are met.
(2) 
The AE or AH Zones on the FIRM accompanying the FIS shall be those areas for which 1% annual chance flood elevations have been provided and the floodway has not been delineated. The following provisions shall apply within an AE or AH Zone [44 CFR 60.3(c)] where FEMA has provided base flood elevations [NOTE: The requirement in 60.3(c)(10) only applies along rivers, streams, and other watercourses where FEMA has provided base flood elevations. The requirement does not apply along lakes, bays and estuaries, and the ocean coast]:
(a) 
Until a regulatory floodway is designated, no new construction, substantial improvements, or other development (including fill) shall be permitted within the areas of special flood hazard, designated as Zones A1-30, AE, or AH on the FIRM, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the Buchanan County.
(b) 
Development activities in Zones A1-30, AE, or AH on the Buchanan County FIRM which increase the water surface elevation of the base flood by more than one foot may be allowed, provided that the applicant first applies, with the Buchanan County's endorsement, for a conditional letter of map revision and receives the approval of the Federal Emergency Management Agency.
(3) 
The A Zone on the FIRM accompanying the FIS shall be those areas for which no detailed flood profiles or elevations are provided, but the 1% annual chance floodplain boundary has been approximated. For these areas, the following provisions shall apply [44 CFR 60.3(b)]:
(a) 
The Approximated Floodplain District shall be that floodplain area for which no detailed flood profiles or elevations are provided, but where a 1% annual chance floodplain boundary has been approximated. Such areas are shown as Zone A on the maps accompanying the FIS. For these areas, the base flood elevations and floodway information from federal, state, and other acceptable sources shall be used, when available. Where the specific 1% annual chance flood elevation cannot be determined for this area using other sources of data, such as the U.S. Army Corps of Engineers Floodplain Information Reports, U.S. Geological Survey Flood-Prone Quadrangles, etc., then the applicant for the proposed use, development and/or activity shall determine this base flood elevation. For development proposed in the approximate floodplain, the applicant must use technical methods that correctly reflect currently accepted practices, such as point on boundary, high water marks, or detailed methodologies hydrologic and hydraulic analyses. Studies, analyses, computations, etc., shall be submitted in sufficient detail to allow a thorough review by the Floodplain Administrator.
(b) 
The Floodplain Administrator reserves the right to require a hydrologic and hydraulic analysis for any development. When such base flood elevation data is utilized, the lowest floor shall be elevated to or above the base flood level plus 18 inches. [NOTE: The flood maps anticipate one foot of rise in BFE due to fill in the floodplain, so while building to BFE is all that is required, it will result in flooding if all assumptions made in mapping are correct. Flood insurance rounds up for freeboard so an eighteen-inch requirement offers the best "bang for the buck" in reducing flood insurance rates and allows for an additional margin of safety in case the models have an error or are based on incomplete data.]
(c) 
During the permitting process, the Floodplain Administrator shall obtain:
[1] 
The elevation of the lowest floor (in relation to mean sea level), including the basement, of all new and substantially improved structures; and
[2] 
If the structure has been floodproofed in accordance with the requirements of this article, the elevation (in relation to mean sea level) to which the structure has been floodproofed.
(d) 
Base flood elevation data shall be obtained from other sources or developed using detailed methodologies comparable to those contained in a FIS for subdivision proposals and other proposed development proposals (including manufactured home parks and subdivisions) that exceed 50 lots or five acres, whichever is the lesser. [NOTE: The recommended standard here is five lots instead of 50. Fifty lots is the breakpoint suggested in the federal regulations but the 5/5 rule is less confusing and captures more commercial development.]
(4) 
The AO Zone on the FIRM accompanying the FIS shall be those areas of shallow flooding identified as AO on the FIRM. For these areas, the following provisions shall apply [44 CFR 60.3(c)]:
(a) 
All new construction and substantial improvements of residential structures shall have the lowest floor, including basement, elevated to or above the flood depth specified on the FIRM, above the highest adjacent grade at least as high as the depth number specified in feet on the FIRM. If no flood depth number is specified, the lowest floor, including basement, shall be elevated no less than two feet above the highest adjacent grade.
(b) 
All new construction and substantial improvements of nonresidential structures shall:
[1] 
Have the lowest floor, including basement, elevated to or above the flood depth specified on the FIRM, above the highest adjacent grade at least as high as the depth number specified in feet on the FIRM. If no flood depth number is specified, the lowest floor, including basement, shall be elevated at least two feet above the highest adjacent grade; or
[2] 
Together with attendant utility and sanitary facilities, be completely floodproofed to the specified flood level so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.
(c) 
Adequate drainage paths around structures on slopes shall be provided to guide floodwaters around and away from proposed structures.
(5) 
The mapped floodplain includes all of the above regions and also the regions designated as having a 0.2% annual chance of flooding on any flood map or flood insurance study. In this area, no emergency service, medical service, or governmental records storage shall be allowed except by special exception using the variance process. [NOTE: This limitation on the use of the 0.2% floodplain is not required by NFIP regulations but is an accepted standard for critical facilities in emergency management. Critical facilities that are built in mapped floodplain might not be eligible for rebuilding assistance after a disaster; therefore, DCR recommends this provision to ensure that any decision made to build in these circumstances is carefully considered.]
(6) 
Landowners with real property located in any part of the floodplain are required to keep said real property free of any vegetative debris or any other type of debris that would create a risk of increasing flood damage by blocking the floodway and thus increase the height of floodwaters. Upon the request of the landowner and upon the landowner's execution of a right of entry agreement with the County, the County will assist the landowner with the removal of said debris.