§ 45-3114. Establishment of flood hazard overlay district.

(a)

An overlay district to be known as the FH-flood hazard district is hereby established. Upon identification by the floodplain administrator, areas having special flood hazards but where water surface elevation data for the one-hundred-year flood and data sufficient to identify the floodway have not been delineated, the definitions of section 45-3112 are in effect.

(1)

Basis of district. The various floodplain districts shall include the special flood hazard areas (SFHAs). The basis for the delineation of these districts shall be the flood insurance study (FIS) and the flood insurance rate maps (FIRM) for the city of Newport News prepared by the Federal Emergency Management Agency, Federal Insurance Administration, dated December 9, 2014 and any subsequent revisions or amendments thereto.

The city of Newport News 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.

The boundaries of the SFHA districts and floodplain districts are established as shown on the FIRM, which is declared to be a part of this division and which shall be kept on file at the City of Newport News Department of Engineering.

a.

The floodway district is in an AE Zone and is delineated, for purposes of this regulation, using the criterion that certain areas within the floodplain must be capable of carrying the waters of the one (1) percent annual chance flood without increasing the water surface elevation of that flood more than one (1) foot at any point. The areas included in this district are specifically identified in the above-referenced FIS and shown on the accompanying FIRM. The following provisions shall apply within the floodway district of an AE zone (see, 44 CFR 60.3(d)):

1.

Within any floodway area, no encroachment, 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.

Development activities which increase the water surface elevation of the base flood may be allowed, provided that the applicant first applies, with the city on Newport News' endorsement, for a conditional letter of map revision (CLOMR), and receives the approval of the Federal Emergency Management Agency.

If the requirements of this section are satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of article 4.

2.

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.

(b)

The AE zone on the FIRM accompanying the FIS shall be those areas for which one (1) percent annual chance flood elevations have been provided and the floodway has not been delineated, The following provisions shall apply within an AE zone:

(1)

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 and AE 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 (1) foot at any point within the City of Newport News. This requirement, pursuant to 44 CFR 63.3(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.

(2)

Development activities in Zones A1-A30 and AE, on the city of Newport News FIRM which increase the water surface elevation of the base flood by more than one (1) foot may be allowed, provided that the applicant first applies, with the City of Newport News' endorsement, for a conditional letter of map revision, receives the approval of the Federal Emergency Management Agency.

(c)

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 one (1) percent annual chance floodplain boundary has been approximated. For these areas, the following provisions shall apply, pursuant to 44 CFR 60.3(b):

(1)

The approximated floodplain district shall be that floodplain area for which no detailed flood profiles or elevations are provided, but where a one-hundred-year 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, local and other acceptable sources shall be used, when available. Where the specific one (1) percent 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 non-detailed technical concepts, such as point on boundary, high water marks, or detailed methodologies hydrologic and hydraulic analyses. Studies, analysis, computations, etc., shall be submitted in sufficient detail to allow a thorough review by the floodplain administrator.

(2)

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 two (2) feet above the base flood level. During the permitting process, the floodplain administrator shall obtain:

a.

The elevation of the lowest floor (including the basement) of all new and substantially improved structures; and

b.

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.

(3)

Base flood elevation data shall be obtained from other sources or develop 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 fifty (50) lots or five (5) acres, whichever is the lesser.

(d)

The AO zone on the FIRM accompanying the FIS shall of those areas of shallow flooding identified as AO on the FIRM. For those areas the following provisions shall apply:

(1)

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 (2) feet above the highest adjacent grade.

(2)

All new construction and substantial improvements of non-residential structures shall:

a.

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 (2) feet above the highest adjacent grade; or

b.

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 wall substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyance.

(3)

Adequate drainage paths around structures on slopes shall be provided to guide flood waters around and away from proposed structures.

(e)

The Coastal A Zone District shall be those areas designated as Limits of Moderate Wave Action (LiMWA) line and the VE Zone on the FIRM, and subject to wave heights between one and one-half (1.5) feet and three (3) feet. Buildings and structures in the these areas shall have the lowest floor elevated to or above the base flood elevation plus two (2) feet of freeboard, and must comply with applicable provisions of sections 45-3114 and 45-3115 of this division.

(f)

The VE or V Zones on FIRMs accompanying the FIS shall be those areas that are known as Coastal High Hazard areas, extending from offshore to the inland limit of a primary frontal dune along an open coast. For these areas, the following provisions shall apply:

(1)

All new construction and substantial improvements in Zones V and VE (V if base flood elevation is available) shall be elevated on pilings or columns so that:

a.

The bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated two (2) feet above the base flood level if the lowest horizontal structural member is parallel to the direction of wave approach or elevated at least two (2) feet above the base flood level of the lowest horizontal structural member is perpendicular to the direction of wave approach; and.

b.

The pile or column foundation and structure attached thereto is anchored to resist flotation, collapse and lateral movement due to the effects of wind and water loads acting simultaneously on all building components. Wind and water loading values shall each have a one (1) percent chance of being equaled or exceeded in any given year (one (1) percent chance).

(2)

A registered professional engineer or architect shall develop or review the structural design, specifications, and plans for the construction, and shall certify that the design and methods of construction to be used are in accordance with accepted standards of practice for meeting the provisions of these regulations.

(3)

The floodplain administrator shall obtain the elevation (in relation to mean sea level) of the bottom of the lowest horizontal structural member of the lowest floor (excluding pilings and columns) of all new and substantially improved structures in Zones V and VE. The floodplain administrator shall maintain a record of all such information.

(4)

All new construction shall be located landward of the reach of mean high tide.

(5)

All new construction and substantial improvements shall have the space below the lowest floor either free of obstruction or constructed with non-supporting breakaway walls, open wood-lattice work, or insect screening intended to collapse under wind and water loads without causing collapse, displacement, or other structural damage to the elevated portion of the building or supporting foundation system. For the purpose of this section, a breakaway wall shall have a design safe loading resistance of not less than ten (10) and no more than twenty (20) pounds per square foot. Use of breakaway walls which exceed a design safe loading resistance of twenty (20) pounds per square foot (either by design or when so required by local codes) may be permitted only if a registered professional engineer or architect certifies that the designs proposed meet the following conditions:

a.

Breakaway wall collapse shall result from water load less than that which would occur during the base flood; and

b.

The elevated portion of the building and supporting foundation system shall not be subject to collapse, displacement, or other structural damage due to the effects of wind and water loads acting simultaneously on all building components (structural and nonstructural). Maximum wind and water loading values to be used in this determination shall each have a one (1) percent chance of being equaled or exceeded in any given year.

(6)

The enclosed space below the lowest floor shall be used solely for parking of vehicles, building access, or storage. Such space shall not be portioned into multiple rooms, temperature-controlled, or used for human habitation.

(7)

The use of fill for structural support of buildings is prohibited. When non-structural fill is proposed in a coastal high hazard area, appropriate engineering analyses shall be conducted to evaluate the impacts of the fill prior to issuance of a development permit.

(8)

The man-made alteration of sand dunes, which would increase potential flood damage, is prohibited.

(g)

Overlay concept. The floodplain districts described above shall be overlays to the existing underlying districts as shown on the official zoning ordinance map, and as such, the provisions for the floodplain districts shall serve as a supplement to the underlying district provisions.

If there is any conflict between the provisions or requirements of the floodplain districts and those of any underlying district, the more restrictive provisions and/or those pertaining to the floodplain districts shall apply.

In the event any provision concerning a floodplain district is declared inapplicable as a result of any legislative or administrative actions or judicial decision, the basic underlying provisions shall remain applicable.

(Ord. No. 5028-97, § 1; Ord. No. 6577-09; Ord. No. 7123-14, § 1)

(Ord. No. 5028-97, § 1; Ord. No. 6577-09; Ord. No. 7123-14, § 1)