§ 3.06.02. Standards and Criteria

A.

Basis for Establishing the Areas of Special Hazard

See Section 3.06.01.C of this Part.

B.

Use of Other Base Flood Data

When base flood elevation data have not been provided in accordance with 3.06.02 A, Basis for Establishing the Areas of Special Hazard, then the Flood Damage Control Administrator shall obtain, review, and reasonably utilize any base flood elevation data available from a Federal, state, or other source, in order to administer 3.06.02 A. The best available information shall be used in all cases in the administration of the Flood Damage Control regulations.

C.

General Standards

1.

In all areas of special flood hazards, building and construction shall meet provisions contained within the Hillsborough County Construction Code.

2.

All new and replacement utility supply systems shall be designed to prevent contamination or damage by flood waters.

3.

New and replacement sanitary sewerage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters and to prevent damage to treatment plant equipment by flood waters, and on-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

D.

Specific Standards

In all areas of special flood hazards where base-flood and design-flood elevation data has been provided, all of the following provisions are required:

1.

New developments or substantially improved developments shall have the lowest floor of structures, including basement when within the Special Flood or Coastal High Hazard Areas elevated pursuant to Chapter 3 of the Hillsborough County Construction Code. Elevation of said lowest livable floor area shall be prepared, signed and sealed by a professional engineer or registered land surveyor, and such development shall comply with all other Hillsborough County Development regulations.

2.

Floodways: When floodways are designated within areas of special flood hazard, additional criteria will be met. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles, and erosion potential, notwithstanding any of the above, the following provisions shall apply:

a.

Encroachment or placement of an obstruction is prohibited, including fill, new construction, substantial improvements (includes replacement of an existing manufactured home, unless it is a DCA Certified modular home), mounded septic systems, docks, and other development unless it has been demonstrated through a no-impact analysis (hydrologic and hydraulic analyses that are also referred to as a No Rise Impact Analysis) with supporting technical data submitted by a State of Florida Registered Engineer demonstrating that the proposed encroachment shall not result in any increase in flood levels within the community during the occurrence of the base flood discharge. Background and analyses details shall be provided pursuant to the Federal Emergency Management Agency bulletins provided for said process. If this Section of this Code is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this Code and those within the Hillsborough County Construction Code.

b.

The placement, or replacement, of any manufactured home, except in a pre-FIRM manufactured home park or subdivision that has not had a manufactured home flooded, is prohibited within the designated floodway.

3.

Standards for streams or riverine systems. A Zones without established Base Flood Elevation, or floodways located within the areas of special flood hazard where streams exist for which no base flood elevation data or regulatory floodway has been provided by FEMA, the following provisions shall apply:

a.

All new subdivision proposals and other proposed developments (including proposals for manufactured home parks and subdivisions) greater than 50 lots or five acres, whichever is less, include within such proposals design- and base-flood elevation data.

b.

All new developments shall provide that structure elevations shall meet requirements of this Chapter and those within the Hillsborough County Construction Code where applicable. Information that shall be submitted and maintained and shall include:

(1)

required design-flood elevation (in relation to the mean sea level) of the lowest floor including the basement) of all new and substantially improved structures, and

(2)

non-residential structure floodproofing certificate and information in accordance with the requirements of this Chapter and the elevation in relation to the mean sea level to which the structure has been floodproofed.

c.

Notify, in riverine situations, adjacent communities where streams or rivers enter or leave boundaries and the State NFIP Coordinating Office prior to any alteration or relocation of a watercourse, and submit copies of such notifications to FEMA along with an application of Letter of Map Revision.

d.

Assure that the flood carrying capacity within an altered or relocated portion of any watercourse is maintained, unless mitigated pursuant to this Chapter, the Hillsborough County Construction Code, and the Stormwater Technical Manual. Variations to requirements within this Part shall be approved pursuant to the Hillsborough County Construction Code.

e.

Manufactured home subdivisions shall be designed using methods and practices that minimize flood damage and meet elevation requirements, which include having structures elevated and anchored to prevent flotation, collapse, or lateral movement.

f.

Require for riverine areas without a regulatory floodway boundary defined on the Flood Insurance Rate Map, that no new construction, substantial improvements, or other development (including fill) shall be permitted within Zones A1-30 and AE on the community's FIRM, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the community.

g.

Require compensation storage pursuant to minimum standards within the Hillsborough County Stormwater Technical Manual and with Hillsborough County's participation with the National Flood Insurance Program, and within this Chapter.

4.

Coastal High Hazard Areas have special flood hazards associated with high velocity waters from tidal surge and hurricane wave wash. Therefore, except within areas presently utilized for port or marina facilities, or zoned for such use, the following provisions shall apply:

a.

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

b.

Compliance with provisions of this ordinance shall be certified by a Professional Engineer in the State of Florida.

c.

There shall be no fill used as structural support.

d.

There shall be no alteration of sand dunes or mangrove stands which would increase potential flood damage.

e.

Coastal A Zones are those A and AE zones are areas with similarities to those areas within designated velocity zones shown on the Flood Insurance Rate Map (FIRM) and within the Flood Insurance Study (FIS) that have been identified through standard engineering practices to have potential breaking waves less than three feet in height. The waves in these areas have sufficient force to modify the landscape and damage or destroy the built environment if not properly designed and constructed to counter such forces. Pursuant to ASCE standards, new or substantially improved developments must be designed to have considered, in addition to other requirements of this ordinance, effects from erosion and scour, and to have considered appropriate factors necessary to resist erosion and effects that may affect proposed development due to effects from the one-percent probability flood event. Designs for meeting this requirement must be performed by design professionals, which are required to certify their work through sealing and signing drawings and any other documents (i.e., calculations, etc.) as is appropriate by regulations.

f.

Coastal High Hazard Areas, also V-zone, are designated on the Flood Insurance Rate Map and within the Flood Insurance Study in which a design professional shall perform an analysis, or analyses, prior to allowable development that may become obstructions and designed to be placed into the V-zone. The analysis, or analyses, shall show that there shall be no impact with respect to ramping and, or, deflection of velocity waters, or erosion damage to the structure or nearby developments. Respective analyses and background data shall be submitted for approval and recording with the permit application. The analysis, or analyses, shall be performed in conformance to standards identified within the U.S. Army Corps of Engineers' Coastal Shore Protection and the FEMA's Coastal Construction manuals. If impacts are to be mitigated, a variance in accordance with this Chapter and Code shall first be obtained prior to a permit application being granted. Mitigation techniques shall be a condition of a Flood Damage Control Board Order and shall be shown on construction plans and put into place prior to impacts.

g.

Prohibit the use of fill for non-structural use, except when such does not exceed the elevation of the existing grade by more than three inches or otherwise does not require a permit for minor ground stabilizing or landscaping purposes. No permit shall be issued for the use of fill in V-zone, as designated on the Flood Insurance Rate Map, unless it is has been demonstrated through appropriate engineering analyses and background data has been submitted for recording with the permit application that the subject fill does not cause any adverse impacts to the structure on site or adjacent properties.

5.

Standards for Subdivision Proposals:

a.

All subdivision proposals shall be consistent with the need to minimize flood damage.

b.

All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage.

c.

All subdivision proposals shall have adequate drainage provided to reduce exposure to flood hazards.

d.

Base and design flood elevation data shall be provided by the developers for subdivision proposals and other proposed development.

e.

All subdivision proposals must comply with all pertinent provisions of the Subdivision Regulations and any other development regulations, including manufactured home parks and subdivisions that exceed 50 lots or five acres, whichever is less.

f.

All subdivision lot-grading plans shall list both the NGVD and the NAVD vertical datum elevations, with appropriate conversion factor(s), required for an individual structure's finished-floor and design- and base-flood elevations, where applicable, and the elevation shall be listed for easy identification for each lot until such time the County's Flood Insurance Rate Maps and Flood Insurance Study have elevations listed using the NAVD vertical datum. At such time, the vertical datum shall be listed using NAVD.

g.

All subdivision lot-grading plans shall have residential structures lowest-floor elevations designed pursuant to the Hillsborough County Construction Code. Where said grading plans are for commercial buildings, lowest-floor elevations may be below the design-flood elevation so long it is identified that structures will be constructed pursuant to the Hillsborough County Construction Code.

6.

All new development or substantially improved structures within a designated Coastal Barrier Resource System area will not be eligible for Federal flood insurance pursuant to the Coastal Barrier Improvement Act of 1990 (Public Law 101-591).

(Ord. No. 00-21, § 2, 5-18-00; Ord. No. 00-38, § 2, 11-2-00; Ord. No. 08-15, § 2, 6-12-08, eff. 10-1-08)