In addition to the general requirements of Article IV, the requirements of this section apply to all development proposed in special flood hazard areas other than coastal high hazard areas. These areas include Zones A, AE, and AO.
A. 
Elevation requirements.
(1) 
The lowest floor (including basement) shall be elevated to or above the base flood elevation plus 18 inches.
(2) 
In areas of shallow flooding (Zone AO), the lowest floor (including basement) shall be elevated at least as high above the highest adjacent grade as the depth number specified in feet on the Flood Insurance Rate Map plus 18 inches, or at least two feet plus 18 inches if a depth number is not specified; adequate drainage paths shall be provided to guide floodwaters around and away from the structure.
(3) 
Enclosures below the lowest floor shall meet the requirements of Subsection B.
B. 
Enclosures below the lowest floor.
(1) 
Enclosures below the lowest floor shall be used solely for parking of vehicles, building access, crawlspaces, or limited storage.
(2) 
Enclosures below the lowest floor shall be constructed using flood-damage-resistant materials. See FEMA Technical Bulletin No. 2, Flood Damage-Resistant Materials Requirements.
(3) 
Enclosures below the lowest floor (including crawlspaces) shall be provided with flood openings which shall meet the following criteria (see FEMA Technical Bulletin No. 1, Openings in Foundation Walls and Walls of Enclosures):
(a) 
There shall be a minimum of two openings on different sides of each enclosed area; if a building has more than one enclosed area below the base flood elevation, each area shall have openings on exterior walls.
(b) 
The total net area of all openings shall be at least one square inch for each square foot of enclosed area, or the openings shall be designed and certified by a registered engineer or architect to provide for equalization of hydrostatic flood forces on exterior walls by allowing for the automatic entry and exit of floodwaters.
(c) 
The bottom of each opening shall be one foot or less above the adjacent ground level.
(d) 
Any louvers, screens or other opening covers shall allow the automatic flow of floodwaters into and out of the enclosed area.
(e) 
Where installed in doors and windows, openings that meet requirements of Subsection B(3)(a) through (d), are acceptable; however, doors and windows without installed openings do not meet the requirements of this section.
(4) 
Crawlspaces shall have the finished interior ground level equal to or higher than the outside finished ground level on at least one entire side of the foundation wall.
C. 
Manufactured homes.
(1) 
New or replacement manufactured homes, including substantial improvement of existing manufactured homes, shall:
(a) 
Be elevated on a permanent, reinforced foundation that raises the lowest floor to or above the base flood elevation plus 18 inches and is otherwise in accordance with Subsection A.
(b) 
Be installed in accordance with the anchor and tie-down requirements of the building code or the manufacturer's written installation instructions and specifications.
(c) 
Have enclosures below the elevated manufactured home, if any, meet the requirements of Subsection B.
(2) 
For the purpose of this requirement, the lowest floor of a manufactured home is the bottom of the lowest horizontal supporting member of the lowest floor.
A. 
Elevation requirements.
(1) 
The lowest floor (including basement) shall be elevated to or above the base flood elevation plus 18 inches, or the structure shall be dry floodproofed in accordance with Subsection B.
(2) 
In areas of shallow flooding (Zone AO), if not dry floodproofed, the lowest floor (including basement) shall be elevated at least as high above the highest adjacent grade as the depth number specified in feet on the Flood Insurance Rate Map plus 18 inches, or at least two feet plus 18 inches if a depth number is not specified; adequate drainage paths shall be provided to guide floodwaters around and away from the structure.
(3) 
Enclosures below the lowest floor, if not dry floodproofed, shall meet the requirements of § 130-26B.
B. 
Dry floodproofing requirements. Dry floodproofed structures, together with attendant utility and sanitary facilities, shall:
(1) 
Be designed to be dry floodproofed such that the structure is watertight with walls and floors substantially impermeable to the passage of water to the level of the base flood elevation plus 18 inches. In areas of shallow flooding (Zone AO), the structure shall be dry floodproofed at least as high above the highest adjacent grade as the depth number specified in feet on the Flood Insurance Rate Map plus 18 inches, or at least two feet plus 18 inches if a depth number is not specified.
(2) 
Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.
(3) 
Be certified by a licensed professional engineer or licensed professional architect with a Floodproofing Certificate, that the design and methods of construction meet the requirements of this section. Refer to FEMA Technical Bulletin No. 3, Non-Residential Floodproofing - Requirements and Certification, for guidance.
Accessory structures shall meet the requirements of these regulations. Accessory structures that have a footprint of no more than 200 square feet may be allowed without requiring elevation or floodproofing provided such structures meet all of the following requirements:
A. 
Usable only for parking or limited storage;
B. 
Constructed with flood damage-resistant materials below the base flood elevation;
C. 
Constructed and placed to offer the minimum resistance to the flow of floodwaters;
D. 
Firmly anchored to prevent flotation, collapse, and lateral movement;
E. 
Electrical service and mechanical equipment elevated to or above the level of the base flood elevation plus 18 inches; and
F. 
Equipped with flood openings that meet the requirements of § 130-26B.
G. 
For guidance, see FEMA Technical Bulletin No. 7, Wet Floodproofing Requirements.
A. 
Development in floodways.
(1) 
Within any floodway area designated on the Flood Insurance Rate Map, no encroachments, including fill, new construction, substantial improvements, or other development shall be permitted unless it has been demonstrated through hydrologic and hydraulic engineering analysis that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge. Such technical data shall be submitted to the Floodplain Administrator and to FEMA. The analyses shall be prepared by a licensed professional engineer in a format required by FEMA for a Conditional Letter of Map Revision or Letter of Map Revision. Submittal requirements and processing fees shall be the responsibility of the applicant.
(2) 
The proposed development activity may be permitted if the analyses demonstrate that the activity:
(a) 
Will not result in any increase in the base flood elevation; or
(b) 
Will result in an increase in the base flood elevation and the compensatory storage requirements of Subsection D are met and a Conditional Letter of Map Revision has been issued by FEMA; or
(c) 
Will result in an increase in the base flood elevation, provided that a Conditional Letter of Map Revision has been issued by FEMA and the applicant completes all of the following:
[1] 
Submits technical data required in § 130-12A(12)(e);
[2] 
Evaluates alternatives which would not result in increased base flood elevations and an explanation why these alternatives are not feasible;
[3] 
Certifies that no structures are located in areas which would be impacted by the increased base flood elevation;
[4] 
Documents that individual legal notices have been delivered to all impacted property owners to explain the impact of the proposed action on their properties;
[5] 
Requests and receives concurrence of the City Administrator of the City of New Castle and the Chief Executive Officer of any other community impacted by the proposed actions; and
[6] 
Notifies the Delaware Department of Natural Resources and Environmental Control (Division of Watershed Stewardship).
B. 
Filling in floodway fringe areas.
(1) 
For development activities that involve the placement of fill in floodway fringe areas, the applicant shall develop hydrologic and hydraulic engineering analyses and technical data reflecting the proposed activity and shall submit the analyses and data to the Floodplain Administrator. The analyses shall be prepared by a licensed professional engineer.
(2) 
The proposed development activity may be permitted if the analyses demonstrate that the cumulative effect of the proposed development activity, when combined with all other existing and potential flood hazard area encroachments will not increase the base flood elevation more than 0.1 foot at any point; compensatory storage in compliance with Subsection D may be provided to meet this requirement.
C. 
Development in areas with base flood elevations but no floodways.
(1) 
For development activities in a special flood hazard area with base flood elevations but no designated floodways, the applicant shall develop hydrologic and hydraulic engineering analyses and technical data reflecting the proposed activity and shall submit such analyses and data to the Floodplain Administrator and to FEMA. The analyses shall be prepared by a licensed professional engineer in a format required by FEMA for a Conditional Letter of Map Revision or Letter of Map Revision. Submittal requirements and processing fees shall be the responsibility of the applicant.
(2) 
The proposed development activity may be permitted if the analyses demonstrate that the cumulative effect of the proposed development activity, when combined with all other existing and potential special flood hazard area encroachments will not increase the base flood elevation more than 0.1 foot at any point; compensatory storage in compliance with Subsection D may be provided to meet this requirement.
D. 
Compensatory storage. If the compensatory storage alternative in Subsection A(2) or B is selected to compensate for the loss of storage volume due to development, the following requirements shall apply:
(1) 
Compensatory storage shall be hydraulically equivalent and such equivalency shall be demonstrated through hydrologic and hydraulic engineering analyses;
(2) 
Compensatory storage areas shall be designed to drain freely to the watercourse; and
(3) 
A restriction against modification of the compensatory storage area shall be recorded on the deed of the property where it is located and the restriction shall be binding on future owners.
E. 
Deliberate alterations of a watercourse.
(1) 
For the purpose of these regulations, a watercourse is deliberately altered when a person causes a change to occur within its banks. Deliberate changes to a watercourse include, but are not limited to, widening, deepening or relocating of the channel; installation of culverts; construction of bridges; and excavation or filling of the channel or watercourse banks.
(2) 
For any proposed deliberate alteration of a watercourse, the applicant shall develop hydrologic and hydraulic engineering analyses and technical data reflecting such changes and submit such technical data to the Floodplain Administrator and to FEMA. The analyses shall be prepared by a licensed professional engineer in a format required by FEMA for a Conditional Letter of Map Revision or Letter of Map Revision. Submittal requirements and processing fees shall be the responsibility of the applicant.
(3) 
The proposed alteration of a watercourse may be permitted upon submission, by the applicant, of the following:
(a) 
Documentation of compliance with Subsection A if the alteration is in a floodway or Subsection C if the alteration is in a watercourse with base flood elevations but no floodway.
(b) 
A description of the extent to which the watercourse will be altered or relocated as a result of the proposed development.
(c) 
A certification by a licensed professional engineer that the bankful flood-carrying capacity of the watercourse will not be diminished.
(d) 
Evidence that adjacent communities, the United States Army Corps of Engineers, and the Delaware Department of Natural Resources and Environmental Control (Division of Watershed Stewardship) have been notified of the proposal and evidence that such notifications have been submitted to the Federal Emergency Management Agency.
(e) 
Evidence that the applicant shall be responsible for providing the necessary maintenance for the altered or relocated portion of the watercourse so that the flood-carrying capacity will not be diminished. The Floodplain Administrator may require the permit holder to enter into an agreement with the City of New Castle specifying the maintenance responsibilities; if an agreement is required, the permit shall be conditioned to require that the agreement be recorded on the deed of the property which shall be binding on future owners.