Design and Construction Standards. In order to prevent excessive damage to buildings, structures, and related utilities and facilities, the following restrictions apply to all development, subdivision proposals, manufactured home parks, new construction and to construction of substantial improvements, and the repair of substantial damage, to existing structures occurring in the Special flood hazard area.
(a) Basements and Lowest Floors.
(1) Residential Structures - All new construction, relocation, substantial improvements, including repair of substantial damage, of residential structures shall have the lowest floor, including basement, ductwork and utilities, elevated to two feet above the Base Flood Elevation.
(2) Non-residential Structures - All new construction, relocation, substantial improvements, including repair of substantial damage, of non-residential structures shall have the lowest floor, including basement, ductwork and utilities, elevated to two feet above the Base Flood Elevation; or, together with attendant utility and sanitary facilities, be designed so that the structure is water tight with walls substantially impermeable to the passage of water from the lowest structural element to two feet above the Base Flood Elevation.
(3) Openings - For all new construction, relocation, substantial improvements, and repair of substantial damage, those fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for entry and exit of floodwaters. Designs for meeting this requirement shall either be certified by a Registered Professional Engineer or meet or exceed the following minimum criteria:
A. A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.
B. The bottom of all openings shall be no higher than one foot above grade.
C. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
(4) A non-conversion agreement shall be signed by the applicant on all flood-proofed structures and any elevated structures when the City of Keyser determines that the area below the first floor could be converted to a non-conforming use (generally applies to the enclosed areas below base flood elevation that are 5 ft. high or more). This agreement shall state:
A. The area below the Base Flood Elevation shall not be converted for use other than for parking, building access or for allowable storage as detailed in this Ordinance.
B. The applicant agrees to notify prospective buyers of the existence of the non-conversion agreement. It shall be the responsibility of the applicant to transfer the agreement at closing to the new owner via notarized signature. A copy of all new agreements shall be provided to the Floodplain Administrator. Failure to transfer the agreement and provide a signed copy to the Floodplain Administrator shall subject the violator to the penalties set forth in Section 1721.08
(c).
(b) Manufactured Home Placement. Certain unique characteristics of manufactured homes installed in special flood hazard areas pose an elevated risk to safety and substantial damage to property. Therefore:
(1) All manufactured homes to be sited within the special flood hazard areas of the City of Keyser shall be installed by a contractor possessing a valid WV Manufactured Home Installer's License. The Licensed Manufacturer Home Installer shall use an installation design engineered to withstand flood hazards specific to the particular home site. Manufactured homes to be placed or substantially improved within the special flood hazard areas shall be installed in accordance with the following standards:
A. The lowest floor, ductwork and utilities including HVAC/heat pump shall be elevated two feet above the Base Flood Elevation.
B. Elevation shall be on reinforced piers on a permanent foundation or shall use foundation elements of at least equivalent strength engineered for use in a flood hazard area. Installation designs incorporating dry stacked block piers shall not be used in special flood hazard areas.
C. All manufactured homes shall be securely anchored to an adequately anchored foundation system in compliance with the requirements of 42 West Virginia Code of State Regulations, Series 19, Sections 10.1,10.2, and 10B as authorized by West Virginia Code § 21-9-4 or the most recent revisions thereof. The anchoring shall be adequate to resist flotation, collapse, or lateral movement. Methods of anchoring may include but are not limited to the over-the-top and frame ties, attached to permanent foundation elements. Ground anchors may not be adequate to satisfy flood specific anchoring requirements. This requirement is in addition to applicable State and Local anchoring requirements for resisting wind forces.
D. Permanently attached rigid skirts and/or perimeter wall skirts of brick or block shall have openings to prevent collapse and damage to supporting piers. The openings shall be designed to automatically equalize hydrostatic flood forces by allowing for entry and exit of floodwaters. Designs for meeting this requirement shall either be certified by a Registered Professional Engineer or meet or exceed the following minimum criteria:
i. A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.
ii. The bottom of all openings shall be no higher than one foot above grade.
iii. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
E. Any additions to a manufactured home shall be similarly anchored and vented.
(2) The licensed WV manufactured home installer placing the unit shall perform a site inspection and certify in writing that the manufactured home has been installed to the standards set forth in this Ordinance.
(c) Appurtenant Structures.
(1) Except as provided in subsection 2 below, appurtenant structures shall be located out of the Special Flood Hazard Area or elevated to two feet above the Base Flood Elevation.
(2) Where appurtenant structures not connected to the principal structure are to be located on sites below the Base Flood Elevation, the following flood damage reduction provisions apply:
(3) Use of the structure shall be restricted to parking or limited storage.
A. Structures shall be no more than 200 square feet in size and valued at less than $5,000.00.
B. Floors shall be at or above grade on at least one side.
C. Structures shall be located, oriented and constructed to minimize flood damage.
D. Structures shall be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.
E. Flood resistant materials as detailed in FEMA Technical Bulletin 2 shall be used in the construction of the below BFE.
F. Machinery, electric devices or appliances, and all utilities shall be located at least two feet above the Base Flood Elevation.
G. The venting requirements contained in subsection (a) hereof are applicable and shall be strictly adhered to.
(4) A non-conversion agreement shall be signed by the applicant stating that the use of the appurtenant structure or detached or attached garage shall not be changed from the use permitted, acknowledging that the structure may be subject to greater flood risk and that higher flood insurance premiums may be possible, and that a change in use may require full compliance with this Ordinance. The applicant agrees to notify prospective buyers of the existence of this agreement. It shall be the responsibility of the applicant to transfer the agreement at closing to the new owner via notarized signature. A copy of all new agreements shall be provided to the Floodplain Administrator. Failure to transfer the agreement and provide a signed copy to the Floodplain Administrator shall subject the violator to the penalties set forth in Section1721.08
(c).
(d) Recreational Vehicle Placement. Recreational vehicles to be placed within any special flood hazard area shall either:
(1) Be on site for fewer than 180 consecutive days. Or,
(2) Be fully licensed and ready for highway use. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnected utilities and security devices, and has no permanently attached additions. Or,
(3) Be installed in accordance with the manufactured home placement requirements and all other flood reduction requirements contained in this Ordinance.
(e) Fill.
(1) The City of Keyser officially recognizes the beneficial functions the floodplain serves in storage and transportation of water during floods. Therefore:
(2) Placement of fill in the special flood hazard area is discouraged and should be minimized.
(3) Placement of fill in other areas of the special flood hazard area shall be restricted to functional purposes such as elevating a structure. Fill shall only be permitted in the same permit with the related structure or other functional purpose. Placement of fill to dispose of soil from excavation or to elevate yards, parking lots, or fields will not generally be considered a functional purpose. The Floodplain Administrator may require the developer to provide compensatory storage before permitting fill.
(4) No fill shall be permitted in the Floodway
(5) No fill shall be permitted unless it meets the requirements of Section 1721.04
(a). All fill placed in the special flood hazard area shall meet or exceed the following standards:
A. Fill shall be used only to the extent to which it does not adversely affect adjacent properties. The City of Keyser may require the applicant to demonstrate through engineering reports that proposed fill would not adversely affect adjacent properties. When required,
hydrologic and hydraulic analyses shall be undertaken only by Registered Professional Engineers who shall certify that the technical methods used correctly reflect currently accepted technical concepts. The resultant study shall include a cover letter, signed and sealed by the responsible professional, providing a statement of findings in basic terms. In addition, studies, analyses, computations, etc., shall be submitted in sufficient detail to allow a thorough technical review by the City of Keyser. During permit review the City of Keyser shall consider the following issues that have the potential to cause adverse impact to the subject property and adjacent properties:
i. Unacceptable increases in flood heights.
ii. Blocking drainage from adjacent properties.
iii. Deflection of floodwaters onto adjacent existing structures.
iv. Increases to stream velocity initiating or exacerbating erosion problems.
v. Other unique site conditions may be considered when determining whether fill will cause adverse impact to adjacent property including, but not limited to, subsidence areas, karst topography, stream blockages, and steep topography adjacent to the channel.
B. Fill shall be used only to the extent to which it does not adversely affect the capacity of channels or floodways of any tributary to the main stream, drainage ditch, or any other drainage facility or system.
C. Fill Site shall be contoured to drain properly (avoid ponding)
D. Fill shall extend beyond a structure for a sufficient distance to provide acceptable access. For residential structures, fill shall extend laterally fifteen (15) feet beyond the building line from all points before the start of sloping required in following subsection. For non-residential structures, fill shall be placed to provide access acceptable for intended use. At grade access, with fill extending laterally fifteen (15) feet beyond the building line shall be provided to a minimum of twenty-five (25) percent of the perimeter of a non-residential structure.
E. Fill shall consist of soil or rock material only. Sanitary landfills shall not be permitted; no trash or woody debris shall be buried on site.
F. Fill material shall be compacted to provide the necessary stability and resistance to erosion, scouring or settling. Fill compaction standards shall be appropriate to proposed post fill use, particular attention is necessary when fill is being used to elevate a structure.
G. Fill slopes shall be no steeper than one (1) vertical on two (2) horizontal, unless substantiating data justifying steeper slopes are submitted to and approved by the Floodplain Administrator.
H. Fill site and fill must be protected from erosion.
i. Fill slopes exposed to flood waters with expected velocities during the occurrence of the base flood of five feet per second or less will be protected from erosion by covering them with grass, vines, weeds, or similar vegetative undergrowth.
ii. Fill slopes exposed to flood waters with expected velocities during the occurrence of the base flood of greater than five feet per second will be protected from erosion by armoring them with stone or rock slope protection.
I. All applicants placing fill in a special flood hazard area shall obtain a Conditional Letter of Map Revision (CLOMR) from FEMA when directed to do so by the Floodplain Administrator before a permit can be issued. After fill is finished the applicant shall convert the CLOMR to a Letter of Map Revision based on Fill (LOMR-F) before a Certificate of Compliance can be issued.
J. The applicant shall submit any maps, computations or other material required by the Federal Emergency Management Agency (FEMA) to revise the Flood Insurance Study and/or Flood Insurance Rate Maps, when notified by the Floodplain Administrator, and shall pay any fees or other costs assessed by FEMA for this purpose.
(f) Placement of Structures and Other Development. All structures and other development shall be constructed and placed on the lot so as to offer the minimum obstruction to the flow of water and shall be designed to have a minimum obstruction effect upon the flow and height of floodwater.
(1) Whenever possible, structures and other development shall be constructed with the longitudinal axis parallel to the direction of flood flow and,
(2) So far as practicable, structures and other development shall be placed approximately on the same flood-flow lines as those of adjoining structures or development.
(g) Anchoring.
(1) All structures and other development including stream crossings shall be firmly anchored in accordance with accepted engineering practices to prevent flotation, collapse, and lateral movement, thus reducing the threat to life and property and decreasing the possibility of the blockage of bridge openings and other restricted sections of the watercourse
(2) All air ducts, large pipes, swimming pools and storage tanks located at or below the Base Flood Elevation shall be firmly anchored to resist flotation.
(h) Flood Protection Setback. A Flood Protection Setback equal to twice the width of the watercourse channel measuring from the top of one bank to the top of the opposite bank or 50 feet, whichever is less, shall be maintained from the top of the banks of all watercourses. To reduce erosion, natural vegetation shall be maintained in this area. Where natural vegetation does not exist along the watercourse and conditions for replanting are suitable, high priority shall be given to planting vegetation in the setback area to stabilize banks, enhance flood protection and benefit aquatic resources.
(1) Necessary public works and temporary construction may be exempted from this subsection.
(2) The Floodplain Administrator may consider an appeal to the Flood Protection Setback requirement if the applicant demonstrates that it is impossible to allow any development without encroachment into the Flood Protection Setback Area. The conditions shall be the minimum necessary and shall be made only after due consideration is given to varying other siting standards, such as side, front and back lot line setbacks.
(i) Storage.
(1) No materials that are buoyant, flammable, explosive, or in times of flooding could be injurious to human, animal or plant life, shall be stored below Base Flood Elevation.
(2) Storage of other material or equipment may be allowed if not subject to major damage by floods and firmly anchored to prevent flotation or readily removable from the area within the time available after flood warning.
(3) Due to the potential of masking the natural elevation and making it more difficult to enforce this Ordinance, material that resembles "fill" material shall not be considered "storage" material for purposes of this subsection.
(j) Utility and Facility Requirements.
(1) All new or replacement water systems whether public or private, shall be designed to minimize or eliminate infiltration of floodwaters into the systems.
(2) All new or replacement sanitary disposal systems, whether public or private, shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharges from the systems into floodwaters.
(3) All other new or replacement public and/or private utilities and facilities shall be located and constructed to minimize or eliminate flood damage.
(4) Onsite waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
(k) Drainage.
(1) Adequate drainage shall be provided to reduce exposure to flood hazard.
(2) Adequate drainage paths are required around structures on slopes within zones AH and AO to guide floodwaters around and away from proposed structures
(l) Backflow Preventers. Back flow prevention valves should be used for all enclosed structures with sewage or drainage facilities located in the special flood hazard area Floodplain Area. (Passed 2-14-18.)