Drafter
Clerk 07/01/2011
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AN ORDINANCE relating to coastal high hazard areas regulations; adding a new section to K.C.C. chapter 21A.06 and adding a new section to K.C.C. chapter 21A.24.
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STATEMENT OF FACTS:
1. King County and nearly twenty-one thousand other communities across the United States and its territories participate in the National Flood Insurance Program by adopting and enforcing floodplain management regulations to reduce future flood damage.
2. King County floodplain management regulations are based on mapping of the one-hundred-year floodplain in accordance with the Federal Emergency Management Agency's mapping standards.
3. The historic Federal Emergency Management Agency mapping of the coastal high hazard areas of Vashon-Maury Island is over thirty years old and did not use detailed hydraulic analyses to establish flood heights or depths of flooding from storm-induced velocity wave action.
4. The 2006 King County Flood Hazard Management Plan recommended remapping of the coastal high hazard area of Vashon-Maury Island using the most current models and data to more accurately identify the risk from coastal flooding based on storm-induced velocity wave action.
5. King County is currently preparing revised coastal high hazard area maps for Vashon-Maury Island, which were released to the public for review in April 2011.
6. Once draft maps are released to the public they are considered best available data and King County must regulate development to these maps.
7. King County's flood hazard regulations in K.C.C. 21A.24.230 through 21A.24.270 are not applicable to coastal high hazard areas because they are developed for riverine floodplains with designated floodways.
8. Coastal high hazard areas regulations must be adopted so King County can comply with the code of federal regulations (44 C.F.R. 60.3(b)(4) to regulate floodplain development using the best available data.
BE IT ORDAINED BY THE COUNCIL OF KING COUNTY:
NEW SECTION. SECTION 1. There is hereby added to K.C.C. chapter 21A.06 a new section to read as follows:
Coastal high hazard area: Coastal high hazard area means an area of special flood hazard extending from offshore to the inland limit of a primary frontal dune along an open coast and any other area subject to high velocity wave action from storms. The area is designated on the flood insurance rate maps as zone V1-30, VE or V, and AE, AO or AH zones that are immediately adjacent to the V1-30, VE or V zones.
NEW SECTION. SECTION 2. There is hereby added to K.C.C. chapter 21A.24 a new section to read as follows:
Within coastal high hazard areas the following applies:
A. All buildings and substantial improvements to existing buildings shall be elevated on pilings and columns so that:
1. The bottom of the lowest horizontal structural member of the lowest floor, excluding the pilings or columns, is elevated to the flood protection elevation; and
2. The pile or column foundation and building 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 percent chance of being equaled or exceeded in any given year;
B. A registered professional engineer or architect licensed by the state of Washington shall prepare the structural design, specifications and plans for the building, 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 subsection A. of this section;
C. The applicant shall provide a FEMA elevation certificate completed by a land surveyor licensed by the state of Washington documenting the elevation of the bottom of the lowest structural member of the lowest floor, excluding pilings and columns, of all new and substantially improved buildings and whether or not such buildings contain a basement. The department shall maintain the FEMA elevation certificates required by this section for public inspection and for certification under the National Flood Insurance Program;
D. All buildings shall be located landward of the reach of mean high tide;
E. All buildings and substantial improvements to existing buildings shall maintain the space below the lowest floor free of obstruction. The space can include nonsupporting open wood lattice-work or insect screening that is intended to collapse under wind and wave loads without causing collapse, displacement or other structural damage to the elevated portion of the building or supporting foundation system. The space below the lowest floor can be used only for parking of vehicles, building access or storage. The space shall not be used for human habitation;
F. Fill for structural support of buildings is prohibited;
G. All manufactured homes to be placed or substantially improved within coastal high hazard areas shall meet the standards in subsections A. through F. of this section;
H. Recreational vehicles placed on sites within zones V1-30, VE and V and adjacent AE, AO and AH zones must either:
1. Be on the site for fewer than one hundred eighty consecutive days; or
2. Be fully licensed and ready for highway use, on their wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; and
I. The flood hazard standards in K.C.C. 21A.24.230 through 21A.24.270 do not apply to coastal high hazard areas.
SECTION 3. If any provision of this ordinance or its application to any person or
circumstance is held invalid, the remainder of the ordinance or the application of the provision to other persons or circumstances is not affected.
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Official paper, 30 days prior
Public hearing: 8/29/11
Newspaper: Seattle Times
Publish: Wednesday, July 27, 2011