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Title 17E
Chapter 17E.030
Section 17E.030.170
 

Title 17E Environmental Standards

Chapter 17E.030 Floodplain Management

Section 17E.030.170 Standards for Shallow Flooding Areas (AO Zones)
  1. Shallow flooding areas appear on FIRMS as AO zones with depth designations. The base flood depths in these zones range from one to three feet above ground where a clearly defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as sheet flow. In these areas, the following provisions apply:
    1. New construction and substantial improvements of residential structures and manufactures homes within AO zones shall have the lowest floor (including basement) elevated above the highest adjacent grade to the structure, two feet or more above the depth number specified in feet on the community’s FIRM (at least two feet above the highest adjacent grade to the structure if no depth number is specified).
    1. New construction and substantial improvements of nonresidential structures within AO zones shall either:
      1. have the lowest floor (including basement) elevated above the highest adjacent grade of the building site, two feet or more above the depth number specified on the FIRM (at least two feet if no depth number is specified); or
      1. together with attendant utility and sanitary facilities, be completely flood proofed to or above that level so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic an hydrodynamic loads and effects of buoyancy. If this method is used, compliance shall be certified by a registered professional engineer or architect as in SMC 17E.030.140(B)(3).
    1. Adequate drainage paths shall be required around structures on slopes to guide floodwaters around and away from proposed structures.
    1. Recreational vehicles placed on sites within AO zones on the community’s FIRM are required to either:
      1. be on the site for fewer than one hundred eighty consecutive days, or
      1. be fully licensed and ready for highway use, on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions; or
      1. meet the requirements of subsections (A)(1) and (A)(3) of this section and the anchoring requirements for manufactured homes (SMC 17E.030.130(A)(2)).
  1. Essential Public Facilities.

Construction of new essential public facilities shall be, to the extent possible, located outside the limits of the special flood hazard area. Construction of new essential public facilities shall be permissible within the special flood hazard area if no feasible alternative site is available. Essential public facilities constructed within the special flood hazard area shall have the lowest floor elevated three feet or more above the level of the base flood elevation at the site. Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into floodwaters. All essential public facilities shall have access routes elevated to or above the level of the base flood elevation.

Date Passed: Monday, February 21, 2005

Effective Date: Wednesday, March 30, 2005

ORD C33583 Section 2