Chapter 17.48

Other

• Anchoring of structures

  All new construction and substantial improvements of structures, including manufactured homes, shall be adequately anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

• Development permit required

  A development permit shall be obtained before any construction or development begins within any area of special flood hazard established in Section 17.48.060.

• Flood resistant materials

  All new construction and substantial improvement shall be constructed with flood resistant materials as specified in FEMA Technical Bulletin TB 2-93, and utility equipment resistant to flood damage; using methods and practices that minimize flood damage; with electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

• Floodway encroachment prohibition

  Prohibit encroachments, including fill, new construction, substantial improvement, and other new development unless certification by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in [the base] flood elevation during the occurrence of the base flood discharge.

• Minimum manufactured homeManufactured homeA dwelling built in a factory to a federal standard and transported to the site. chassis heightMaximum heightThe tallest a building may be, given in feet, in storeys, or both — whichever binds first.36 in

  The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than thirty-six inches in height above grade.

• Minimum manufactured homeManufactured homeA dwelling built in a factory to a federal standard and transported to the site. elevation2 ft

  All manufactured homes that are placed or substantially improved, within zones A1-30, AH, and AE on the community's Flood Insurance Rate Map, on sites located outside of a manufactured home park or subdivision, in a new manufactured home park or subdivision, in an expansion to an existing manufactured home park or subdivision, or in an existing manufactured home park or subdivision on a site upon which a manufactured home has incurred 'substantial damage' as the result of a flood, shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated a minimum two feet above the base flood elevation and be securely fastened to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

• Minimum opening area for enclosed areas below lowest floor1 sq in/sq ftsq ftSquare feet. An acre is 43,560 sq ft; a typical suburban lot is 7,000–10,000.

  Have 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. The bottom of all openings shall be no higher than one foot above grade.

• Minimum residential lowest floor elevation above base flood elevation2 ft

  In an A zone, elevated to a minimum of two feet above the base flood elevation, as determined by the community.

• Minimum residential elevation in AO zone2 ft

  In an AO zone, elevated above the highest adjacent grade to a height equal to or exceeding the depth number specified in feet on the FIRM, or elevated at least two feet above the highest adjacent grade if no depth number is specified.

• Nonresidential floodproofing

  All new construction or substantial improvements of nonresidential structures shall either be elevated to conform with Section 17.48.200(c)(1) or floodproofed, together with attendant utility and sanitary facilities, below the elevation recommended under Section 17.48.200(c)(1), so that the structure is watertight with walls substantially impermeable to the passage of water.

• Recreational vehicle stay limit180 days

  All recreational vehicles placed on sites within zones A1-30, AH, and AE on the community's Flood Insurance Rate Map will either be on the site for fewer than one hundred eighty consecutive days, and be fully licensed and ready for highway use, or meet the permit requirements and the elevation and anchoring requirements for manufactured homes.

• Subdivision SFHA identification50 lots

  All new subdivisions proposals and other proposed development, including proposals for manufactured home parks and subdivisions, greater than fifty lots or five acres, whichever is the lesser, shall identify the special flood hazard areas (SFHA) and base flood elevations (BFE).

• Utility flood design

  All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the systems into floodwaters. On-site waste disposal systems shall be located to avoid impairment to them, or contamination from them during flooding.