17.40.150-200

Floodplain

• Alluvial fan fillGrading (cut & fill)Reshaping land by removing earth (cut) or adding it (fill), often capped by volume. extension10 ft

  Fill used for elevation shall extend beyond the footprint of the structure a minimum of 10 feet on all sides.

• Alluvial fan fillGrading (cut & fill)Reshaping land by removing earth (cut) or adding it (fill), often capped by volume. slope2 ratio

  Fill used for elevation shall be compacted and sloped at no steeper than 2:1 (horizontal to vertical).

• Floodway encroachment prohibition

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

• Manufactured homeManufactured homeA dwelling built in a factory to a federal standard and transported to the site. elevation

  New manufactured homes and replacement manufactured homes shall be elevated so that the lowest floor is at or above the base flood elevation and shall be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

• Manufactured homeManufactured homeA dwelling built in a factory to a federal standard and transported to the site. pier 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 no less than 36 inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

• Nonresidential floodproofing

  New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to or above the base flood elevation; or, together with attendant utility and sanitary facilities, shall be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water.

• Recreational vehicle duration180 days

  Recreational vehicles placed on sites within Zones A1-30, AH, and AE on the community's FIRM either: Be on the site for fewer than 180 consecutive days; or Be fully licensed and ready for highway use, on wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions.

• Residential lowest floor elevation

  New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above the base flood elevation.

• Shallow flooding AH zone elevation

  In AH zones, new construction and substantial improvements shall have the lowest floor (including basement) elevated to or above the base flood elevation.

• Shallow flooding AO zone elevation1 ft

  In AO zones, new construction and substantial improvements shall have the lowest floor (including basement) elevated above the highest adjacent grade at least one foot above the depth number specified in feet on the FIRM (at least two feet if no depth number is specified).

• Stream without base flood elevation1 ft

  In areas where base flood elevations have not been provided, new construction and substantial improvements shall have the lowest floor elevated at least one foot above the highest adjacent grade.

• VarianceVariancePermission to depart from a specific dimensional rule, granted on a showing of hardship. lot size0.5 acreacre43,560 square feet — about the size of an American football field without the end zones.

  Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level.