Hold PHearing Amending Kittitas County Code Ch. 14.08_Flood Damage Prevention

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in KCC 14.08.040. Basis for establishing the areas of special flood hazard, or ,KCC 14.08.120, Use of other base flood data, the following provisions are required. (Ord. 200103; Ord. 93-18 § 5.2, 1993). 14.08.250 Residential construction. 1. In AE and Al -30 zones, or other A zoned areas where the BFE has been determined or can be reasonably obtained, new construction, substantial improvement, and reconstruction due to substantial damage of any residential structure shall have the lowest floor, including basement, elevated one foot or more above the base flood elevation. 2. Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or if used solely for parking access or storage shall be designed to automatically equalize hydrostatic and hydrodynamic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or must 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, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters. d. A garage attached to a residential structure, constructed with the garage floor slab below the BFE, must be designed to allow for the automatic entry and exit of floodwaters. e. Because of hydrodynamic loads, below grade crawlspace construction is not permitted in areas with flood velocities greater than 5 feet per second unless the design is approved by a registered architect or licensed engineer. 3. Any interior or exterior building utility systems must be elevated one -foot or more above the Base Flood Elevation (BFE) with the exception of utility meters and equipment specifically designed to withstand inundation according to the standards of the International Residential Codes and the NFIP . 4. Portions of buildings below the BFE must be constructed using methods and practices that minimize flood damages, and with materials resistant to flood damage. This includes any joists, pony walls, beams, posts, insulation, wall coverings, wall sheathing or other materials that extend below the BFE. 5. The elevation of the interior crawlspace grade (inside of the foundation walls in crawlspace construction) must be at or above the lowest elevation of the exterior grade. Below -grade crawlspace foundations will be allowed only if all of the following conditions are met, in addition to the minimum criteria set forth above in this subsection: (buildings that have below -grade crowlspaces may have higher flood insurance premiums than buildings that have the preferred crawlspace construction, with the interior elevation at or above the lowest adjacent exterior grade). a. The interior grade of the crawlspace (below the BFE) must not be more than 2 feet below the lowest adjacent exterior grade. b. The height of the below -grade crawlspace, measured from the interior grade of the crawlspace to the top of the crawlspace foundation wall must not exceed 4 feet at any point. c. There must be an adequate drainage system that removes floodwaters from the interior of the crawlspace. Possible options include natural drainage through porous, well drained soils and drainage systems such as perforated pipes, drainage tiles, gravel or crushed stone drainage by gravity, or mechanical means.