Ordinance 3766-20 - Laserfiche WebLink

c) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters; d) Onsite waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding,and in accordance with requirements of the Snohomish Health District. 4. Subdivision Proposals and Development.All subdivisions,as well as new development shall: a) Be consistent with the need to minimize flood damage; b) Have public utilities and facilities,such as sewer,gas,electrical,and water systems located and constructed to minimize or eliminate flood damage; c) Have adequate drainage provided to reduce exposure to flood damage. d) Where subdivision proposals and other proposed developments contain greater than 50 lots or 5 acres(whichever is the lesser) base flood elevation data shall be included as part of the application. B. Specific Standards. In all areas of special flood hazards where base flood elevation data has been provided as set forth in Section 19.30.030, BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD HAZARD, or Section 19.30.080.C.2, USE OF OTHER BASE FLOOD DATA.The following provisions are required: 1. Residential Construction. a) In AE and A1-30 zones or other A zoned areas where the BFE has been determined or can be reasonably obtained, new construction and substantial improvement of any residential structure shall have the lowest floor, including basement,elevated one foot or more above the BFE. Mechanical equipment and utilities shall be waterproof or elevated least one foot above the BFE. b) New construction and substantial improvement of any residential structure in an Unnumbered A zone for which a BFE is not available and cannot be reasonably obtained shall be reasonably safe from flooding, but in all cases the lowest floor shall be at least two feet above the Highest Adjacent Grade. c) New construction and substantial improvement of any residential structure in a V,V1-30,or VE zone shall meet the requirements in 19.30.300. d) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited,or shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs must meet or exceed the following minimum criteria: i. Have a minimum of two openings with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding. ii. The bottom of all openings shall be no higher than one foot above grade. iii. Openings may be equipped with screens, louvers,valves,or other coverings or devices provided that they permit the automatic entry and exit of floodwater. iv. 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 flood waters. Alternatively,a registered engineer or architect may design and certify engineered openings. 2. Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet the requirements of subsection a or b, below. a) New construction and substantial improvement of any commercial,industrial or other nonresidential structure shall meet all of the following requirements: i. In AE and A1-30 zones or other A zoned areas where the BFE has been determined or can be reasonably obtained: New construction and substantial improvement of any commercial, industrial, or other nonresidential structure shall have the lowest floor, including basement, elevated one foot or more above the BFE,or elevated as required by ASCE 24,whichever is 13