Article V. Provisions for Flood Hazard Reduction
15.15.160 General standards.
In all areas of special flood hazards, the following standards are required:
(1) Anchoring.
(a) All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
(b) All manufactured homes must likewise be anchored to prevent flotation, collapse, or lateral movement, and shall be installed using methods and practices that minimize flood damage. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to ground anchors (reference FEMA’s “Manufactured Home Installation in Flood Hazard Areas” guidebook for additional techniques).
(2) Construction Materials and Methods.
(a) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
(b) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.
(c) Electrical, heating, ventilation, plumbing, and air-conditioning equipment and other service facilities shall be designed and/or otherwise elevated or located so as to prevent water from entering or accumulating within the components during conditions of flooding.
(3) Utilities.
(a) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;
(b) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the systems into flood waters; and
(c) On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding consistent with the Oregon Department of Environmental Quality.
(4) Subdivision Proposals.
(a) All subdivision proposals shall be consistent with the need to minimize flood damage;
(b) All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize or eliminate flood damage;
(c) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and
(d) Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated for subdivision proposals and other proposed developments which contain at least 50 lots or five acres (whichever is less).
(5) Review of Building Permits. Where elevation data is not available either through the flood insurance study, FIRM, or from another authoritative source (YMC 15.15.140(2)), applications for building permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a local judgment and includes use of historical data, high water marks, photographs of past flooding, etc., where available. Failure to elevate at least two feet above grade in these zones may result in higher insurance rates.
(6) AH Zone Drainage. Adequate drainage paths are required around structures on slopes to guide flood waters around and away from proposed structures. (Ord. 406 § 5.1, 2010).