§ 295-1119 — Standards Applicable to All Floodplain Overlay Zones

295-1119. Standards Applicable to All Floodplain Overlay Zones.

1. The commissioner of neighborhood services shall review all permit applications to determine whether proposed building sites will be reasonably safe from flooding and sure that all necessary permits have been received from those governmental agencies whose approval is required by federal or state law. 2. If a proposed building site is in a flood-prone area, all new construction and substantial improvements shall be: a. Designed and anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy; b. Constructed with flood-resistant materials; c. Constructed by methods and practices that minimize flood damage; and d. In the case of mechanical and utility equipment, elevated to or above the flood protection elevation. 3. If a subdivision or other proposed new development is in a flood-prone area, the commissioner of neighborhood services shall assure that: a. The proposed subdivision or other new development is consistent with the need to minimize flood damage within the flood-prone area; b. Public utilities and facilities such as sewer, gas, electrical and water systems are located and constructed to minimize or eliminate flood damage; and c. Adequate drainage is provided to reduce exposure to flood hazards. 4. All subdivision proposals, including manufactured home parks, shall include regional flood elevation and floodway data for any development that meets the definition of a subdivision and all other requirements of s. 295-1129. 5. No floodplain development shall result in either of the following: a. Obstruct flow, defined as development which blocks the conveyance of floodwaters by itself or with other development, causing any increase in the regional flood height. b. Cause any increase in the regional flood height due to floodplain storage area lost. 6. The commissioner shall deny permits if it is determined the proposed development will obstruct flow or cause any increase in the regional flood height, based on the officially adopted flood insurance rate map or other adopted map, unless the provisions of sub. 3 are met. 7. Obstructions, or any increases to base flood elevations shown on the officially adopted flood insurance rate map or other adopted map, may only be permitted if amendments are made to this subchapter, the official floodplain zoning map, floodway lines and water surface profiles, in accordance with s. 295-1117. Any such alterations shall be reviewed and approved by the federal emergency management agency and the Wisconsin department of natural resources. 8. Development shall not adversely affect channels, floodways or banks of any tributaries of the city’s watercourses, or land outside of the floodplain. 9. No river or stream shall be altered or relocated until a floodplain overlay zone zoning map amendment is approved by the common council in accord with s. 295-1117-3. 10. No permit to alter or relocate a watercourse in a mapped floodplain shall be issued until the commissioner has notified, in writing, all adjacent municipalities and the regional offices of the Wisconsin department of natural resources and the federal emergency management agency, and has required the applicant to secure all necessary state and federal permits. The standards of sub. 1 shall be met, and the flood-carrying capacity of any altered or relocated watercourse shall be maintained. As soon as is practicable, but not later than 6 months after the date of the watercourse alteration or relocation, and pursuant to s. 295-1143, the commissioner shall, on behalf of the city, apply for a letter of map revision from the federal emergency management agency. Any such alterations shall be reviewed and approved by the federal insurance management agency and the Wisconsin department of natural resources through the letter-of-map-revision change process.