Article IV. Utilization Of The Floodplain Area
Section 4.1 Floodway (F1)
Within any floodway area (F1), no encroachments, including fill, new construction, substantial improvements, or other development shall be permitted unless it has been demonstrated through hydrologic and hydraulic analysis performed in accordance with standard engineering practice that the proposed encroachment will not result in any increase in the Base Flood Elevation.
Section 4.2 Floodway Fringe (F2) and Approximated Floodplain (F4)
In the Floodway Fringe (F2) and Approximated Floodplain (F4), any development and/or use of land shall be permitted provided that all such uses, activities and/or development shall be undertaken in strict compliance with the flood-proofing and related provisions contained herein and in all other applicable codes, ordinances and regulations.
Section 4.3 AE area without floodway (F3)
Within any AE area without floodway, no new construction or development shall be allowed unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the elevation of the 100-year flood more than one (1) foot at any point. This requirement can be satisfied by utilization of the floodway area where determined.
Section 4.4 Alteration or relocation of a stream
- Whenever a developer/person intends to alter or relocate a stream within the Floodplain Area, the developer/person shall notify in writing, via certified mail, the Jefferson County Floodplain Administrator, the State Coordinating Office, any adjacent communities/municipalities, and any adjacent property owners, of all such intended activities prior to the alteration or relocation of the stream. Copies of all required notifications must be submitted to the Federal Insurance Administration. In addition, the developer/person shall provide copies of all permits required by other agencies, to the Jefferson County Floodplain Administrator.
- The developer shall also assure the Jefferson County Floodplain Administrator in writing that the carrying capacity within the altered or relocated portion of the stream will be maintained. The Floodplain Administrator may require the applicant to demonstrate that the altered or relocated portion of stream will provide equal or greater conveyance than the original stream segment. When Hydrologic and hydraulic analyses are required, they shall only be undertaken by a registered professional engineer, who shall certify that the technical methods used reflect currently accepted technical concepts and methodology. A summary of the study and the findings along with the detailed study, analyses, computations, etc. shall be submitted in sufficient detail to allow a thorough technical review by the Floodplain Administrator.
- The Floodplain Administrator may require the use of certain “best practice” techniques in the construction of bridges, culverts or stream crossings to prevent damage, loss of stream crossings and localized flooding caused by blockage. These techniques may include, but are not limited to, wing walls, trash grates or requiring openings to be of sufficient size to pass debris and/or anticipated future increases in flood heights. D. All new and replacement bridges, culverts and other stream crossings shall adhere to the relevant anchoring requirements contained in this ordinance. E. The developer is required to provide the community a legal agreement detailing all scheduled inspections and maintenance to be performed on altered or relocated watercourses including culverts, bridges and other stream crossings. It shall be the responsibility of the applicant to transfer this agreement to the new owner when the land associated with the watercourse alteration is transferred. A copy of all new agreements shall be provided to the Floodplain Administrator. Failure to transfer the agreement and provide a signed copy to the Floodplain Administrator shall subject the violator to the penalties set forth in Section 8.3 of this ordinance. F. The applicant must submit any maps, computations or other material required by the Federal Emergency Management Agency (FEMA) to revise the Flood Insurance Study and/or Flood Insurance Rate Maps, when notified by the Floodplain Administrator, and must pay any fees or other costs assessed by FEMA for this purpose.