(A) Stream Corridor Protection Zones (SCPZs) are established as provided in this section.
(C) The SCPZ width shall be the width of the FEMA-designated 100-year flood plain, or in areas where a FEMA-designated 100 year flood plain has not been designated, a width defined by the following according to the contributing drainage area:
MINIMUM SCPZ WIDTH BY CONTRIBUTING DRAINAGE AREA OF STREAM | |
Contributing Drainage Area (ac) | SCPZ Width (ft) |
MINIMUM SCPZ WIDTH BY CONTRIBUTING DRAINAGE AREA OF STREAM | |
Contributing Drainage Area (ac) | SCPZ Width (ft) |
<100 | 25 |
101-250 | 38 |
251-500 | 50 |
501-800 | 63 |
801-1200 | 75 |
1201-2000 | 88 |
>2000 | 100 |
In most instances the calculated stream corridor protection zone shall be placed at the ordinary high water mark on each side of the channel and extend outward. This will result in a total SCPZ width of two times the minimum SCPZ width (stated in the guidance table above) plus the width of the stream. However, individual site conditions including, but not limited to, topography and slope must be considered when determining the precise location of the stream corridor protection zone and shall be left to the city's discretion.
(D) The width of the SCPZ may be extended to include slopes that are greater than 15% and begin at a point within the SCPZ. The maximum width of the SCPZ extension shall be to the top of the slope or to a point up slope, as measured horizontally, where the width of the SCPZ is doubled, whichever is less. Slope protection widths may be extended beyond these limits at the city's discretion on a case-by-case basis.
(E) The following are exempt from the terms and protection of this chapter: grassy swales, drainage ditches created at the time of a subdivision to convey stormwater water to another system, tile drainage systems, and stream culverts.
(F) The following shall apply to the SCPZ:
(1) The width of the SCPZ shall be measured in a horizontal direction outward from the ordinary high water mark of each designated watercourse.
(2) Except as otherwise provided in this regulation, SCPZs shall be preserved in their natural state.
(3) The applicant shall be responsible for determining if jurisdictional wetlands have been identified within any proposed development site. Where existing wetlands protected under federal or state law are identified within the SCPZ, the SCPZ shall consist of the full extent of the wetlands plus any additional setback distance mandated by state or federal permit.
(4) The applicant shall be responsible for delineating a rough layout of the SCPZ, including any expansions or modifications as required by divisions (B) through (D) of this section, and identifying this setback on all preliminary subdivision or land development plans, and/or building permit applications. Final development plans shall delineate the SCZP by a metes and bounds survey. This final delineation shall be subject to review and approval by the City Engineer or designee. As the result of this review, the Engineer or designee may require further studies from the applicant.
(5) Prior to any earth-disturbing activity, the SCPZ shall be clearly delineated with construction fencing or other suitable material by the applicant on site, and such delineation shall be maintained throughout earth-disturbing activities. The delineated area shall be maintained in an undisturbed state unless otherwise permitted by these regulations. All fencing shall be removed when a development project is completed.
(6) If earth-disturbing activities will occur within 50 feet of the outer boundary of the SCPZ, the SCPZ shall be clearly delineated by the applicant on site with construction fencing, and such delineation shall be maintained throughout earth-disturbing activities.
(7) No approvals or permits shall be issued by the City Engineer or designee prior to delineation of the SCPZ in conformance with these regulations.
(8) Upon completion of an approved subdivision, the SCPZ shall be permanently recorded on the plat records for the city.
(G) In order to preserve floodplain storage volumes and thereby avoid increases in water surface elevations along FEMA regulated streams, filling within FEMA delineated 100-year floodplains may only occur outside of the floodway plus 20 feet, and must be compensated by removing an equivalent volume of material. Compensating storage shall be determined by the volume of material removed above the ordinary high water table and below the 100-year flood elevation established for that area. Compensating storage shall be provided within the legal boundaries of the development. No stormwater management facilities required by the city shall be permitted in the floodplain unless, at city's discretion, the applicant demonstrates that it does not remove floodplain storage when operating at its design capacity. First consideration for the location(s) of compensatory floodplain volumes should be given to areas where the stream channel will have immediate access to the new floodplain within the limits of the development site. Embankment slopes used in compensatory storage areas must reasonably conform to the natural slopes adjacent to the disturbed area. The use of vertical retaining structures is specifically prohibited.
(H) Degraded SCPZs shall be re-graded and re-vegetated such that riparian habitat is recovered and the streambank stabilized in a manner suitable for the native site conditions.
(I) Stream relocation.
(1) Streams may be relocated if the applicant's design demonstrates, to the satisfaction of the city, that the following criteria are met:
(a) Maintain or improve geomorphic stability.
(b) Maintain or improve flood storage capacity.
(c) Maintain or lower regulatory flood water surface elevations.
(d) Enhance aquatic and riparian habitats.
(e) Provide increased recreational opportunities.
(f) Produce zero or positive impacts on water and land resources.
(g) Minimize operations and maintenance requirements.
(h) Maximize safety conditions.
(2) The project's design shall be performed by a qualified professional engineer with experience in fluvial geomorphology.
(3) If floodplain boundaries change as a result of the relocation, the requirements of Chapter 151 of the Dublin Code of Ordinances become applicable.
(J) SCPZ's shall be clearly delineated on preliminary development plans, final plats, final development plans, final construction drawings, building permit site plans and stormwater management plans. Final plats or applicable portions of the final development plan documentation shall be recorded in Franklin, Deleware, or Union County at no expense to the city and shall constitute a covenant running with the land.
(Ord. 48-05, passed 9-6-05; Am. Ord. 86-14, passed 9-8-14)