§ 34-8. Stormwater management plan submittal and approval requirements for development other than residential or duplex development on individual lots.
(a)
Preparer's certification. For commercial, mixed-use or multi-lot development such as a subdivision, stormwater management plans and supporting technical documents shall be prepared by a qualified and registered design professional knowledgeable within the field of work for the performance of the design, construction, and operation and maintenance of what is being proposed.
(b)
Supporting plans and documentation including assumptions, methodology, calculations and conclusions shall be submitted to the town as part of the application.
(1)
For all subdivisions and commercial applications, a stormwater management plan with all supporting documentation meeting all town requirements and standards shall be submitted with the plat or site plan application for approval by the town engineer.
(2)
For conditional uses, a preliminary stormwater management plan shall be submitted with the conditional use permit application. A stormwater management plan with all supporting documentation meeting all town requirements and standards shall be submitted with, or in advance of, the application for a building permit.
(c)
The stormwater management plan shall include engineered drawings, non-engineered drawings, maps, assumptions, calculations and narrative statements, including:
(1)
Existing conditions. Sheets or maps indicating existing features, including buildings, ground surface elevations, landforms, parking areas, roadways, structures, subsurface utilities, surface utilities, surface waters, watercourses, vegetation, and other significant elements. Elevations shall be provided in sufficient detail to determine the efficacy of proposed stormwater improvements and compliance with all stormwater and fill requirements. At a minimum, pre-disturbance spot elevations shall be provided beneath proposed improvements and along property lines adjacent to any fill slopes.
(2)
Project boundaries clearly depicted and labeled, including any staging areas.
(3)
Locations and elevations of the adjoining street pavement, shoulder, ditches, and drainage systems, as well as upstream and downstream driveway culverts.
(4)
Approximate elevation of seasonal high water table. "Seasonal high wetness condition" as indicated by the Dare County Health Department site evaluation is acceptable for determining vertical separation compliance of SCMs on single-family and duplex residential projects. Also include any fill requirements provided with the Dare County Health septic approval.
(5)
Distance measurements. Lateral and vertical separation distances from AECs, state surface waters, subsurface water conditions, above ground and underground utilities, or other separation distances as required by existing federal, state or local laws clearly depicted.
(6)
Proposed conditions. Sheets or maps indicating location of proposed features including areas where fill will be placed including the toe of fill slopes, buildings, ground surface elevations, landforms, parking areas, roadways, structures, subsurface utilities, landscaping, and other significant elements.
(7)
Drawings shall describe the proposed elements and their association with existing elements with spot elevations depicted in areas of proposed fill and finished floor elevations for all proposed buildings/structures described. Notational information shall be provided which includes existing surface elevation at each site element, proposed maximum fill depths for each site element, and maximum fill depth within the project site.
(8)
Location and description of stormwater BMPs proposed to capture runoff from all surfaces within a given drainage area.
(9)
Location of erosion control measures relative to fill slopes and disturbed areas. This shall include any temporary measures that will be necessary to retain stormwater or other construction related water discharges on the property during construction prior to the installation of final stormwater improvements.
(d)
An operations and maintenance agreement shall be submitted to and be approved by the town. The operations and maintenance agreement shall address sediment removal, mowing and re-vegetation, immediate repair of eroded areas, debris removal, and unclogging of any structures. The operations and maintenance agreement may provide for access by the town and its agents to all stormwater management measures at the site for the purposes of inspection, maintenance, reporting, and repair operations. The operations and maintenance plan shall run with the property and compliance shall be the responsibility of the property owner.
(e)
Copies of all recorded easements or covenants that run with the property and are necessary for continued function of the best management practices utilized for plan approval.
(f)
Certification. Upon completion of construction, stormwater management facilities shall be certified by the stormwater plan preparer or a qualified and authorized professional as having been constructed in substantial conformity with the town-approved plans and specifications. The acceptability of a certification by any other person than the person who prepared the original design shall be at the sole discretion of the town. A copy of this documentation shall be submitted to the town prior to the issuance of a certificate of compliance.
(g)
Construction record or as-built plans. The construction record survey or plan shall include any on-site stormwater management measures and shall be prepared once final construction has been completed. These plans shall be prepared by a licensed surveyor and shall include all of the elements shown as proposed on the approved construction plans and depict sufficient topographic information to demonstrate compliance with the approved plans. These shall be submitted to the town prior to the issuance of a certificate of compliance.
(Ord. No. 15-06-016 , Pt. I, 6-3-2015; Ord. No. 18-12-017 , Pt. III, 12-5-2018)