(a) Any person or persons proposing to develop or redevelop land (for any of the uses listed above) as defined under Section 1371.01(9) and (51) shall design and implement a site grading and drainage development plan which will:
(1) Yield quantities of surfacewater runoff from the development site at rates which are the same as or less that those before development occurred and result in rates of gross erosion as specified by Section 1371.03.
(2) Not result in increasing current potentials for sedimentation of lands, siltration of waters, and flooding of watercourses that are at lower elevations off-site.
(b) No changes subject to regulation under this section shall be made in the existing natural surface composition or subsurface configuration of any land proposed for development or redevelopment within the City (for land uses specified under Section 1371.03(a) without prior written approval of a site development plan by City Engineer. Approval of a site development plan required according to Section 1371.05 shall not be given:
(1) Unless a determination is made by the City Engineer that implementation of an approved site grading and drainage development plan would not cause runoff, erosion, and sediment impacts that would be harmful or damaging to the lands and waters off-site, or,
(2) Until a plan for minimizing the harmful and damaging potentials of runoff, erosion and sediment impacts anticipated to result from implementation of a proposed site grading and drainage development plan has been approved by the City Engineer.
(c) Development situations may exist such that the development will have none of the harmful effects associated with increased runoff rates and volumes or sediment disposition. Such developments are eligible for a waiver from these standards; however, the waiver applies only to the following requirements and may have specific conditions attached by the City Engineer, including but not limited to:
(1) The preparation of plans, maps, and/or information specified in Section 1371.06.
(2) The installation of sediment abatement control devices until such time as site inspection indicates they may be necessary.
(3) Controlling runoff to predevelopment conditions as specified in Section 1371.03, except that stormwater runoff must be controlled to the maximum volume and minimum rate feasible for the site as determined by the City Engineer.
(d) The request for a waiver shall be in writing and shall include sufficient detail to determine that granting a waiver will not be detrimental to abutting properties or to the drainage system. However, the waiver does not in any way imply a relaxation of any of the other standards in this regulation including the requirement for adequate on-site drainage, the ability to accept runoff from land tributary to the development or reasonable control of soil erosion and sediment.
Development activities for which waivers may be considered include the following:
(1) Single family residential developments involving improvement of an individual lot in a previously approved subdivision.
(2) Multi-family residential, commercial, or industrial developments which total two (2) acres or less.
(3) Modification to, or redevelopment of, an existing development which will not result in additional impervious areas.
(4) Additions of 250 sq. ft. or more to existing property, such as driveways, sidewalks, patios, etc.)
(5) Modifications to existing development that is less than 70% of the cost of existing development.
(6) Regular farming procedures on land designed for such use.
(e) Development activities that are exempt from this ordinance include the following:
Additions of less than 250 sq. ft. to existing property such as driveways, sidewalks, patios, etc. (Ord. 26-03. Passed 11-17-03.)