§ 152.066  RESIDENTIAL PLAN CRITERIA (GRADING AND SINGLE-LOT GRADING PLANS).
   The grading plan checklist requirements relating to this code must be adhered to and at a minimum the following:
   (A)   Maximum slope.
      (1)   The maximum slope may not exceed 10% within 20 feet of a proposed structure on front and rear yards. The side yard maximum slope may not exceed 3:1. The maximum slope more than 20 feet beyond a structure may not exceed 3:1 to the property line or existing grade. In an environmentally sensitive area or if adherence to these standards will result in a violation of any other chapters of this Code, these requirements may be altered by the county.
      (2)   All slopes of 2:1 or steeper shall be indicated on the plan. Special stabilization notes shall be required on plans that include slopes of 2:1 or steeper.
      (3)   The provisions of this section are not intended to prevent the design and use of slopes steeper than 3:1 in open space areas at the discretion of the county and when in compliance with the Standards and Specifications.
   (B)   Minimum slope.  The minimum slope away from a structure shall be 5% to convey the runoff for a distance of ten feet.
   (C)   Driveway grades.  For driveway grades ranging from 12% to 17%, a detailed drawing showing a profile of the driveway and how drainage will be conveyed shall be provided. The plan shall show that runoff will not adversely affect a public road or neighboring property. This portion of the driveway shall be paved and tie into the driveway apron if runoff is directed toward a public road. Driveway grades greater than 17% are prohibited.
   (D)   Plan scale.  The scale of the plan shall be no less than one inch equals 50 feet. Two-foot existing and proposed contour intervals are required on all grading plan submittals.
   (E)   Safety features.  In the event that extreme slope conditions exist or are proposed, the county may require that appropriate safety devices be installed, including but not limited to fences, guardrails, and retaining walls in accordance with Chapter 170, Construction Codes, and landscape plantings in accordance with the Landscape Manual (see Chapter 157).
   (F)   Structure proximity to a watercourse.
      (1)   The proposed structure may not be located within 20 feet of a natural or man-made waterway which only conveys stormwater runoff.
      (2)   The proposed structure shall be located in accordance with Chapter 153, Floodplain Management, and Chapter 154, Water Resource Management, and any buffers required by those chapters.
   (G)   Structure requirements.  Proposed first floor elevations and proposed house styles shall be shown on the grading plan in all residential zoning districts and for all planned unit and clustered subdivisions. For other zoning districts, these details may be required at the discretion of the county during preliminary plan review or with the proposed construction drawings.
   (H)   Swales.  Water shall be allowed to sheet flow whenever possible. Where swales are necessary, the swales shall be located on property lines within drainage and utility easements.
      (1)   An engineering analysis of proposed swales shall be certified by a professional engineer or land surveyor and submitted to the county as part of the plan submittal.
      (2)   Stormdrain inlets shall be provided for every four lots with additional inlets as required to limit the discharge of the ten-year storm to two cubic feet per second (CFS) or three inches of depth within the swale.
(2004 Code, § 121-20)  (Ord. 2012-09, passed 12-11-2012)