§ 87.06.040  Site Preparation and Grading for Subdivision Construction.
   (a)   Grading.  Before the issuance of a Building Permit, a grading plan prepared and signed by a registered civil engineer shall be submitted to and approved by the Building and Safety Division. Grading plans shall show the elevations of the natural ground at all lot corners, the finished grade at corners, the finished pad elevation, finished floor elevations, rates and directions of all drainage swales, elevation height of all retaining or perimeter walls and finished sidewalk elevations at all front lot lines, and existing topographic elevations and drainage direction 100 feet outside the boundary of proposed project area and/or map.
      (1)   Minimum Slopes.  The minimum grade of all drainage swales on parcels shall be two percent unless approved differently by the Building Official.
      (2)   Pad Elevation, Residential.  The building pad elevation of residential parcels shall be established at a minimum of ten inches above the design sidewalk elevation at the lowest point of the parcel. The finished floor elevation of slab floor houses shall be a minimum of 16 inches above the sidewalk elevation. The pad elevation of all residential parcels shall be established at least one foot above the maximum water surface in an adjacent storm drain channel or the ponded surface in an adjacent sump for collection of storm drain waters. An exception may be allowed in the case of a proposed subdivision served by a storm drain pump station. The standards of this Subdivision shall apply to any building pad elevation, except where the requirements of the California Building Code (CBC) exceed these standards, in which case the requirements of the CBC shall apply.
      (3)   Drainage Plan.  No inter-parcel or “cross drainage” shall be allowed. Each parcel shall drain its own water to a public street, approved public or private drainage facility, or natural drainage course without passing through or across an adjacent parcel, except where a legal right exists (e.g., a drainage easement), and is authorized by the Building Official. No parcel shall drain water over the bank of a flood control channel.
      (4)   Grading Practices.  All grading within the County shall employ the best available management practices, as determined by the Building Official, to minimize erosion, sedimentation, and unnecessary grading.
      (5)   Grading Exceptions.  Specific exceptions to the above requirements may be authorized at the discretion of the Building Official.
      (6)   Bonding.  The County may require as a condition of approval that a bond be secured before any grading when the grading is proposed before recordation of the Parcel or Final Map. This bond would be used to install landscaping and appropriate erosion control measures as needed if the subdivider abandons the project after grading occurs. All bonding shall be in compliance with § 87.07.040 (Improvement Agreements, Lien Agreements and Securities).
      (7)   Hillside Grading.  If the subject property is within an area having a natural slope gradient of 15 percent or greater, refer to Chapter 83.08 (Hillside Grading Standards) for applicable procedures and standards.
   (b)   Erosion and Sediment Control.  A proposed subdivision shall be designed so that all grading incorporates appropriate erosion and sediment control measures.
(Ord. 4011, passed - -2007)