1113.02 GRADING.

   (a)   Subdivision Grading Plan Required. A subdivision grading plan shall be prepared for any Major Subdivision to demonstrate that the planned grading of the subdivision as a whole, its improvements, and the individual lots have been comprehensively designed and will comply with the grading standards of the City.

      (1)   The subdivision grading plan shall be prepared consistent with the general requirements for drawings at Section 1107.01.

      (2)   The plan shall indicate the following at a level of detail as required by the Engineering Construction Standards:

         A.   The existing and proposed grades of land within the subdivision and to a distance of one hundred (100) feet outside of the boundaries of the subdivision. The Director of Engineering, Utilities, and Inspection may require a greater distance with cause.

         B.   The planned grades of all roads, rights-of-way, lots, planned surface drainage courses, natural watercourses and lots. Finished grade "spot" elevations and existing grade elevations are to be shown at each corner of lots and at intervals of no more than fifty (50) feet along every lot line. Existing and proposed contours shall be shown at an interval of no less than two (2) feet.

         C.   The elevations of all planned drainage inlets and the inverts of all underground drainage facilities.

         D.   The planned finished floor elevations of all buildings, including dwellings.

         E.   The limits of clearing and grading and all areas of excavation or other soil-disturbing activity to be conducted by the applicant.

          F.   Those areas of cut or fill from the existing, undisturbed grade which exceed a depth of three (3) feet.

      (3)   Calculations shall be submitted for: the amount of soil which will be removed from the subdivision, a description of the location where the soil will be disposed and the manner of disposal; and the amount of soil which will be imported to the subdivision, and a description of its source.

   (b)   Site Grading Plans for Sublots and Site Developments Required. A site grading plan shall be submitted to show that the proposed grading of a site development has been designed to comply with the regulations of the City, will be compatible with any subdivision grading plan of which the site is a part (subject to modifications permitted or required by the Director of Engineering, Utilities, and Inspection), will comply with all other applicable regulations, and will be compatible with the grading of abutting and nearby lots. The sublot or site grading plan shall be prepared consistent with the general requirements for drawings at Section 1107.01 and shall provide the level of detail as required by the Engineering Construction Standards.

   (c)   Grading Standards. The following standards shall apply to the grading of all subdivisions, lots, and other areas of the City.

      (1)   Grading Generally.

         A.   The grading of subdivisions, blocks, and lots shall be planned to preserve natural topography, preserve existing site and drainage patterns to the extent feasible, minimize the export and import of soil, minimize the disturbance of natural topsoil, to minimize the destruction of trees, to provide sites suitable for planned land uses, and to provide for efficient and effective systems of roads, walks, utilities, and storm water management.

         B.   Natural Drainage. Subdivisions shall be designed to take every advantage of natural grades and existing drainage patterns so that all the land can be drained without excessive grading, overland flow of stormwater is promoted, and the need for stormwater management facilities is minimized. Unless watercourses or drainage ways are enclosed, lots shall be arranged so rear lot lines will be approximately parallel to the natural or straightened course, and only where such a plan is not possible may side lot lines be arranged parallel to an open drainage course. Easements for drainage ways or land which is subject to flooding may be included as part of a lot but shall not be used as a building site.    

         C.   Natural Features. Natural features, changes in level, brooks, lakes, hilltops and other focal points within the site and distant view outside the subdivision, shall be integrated in the design to obtain natural variations and interest in each neighborhood and to create attractive building sites.

         D.   A grading plan shall be submitted and approved prior to the filling or removal of material which alters the existing grade of any land. Any filling or cutting shall be in a manner approved by the Director of Engineering, Utilities, and Inspection suitable for the use for which the lot is intended or for which it may be used. The Director of Engineering, Utilities, and Inspection may require inspections and testing.

         E.   The City shall require that topsoil stripped from the roadway and construction areas shall be preserved for use on each site.
(Ord. 2013-130. Passed 1-27-14.)

      (2)   Lot Grading.  

         A.   The floor elevation of each building shall be set in relation to the road. The garage floor elevation is to be established and shown, at a minimum of one and one-half (1.5) feet above the finished road centerline grade. The lot shall be graded so water drains away from each building at a minimum grade of two percent (2%) over a distance of at least ten (10) feet in all directions.. When a building is constructed within a subdivision with an approved subdivision grading plan, the finished floor elevation of the building shall be no more than one (1) foot higher or lower than approved in the subdivision grading plan. When a new building is constructed next to an existing building where no subdivision grading plan exists, the finished floor elevation of the new building shall be no more than one (1) foot higher than the adjacent building. For new buildings constructed between two existing buildings, the finished floor elevation shall be no higher than the highest finished floor of the adjacent buildings. The Director of Engineering, Utilities, and Inspection may approve floor elevations exceeding the limits above.

            (Ord. 2016-102. Passed 11-21-16.)

         B.   Surface drainage swales shall have a minimum grade of one percent (1%) so surface water will drain into a road gutter, storm sewer, drain inlet or natural drainage way.

         C.   The minimum grades of driveways shall be one-half percent (0.5%) and maximum of ten percent (10%). Grading shall be adjusted so there will be no abrupt grades in the front yards and along side lot lines.

         D.   The grades of earth terraces shall not exceed one and one-half to one (1.5:1) and shall be seeded or sodded as directed by the City.

         E.   Retaining walls exceeding three (3) feet in height shall have a hedge, fence or rail at the top edge of the wall. A Certified Professional Engineer shall certify all retaining walls in excess of four feet in height measured from the bottom of the footing to the top of the wall. All retaining walls supporting a surcharge or impounding Class I, II or III - A liquids, regardless of height, must also be certified by a professional engineer.

         F.   Each lot shall be shown to be graded so that the front yard slopes toward the street and that the ground slopes away from the building. Side yard swales shall be constructed and maintained between all houses to a minimum depth of three (3) inches below finished grade at the lowest adjacent house, and shall be deep enough to drain any swale at the rear of the house.

         G.   Where the rear yard slopes towards the house, a swale shall be constructed at least thirteen feet to the rear of the house to a minimum depth of three inches below the finish building grade of that house and shall drain to the side yard swales.

          H.   In a case where lots behind the subject lot are higher in elevation and the rear yards of the higher lots slope toward the rear of the subject lot, swales on the lower lots or lots shall be constructed along the side lot lines with an average depth of three inches below the lowest adjacent lot surface at the building and shall extend from the front lot line to the rear lot line. In this case, drainage from no more than two high rear lots shall accumulate to outlet along a side line of a given low lot.

         I.   Where the rear yards slope toward the rear of the lot and the method of grading described above is not possible, a catch basin shall be constructed in a swale constructed along the rear lot line. In subdivisions, the maximum distance between catch basins along the length of any such rear swale shall be 100 feet and each lot shall have a catch basin at its rear lot line. Catch basins shall be either constructed during the development phase or the building phase, but shall exist prior to the issuance of an occupancy permit. Each such swale and catch basin shall be maintained by the property owner to ensure effective and total storm water control. In a development, the center of the swale may be along the property line and in any other case it shall be at least six feet, but not more than ten feet, onto the property being developed and a minimum of four inches below the lower property.

         J.   For additions to existing dwellings and detached garage construction on an existing site, the site plan may be waived, but site drainage shall be maintained in accordance with these Regulations.

         K.   All lots shall be finish graded in accordance with a similar plan to that sample nearest resembling the lot to be graded as shown on the attached sample grading plans, no yard slope shall exceed a one foot rise vertically for a five foot horizontal distance when possible.

      (3)   Road Grades. The grading of roads shall comply with the following:

         A.   Roads shall be designed to avoid extensive cuts and fills so that lots on one side of the road will not be excessively above the road grade.

         B.   The grading of the roadway shall extend the full width of the right of way.

         C.   Tree lawns shall be graded at a gradient of not less than two percent (2%) nor more than five percent (5%) upward from the curb to the sidewalk or property line.

         D.   Filling and grading for the purposes of supporting roads, drives, walks or bikeways, whether in public rights-of-way or for private developments or lots, shall comply with the standards for culverts and bridges in these Regulations.

            (Ord. 2013-130. Passed 1-27-14.)