Tenafly City Zoning Code
§ 35-816.4
Submission of Grading, Drainage and Landscaping Plans for Steep Sloped Areas.
[Ord. No. 10-24 § 32]
Any applicant proposing to disturb topographic slopes equal to or exceeding a 15% grade in the Borough of Tenafly shall submit the following information to the Borough Engineer or to the Planning Board or the Zoning Board of Adjustment, as the case may be, and all submitted plans, details and calculations shall be prepared, signed, and sealed by a New Jersey licensed professional engineer:
a.
A steep slope analysis, including the following and utilizing the best available topographic information, provided that the Borough Engineer may require additional information, including, but not limited to, an on-site topographic survey utilizing a five-foot contour interval or spot elevations on the site to document "steep sloped areas:"
1.
Existing contours at two-foot intervals, with the following groups of slopes clearly delineated by shading: areas of slopes with grades from zero up to, but not including, 15%; areas of slopes 15% up to, but not including, 25%; and areas of slopes 25% and greater; and
2.
The proposed grading plan superimposed on the existing contours, also shown at two-foot intervals, and also with the three groups of slopes noted in paragraph a1 above in this subsection appropriately shaded.
b.
The grading plan, which shall be prepared at a minimum scale of one inch equals 50 feet, including the following information in addition to all other applicable requirements of the Land Development Regulation.
1.
Plans showing the location of, and details for, all drainage devices, retaining walls, cribbing, dams or other protective devices to be constructed, and any existing or proposed swales, ditches, brooks or other drainage patterns;
2.
Plans, profiles, cross-sections, and details of all retaining walls showing the height of each wall, the elevation at the top and bottom of each wall, the materials to be used, a profile and cross-section of each wall, any proposed plantings, any safety barriers, the calculations of anticipated earth and hydrostatic pressures and surcharges, and the calculations detailing the design of each wall; and
3.
The limits of clearing and disturbance, which shall be held to be the maximum permitted on the site.
c.
Drainage plans and supporting computations for any storm drainage system, including the following information as may be required by the Borough Engineer:
1.
All existing or proposed storm sewer lines within or adjacent to the tract, showing the profile, size and slope of the lines, the direction of flow, and the location of each catch basin, inlet, manhole, culvert, headwall and utility line, including pipe sizes and grades;
2.
A map, drawn to scale (minimum scale one inch equals 100 feet, showing the contributing area to each inlet or cross drain;
3.
The weighted runoff coefficient for each drainage area that was utilized in the submitted computations; and
4.
A report by the design engineer containing the design criteria used, the alternates considered, the reasons for the final selections and the design calculations.
d.
Landscaping plans, indicating the following information:
1.
The proposed limits of disturbance of the subject site;
2.
All existing and proposed vegetation within the area to be disturbed; and
3.
A specific identification within the area to be disturbed of all individual trees or groups of trees which have a caliper of six inches or more measured three feet above the ground level, with an indication of which trees are to remain and which are to be removed.
e.
Any additional information that is deemed necessary by the Borough Engineer to evaluate the site conditions where the effects of the disturbance to the "steep sloped areas" may pose special problems for the tract and/or for the surrounding area.