Oakland City Zoning Code
§ 59-66.3
Steep Slopes.
[Added 12-19-1990 by Ord. No. 90-Code-191]
A.
Statement of purpose. It is the express purpose of this section to provide for special qualitative and quantitative development controls for all lands located within the Borough of Oakland which have present within their boundaries topographical conditions, hereinafter defined as "Steep Slopes."
These special development controls are provided in recognition of the potentially negative impacts of construction in steep slope areas in the form of erosion, siltation, excessive removal of vegetation and soil, flooding soil slippage, water runoff, and destruction of unique land forms and predominant views. It is further the purpose of this section to encourage good land use planning and design and to maximize the best use of the natural terrain and maintain ridge lines and skylines intact.
Effective and reasonable application of these regulations will protect the health, safety, and welfare of the citizens of the Borough of Oakland.
This section is further promulgated to provide a functional land use design and control mechanism which will augment the basic land use controls of the zoning ordinance and the administrative implementing devices contained within the borough's site plan and subdivision ordinance.
B.
Applicability. The requirements, guidelines, and controls promulgated under this section shall be applicable to all properties within all zone districts situated in the Borough of Oakland in their existing physical state or condition as of the date of the passage of this section. Said applicability shall apply only to new construction where said properties fall within a 15% or greater slope area, except as provided for in subsection E. This section shall further apply to building reconstruction where over 50% of any structure on a property or parcel of land is destroyed by fire or other natural occurrence or as a result of redevelopment and the entire footprint of said structure falls within a 15% or greater slope area.
C.
Definitions.
(1)
STEEP SLOPE — Steep slopes are defined to include slopes in excess of 115% in gradient as measured and documented in accordance with the "Slope Measurement Criteria" definition.
(2)
SLOPE MEASUREMENT CRITERIA — The following "Slope Measurement Criteria" shall serve as the basic means of identifying and categorizing "Steep Slopes" as further regulated under this section.
(a)
VERTICAL MEASUREMENT — Vertical measurement shall be determined utilizing two foot contours as documented and determined by on-site survey or the use of photogrammetric aerial topography.
(b)
HORIZONTAL MEASUREMENT — Horizontal measurement shall be determined by use of an appropriate scale as required by Borough Site Plan or Subdivision Ordinance measuring a minimum horizontal section 30 feet in length.
(c)
APPLICATION OF VERTICAL AND HORIZONTAL MEASUREMENTS — The vertical and horizontal measurements are utilized to determine the slope by measuring the vertical rise on the basis of two foot contours in a thirty-foot horizontal length.
(3)
DISTURBANCE — Disturbance shall be defined as any physical activity which results in removal of vegetation, modification of topography by cutting or filling, stripping of top soil, and/or placing of physical structures or improvements thereon.
(4)
PERMITTED DENSITY — Permitted density shall be based upon the minimum required lot areas and maximum allowed building coverage as provided in Section 59-47 Lot Area and Bulk Regulations of the Borough of Oakland Zoning Ordinance.
(5)
ADJUSTED DENSITY — Adjusted density shall be a function of the application of the following density control criteria as applied to slope characteristics determined in accordance with slope measurement criteria.
(6)
DENSITY CONTROL CRITERIA — Density control criteria shall be those criteria set forth in subsection D of this section.
(8)
GRADING — Any disturbance of the original grade by stripping, cutting, filling, stockpiling, or any combination thereof.
(9)
TRANSITIONAL GRADING — The disturbance in that area of land between the original grade and the finished grade to accommodate roads, parking areas, structures, and other like improvements.
D.
Density control criteria and computations.[1] To meet the purposes, goals, and standards set forth in this section, the applicable provisions of the Zoning Ordinance relating to minimum lot sizes, density, and building coverage "permitted density" of development shall be modified in areas of slopes greater than 15%.
(1)
The maximum disturbance allowed shall be determined by multiplying the total land area in various slope categories by the following limiting factors:
Slopes (percent) | Factor | Disturbance Allowed |
|---|---|---|
35% or greater | 0 | No disturbance allowed |
25.0 - 34.9% | 0.3 | Only transitional grading |
15.0 - 24.9% | 0.5 | Only transitional grading or road construction |
0.0 - 14.9% | 1.0 | All construction allowed |
(2)
The maximum number of dwelling units allowed on any tract shall be computed as follows:
Application of Slope Criteria |
(Land with 35% or more slopes x 0) |
+ (Land with 25.0 to 34.9% slopes x 0.3) |
+ (Land with 15.0 to 24.9% slopes x 0.5) |
+ (Land with 0 to 14.9% slopes) |
= Total Land Area available for Development (TLD) which shall include areas for building lots, road easements, water retention and/or detention, wetlands, flood plains, and other such improvements/restrictions |
[1]
Editor's Note: For examples of computation for density control, see Appendices A and B, included as attachments to this chapter.
E.
Construction control limitations. Only the following uses and physical development activities shall be allowed as set forth below:
Slope Category | Grading Limitations | Activity Allowed |
|---|---|---|
0.0% - 14.9% | 100% | All construction allowed |
15.0 - 24.9% | 50% | Only transitional grading or road construction |
25.0 - 34.9% | 30% | Only transitional grading |
35.0% and above | 0% | No disturbance allowed |
F.
Exemptions. All existing developed structures shall be exempt from this section, except as provided for in Subsection B.
G.
Soil moving. Nothing herein shall be construed to affect the provisions of the Borough of Oakland's Soil Moving Ordinance.
H.
Planning Board jurisdiction and variances. Nothing in this section shall be construed to limit the jurisdiction of the Planning Board or Zoning Board of Adjustment over site plan approval or to grant variances or waivers in accordance with the Municipal Land Use Law as amended.