501.06: GRADING: — Porterville Zoning Code

A. General Grading Requirements:

Landform grading techniques such as varying slope height, rounding tops and toes of slopes, and incorporating variable gradients shall be used to ensure that manufactured slopes mimic natural hill forms. Landform grading shall be used for all postdisturbance conditions unless determined by the zoning administrator and the city engineer that landform grading is not feasible due to soils conditions, encroachment into sensitive biological resource areas, protection of watersheds or

watercourses, or other similar considerations. Findings shall be recorded as part of the hillside development permit record as to why landform grading is not feasible. Grading shall be kept to a minimum and shall be preformed in a way that preserves significant natural features and visually blends with adjacent properties. Factors to be considered include the natural features of the site, slope and soil characteristics, vegetative cover, access to the site and orientation and visibility of both the site and the proposed development.

FIGURE 501.06A1: GRADING

Construction of artificial ridgelines shall be used to mask the view of dwelling from off site locations, to preserve the appearance of a natural undeveloped hillside, and to preserve the appearance of open space.
A combination of berming and landscaping shall be used to screen utilitarian features such as, but not limited to, water tanks and detention basins.
Slopes which are readily visible from existing or proposed public right of way shall be landform graded.
Grading of any site shall conform to the following grading standards, based upon the percent of average slope:

a. Six (6) to fifteen percent (15%): Redistribution of earth over large areas may be permitted.
b. Fifteen (15) to twenty percent (20%): Some grading may occur, but landforms shall retain their natural character.
Padded building sites may be allowed, but custom foundations, split level designs, stacking and clustering are expected to mitigate the need for large padded building areas.
c. Twenty (20) to twenty five and nine-tenths percent (25.9%): Grading will be minimal, custom homes sites and access shall follow the natural slope of the ground, custom foundations and split level design required to reduce disturbance.
d. Twenty six percent (26%) and steeper: No grading shall be allowed other than house pad and access to pad.
e. Minimize pad size to accommodate the structure and a reasonable amount of open space. A maximum of the remaining lot area shall be kept in the natural state of the original slope.
f. Sloping lot designs, such as split level building terraces are encouraged to reduce pad size.
g. Minimize grading within twenty feet (20') of all perimeter property lines of the project site, unless the grading naturally conforms to the existing adjacent slopes or to the planned grading of the adjacent slopes.
B. Prohibited Grading Practices:

The cutting of significant ridgelines is prohibited.
Graded slopes that are characterized by linear (in plan), planar slope surfaces with unvarying gradients and angular slope intersections are prohibited.
Manufactured slopes shall complement the adjacent natural slopes in terms of hill form and slope height.

C. Berming:

Any berm three feet (3') or greater in vertical height shall be landform graded no steeper than three to one (3:1).
All berms shall have varying slope gradients and rounded tops with a horizontal dimension half the vertical height of the berm.
A combination of berming and landscaping shall be used to screen utilitarian features such as, but not limited to, water tanks and detention basins.
Landscaping materials used on berms shall be drought tolerant and fire resistant and must be approved by the parks and leisure services director.

FIGURE 501.06C: BERMING

D. Slopes Between Residential Pads: Where there is at least a four foot (4') elevation difference between residential flat pads, slopes shall be contour graded no steeper than two to one (2:1).

FIGURE 501.06D: SLOPES BETWEEN RESIDENTIAL PADS

E. Road Systems Along Project Edges: Road systems shall be placed along project edges to the greatest extent practicable to maximize the use of aesthetic landscape buffers surrounding a development and to buffer residential neighborhoods from vehicular traffic. Project edges along roadway systems shall consist of varied slope and landscape treatments to provide visual interest.

FIGURE 501.06E: ROAD SYSTEMS ALONG PROJECT EDGES

F. Use Of Loffelstein And Similar Living Walls: The use of Loffelstein walls and other similar living wall systems that allow for landscaping opportunities with planting pockets and stepped designs is required. Such wall shall be subject to the following development standards:

The minimum height shall be fifteen feet (15'), with a maximum height of thirty feet (30').
Such walls shall utilize a curvilinear slope pattern to mimic the appearance of natural hillside terrain.
Such walls shall be planted with landscape material suitable for the climate, wall exposure relative to the sun, and taking into consideration the landscape aesthetic effect to be achieved by the overall development. The color palette and materials selected for the retaining wall shall blend in with adjacent hillsides and landscape plant palette. FIGURE 501.06F: USE OF LOFFELSTEIN AND SIMILAR LIVING WALLS

G. Contour Construction And Materials: Retaining walls shall follow the natural contours of the slope to the greatest degree practicable, and all materials used to construct retaining walls shall consist of native stone, poured in place concrete, precast concrete block, and shall be of a color and texture that mimic the color and texture of surrounding native plant materials.

H. Retaining Wall Height Standards: The cumulative height of any retaining wall built to retain a cut slope or fill slope shall not exceed six feet (6') in height. "Cumulative height" shall mean the combined height of any wall or series of walls required to retain a single slope. (Ord. 1801, 12-3-2013)