§ 9652.13. General design and development standards.

Subject to the limitations of the underlying district, as it relates to potential uses and except as modified by the planning commission in a manner consistent with the purposes of this section, any development of a hillside area shall be in conformity with the following design and development standards:

A.

Dwelling density. The maximum number of dwelling units permitted on a parcel of land shall be determined according to the following table:

Percent Slope	Minimum Average Acreage per Dwelling Unit (in acres)
1. 10—15	0.50
2. 16—20	0.66
3. 21—25	1.00
4. 26—30	1.66
5. 31—35	2.50
6. 36—over	20.00

 

With respect to parcels of land five (5) acres or larger in size, the dwelling units shall be clustered on the flatter portions of such parcels when appropriate.

In the event that the foregoing density limitations would prohibit the use of a parcel of land otherwise permitted by this chapter, one (1) residential dwelling unit shall be permitted on such parcel provided that:

(a)

Such parcel was lawfully created prior to the adoption of this section; and

(b)

A change in ownership of such parcel occurring after the adoption of this section has not resulted in such parcel no longer being considered part of a larger parcel of land under this chapter; and

(c)

A private septic system will not be installed for any dwelling unit located on a parcel of land consisting of less than one (1) acre in area; and

(d)

A conditional use permit authorizing such dwelling unit is granted in accordance with the requirements of this section.

B.

Development area. For properties zoned residential or open space, a minimum percentage of a parcel of land shall remain in open space. The minimum percentage shall be determined based upon the following table:

Percent Slope	Minimum Percent of Parcel to Remain in Open Space
1. 10—15	32.5
2. 16—20	47.5
3. 21—25	62.5
4. 26—30	77.5
5. 31—35	92.5
6. Greater than    35	97.5

 

In the event that the foregoing open space limitations would prohibit the use of a parcel of land otherwise permitted by this chapter, one (1) residential dwelling unit shall be permitted on such parcel provided that:

(a)

Such parcel was lawfully created prior to the adoption of this section;

(b)

A change in ownership occurring after the adoption of this section has not resulted in such parcel no longer being considered part of a larger parcel of land under this chapter;

(c)

A private septic system will not be installed for any dwelling unit located on a parcel of land consisting of less than one (1) acre in area;

(d)

A conditional use permit authorizing such dwelling unit is granted in accordance with the requirements of this section. The terms of such conditional use permit shall specify the minimum percent of required open space on such parcel of land.

For properties zoned commercial and business park, the maximum allowable floor area ratio (ratio of square footage of building floor to square footage of lot) shall be determined based on the following table:

Percent Slope	Maximum Floor Area Ratio
10-15%	0.25
15.10%	0.2492
15.20%	0.2484
15.30%	0.2476
15.40%	0.2468
15.50%	0.246
15.60%	0.2452
15.70%	0.2444
15.80%	0.2436
15.90%	0.2428
16%	0.242
16.10%	0.2412
16.20%	0.2404
16.30%	0.2396
16.40%	0.2388
16.50%	0.238
16.60%	0.2372
16.70%	0.2364
16.80%	0.2356
16.90%	0.2348
17%	0.234
17.10%	0.2332
17.20%	0.2324
17.30%	0.2316
17.40%	0.2308
17.50%	0.23
17.60%	0.2292
17.70%	0.2284
17.80%	0.2276
17.90%	0.2268
18%	0.226
18.10%	0.2252
18.20%	0.2244
18.30%	0.2236
18.40%	0.2228
18.50%	0.222
18.60%	0.2212
18.70%	0.2204
18.80%	0.2196
18.90%	0.2188
19%	0.218
19.10%	0.2172
19.20%	0.2164
19.30%	0.2156
19.40%	0.2148
19.50%	0.214
19.60%	0.2132
19.70%	0.2124
19.80%	0.2116
19.90%	0.2108
20%	0.21
20.10%	0.2094
20.20%	0.2088
20.30%	0.2082
20.40%	0.2076
20.50%	0.207
20.60%	0.2064
20.70%	0.2058
20.80%	0.2052
20.90%	0.2046
21%	0.204
21.10%	0.2034
21.20%	0.2028
21.30%	0.2022
21.40%	0.2016
21.50%	0.201
21.60%	0.2004
21.70%	0.1998
21.80%	0.1992
21.90%	0.1986
22%	0.198
22.10%	0.1974
22.20%	0.1968
22.30%	0.1962
22.40%	0.1956
22.50%	0.195
22.60%	0.1944
22.70%	0.1938
22.80%	0.1932
22.90%	0.1926
23%	0.192
23.10%	0.1914
23.20%	0.1908
23.30%	0.1902
23.40%	0.1896
23.50%	0.189
23.60%	0.1884
23.70%	0.1878
23.80%	0.1872
23.90%	0.1866
24%	0.186
24.10%	0.1854
24.20%	0.1848
24.30%	0.1842
24.40%	0.1836
24.50%	0.183
24.60%	0.1824
24.70%	0.1818
24.80%	0.1812
24.90%	0.1806
25%	0.18
25.10%	0.1774
25.20%	0.1788
25.30%	0.1782
25.40%	0.1776
25.50%	0.177
25.60%	0.1764
25.70%	0.1758
25.80%	0.1752
25.90%	0.1746
26%	0.174
26.10%	0.1734
26.20%	0.1728
26.30%	0.1722
26.40%	0.1716
26.50%	0.171
26.60%	0.1704
26.70%	0.1698
26.80%	0.1692
26.90%	0.1686
27%	0.168
27.10%	0.1674
27.20%	0.1668
27.30%	0.1662
27.40%	0.1656
27.50%	0.165
27.60%	0.1644
27.70%	0.1638
27.80%	0.1632
27.90%	0.1626
28%	0.162
28.10%	0.1614
28.20%	0.1608
28.30%	0.1602
28.40%	0.1596
28.50%	0.159
28.60%	0.1584
28.70%	0.1578
28.80%	0.1572
28.90%	0.1566
29%	0.156
29.10%	0.1554
29.20%	0.1548
29.30%	0.1542
29.40%	0.1536
29.50%	0.153
29.60%	0.1524
29.70%	0.1518
29.80%	0.1512
29.90%	0.1506
30%	0.15
30.10%	0.1494
30.20%	0.1488
30.30%	0.1482
30.40%	0.1476
30.50%	0.147
30.60%	0.1464
30.70%	0.1458
30.80%	0.1452
30.90%	0.1446
31%	0.144
31.10%	0.1434
31.20%	0.1428
31.30%	0.1422
31.40%	0.1416
31.50%	0.141
31.60%	0.1404
31.70%	0.1398
31.80%	0.1392
31.90%	0.1386
32%	0.138
32.10%	0.1374
32.20%	0.1368
32.30%	0.1362
32.40%	0.1356
32.50%	0.135
32.60%	0.1344
32.70%	0.1338
32.80%	0.1332
32.90%	0.1326
33%	0.132
33.10%	0.1314
33.20%	0.1308
33.30%	0.1302
33.40%	0.1296
33.50%	0.129
33.60%	0.1284
33.70%	0.1278
33.80%	0.1272
33.90%	0.1266
34%	0.126
34.10%	0.1254
34.20%	0.1248
34.30%	0.1242
34.40%	0.1236
34.50%	0.123
34.60%	0.1224
34.70%	0.1218
34.80%	0.1212
34.90%	0.1206
35%	0.12
>35%	0.08

 

Pre-graded pads that existed prior to January 1, 1999 shall be exempted from the above maximum allowable floor area ratio limitations. The director of planning and community development has the discretion to exclude concave lots with an average slope greater than ten (10) percent from the above maximum floor area ratio limitations.

C.

Circulation.

1.

Streets within any project proposed in a hillside area shall be designed and constructed to accomplish the following purposes:

(a)

Minimize grading so as to compliment the natural features of the hillsides and reflect a rural rather than an urban character.

(b)

Permit safe and efficient travel for motor vehicles, bicycles and pedestrians, and to provide access for emergency vehicles.

2.

In order to accomplish the purposes of this subsection, all streets in a hillside area development shall be designed, where possible, to:

(a)

Parallel the natural contours and natural grades of the land. Streets running perpendicular to the grade of the slope shall be avoided, when feasible, to reduce grading and aid in drainage. When streets must cut across grade contours, the principle of grading shall be half cut/half fill at locations not visible to a large area. Bridges shall be provided when streets must cross drainage ways and ravines of exceptional environmental setting.

(b)

Use split level streets when access to abutting parcels of land is from other streets to avoid excess cut and fill and minimize scarring effects of hillside development.

(c)

Provide a minimum sight distance of one hundred fifty (150) feet for all horizontal and vertical curves. The minimum centerline curve radius on residential streets shall be one hundred (100) feet. Reversed curves shall be connected with tangents as long as practicable. All major streets shall be designed to incorporate curves greater than the minimum to provide for increased traffic flow.

(d)

Have a maximum centerline grade for streets of fifteen (15) percent except at intersections and areas of transition where the gradient shall be zero to two (2) percent. Maximum grade for major streets shall be less than twelve (12) percent. Changes in grade of more than five-tenths of one (1) percent shall be connected by vertical curves conforming to standard sight distances.

(e)

Provide adequate private off-street parking to minimize the need for parking on narrow hillside streets. Parallel parking on the hillside streets may be eliminated in order to reduce road width in critical areas in which even parking spaces shall be provided in off-street bays at more suitable locations.

(f)

Provide sidewalks and walkways in accordance with a pedestrian circulation plan that is not dependent upon and identical to the plan for vehicular circulation.

(g)

Provide bicycle and equestrian trails where appropriate.

(h)

Provide hillside public streets with street lighting designed to lessen the impact on views.

(i)

Discourage the protrusion of streets on ridgelines.

D.

View preservation. View preservation shall take into consideration existing residences, views from scenic roadways, and the freeways. Such provisions as increased setbacks to minimize mass, utilizing natural earth and berms to reduce prominence in viewshed, and the retention of natural land form features shall be used. In addition, viewshed in a hillside area shall be protected by:

1.

Facing dwelling units onto open, green or view areas;

2.

Locating dwelling units in such a manner as to avoid obstructing the view from other dwelling units;

3.

Locating structures with a minimum building setback of thirty (30) feet to the top of the slope, for properties zoned commercial or business park. Pre-graded pads which existed prior to January 1, 1999 shall be exempted from this provision.

E.

Fire protection. The following requirements shall apply in a hillside area:

1.

Clearance of brush or vegetative growth from the vicinity of structures and roadways shall be in accordance with the Fire Code and approved by the city;

2.

Roofs shall be of fire retardant material in accordance with the requirements of the Building Code. Block walls or other fire resistant walls shall be constructed between a dwelling and any adjacent areas of known fire hazard such as open space areas;

3.

All easements for firebreaks shall be dedicated in writing for this purpose and recorded with the Los Angeles County recorder;

4.

Special design restrictions shall apply in brush fire areas where narrow canyons act as chimneys, funneling hot winds up the canyons to the ridge. Stilt and cantilevered structures proposed to be constructed on canyon slopes shall be discouraged. Any single-family residential dwelling built on a ridge at the top of such a canyon shall be set back thirty (30) feet from the slope of the canyon rim.

F.

Erosion control.

1.

All manufactured slopes shall be planted or otherwise protected from the effects of storm runoff and erosion within thirty (30) days after completion of any grading. Such planting shall be designed to blend with the surrounding terrain and the character of development;

2.

The face of cut and fill slopes shall be prepared and maintained by the developer so as to control erosion until such time as the parcel of land is occupied. Such control measures may consist of effective planting or soil reinforcement. The protection for the slopes shall be installed as soon as practicable after the completion of any grading but in no event later than thirty (30) days thereafter;

3.

Other erosion devices, when necessary, such as check drains, debris basins, cribbing, or other devices or methods to control erosion and provide safety, shall be installed or implemented at the direction of the building official.

G.

Drainage control.

1.

All drainage and terracing in a hillside area shall meet or exceed the requirements of existing standards and codes;

2.

Drainage devices shall be placed on graded slopes as inconspicuously as possible. In addition:

(a)

Down drains shall be placed in swales;

(b)

Sides of any drain which are visible from a public way shall be concealed as much as possible. Vegetation landscaping also shall be used, when feasible, to conceal drains and terraces;

(c)

Concrete in any drain or terrace shall be tinted to blend with the landscape;

(d)

Drain slope gradients may become steeper as the drain moves down the slope. However, all drain gradients shall be approved by the city;

(e)

All drainage facilities shall be designed to carry water to the nearest practicable drainage way approved by the city;

(f)

Erosion shall be prevented by installation of nonerosive down drains or other drain devices;

(g)

Each building pad shall have a drainage gradient of at least two (2) percent toward the street or toward an approved engineered drainage facility;

(h)

Interceptor drains shall be installed along the top of all cut slopes where the tributary drainage area slopes toward the cut, and has a drainage path greater than forty (40) feet measured horizontally. Interceptor drains shall be paved with a minimum of three (3) inches of reinforced concrete or gunite, be at least one (1) foot in depth and at least thirty (30) inches in width. All slopes of drain terraces and interceptor drains, shall be approved by the building official;

3.

Streets and sidewalk drains shall be designed to contain and control the one-hundred-year frequency storm including debris production in accordance with the Los Angeles County flood control district design manual and to be usable during the maximum design storm. All developed properties shall drain toward the street or a storm drain;

4.

Terracing for cut and fill slopes shall be in conformance with the provisions of the city's grading ordinances and the following:

(a)

Terraces at least eight (8) feet wide shall be constructed on all cut and fill slopes that are twenty-five (25) feet or less in height, in order to control surface drainage and debris. Where only one (1) terrace is required, however, it shall be at midheight of the slope.

(b)

If higher slopes are ever permitted by whatever method, the following shall be permitted: cut or fill slopes of greater than twenty-five (25) feet and less than one hundred (100) feet in vertical height shall be constructed with a minimum of one (1) terrace of not less than twelve (12) feet in width at midheight of the slope. The spacing and width of terraces on cut or fill slopes greater than one hundred (100) feet in height shall be designed by a civil engineer.

(c)

All swales or ditches located on a terrace shall be a minimum of one (1) foot in depth and a minimum of five (5) feet in width and shall have a gradient of between four (4) percent and twelve (12) percent. Every swale and ditch shall be paved with concrete not less than three (3) inches thick reinforced with six-inch by six-inch, ten-gauge welded wire fabric or equivalent reinforcement.

(d)

A single runoff swale or ditch shall not collect runoff from a contributing area in excess of thirteen thousand five hundred (13,500) square feet without discharge into a structured downdrain system.

(e)

Subsurface drainage of cut and fill slopes shall be required if in the opinion of a geologist and/or soil engineer such drainage is necessary.

(f)

Subdrains shall be designed and constructed when fill is to be placed in natural drainage courses or in other areas where seepage is evident.

H.

Ridgelines. The development of primary and secondary ridgelines as specified in the city's general plan shall be discouraged. This prohibition shall include, all buildings, solid fencing or walls, paved roads, exotic landscaping, water tanks, and the like which would noticeably detract from the natural skyline.

I.

Building Design.

1.

Architectural enrichments and variations in roof massing are encouraged. Roofs shall minimize their visual impact by keeping a low profile and the roof pitch shall follow the slope of the hillside instead of being perpendicular to the hillside or opposing the hillside slope. Upper stories should not be cantilevered out in the opposite direction of the hillside slope.

2.

Avoid large expanses of a single material on walls, roofs, or paving areas. Create interesting, small scale patterns by breaking up building mass, varying building materials, and through design and placement of windows and doors.

3.

Provide architectural treatment to all sides of a structure. Elements of architectural treatment used on the front facade shall be repeated on all sides of a structure with additional emphasis on those elevations visible from adjacent properties or public rights-of-way.

4.

Building materials and color schemes shall blend with the natural landscape. Colors shall be earth tones and the specific hues shall be compatible with the surrounding natural environment.

J.

Landscaping.

1.

Native or naturalized plants, or other plant species that blend naturally with the landscape shall be used.

2.

Natural landform planting shall be used to soften the impact of development and provide erosion control. These landscape techniques shall serve to reintroduce landscape patterns that occur in nature including concentrating trees and shrubs in concave areas while convex portions are planted mainly with ground cover.

3.

Trees and shrubs are to be arranged in informal masses and shall be placed selectively to reduce the scale of long, steep slopes.

4.

Berming shall be incorporated into the grading plans to help soften the appearance of buildings from public view.

(Ord. No. 99-293, § 2, 2-10-99; Ord. No. 11-388, § 55, 12-14-2011)