SEC. 91.7012. PLANTING AND IRRIGATION OF CUT AND FILL SLOPES IN HILLSIDE AREAS.

   (Amended by Ord. No. 181,758, Eff. 8/8/11.)

91.7012.1. General. All fill and cut slopes in designated hillside areas shall be planted and irrigated to promote the growth of ground cover plants to protect the slopes against erosion, as required in this Section.

   The owner shall be responsible for planting and maintaining all slopes where such is required in this Section.

   Planting and irrigation shall comply with the provisions of LAMC Sections 12.40, 12.41 and 12.42. (Amended by Ord. No. 185,587, Eff. 7/16/18.)

91.7012.2. Minimum Requirements.

91.7012.2.1. Low Slopes to 15 Feet (4572 mm) in Vertical Height. Slopes with vertical height of less than 15 feet (4572 mm) shall comply with the following:

   1.   Plant with grass or ground cover plants.

   2.   An irrigation system shall be installed to irrigate these slopes.

   3.   The owner shall water the slopes which have been planted with grasses and/or ground cover plants at sufficient time intervals to promote growth.

   EXCEPTION: Where the Department finds the slope is located in such an area as to make hand watering possible, conveniently located hose bibs will be accepted in lieu of the required irrigation system when a hose no longer than 50 feet (15 240 mm) would be necessary.

91.7012.2.2. Slopes over 15 Feet (4572 mm) in Vertical Height. Slopes with vertical height over 15 feet (4572 mm) shall comply with the following:

   1.   Plant with grass or ground cover plants.

   2.   In addition to grass or ground cover plants, approved shrubs having a one gallon minimum size shall be planted on the slope at 10 feet (3048 mm) on center in both directions or trees at 20 feet (6096 mm) on center in both directions. A combination of shrubs and trees may be utilized. The plants and planting pattern may be varied on the recommendation of the landscape architect.

   3.   Install an adequate irrigation system during grading prior to planting of the shrubs and trees and before grading is approved.

91.7012.3. Special Requirements for Sprinkler Systems.

91.7012.3.1. Plans for the sprinkler system shall be submitted to and approved by the Department prior to installation.

91.7012.3.2. Irrigation systems shall be designed to provide a uniform water coverage at a rate of precipitation of not more than 3/10 inch (7.6 mm) per hour on the planted slope. In no event shall the duration of sprinkling be permitted such as to create a saturated condition and cause an erosion problem, or allow the discharge of excess water into any public or private street.

91.7012.3.3. A check valve and balance cock shall be installed in the system where the drainage from sprinkler heads will create an erosion problem.

91.7012.3.4. Adequate backflow protection shall be installed in each irrigation system as required by the Plumbing Code.

91.7012.3.5. A functional test of the irrigation system shall be performed by the installer for every sprinkler system prior to approval.

91.7012.3.6. Where PVC pipes are used on slopes, they shall be a minimum of schedule 40 and embedded at least eight inches (203 mm) below grade. Such pipes may be exposed for above ground installations provided they are ASTM rated as resistant to ultraviolet sunlight. All risers, sprinkler heads, valves and fittings shall be brass or galvanized metal, or rated as sunlight resistant.

91.7012.4. Plants. All plants required by this Section shall be selected with consideration given to deep-rooted plants needing limited watering, low maintenance and having fire-retardant characteristics.