§ 98-98. Plant selection.

(a)

Water use criteria. All landscapes shall comply with the following water use criteria:

(1)

The maximum amount of water that can be applied per year to any landscape shall average no greater than 30 inches of supplemental water.

(2)

The planted area shall balance the water demands of different plant species to create an overall landscape which requires a moderate amount of water. For design purposes, planting area shall be defined as low use, medium use, or high use areas. Refer to section 98-102 for a list of low, medium and high use plants. Water use values in table I reflect the relative water use of each type of planting area. To check a landscape design for compliance, multiply the water use value by its respective planting area.

Example: Assume a two-acre landscape plan consists of 20 percent high use plants (turf), 50 percent medium use plants, and 30 percent low use plants.

20% (2 acres)	0.40 acres × 1.6 =   0.64
50% (2 acres)	1.0 acres × 1.0 =   1.00
30% (2 acres)	0.60 acres × 0.4 =  0.24 / 1.88 - 2

 

Since the sum of the water use factors is less than the area (two acres), the design is acceptable. If the sum of the water use factors exceeded two, the design would not be acceptable, and the designer would be required to substitute some high use species with low or medium use species to reduce the sum of water use factors to two or less.

TABLE I

Planting Type	Water Use Values
Low use	0.40
Medium use	1.0
High use (includes turf and water bodies)	1.6

 

Water use calculations including plant key and planting area shall be shown on the planting plan according to the format in the following example:

Assume a landscape design involves 2,600 square feet of planting area. The planting plan consists of 600 square feet of Cistus purpureus (CP), 600 square feet of Nerium oleander (NO), 400 square feet of Pittosporum tobira (PT), Juniperus horizontals (JH), and Liquidambar styraciflue (LS), and 1,000 square feet of turf.

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WATER USE CALCULATION

Water Use	Plant Key	Square Feet	Water Use Factor (Total Sq. Ft. × Use Value)
Low	CP NO	600 600	1,200 × 0.4 = 480
Medium	PT, JH and LS	400	400 × 1.0 = 400
High	Turf	1,000	1,000 × 1.6 = 1,600 / 2,480
		2,600

 

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(b)

Turf selections and use. Turf selections and use shall be in accordance with the following:

(1)

Turf shall not be permitted in planted areas ten feet or less in width or in median strips.

(2)

Under no circumstances shall turf be installed on slopes greater than 20 percent. The toe of any sloping section shall be a minimum of 24 inches behind a curb or sidewalk.

(3)

Turf areas which exceed 2,500 square feet are required to use soil moisture sensors and rain shutoff devices as a part of the irrigation system. Device type and installation shall be per the manufacturer's recommendations.

(4)

Turf shall not be installed within ten feet of the dripline of native oak trees.

(5)

Turf shall be of a variety well suited to the local climate (i.e., tall fescue).

(c)

Nonturf selections. Nonturf selections shall be in accordance with the following:

(1)

Plants selected for use in nonturf areas should be well suited or adaptable to the climate of this region. Plants shall be grouped according to their water needs and irrigated separately. Species of different water needs may be grouped (i.e., low with medium and medium with high) but the highest water use value of the two shall be used to determine compliance with this division. Low and high use species may not be used in the same irrigation area. To use species other than those listed in section 98-102, the designer may provide the city with information indicating the water requirement of the species. Information may include the listing of a plant in an acceptable reference (see section 98-102) stating its water requirement characteristics, comparing it to a species in the plant list, field data, etc.

(2)

A minimum of three inches of an organic mulch shall be placed in shrub areas on the soil surface after planting. Nonporous materials shall not be placed under the mulch.

(Ord. No. 97-01, § 2(14.10.080), 1-2-1997; Ord. No. 97-13, § 2, 3-26-1997; Ord. No. 97-17, § 2, 9-24-1997)