§ 26.40

The State Legislature has found that the limited supply of State waters is subject to ever increasing demands; that California's economic prosperity depends on adequate supplies of water; that State policy

promotes conservation and efficient use of water; that landscapes provide recreation areas, clean the air and water, prevent erosion, offer fire protection, and replace ecosystems displaced by development; and that landscape design, installation, and maintenance can and should be water efficient.

The purpose of this chapter is to promote the values and benefits of landscapes while recognizing the need to invest water and other resources as efficiently as possible; establish a structure for designing, installing, and maintaining water efficient landscapes in new projects; and establish provisions for water management practices and water waste prevention for established landscapes.

(Ord. No. 1924, § I, 11-16-92)

For the purpose of this chapter, the following words and phrases are defined and shall be construed as set forth in this section.

(1)

Antidrain valve or check valve: A valve located under a sprinkler head to hold water in the system so it minimizes drainage from the lower elevation sprinkler heads.

(2)

Application rate: The depth of water applied to a given area, usually measured in inches per hour.

(3)

Applied water: The portion of water supplied by the irrigation system to the landscape.

(4)

Automatic controller: A mechanical or solid state timer, capable of operating valve stations to set the days and length of time of a water application.

(5)

Backflow prevention device: A safety device used to prevent pollution or contamination of the water supply due to the reverse flow of water from the irrigation system.

(6)

Conversion factor (0.62): A number that converts the maximum applied water allowance from acre-inches per acre per year to gallons per square foot per year. The conversion factor is calculated as follows:

325,829 gallons/43,560 square feet/12 inches = (0.62)

325,829 gallons = 1 acre-foot

43,560 square feet = 1 acre

12 inches = 1 foot

To convert gallons per year to 100 cubic feet per year, another common billing unit for water, divide gallons per year by 748. (748 gallons = 100 cubic feet)

(7)

Director of Parks, Forestry and Maintenance Services: The Director of Parks, Forestry and Maintenance Services or the Director's designee.

(8)

Ecological restoration project: A project where the site is intentionally altered to establish a defined, indigenous historic ecosystem.

(9)

Effective precipitation or usable rainfall: The portion of total precipitation that is used by the plants. Precipitation is not a reliable source of water but can contribute to some degree toward the water needs of the landscape. For the purpose of this document, "effective precipitation" is twenty-five (25) percent of local annual mean precipitation.

(10)

Emitter: Drip irrigation fittings that deliver water slowly from the system to the soil.

(11)

Established landscape: The point at which plants in the landscape have developed roots into the soil adjacent to the root ball.

(12)

Establishment period: The first year after installing the plant in the landscape.

(13)

Estimated applied water use: The portion of the estimated total water use that is derived from applied water. The estimated applied water use shall not exceed the maximum applied water allowance. The estimated applied water use may be the sum of the water recommended through the irrigations schedule as referenced in section 26.40.030(3).

(14)

Estimated total water use: The annual total amount of water estimated to be needed to keep the plants in the landscaped area healthy. It is based upon such factors as the local evapotranspiration (ET) rate, the size of the landscape area, the types of plants, and the efficiency of the irrigation system, as described in section 26.40.030(4).

(15)

ET adjustment factor: A factor of 0.8, that, when applied to reference evapotranspiration, adjusts for plant factors and irrigation efficiency, two (2) major influences upon the amount of water that needs to be applied to the landscape.

A combined plant mix with a site-wide average of 0.5 is the basis of the plant factor portion of this calculation. The irrigation efficiency for purpose of the ET Adjustment Factor is 0.625.

(16)

Flow rate: The rate at which water flows through pipes and valves (gallons per minute or cubic feet per second).

(17)

Hydrozone: A portion of the landscaped area having plants with similar water needs that are served by a valve or set of valves with the same schedule. A hydrozone may be irrigated or nonirrigated. For example, a naturalized area planted with native vegetation that will not need supplemental irrigation once established is a nonirrigated hydrozone.

(18)

Infiltration rate: The rate of water entry into the soil expressed as a depth of water per unit of time (inches per hour).

(19)

Irrigation efficiency: The measurement of the amount of water beneficially used divided by the amount of water applied. Irrigation efficiency is derived from measurements and estimates of irrigation system characteristics and management practices. The minimum irrigation efficiency for purposes of this ordinance is 0.625. Greater irrigation efficiency can be expected from well designed and maintained systems.

(20)

Landscape irrigation audit: A process to perform site inspection, evaluate irrigation systems, and develop efficient irrigation schedules.

(21)

Landscape area: The entire parcel less the building footprint, driveways, nonirrigated portions of the parking lots, hardscape such as decks and patios, and other nonporous areas. Water features are included in the calculation of the landscaped area. Areas dedicated to edible plants such as orchards or vegetable gardens are not included.

(22)

Lateral line: The water delivery pipeline that supplies water from the water source to the valve or outlet.

(23)

Main line: The pressurized pipeline that delivers water from the water source to the valve or outlet.

(24)

Maximum applied water allowance: For design purposes, the upper limit of annual applied water for the established landscape areas described in section 26.40.030(2). It is based upon the area's reference evapotranspiration, the ET adjustment factor, and the size of the landscape area. The estimated applied water use shall not exceed the maximum applied water allowance.

(25)

Mined land reclamation projects: Any surface mining operation with a reclamation plan approved in accordance with the Surface Mining and Reclamation Act of 1975.

(26)

Mulch: Any material such as leaves, bark, straw, or other materials left loose and applied to the soil surface to reduce evaporation.

(27)

Operating pressure: The pressure at which a system of sprinklers is designed to operate, usually indicated at base of sprinkler.

(28)

Overspray: The water which is delivered beyond the landscape area, wetting pavements, walks, structures, or other nonlandscaped areas.

(29)

Plant factor: A factor that when multiplied by reference evapotranspiration, estimates the amount of water used by plants. For purposes of this ordinance, the average plant factor of low water-using plants range from 0 to 0.3, for average water-using plants the range is 0.4 to 0.6, and for high water-using plants the range is 0.7 to 1.0.

(30)

Rain sensing device: A system which automatically shuts off the irrigation system when it rains.

(31)

Record drawing or as-builts: A set of reproducible drawings which show significant changes in the work made during construction and which are usually based on drawings marked up in the field and other data furnished by the contractor.

(32)

Recreational area: Areas of active play or recreation such as sports fields, school yards, picnic grounds, or other areas with intense foot traffic.

(33)

Recycled water, reclaimed water, or treated sewage effluent water: Treated or recycled wastewater of a quality suitable for nonpotable uses such as landscape irrigation; not intended for human consumption.

(34)

Reference evapotranspiration or ETo: A standard measurement of environmental parameters which affect the water use of plants. ETo is given in inches per day, month, or year and is an estimate of the evapotranspiration of a large field of four- to seven-inch tall, cool-season grass that is well watered. Reference evapotranspiration is the maximum applied water allowance so that regional differences in climate can be accommodated.

(35)

Rehabilitated landscape: Any relandscaping project that requires a permit.

(36)

Runoff: Water which is not absorbed by the soil or landscape to which it is applied and flows from the area. For example, runoff may result from water that is applied to too great a rate (application rate exceeds infiltration rate) or when there is a severe slope.

(37)

Soil moisture sensing device: A device that measures the amount of water in the soil.

(38)

Soil texture: The classification of soil based on the percentage of sand, silt, and clay in the soil.

(39)

Sprinkler head: A device which sprays water through a nozzle.

(40)

Static water pressure: The pipeline or municipal water supply pressure when water is not flowing.

(41)

Station: An area served by one valve or by a set of valves that operate simultaneously.

(42)

Turf: A surface layer of earth containing mowed grass with its root. Annual bluegrass, Kentucky bluegrass, perennial ryegrass, red fescue, and tall fescue are cool-season grasses. Bermuda grass, Kikuygrass, Seashore paspalum, St. Augustine grass, Zoysia grass, and Buffalo grass are warm-season grasses.

(43)

Valve: A device used to control the flow of water in the irrigation system.

(44)

Water conservation concept statement: A one-page checklist and a narrative summary of the project as shown in section 26.40.030(1).

(Ord. No. 1924, § I, 11-16-92)