Definitions. The following definitions are established for the purpose of this article. A complete list of WELO definitions is included in the Town's Landscape Guidelines. The meaning and construction of words and phrases is as follows:
Applied watermeans the water supplied by the irrigation system to the landscape.
Certified professionalmeans a certified irrigation designer, certified landscape irrigation auditor, licensed landscape architect, licensed landscape contractor, licensed professional engineer, or any other person authorized by the state to design a landscape, an irrigation system, or authorized to complete a water budget.
Established landscapemeans the point at which plants in the landscape area have developed significant root growth into the soil. Typically, most plants are established after one or two years of growth.
Estimated total water use (ETWU)means the total water used for the landscape as calculated in subsection (d) of this section, "Water Efficient Landscape Worksheet."
ET adjustment factor (ETAF)means a factor of 0.55 for residential areas and 0.45 for non-residential areas, that when applied to reference evapotranspiration, adjusts for plant factors and irrigation efficiency. The ETAF for new and existing (non-rehabilitated) special landscape areas shall not exceed 1.0. The ETAF for existing non-rehabilitated landscapes is 0.8.
Evapotranspiration (ET) ratemeans the quantity of water evaporated from adjacent soil and other surfaces and transpired by plants during a specified time.
Graywatermeans untreated wastewater that has not been contaminated by any toilet discharge, has not been affected by infectious, contaminated, or unhealthy bodily wastes, and does not present a threat from contamination by unhealthful processing, manufacturing, or operating wastes. Graywater includes, but is not limited to, wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs, but does not include wastewater from kitchen sinks or dishwashers.
Hydrozonemeans a portion of the landscaped area having plants with similar water needs and rooting depth. A hydrozone may be irrigated or non-irrigated.
Invasive plant speciesmeans species of plants not historically found in California that spread outside cultivated areas and can damage environmental or economic resources. Lists of invasive plants are maintained at the California Invasive Plant Inventory and USDA invasive and noxious weeds database.
Irrigation auditmeans an in-depth evaluation of the performance of an irrigation system conducted by a certified professional. An irrigation audit includes, but is not limited to: inspection, system tune-up, system test with distribution uniformity or emission uniformity, reporting overspray or runoff that causes overland flow, and preparation of an irrigation schedule. The audit must be conducted in a manner consistent with the Irrigation Association's Landscape Irrigation Auditor Certification Program or other U.S. Environmental Protection Agency "WaterSense" labeled auditing program.
Irrigation efficiency (IE)means 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 average irrigation efficiency for purposes of this section are 0.75 for overhead spray devices and 0.81 for drip systems.
Irrigation surveymeans an evaluation of an irrigation system that is less detailed than an irrigation audit and includes, but is not limited to: inspection, system test, and written recommendations to improve performance of the irrigation system.
Landscape area (LA)means all the irrigated planting areas, turf areas and water features in a landscape design plan subject to the maximum applied water allowance calculation.
Landscape projectmeans the total area comprising the proposed irrigated landscape area, as defined in this section.
Landscape water metermeans an inline device installed at the irrigation supply point that measures the flow of the water into the irrigation system and is connected to a totalizer to record water use.
Local water purveyormeans any entity, including a public agency, city, county, district or private water company that provides retail water service.
New constructionmeans the construction of a new building or structure containing a landscape or other new land improvement, such as a park, playground, or greenbelt without an associated building.
Nonresidential landscapemeans landscapes in commercial, institutional, and public settings that may have areas designated for recreation or public assembly.
Overspraymeans the irrigation water which is delivered beyond the target area.
Parcel water budget (PWB)means the upper limit of annual applied water purchased from the local water purveyor for the parcel as specified in subsection (c) of this section, "Parcel Water Budget."
Permitmeans an authorizing document issued by local agencies for the installation of new or rehabilitated landscapes.
Perviousmeans any surface or material that allows the passage of water through the material and into the underlying soil.
Plant factor or plant water use factoris a factor, when multiplied by ETo, estimates the amount of water needed by plants. The plant factor range for very low water use plants is 0.0 to 0.1, the plant factor range for low water use plants is 0.1 to 0.3, the plant factor range for moderate water use plants is 0.4 to 0.6, and the plant factor range for high water use plants is 0.7 to 1.0.
Project applicantmeans the individual or entity requesting a permit or plan check from the Town. A project applicant may be the property owner or designee.
Reference evapotranspiration or ETomeans a standard measurement of environmental parameters which affect the water use of plants. ETo is expressed 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. The ETo for Los Altos Hills, based on the state's reference evapotranspiration table, is 43.0.
Runoffmeans water which is not absorbed by the soil or landscape to which it is applied and flows from the irrigated landscape area.
Special landscape area (SLA)means an area of the landscape dedicated solely to edible plants, recreation areas, areas irrigated with recycled water, or water features using recycled water.
Turfmeans a ground cover surface of mowed grass. Annual bluegrass, Kentucky bluegrass, Perennial ryegrass, Red fescue, and Tall fescue are cool-season grasses. Bermuda grass, Kikuyu grass, Seashore Paspalum, St. Augustine grass, Zoysia grass, and Buffalo grass are warm-season grasses.
Water featuremeans a design element where open water performs an aesthetic or recreational function. Water features include ponds, lakes, waterfalls, fountains, artificial streams, spas, and swimming pools (where water is artificially supplied). The surface area of water features are included in the high water use hydrozone of the landscape area. Constructed wetlands that are not irrigated and stormwater retention basins are not water features.
WUCOLSmeans the Water Use Classification of Landscape Species published by the University of California Cooperative Extension and the Department of Water Resources in 2014.