1. (a) The terms used in this model ordinance have the meaning set forth below:

   1. (1) “applied water” means the portion of water supplied by the irrigation system to the landscape.
   2. (2) “applicant signature” means the signature of the property owner or their designee.
   3. (3) “application rate” or “precipitation rate” means the rate at which an irrigation system applies water to a given area by an emission device(s), it is usually expressed as depth or volume per unit time (i.e., inches per hour or gallons per hour). Application rate is generally used with drip irrigation while precipitation rate is generally used with overhead irrigation.
   4. (4) “automatic irrigation controller” means a timing device with stations that can be used to remotely control valves that operate an irrigation system. For the purposes of this model ordinance, automatic irrigation controllers are able to self-adjust and schedule irrigation events using either evapotranspiration (weather-based) or soil moisture (sensor-based) data.
   5. (5) “backflow prevention device” means a safety device required by the California Plumbing Code (California Code of Regulations, Title 24, Part 5, Chapter 6) used to prevent pollution or contamination of the water supply due to the reverse flow of water from the irrigation system.
   6. (6) “Certificate of Completion Package” means the document with the required elements pursuant to Section 494.
   7. (7) “certified landscape irrigation auditor” means a person certified to perform landscape irrigation audits by an accredited academic institution, a professional trade organization or other program labeled by the US Environmental Protection Agency's WaterSense professional certification program, July 2014, which is herein incorporated by reference.
   8. (8) “check valve” or “anti-drain valve” means a valve used in a pipeline or emission device that holds water in the system to prevent drainage from emission devices when the system is off.
   9. (9) “common interest developments” means community apartment projects, condominium projects, planned developments, and stock cooperatives per Civil Code section 4100 and applies to this model ordinance when there is a separate interest coupled with an interest in the common area or membership in the association per Chapter 2 (commencing with Section 4200), Part 5 of the Civil Code.
   10. (10) “compost” means the safe and stable product of controlled biologic decomposition of organic materials that is beneficial to plant growth.
   11. (11) “conversion factor (0.62)” means the number used in the Maximum Applied Water Allowance (MAWA) calculation that converts acre-inches per acre per year to gallons per square foot per year.
   12. (12) “dedicated irrigation meter” means a customer service meter dedicated to landscape use provided by the local water purveyor.
   13. (13) “designee” means a person or entity authorized to sign documents on behalf of the project applicant.
   14. (14) “designer of record,” for the purposes of this model ordinance means the person, professional practitioner, or project applicant functioning and providing services in compliance with Division 3, Chapter 3.5, Article 3 of the Business and Professions Code.
   15. (15) “design review” means review by the jurisdiction having authority for enforcing the model water efficient landscape ordinance.
   16. (16) “distribution uniformity” means the measure of the uniformity of irrigation water over a defined area.
   17. (17) “drip irrigation” means any non-spray low volume irrigation system utilizing emission devices where water is slowly applied at or below the soil surface and at or near the root zone of plants. Drip irrigation emission devices have a manufacturer specification for flow rate measured in gallons per hour.
   18. (18) “dynamic pressure” means the measure of water pressure with the water in motion, also known as working pressure.
   19. (19) “ecological restoration project” means a project where the site is intentionally altered to establish a defined, indigenous, historic ecosystem.
   20. (20) “effective precipitation” (Eppt) means the portion of total precipitation which becomes available for plant growth.
   21. (21) “emission device” means an irrigation system component that dispenses water to the landscape.
   22. (22) “established landscape” means the stage at which plants in the landscape have developed significant root growth into the soil. Typically, most plants are established after one or two years of growth.
   23. (23) “establishment period of the plants” or “establishment period” means the first year after installing the plant in the landscape or the first two years if irrigation will be terminated after establishment. Typically, most plants are established after one or two years of growth. Native habitat mitigation areas and trees may need three to five years for establishment.
   24. (24) “Estimated Total Water Use” (ETWU) is the sum of each hydrozone's estimated water use (EWU) and means the total water used for the landscape as described in Section 493.3. ETWU must be equal to or below the maximum applied water allowance (MAWA) to comply with MWELO.
   25. (25) “Estimated Water Use” (EWU) is the calculated water used for each hydrozone as described in Section 493.3.

   26. (26) “ET adjustment factor” (ETAF) means a factor that, when applied to reference evapotranspiration, adjusts for plant factors and irrigation efficiency, two major influences upon the amount of water that needs to be applied to the landscape. The maximum ETAF allowed in the MAWA equation must be equal to or below:

       1. (A) 0.55 for residential regular landscapes areas.
       2. (B) 0.45 for non-residential regular landscape areas.
       3. (C) 1.0 for Special Landscape Areas.
       4. (D) 0.8 for existing non-rehabilitated regular landscape areas over one acre in size installed before December 1, 2015, per Section 491.1.
   27. (27) “evapotranspiration rate” means the quantity of water evaporated from adjacent soil and other surfaces and transpired by plants during a specified time.
   28. (28) “flow rate” means the volume of water per unit of time that flows through pipes, valves, and emission devices, and commonly measured in gallons per minute, gallons per hour, or cubic feet per second.
   29. (29) “flow sensor” means an inline device installed at the supply point of the irrigation system that produces a repeatable signal proportional to flow rate. Flow sensors must be connected to a compatible automatic irrigation controller, or flow monitor capable of receiving flow signals and operating master valves. For the purposes of this definition, “compatible” means the flow sensor can communicate with the irrigation controller to allow the controller to record and report actual water usage. This combination flow sensor/controller may also function as a privately-owned submeter.
   30. (30) “friable” means a soil condition that is easily crumbled or loosely compacted down to a minimum depth per planting instructions for the plant material, whereby the root structure of newly planted material will be allowed to spread unimpeded.
   31. (31) “Fuel Modification Plan Guideline” means landscaping guidelines from a local fire authority to assist residents and businesses that are developing land or building structures in a fire hazard severity zone as described in Section 490.1(a)(6).
   32. (32) “gray water” means 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. “Gray water” includes wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs, but does not include wastewater from kitchen sinks or dishwashers per Health and Safety Code section 17922.12.
   33. (33) “hardscapes” means any durable material (pervious and non-pervious).
   34. (34) “hydrozone” means a section of the landscaped area having plants with similar water needs (i.e. “plant factors” as defined in Section 490.2.(a)(64)) and generally similar rooting depth (e.g., turfgrass (shallow to moderate), shrubs (moderate), and trees (deep)). A hydrozone may be irrigated or non-irrigated.
   35. (35) “infiltration rate” means the rate of water entry into the soil expressed as a depth of water per unit of time (e.g., inches per hour).
   36. (36) “invasive plant species” means species of plants not historically found in California that spread outside cultivated areas and can damage environmental or economic resources. Invasive species may be regulated by county agricultural agencies as noxious species. Lists of invasive plants are maintained by the California Invasive Plant Council in their Inventory and invasive plants and noxious weeds by the USDA in their PLANTS database.
   37. (37) “irrigation audit” means an in-depth evaluation of the performance of an irrigation system conducted by a Certified Landscape Irrigation Auditor. An irrigation audit includes, but is not limited to, inspection, system tune-up, system test with distribution uniformity or emission uniformity, reporting water waste, 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.

   38. (38) “irrigation efficiency” (IE) means the measurement of the amount of water beneficially used divided by the amount of water applied and is expressed as a percentage. Irrigation efficiency is derived from measurements and estimates of irrigation system characteristics and management practices. The average irrigation efficiency used in the Estimated Total Water use equation for purposes of this model ordinance are:

       1. (A) 0.75 for overhead irrigation systems, and
       2. (B) 0.81 for drip irrigation systems.
   39. (39) “irrigation survey” means an evaluation of an irrigation system that is less detailed than an irrigation audit. An irrigation survey includes, but is not limited to, inspection, system test, and written recommendations to improve performance of the irrigation system.
   40. (40) “irrigation water use analysis” means an analysis of water use data based on meter readings and billing data.
   41. (41) “landscape area” (LA) means all the irrigated planting areas, turfgrass areas, and water features in a landscape design plan subject to the Maximum Applied Water Allowance calculation. The irrigated planting area does not include footprints of buildings or structures, sidewalks, driveways, parking lots, decks, patios, gravel or stone walks, other pervious or non-pervious hardscapes, and other non-irrigated areas designated for non-development (e.g., open spaces and existing native vegetation). The landscape area is the sum of the landscape projects' regular landscape areas (RLA) and special landscape areas (SLA). LA = RLA + SLA.
   42. (42) “Landscape Documentation Package” means the documents required per the compliance option chosen by the applicant, as described in Section 491.4.
   43. (43) “landscape project” for the purposes of this model ordinance, means the total landscape area, defined in Section 490.2(a)(41), meeting requirements under Section 491 that requires a building or landscape permit, plan check, or design review.
   44. (44) “lateral line” means the water delivery pipeline that supplies water from the valve to the emission devices.
   45. (45) “local agency” means a city or county, or city and county, including a charter city or charter county, that is responsible for adopting and implementing the model ordinance. The local agency is also responsible for the enforcement of this model ordinance.
   46. (46) “local water purveyor” means any entity, including a public agency, city, county, or private water company that provides retail water service.
   47. (47) “low head drainage” means a condition where water partially or completely drains from the lateral line through the emission device after the irrigation cycle is completed.
   48. (48) “master shut-off valve” is an automatic valve installed at the irrigation supply point which controls water flow into the irrigation system. When this valve is closed water will not be supplied to the irrigation system. A master shut-off valve will greatly reduce any water loss due to a ruptured pipe or leak in the irrigation system.
   49. (49) “matched precipitation rate” or “matched application rate” means that all emission devices within a hydrozone delivers water at a similar precipitation rate per unit of time.
   50. (50) “Maximum Applied Water Allowance” (MAWA) means the upper limit of annual applied water for the established landscaped area as specified in Section 493.3. It is based upon the area's reference evapotranspiration, the maximum ET Adjustment Factor allowed, and the size of the regular landscape area (RLA) and the special landscape area (SLA). MAWA = (ETo) x (0.62) x [ETAF x RLA + 1.0 x SLA]
   51. (51) “median” is a landscape project area between opposing lanes of traffic that may be unplanted or planted with trees, shrubs, perennials, and ornamental grasses.
   52. (52) “mined-land reclamation projects” means any surface mining operation with a reclamation plan approved in accordance with the Surface Mining and Reclamation Act of 1975.
   53. (53) “mulch” means any organic material such as leaves, bark, straw, or compost, applied to the soil surface for the beneficial purposes of reducing evaporation, suppressing weeds, moderating soil temperature, and preventing soil erosion. Mulch includes inorganic mineral materials such as rocks, gravel, or decomposed granite left loose (i.e., may be used for Fire Safe Landscaping).
   54. (54) “multifamily residential landscape” means the landscape area surrounding or associated with any structure designed for human habitation that has been divided into two or more legally created independent living quarters.
   55. (55) “new construction” means, for the purposes of this model ordinance, a new building with a landscape area or other new landscape project, such as a park, playground, or greenbelt without an associated building.
   56. (56) “non-residential landscape” means the landscape area surrounding or associated with commercial, institutional, industrial, and public settings that may have areas designated for recreation or public assembly. It also includes the landscape area associated with common areas of common interest developments with designated recreational areas.
   57. (57) “non-volatile memory” means a type of computer memory used in automatic irrigation controllers that retains stored information after power is removed and will maintain the programmed irrigation schedule after power is restored.
   58. (58) “operating pressure” means the pressure at which the parts of an irrigation system are designed by the manufacturer to operate.
   59. (59) “overhead irrigation systems” means irrigation systems that deliver water through the air.
   60. (60) “overspray” means the irrigation water which is delivered beyond the target area.
   61. (61) “parkway” means the area between a sidewalk and the curb or traffic lane. It may be planted or unplanted, and with or without pedestrian egress.
   62. (62) “permit” means an authorizing document issued by local agencies for new construction or rehabilitated landscapes.
   63. (63) “pervious” means any surface or material that allows the passage of water through the material and into the underlying soil.

   64. (64) “plant factor” or “plant water use factor” is a factor, when multiplied by ETo, estimates the amount of water needed by plants. For purposes of this model ordinance, the plant factor ranges are:

       1. (A) very low water use plants is less than 0.1,
       2. (B) low water use plants is 0.1 to 0.3,
       3. (C) moderate water use plants is 0.4 to 0.6,

       4. (D) high water use plants is 0.7 to 1.0.

          Plant factors cited in this model ordinance are derived from the database “Water Use Classification of Landscape Species.” Plant factors may also be obtained from horticultural researchers from academic institutions or professional associations as approved by the California Department of Water Resources (DWR).

   65. (65) “project applicant” means the individual or entity submitting a Landscape Documentation Package required under Section 491.4, to request a permit, plan check, or design review from the local agency. A project applicant may be the property owner or their designee.
   66. (66) “rain sensor” or “rain sensing shutoff device” means a component that automatically interrupts an irrigation event when it rains.
   67. (67) “record drawing” or “as-builts” means a set of reproducible drawings that show significant changes in the work made during construction and that are usually based on drawings marked up in the field and other data furnished by the contractor.
   68. (68) “recreational area” means areas designated for active play, recreation or public assembly in parks, sports fields, picnic grounds, amphitheaters, or golf course tees, fairways, roughs, surrounds and greens. Private single-family residential landscapes are not recreational areas.
   69. (69) “recycled water” or “reclaimed water” means treated wastewater of a quality suitable for nonpotable uses such as landscape irrigation and water features, as described in California Code of Regulations, Title 22, Division 4, Chapter 3. This water is not intended for human consumption.
   70. (70) “reference evapotranspiration” or “ETo” means a standard measurement of environmental parameters which affect the water use of plants. ETo is expressed in inches per day, month, or year as represented in Appendix C, and is an estimate of the evapotranspiration of a large field of four- to seven-inch tall, cool-season turfgrass that is well-watered. The annual reference evapotranspiration is used as the basis of determining the Maximum Applied Water Allowances so that regional differences in climate can be accommodated.
   71. (71) “Regional Water Efficient Landscape Ordinance” means a local model ordinance adopted by two or more local agencies, water suppliers and other interested parties for implementing a consistent set of landscape provisions throughout a geographical region. Regional ordinances are strongly encouraged to provide a consistent framework for the landscape industry and applicants to adhere to.
   72. (72) “regular landscape area” (RLA) is the portion of the irrigated landscape area that is not a special landscape area. RLA = LA -- SLA.
   73. (73) “rehabilitated landscape” means any landscape renovation project that requires a permit, plan check, or design review, meets the requirements of Section 491, and the modified landscape area is equal to or greater than 2,500 square feet.
   74. (74) “riser” means a length of pipe with male nominal pipe threads on each end usually affixed to a lateral or submain supporting a sprinkler head or anti-siphon valve.
   75. (75) “runoff” means water which is not absorbed by the soil or landscape to which it is applied and flows from the target landscape area. Runoff may result from water that is applied at too great a rate (application rate exceeds infiltration rate), from low head drainage, or when there is a slope.
   76. (76) “single-family residential landscape” means the landscape areas surrounding or associated with a one or two-family dwelling or townhouse. Swimming pools of single-family residential landscapes are water features and not special landscape areas.
   77. (77) “soil moisture sensing device” or “soil moisture sensor” means a device that measures the amount of water in the soil and sends a signal to the automatic irrigation controller to interrupt or initiate an irrigation event.
   78. (78) “soil texture” means the classification of soil based on its percentage of sand, silt, and clay.
   79. (79) “Special Landscape Area” (SLA) means an irrigated area that may be all or part of the landscape project and is permanently and solely dedicated to edible plants such as orchards and vegetable gardens, recreational areas, areas irrigated with recycled water, or water features using recycled water.
   80. (80) “sprinkler head” or “sprinkler” means an emission device that applies water by converting water pressure to a high velocity discharge stream or stream(s) through the air by a nozzle (e.g., spray, rotors, and rotators). Sprinklers have a manufacturer specification for flow rate measured in gallons per minute.
   81. (81) “static water pressure” means the pipeline or municipal water supply pressure when water is not flowing.
   82. (82) “station” means a hydrozone served by a circuit on an automatic irrigation controller that operates either one valve or a set of valves that operate simultaneously.
   83. (83) “swing joint” means an irrigation component that provides a flexible, leak-free connection between the emission device and lateral pipeline to allow movement in any direction and to prevent equipment damage.
   84. (84) “submeter” means a privately owned metering device to measure water applied to the landscape that is installed after the primary utility water meter.
   85. (85) “turfgrass” means a living ground cover surface of mowed grass.
   86. (86) “valve” means a device used to control the flow of water in the irrigation system.
   87. (87) “water budget calculation” means the calculation of a landscape water budget defined by Estimated Water Use (EWU), Estimated Total Water Use (ETWU), and Maximum Applied Water Allowance (MAWA).
   88. (88) “water conserving plant species” means a plant species identified as having a very low or low plant factor.
   89. (89) “water feature” means 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 is included in the high-water use hydrozone of the landscape area. Constructed wetlands used for on-site wastewater treatment or stormwater best management practices that are not irrigated and used solely for water treatment or stormwater retention are not water features and, therefore, are not subject to the water budget calculation.
   90. (90) “water waste” means the overapplication of water through inefficient landscape irrigation that causes runoff to leave the target landscape area onto adjacent property, non-irrigated landscapes, private and public walkways, roadways, parking lots, or structures. Water waste includes low head drainage, overspray, runoff, or other similar conditions that causes overland flow.
   91. (91) “watering window” means the days per week and the hours per day irrigation is allowed.
   92. (92) “WUCOLS” means the Water Use Classification of Landscape Species IV, 2014, which is herein incorporated by reference, and maintained by the California Center for Urban Horticulture, University of California. WUCOLS IV is an online database that classifies and provides regional water needs for commonly available landscape plants.

Note: Authority cited: Sections 65596 and 65596.5, Government Code. Reference: Sections 65593, 65596, 65596.5 and 65598, Government Code.

History

1. New section filed 1-2-2025; operative 1-2-2025 pursuant to Government Code section 11343.4(b)(3) (Register 2025, No. 1).