Article I — Water Efficient Landscaping

• A. The State Legislature has found:

  1. The waters of the State are of limited supply and are subject to ever increasing demands;

  2. The continuation of California’s economic prosperity is dependent on the availability of adequate supplies of water for future uses;

  3. It is the policy of the State to promote the conservation and efficient use of water and to prevent the waste of this valuable resource;

  4. Landscapes are essential to the quality of life in California by providing areas for active and passive recreation and as an enhancement to the environment by cleaning air and water, preventing erosion, offering fire protection, and replacing ecosystems lost to development;

  5. Landscape design, installation, maintenance and management can and should be water efficient;

  6. Section 2 of Article X of the California Constitution specifies that the right to use water is limited to the amount reasonably required for the beneficial use to be served and the right does not and shall not extend to waste or unreasonable method of use; and

  7. In response to the prolonged state drought conditions, Governor Edmund G. Brown, Jr. issued Drought Executive Order (EO) B-19-25 directing the Department of Water Resources (DWR) to update the State’s Model Water Efficient Landscape Ordinance (MWELO). The MWELO requires cities and counties to adopt a water efficient landscape ordinance that is at least as effective for conserving water as the State’s MWELO.

• B. The City hereby finds that:

  1. The City of Walnut has an existing Water Efficient Landscape Ordinance that is required to be amended to comply with state requirements;

  2. Current local design practices in new landscape typically achieve the State MWELO water use goals;

  3. Landscape plan submittal and review is the standard practice in Walnut;

  4. The annual reference evapotranspiration rate (annual ETo) is 47.5.

• C. Consistent with these findings, the purpose of the City’s Water Efficient Landscape Ordinance is to establish an alternative model acceptable under EO B-19-25 as being at least as effective as the State MWELO in the context of conditions in the City in order to:

  1. Promote the values and benefits of landscapes while recognizing the need to invest water and other resources as efficiently as possible;

  2. Establish a structure for planning, designing, installing, maintaining and managing water efficient landscapes in new construction and rehabilitated projects;

  3. Establish provisions for water management practices and water waste prevention for existing landscapes;

  4. Use water efficiently without waste by setting a maximum applied water allowance as an upper limit for water use and reduce water use to the lowest practical amount;

  5. Encourage the use of economic incentives that promote the efficient use of water.

• A. Beginning May 13, 2016, all landscape projects subject to the provisions of this chapter shall first obtain a permit from the Community Development Department prior to the installation of any landscaping. The following landscaping and irrigation related projects shall comply with this chapter and the established guidelines:

  1. New landscape projects with an aggregate landscape area equal to or greater than 500 square feet, requiring a building or landscape permit, plan check, or design review;

  2. Rehabilitated landscape projects with an aggregate landscape area less than 2,500 square feet requiring a building or landscape permit, plan check, or design review, and which are otherwise subject to a discretionary approval of a landscape plan;

  3. New or rehabilitated landscape projects between 500 square feet and 2,500 square feet may comply with the performance requirements of this chapter or conform to the prescriptive measures contained in Appendix E of the Guidelines;

  4. New or rehabilitated projects using treated or untreated graywater or rainwater capture onsite, any lot or parcels within the project that has less than 2,500 square-feet of landscape area and meets the lot or parcel’s landscape water requirement (estimated total water use) entirely with the treated or untreated graywater or through stored rainwater capture on-site is subject only to Appendix E Section (5) of the Guidelines;

  5. Recognizing the special landscape management needs of cemeteries, new landscape installations or landscape rehabilitation projects at cemeteries shall prepare a water efficient landscape worksheet; landscape and irrigation maintenance schedule; and irrigation audit, survey and water use analysis as required in the Guidelines.

• B. Existing Landscapes. As of the effective date of this chapter, all existing landscape areas are exempt from the provisions of this article or this chapter. For all existing landscapes installed before May 13, 2016 that are greater than one acre in size and are served by a dedicated landscape water meter, the City and/or local water purveyor(s) must administer programs to achieve landscape water use efficiency community-wide.

• C. Unless otherwise determined by the City, this chapter and these guidelines do not apply to:

  1. Registered local, state, or federal historical sites;

  2. Ecological restoration projects that do not require a permanent irrigation system;

3. Mined-land reclamation projects that do not require a permanent irrigation system; or

4. Existing plant collections, as part of botanical gardens and arboretums open to the public.

The Planning Commission shall by resolution adopt guidelines providing rules, regulations, requirements, and procedures to assure technical compliance with water efficiency standards at least as efficient as the MWELO described in California Government Code Section 65595(a) .

• A. Prior to installation, a landscape documentation package shall be submitted to the City for review and approval of all landscape projects subject to the provisions of this article. Any landscape documentation package submitted to the City shall comply with the provision of the Guidelines.

• B. Prior to the assembling of a landscape documentation package, applicants are advised to consult with the Community Development Department as to the type of landscape improvements that are to be made, and whether or not the areas of the subject property that are to be landscaped are within designated slope or natural space easements, or within the City’s Lighting and Open Space Maintenance District (LOSMD).

• C. The landscape documentation package shall bear the stamp and signature by a landscape architect licensed in the State of California certifying that the landscape design and water use calculations have been prepared by or under the supervision of the licensed professional and are certified to be in compliance with the provisions of this article and the Guidelines for Water Efficient Landscaping.

  1. Landscape and irrigation plans shall be submitted to the City for review and approval with appropriate water use calculations.

  2. Water use calculations shall be consistent with calculations contained in the Guidelines and shall be provided to the local water purveyor, as appropriate, under procedures determined by the City.

  3. Verification of compliance of the landscape installation with the approved plans shall be obtained through a certification of completion in conjunction with a certificate of use and occupancy or permit final process, as provided in the Guidelines for Water Efficient Landscaping.

• A. For applicable landscape installation or rehabilitation projects subject to Section 6.52.020(A) of this chapter, the estimated applied water (EAW) use allowed for the landscaped area shall not exceed the maximum applied water allowance (MAWA) calculated using an ET adjustment factor of 0.55 for residential areas and 0.45 for nonresidential areas, except for special landscaped areas where the MAWA is calculated using an ET adjustment factor of 1.0; or the design of the landscaped area shall otherwise be shown to be equivalently water-efficient in a manner acceptable to the City; as provided in the Guidelines.

• B. Irrigation of all landscaped areas shall be conducted in a manner conforming to the rules and requirements for water conservation and water waste prevention as determined and

implemented by the local water purveyor or as mutually agreed by the local water purveyor and the local agency.

The City may delegate to, or enter into a contract with, a local agency to implement, administer, and/or enforce any of the provisions of this chapter on behalf of the City.

The following definitions are applicable to this article:

"Common interest developments" a means community apartment projects, condominium projects, planned developments, and stock cooperatives per Civil Code Section 1351 .

"Conversion factor" means the number that converts acre-inches per acre per year to gallons per square foot per year.

"Distribution uniformity" or "DU" is a measure of how uniformly an irrigation head applies water to a specific target area and ranges from 0 to 100%.

"Drip irrigation" means any non-spray low volume irrigation system utilizing emission devices with a flow rate measured in gallons per hour. Low volume irrigation systems are specifically designed to apply small volumes of water slowly at or near the root zone of plants.

"Drought tolerant" means landscaping that utilizes little or no irrigation through the use of waterconserving materials and techniques, including, but not limited to, native drought-tolerant plants, mulch, and efficient irrigation.

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

"Emitter" means a drip irrigation emission device that delivers water slowly from the system to the soil.

"Estimated applied water use" means the average annual total amount of water estimated to be necessary to keep plants in a healthy state, calculated as provided in the Guidelines. It is based on the reference evapotranspiration rate, the size of the landscape area, plant water use factors, and the relative irrigation efficiency of the irrigation system.

"ET adjustment factor" or "ETAF" is equal to the plant factor divided by the irrigation efficiency factor for a landscape project, as described in the Guidelines. The ETAF is calculated in the context of local reference evapotranspiration, using site-specific plant factors and irrigation efficiency factors that influence the amount of water that needs to be applied to the specific landscaped area.

A combined plant mix with a site-wide average plant factor of 0.5 (indicating a moderate water need) and average irrigation efficiency of 0.71 produces an ET adjustment factor of (0.7) = (0.5/0.71), which is the standard of water use efficiency generally required by this chapter and the Guidelines, except that the ETAF for a special landscape area shall not exceed 1.0.

"Evapotranspiration rate" means the quantity of water evaporated from adjacent soil and other surfaces and transpired by plants during a specified time.

"Graywater" 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. "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.

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.

"Guidelines" refers to the Guidelines for Implementation of the Water Efficient Landscape Ordinance, as adopted by the City, which describes procedures, calculations, and requirements for landscape projects subject to this chapter.

"Hardscapes" means any durable material or feature (pervious and non-pervious) installed in or around a landscaped area, such as pavements or walls. Pools and other water features are considered part of the landscaped area and not considered hardscapes for purposes of this chapter.

"Homeowner installed landscape" means any landscaping either installed by a private individual for a single-family residence or installed by a licensed contractor hired by a homeowner. A homeowner, for purposes of this article, is a person who occupies the dwelling he or she owns. This definition excludes speculative homes, which are not owner-occupied dwellings and which are subject under this article to the requirements applicable to developer-installed residential landscape projects.

"Hydrozone" means a portion of the landscaped area having plants with similar water needs and typically irrigated by one valve/controller station. A hydrozone may be irrigated or non-irrigated.

"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).

"Invasive plant species" or "noxious" means species of plants not historically found in California that spread outside cultivated areas and can damage environmental or economic resources. Invasive plant species may be regulated by county agricultural agencies as noxious species.

"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 overspray or runoff that causes overland flow, and preparation of an irrigation schedule.

"Irrigation efficiency" or "IE" means the measurement of the amount of water beneficially used divided by the amount of water applied to a landscaped area. Irrigation efficiency is derived from measurements and estimates of irrigation system characteristics and management practices. The minimum average irrigation efficiency for purposes of these Guidelines is 0.71. Greater irrigation efficiency can be expected from designed and maintained systems. The following irrigation efficiency may be obtained for the listed irrigation heads with an IME of 90%:

1. Spray = 71%

2. Stream rotator heads = 73%

3. Stream rotor heads = 76%

4. Microspray = 76%

5. Bubbler = 77%

6. Drip emitter = 81%

7. Subsurface irrigation = 81%

"Landscape coefficient (KL)" is the product of a plant factor multiplied by a density factor and a microclimate factor. The landscape coefficient is derived to estimate water loss from irrigated landscaped areas and special landscaped areas.

"Landscape contractor" means a person licensed by the State of California to construct, maintain, repair, install, or subcontract the development of landscape systems.

"Landscaped area" means all the planting areas, turf areas, and water features in a landscape design plan subject to the maximum applied water allowance and estimated applied water use calculations. The landscaped 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).

"Landscape documentation package" means the documents required to be provided to the City for review and approval of landscape design projects, as described in the Guidelines.

"Landscape professional" means a licensed landscape architect, licensed landscape contractor, or any other person authorized to design a landscape pursuant to Sections 5500.1 , 5615 , 5641 , 5641.1 , 5641.2 , 5641.3 , 5641.4 , 5641.5 , 5641.6 , 6701 , 7027.5 of the California Business and Professions Code, Section 832.27 of Title 16 of the California Code of Regulations, and Section 6721 of the California Food and Agriculture Code.

"Landscape project" means total area of landscape in a project, as provided in the definition of "landscaped area," meeting the requirements under Section 6.52.020 .

"Lateral line" means the water delivery pipeline that supplies water to the emitters or sprinklers from the valve.

"Local agency" means a city or county, including a charter city or charter county, that is authorized by the City to implement, administer, and/or enforce any of the provisions of this chapter on behalf of the City. The local agency may be responsible for the enforcement or delegation of enforcement of this chapter, including, but not limited to, design review, plan check, issuance of permits, and inspection of a landscape project.

"Local water purveyor" means any entity, including a public agency, city, county, or private water company that provides retail water service.

"Low volume irrigation" means the application of irrigation water at low pressure through a system of tubing or lateral lines and low-volume emitters such as drip, drip lines, and bubblers. Low volume irrigation systems are specifically designed to apply small volumes of water slowly at or near the root zone of plants.

"Main line" means the pressurized pipeline that delivers water from the water source to the valve or outlet.

"Maximum applied water allowance" or "MAWA" means the upper limit of annual applied water for the established landscaped area as specified in Section 2.2 of the Guidelines. It is based upon the area’s reference evapotranspiration, the ET adjustment factor, and the size of the landscaped area. The estimated applied water use shall not exceed the maximum applied water allowance.

"Microclimate" means the climate of a small, specific area that may contrast with the climate of the overall landscaped area due to factors such as wind, sun exposure, plant density, or proximity to reflective surfaces.

"Mined-land reclamation projects" mean any surface mining operation with a reclamation plan approved in accordance with the Surface Mining and Reclamation Act of 1975.

"Mulch" means any organic material such as leaves, bark, straw or compost, or inorganic mineral materials such as rocks, gravel, or decomposed granite left loose and applied to the soil surface for the beneficial purposes of reducing evaporation, suppressing weeds, moderating soil temperature, and preventing soil erosion.

"New construction" means, for the purposes of this chapter, a new building with a landscape or other new landscape such as a park, playground, or greenbelt without an associated building.

"Non-pervious" means any surface or natural material that does not allow for the passage of water through the material and into the underlying soil.

"Permit" means an authorizing document issued by local agencies for new construction or rehabilitated landscape.

"Pervious" means any surface or material that allows the passage of water through the material and into the underlying soil.

"Plant factor" or "plant water use factor" is a factor, when multiplied by ETo, that estimates the amount of water needed by plants. For purposes of this chapter, the plant factor range for low water use plants is 0 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. Plant factors cited in this chapter are derived from the Department of Water Resources 2000 publication "Water Use Classification of Landscape Species."

"Precipitation rate" means the rate of application of water measured in inches per hour.

"Recycled water" or "reclaimed water" means treated or recycled waste water of a quality suitable for nonpotable uses such as landscape irrigation and water features. This water is not intended for human consumption.

"Reference evapotranspiration" or "ETo" means a standard measurement of environmental parameters which affect the water use of plants. ETo is given expressed in inches per day, month, or year as represented in Appendix A of the Guidelines, 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 used as the basis of determining the maximum applied water allowances.

nvironmental parameters which affect the water use of plants. ETo is given expressed in inches per day, month, or year as represented in Appendix A of the Guidelines, 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 used as the basis of determining the maximum applied water allowances.

"Rehabilitated landscape" means any re-landscaping project that meets the applicability criteria of Section 6.52.020(A) , where the modified landscape area is greater than 2,500 square feet, is 50% of the total landscape area, and the modifications are planned to occur within one year.

"Smart automatic irrigation controller" means an automatic timing device used to remotely control valves that operate an irrigation system and which schedules irrigation events using either evapotranspiration (weather-based) or soil moisture data.

"Special landscape area" means an area of the landscape dedicated solely to edible plants such as orchards and vegetable gardens, areas irrigated with recycled water, water features using recycled water, and areas dedicated to active play such as parks, sports fields, golf courses, and where turf provides a playing surface.

"Turf" means 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.

"Valve" means a device used to control the flow of water in an irrigation system.

"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 landscaped area. Constructed wetlands used for on-site wastewater treatment, habitat protection 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.

"WUCOLS" means the Water Use Classification of Landscape published by the University of California Cooperative Extension, the Department of Water Resources, and the Bureau of Reclamation, 2000 ( www.owue.water.ca.gov/docs/wucols00 ).

Property owners or their building or landscape designers, including anyone requiring a building or planning permit, plan check, or landscape design review from the City, who are constructing a new single-family, multifamily, public, institutional, or commercial project with a landscape area greater than 500 square feet, or rehabilitating an existing landscape with a total landscape area greater than 2,500 square feet shall comply with the requirements of Section 3.29.090 of the Walnut Municipal Code.

(Ord. 21-04, § 4)