Chapter 13.40
WATER EFFICIENT LANDSCAPING
Sections:
13.40.040 Submittal requirements.
13.40.050 Landscaping standards.
13.40.060 Irrigation requirements.
13.40.010 Purpose.
The purpose of this chapter is to add provisions to the Rio Dell Municipal Code to address permitting requirements for water efficient landscaping. These changes are necessary to reflect changes in California law (Assembly Bill 1881, Government Code Section 65591 et seq.) and to promote the conservation and efficient use of water. [Ord. 378 § 1, 2020.]
13.40.020 Applicability.
(1) The provisions of this chapter shall apply to all of the following landscape projects that are provided and/or required as part of a building permit, grading permit, discretionary permit, or site plan review:
(a) Public agency and private development projects. New construction and rehabilitated landscape projects with landscape area equal to or greater than 2,500 square feet.
(b) Developer-installed in single-family and multifamily residential projects. New construction and rehabilitated landscape projects with landscape area equal to or greater than 2,500 square feet cumulative.
(c) Homeowner-provided in single-family and multifamily residential projects. New construction landscape projects with landscape area equal to or greater than 5,000 square feet that are served by a community water system.
(2) These provisions shall also apply to the following landscape projects with significant water needs:
(a) Existing landscapes equal to or greater than one acre, with a dedicated water meter. Such landscapes are limited to preparing a water efficient landscape worksheet in accordance with the specifications in the landscape documentation package (RDMC 13.40.040, Submittal requirements). If water use exceeds the maximum applied water allowance, the property owner shall consult the Planning and Public Works Department for recommendations to reduce water use and to prevent water waste.
(b) New and rehabilitated cemeteries. Recognizing the special landscape management needs of cemeteries, new and rehabilitated cemeteries shall require the preparation of a water efficient landscape worksheet and submittal of a certificate of completion. Existing cemeteries are limited to subsection (2)(a) of this section.
(3) The provisions of these regulations shall not apply to the following:
(a) Registered local, State or Federal historical sites;
(b) Ecological restoration and similar projects that do not require irrigation systems for longer than five years in duration to establish the plants;
(c) Mined-land reclamation projects that do not require irrigation systems for longer than five years in duration to establish the plants;
(d) Plant collections, as part of botanical gardens, arboretums, and nature centers open to the public; and
(e) Community gardens. [Ord. 378 § 1, 2020.]
13.40.030 Definitions.
For the purposes of these regulations, unless otherwise apparent from the context, certain words and phrases used in these regulations are defined as follows:
“Backflow prevention device” means a safety device used to prevent pollution or contamination of the water supply due to the reverse flow of water from the irrigation system.
“California Invasive Plant Inventory” means the California Invasive Plant Inventory maintained by the California Invasive Plant Council.
“Check valve” or “anti-drain valve” means a valve located under a sprinkler head, or other location in the irrigation system, to hold water in the system to prevent drainage from sprinkler heads when the sprinkler is off.
“Community garden” means a piece of property or area of a property that is dedicated solely to edible plants and gardened by a cooperative group of people living in the area.
“Community water system” means a public water system which serves at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents.
“Developer-installed” means a landscape project installed by or under the direction of the developer of a development project.
“Ecological restoration project” means a project where the primary function of such project is to assist in the recovery of an ecosystem that has been degraded, damaged, or destroyed. For purposes of this chapter, restoration focuses on establishing the composition, structure, pattern, and ecological processes necessary to make terrestrial and aquatic ecosystems sustainable, resilient, and healthy under current and future conditions.
“Estimated total water use (ETWU)” means the total water used for the landscape.
“ET adjustment factor (ETAF)” means, except for special landscape areas, a factor of 0.7 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 ET adjustment factor for special landscape areas shall not exceed 1.0.
“Evapotranspiration (ETO)” means the quantity of water evaporated from adjacent soil and other surfaces and transpired by plants during a specified time.
“Head to head coverage” means full coverage from one sprinkler head to the next.
“Homeowner-provided landscaping” means any landscaping either installed by a private individual for a single-family residence or installed by a licensed contractor hired by a homeowner.
“Hydrozone” means a portion of the landscaped area having plants with similar water needs. A hydrozone may be irrigated or nonirrigated.
“Invasive plant species” means species of plants not historically found in California that spread outside cultivated areas and can damage environmental or economic resources.
“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 (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 chapter is 0.71. Greater irrigation efficiency can be expected from well designed and maintained systems.
“Landscape area” means all the planting areas, turf areas, and water features in a landscape design plan subject to the maximum applied water allowance calculation. The landscape area does not include footprints of buildings or structures, sidewalks, driveways, parking lots, decks, patios, gravel or stone walks, other pervious or nonpervious hardscapes, and other nonirrigated areas designated for nondevelopment (e.g., open spaces and existing native vegetation).
“Landscape contractor” means a person licensed by the State of California to construct, maintain, repair, install, or subcontract the development of landscape systems.
“Landscape project” means total area of landscape in a project as defined in “landscape area” for the purposes of this chapter, meeting requirements under RDMC 13.40.020, Applicability.
“Low volume irrigation” (also “point source 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 plant.
“Low-head drainage” means water that flows out of the system after the valve turns off due to elevation changes within the system.
“Maximum applied water allowance (MAWA)” means the upper limit of annual applied water for the established landscaped area. It is based upon the area’s reference evapotranspiration, the ET adjustment factor (ETAF), and the size of the landscape area. The estimated total water use shall not exceed the maximum applied water allowance.
“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.
“Mulch” means any organic material such as leaves, bark, straw, compost, or inorganic mineral materials such as rocks, gravel, and 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 or structure with a landscape, such as a house, accessory structure, pool, gazebo, or commercial or industrial building. This definition also includes other new landscapes, such as a park, playground, or greenbelt without an associated building.
“Overhead irrigation system” means a system that delivers water through the air (e.g., spray heads and rotors).
“Overspray” means the irrigation water which is delivered beyond the target area.
“Pervious” means any surface or material that allows the passage of water through the material and into underlying soil.
“Plant 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.”
Point Source Irrigation. See “low volume irrigation.”
“Precipitation rate” means the rate of application of water measured in inches per hour.
“Rain sensor” means a component which automatically suspends an irrigation event when it rains.
“Recycled 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 (ET)” means a standard measurement of environmental parameters that affect the water use of plants, and is an estimate of the evapotranspiration of a large field of four-to-seven-inch-tall, cool-season grass that is well watered.
“Rehabilitated landscape” means any relandscaping project that requires a permit, plan check, or design review, meets the requirements of RDMC 13.40.020, Applicability, and the modified landscape area is equal to or greater than 2,500 square feet, is 50 percent of the total landscape area, and the modifications are completed within one year.
“Runoff” means water which is not absorbed by the soil or landscape to which it is applied and flows from the landscape area. For example, runoff may result from water that is applied at too great a rate (application rate exceeds infiltration rate) or when there is a slope.
“Special landscape area (SLA)” means an area of the landscape dedicated solely to edible plants (food producing gardens), areas irrigated with recycled water, water features using recycled water, stormwater detention basins, and areas dedicated to active play such as parks, sports fields, golf courses, and where turf provides a playing surface.
“Subsurface irrigation” means an irrigation device with a delivery line and water emitters installed below the soil surface that slowly and frequently emit small amounts of water into the soil to irrigate plant roots.
“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.
“Turf” means a groundcover surface of mowed grass. Annual bluegrass, Kentucky bluegrass, perennial ryegrass, red fescue, and tall fescue are cool-season grasses. Seashore paspalum, St. Augustine grass, Zoysia grass, and Buffalo grass are warm-season grasses. The meaning of “turf” does not include landscape areas planted with non-irrigated native California grasses.
“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. [Ord. 378 § 1, 2020.]
13.40.040 Submittal requirements.
(1) Landscape Documentation Package. Prior to commencing construction on a landscape project subject to the provisions of this chapter, a landscape documentation package shall be submitted to the City for review and approval.
(a) The landscape documentation package shall be filed with the Planning and Public Works Department on a City approved application form. The landscape documentation package application shall include all required fees and/or deposits, and all plans, specifications, and submittals required by the Department, including but not limited to:
(i) General project information.
(ii) Water efficient landscape worksheet.
(iii) Soil management report.
(iv) Landscape and grading design plan.
(v) Irrigation design plan.
(b) The landscape documentation package application shall only be approved after the City verifies that the proposed landscape project complies with the provisions of this chapter, other applicable provisions of this code, and any applicable conditions of a discretionary permit or other entitlement.
(2) Certificate of Completion. Following installation of landscaping subject to the provisions of this chapter, the project applicant shall submit a certificate of completion to the City for review and final approval.
(a) Prior to issuance of a certificate of occupancy or final building or grading permit, the certificate of completion shall be submitted to the Planning and Public Works Department on a form prescribed by the City that shall include the following information and documentation:
(i) General project information.
(ii) Certificate of Installation.
(iii) Copy of landscape irrigation audit.
(3) Permit Issuance and Enforcement.
(a) Upon successful completion of the certificate of completion, the City shall issue a “final” landscape permit to the property owner/project applicant.
(b) The City may conduct inspections for the purpose of enforcing this chapter and, as necessary and appropriate, may utilize any of the enforcement mechanisms set forth in the Rio Dell Municipal Code or otherwise authorized by law to address violations. [Ord. 378 § 1, 2020.]
13.40.050 Landscaping standards.
All landscape projects subject to the provisions of this chapter shall comply with the following landscaping standards:
(1) Plant Selection and Grouping.
(a) Any plant may be selected for the landscape, providing the estimated total water use (ETWU) in the landscape area does not exceed the maximum applied water allowance (MAWA), and that the plants meet the specifications set forth in subsections (1)(b), (c), (d), and (e) of this section.
(b) With the exception of special landscape areas, a minimum 25 percent of landscape area shall be comprised of native plants.
(c) Plants having similar water needs shall be grouped together in distinct hydrozones.
(i) Within distinct hydrozones, plants of moderate and low water use, or moderate and high water use, can be mixed, so long as the plant factor of the higher water using plant is used for calculations.
(ii) High water use plants shall not be mixed with low water use plants.
(d) Plants shall be selected appropriately based on their adaptability to the climate, geologic, and topographical conditions of the site. Protection and preservation of existing native California species and natural areas is encouraged.
(e) The use of invasive plant species, as listed in the California Invasive Plant Inventory produced by the California Invasive Plant Council, or as determined by the Director of Planning and Public Works, is prohibited.
(f) Fire prevention needs shall be addressed in fire-prone areas. A defensible space or zone around a building or structure is required per Public Resources Code Sections 4291(a) and (b).
(2) Turf Requirements. Turf shall not be planted on slopes exceeding 25 percent where the toe of the slope is adjacent to or within four feet of an impermeable hardscape (rise divided by run multiplied by 100 equals slope percent).
(3) Soil Amendments, Conditioning, and Mulching.
(a) A minimum three-inch layer of mulch shall be applied on all exposed soil surfaces of planting areas except in turf areas, creeping or rooting groundcovers, or direct seeding applications. To provide habitat for beneficial insects and other wildlife, up to five percent of the landscape area may be left without mulch. Designated insect habitat must be included in the landscape design plan as such.
(b) Stabilizing mulching products shall be used on slopes.
(c) Soil amendments shall be incorporated based on the recommendations of the soil management report.
(4) Water Features.
(a) Recirculating water systems shall be used for all water features.
(b) The surface area of a water feature shall be indicated on the landscape plans and included in the high water use hydrozone area of the water budget calculation.
(c) Recycled water shall be used for decorative water features when available on site.
(5) Stormwater Management.
(a) The landscape project area shall be graded so that all irrigation and normal rainfall remains within the property lines and does not drain on to nonpermeable hardscapes.
(b) Rain gardens, cisterns, and other landscape features and practices that increase rainwater capture and create opportunities for infiltration and/or on-site storage are recommended.
(c) Soil compaction in landscape areas is prohibited unless required by the geotechnical or engineering report. [Ord. 378 § 1, 2020.]
13.40.060 Irrigation requirements.
This section applies to landscaped areas requiring permanent irrigation, not areas that require temporary irrigation solely for the plant establishment period. For the efficient use of water, an irrigation system shall meet all the requirements listed in this section and the manufacturers’ recommendations. The irrigation system and its related components shall be planned and designed to allow for proper installation, management, and maintenance. An irrigation design plan meeting the following design criteria shall be submitted as part of the landscape documentation package. All landscape projects subject to the provisions of this chapter shall comply with the following irrigation requirements:
(1) Irrigation System.
(a) Landscape water meters, defined as either a dedicated water service meter or private submeter, shall be installed for all nonresidential irrigated landscapes of 1,000 square feet but not more than 5,000 square feet (the level at which Water Code Section 535 applies) and residential irrigated landscapes of 5,000 square feet or greater. A landscape water meter may be either:
(i) A customer service meter dedicated to landscape use provided by the local water purveyor; or
(ii) A privately owned meter or submeter.
(b) Automatic irrigation controllers utilizing either evapotranspiration or soil moisture sensor data utilizing nonvolatile memory shall be required for irrigation scheduling in all irrigation systems.
(c) If the water pressure is below or exceeds the recommended pressure of the specified irrigation devices, the installation of a pressure regulating device is required to ensure that the dynamic pressure at each emission device is within the manufacturer’s recommended pressure range for optimal performance.
(i) If the static pressure is above or below the required dynamic pressure of the irrigation system, pressure-regulating devices such as inline pressure regulators, booster pumps, or other devices shall be installed to meet the required dynamic pressure of the irrigation system.
(ii) Static water pressure, dynamic or operating pressure, and flow reading of the water supply shall be measured at the point of connection. These pressure and flow measurements shall be conducted at the design stage. If the measurements are not available at the design stage, the measurements shall be conducted at installation.
(d) Sensors (rain, freeze, wind, etc.), either integral or auxiliary, that suspend or alter irrigation operation during unfavorable weather conditions shall be required on all irrigation systems, as appropriate for local climatic conditions. Irrigation should be avoided during windy or freezing weather or during rain.
(e) Manual shut-off valves (such as a gate valve, ball valve, or butterfly valve) shall be required, as close as possible to the point of connection of the water supply, to minimize water loss in case of an emergency (such as a main line break) or routine repair.
(f) Backflow prevention devices shall be required to protect the water supply from contamination by the irrigation system. A project applicant shall refer to the applicable local agency code (i.e., public health) for additional backflow prevention requirements.
(g) Flow sensors that detect high flow conditions created by system damage or malfunction are required for all nonresidential landscapes and residential landscapes of 5,000 square feet or larger.
(h) Master shut-off valves are required on all projects except landscapes that make use of technologies that allow for the individual control of sprinklers that are individually pressurized in a system equipped with low pressure shutdown features.
(i) The irrigation system shall be designed to prevent runoff, low head drainage, overspray, or other similar conditions where irrigation water flows onto nontargeted areas, such as adjacent property, nonirrigated areas, hardscapes, roadways, or structures.
(j) Relevant information from the soil management plan, such as soil type and infiltration rate, shall be utilized when designing irrigation systems.
(k) The design of the irrigation system shall conform to the hydrozones of the landscape design plan.
(l) The irrigation system must be designed and installed to meet, at a minimum, the irrigation efficiency criteria as described in Section 492.4 of Title 23, Division 2, Chapter 2.7 of the California Code of Regulations (CCR) regarding the maximum applied water allowance.
(m) All irrigation emission devices must meet the requirements set in the American National Standards Institute (ANSI) standard, American Society of Agricultural and Biological Engineers’/International Code Council’s (ASABE/ICC) 802-2014 “Landscape Irrigation Sprinkler and Emitter Standard.” All sprinkler heads installed in the landscape must document a distribution uniformity low quarter of 0.65 or higher using the protocol defined in ASABE/ICC 802-2014.
(n) It is highly recommended that the project applicant or local agency inquire with the local water purveyor about peak water operating demands (on the water supply system) or water restrictions that may impact the effectiveness of the irrigation system.
(o) In mulched planting areas, the use of low volume irrigation is required to maximize water infiltration into the root zone.
(p) Sprinkler heads and other emission devices shall have matched precipitation rates, unless otherwise directed by the manufacturer’s recommendations.
(q) Head to head coverage is recommended. However, sprinkler spacing shall be designed to achieve the highest possible distribution uniformity using the manufacturer’s recommendations.
(r) Swing joints or other riser-protection components are required on all risers subject to damage that are adjacent to hardscapes or in high traffic areas of turfgrass.
(s) Check valves or anti-drain valves are required on all sprinkler heads where low point drainage could occur.
(t) Areas less than 10 feet in width in any direction shall be irrigated with subsurface irrigation or other means that produce no runoff or overspray.
(u) Overhead irrigation shall not be permitted within 24 inches of any nonpermeable surface. Allowable irrigation within the setback from nonpermeable surfaces may include drip, drip line, or other low flow nonspray technology. The setback area may be planted or unplanted. The surfacing of the setback may be mulch, gravel, or other porous material. These restrictions may be modified if:
(i) The landscape area is adjacent to permeable surfacing and no runoff occurs; or
(ii) The adjacent nonpermeable surfaces are designed and constructed to drain entirely to landscaping; or
(iii) The irrigation designer specifies an alternative design or technology as part of the landscape documentation package and clearly demonstrates strict adherence to irrigation system design criteria in Section 492.7(a)(1)(I) of Title 23, Division 2, Chapter 2.7 of the California Code of Regulations (CCR). Prevention of overspray and runoff must be confirmed during the irrigation audit.
(v) Slopes greater than 25 percent shall not be irrigated with an irrigation system with an application rate exceeding 0.75 inches per hour. This restriction may be modified if the landscape designer specifies an alternative design or technology, as part of the landscape documentation package, and clearly demonstrates no runoff or erosion will occur. Prevention of runoff and erosion must be confirmed during the irrigation audit.
(2) Hydrozones.
(a) Each valve shall irrigate a hydrozone with similar site, slope, sun exposure, soil conditions, and plant materials with similar water use.
(b) Sprinkler heads and other emission devices shall be selected based on what is appropriate for the plant type within that hydrozone.
(c) Where feasible, trees shall be placed on separate valves from shrubs, groundcovers, and turf to facilitate the appropriate irrigation of trees. The mature size and extent of the root zone shall be considered when designing irrigation for the tree.
(d) Individual hydrozones that mix plants of moderate and low water use, or moderate and high water use, may be allowed if:
(i) Plant factor calculation is based on the proportions of the respective plant water uses and their plant factor; or
(ii) The plant factor of the higher water using plant is used for calculations.
(e) Individual hydrozones that mix high and low water use plants shall not be permitted.
(f) On the landscape design plan and irrigation design plan, hydrozone areas shall be designated by number, letter, or other designation. On the irrigation design plan, designate the areas irrigated by each valve, and assign a number to each valve. Use this valve number in the Hydrozone Information Table (Appendix B, Section A of Title 23, Division 2, Chapter 2.7 of the California Code of Regulations (CCR)). This table can also assist with the irrigation audit and programming the controller. [Ord. 378 § 1, 2020.]
13.40.070 Public education.
Education is a critical component to promote the efficient use of water in landscapes. The use of appropriate principles of design, installation, management and maintenance that save water is encouraged throughout Rio Dell.
(1) Literature and Resources. The Planning and Public Works Department shall make available information to the general public regarding the design, installation, management, and maintenance of water efficient landscapes.
(2) Model Homes. Landscaping shall be installed, in compliance with this chapter, for all model homes in subdivisions where a final subdivision map has been approved by the City. The landscaping for model homes shall incorporate the policies of this chapter and the developer shall include the following:
(a) Signs that identify the model home landscaping as an example of a water efficient landscape featuring elements such as hydrozones, irrigation equipment, and others that contribute to the overall water efficient theme.
(b) Literature shall be provided to anyone touring a model home that describes the design, installation, management, and maintenance of water efficient landscapes. [Ord. 378 § 1, 2020.]