Division Five: Standards for Landscaping

Chapter I. General

Sec. 501-1 Purpose and Scope

This division establishes the minimum standards of design, materials, plants, and methods to be used in providing landscaping for developments in Kern County. Landscaping required by development or within a County right-of-way shall be maintained by an entity approved by the Director. A County Service Area (CSA) or Park District are examples of acceptable maintenance entities. All landscaping installed in County right-of-way shall require an encroachment permit from the Public Works Department.

Sec. 501-2 Procedures

The following procedures shall be used when landscaping is to be provided:

501-2.01 Maintenance entity/CSA shall be formed prior to approval of landscape plans.

 501-2.02 Landscape plans shall be submitted to the Public Works Department for review and final approval. All Landscape plans and specifications shall be designed in compliance with Assembly Bill No. 1881 (Government Code Section 6551), The California Code of Regulations – Title 23 Waters – Division 2 – Department of Water Resources – Chapter 2.7 – Model Water Efficient Landscape Ordinance (MWELO) and State and/or local regulations and ordinances relating to water conservation. Landscape plans shall be approved by the Director of Public Works and the maintenance entity.

501-2.03       

• Landscape Plans shall identify and label all hydrozones, recreational areas, pervious & non-pervious hardscapes, permanent best management practices, graywater discharge systems and any areas irrigated with recycled water. Landscape Plans must include a Water Efficient Landscape Worksheet which contains two sections (see sample worksheet in Appendix ‘B’):

1.  A Hydrozone Information Table (see Appendix ‘B’, Section ‘A’) for the landscape project; and

2. A Water Budget Calculation (see Appendix ‘B’, Section ‘B’) for the landscape project. For the calculation of the Maximum Applied Water Allowance and Estimated Total Water Use, a project applicant shall use the ETO values from the Reference Evapotranspiration Table in Appendix ‘A’ for geographic areas not covered in Appendix ‘A’, use data from other cities located nearby in the same reference evapotranspiration zone, as found in the CIMIS Reference Evapotranspiration Zones Map, Department of Water Resources, 1999.

• Water budget calculation shall adhere to the following requirements:

1. The plant factor used shall be from the “Water Use Classification of Landscape Species’ website (WUCOLS). The plant factor ranges from 0 to 0.1 for very low water use plants, 0.2 to 0.3 for low water use plants, from 0.4 to 0.6 for moderate water use plants and from 0.7 to 1.0 for high water use plants.
2. All water features shall be included in the high-water use hydrozone and temporarily irrigated areas shall be included in the low water use hydrozone.
3. All Special Landscape Areas shall be identified and their water use calculated as described below. 
4. Evapotranspiration Adjustment Factor (ETAF) is based on the plant factors and irrigation methods selected. ETAF shall not exceed 0.45 exclusive of Special Landscape Areas. ETAF for Special Landscape Areas shall not exceed 1.0.
5. Estimated Total Water Use (ETWU) is calculated based on the plants used, irrigation method selected, Conversion Factor and Eto. The total ETWU must be less than the calculated total MAWA.

• Maximum Applied Water Allowance (MAWA);

The Maximum Applied Water Allowance shall be calculate using the equation:

MAWA = (ETo)(0.62)[(0.45 x LA) + (0.55 x SLA)]

Where:

 MAWA – Maximum Applied Water Allowance (gallons per year)

 ETo = Reference Evapotranspiration (inches per year)

 0.62 – Conversion Factor (to gallons)

 0.45 – ETAF Adjustment Factor (to gallons)

 LA – Landscape Area (square feet)

 0.55 – Additional Water Allowance for SLA (1-ETAF)

 SLA – Special Landscape Area (square feet)

501-2.04 Provisions from Division One, Standards for Streets, Chapter VI shall be met.

501-2.05 The plans shall clearly show the location of all valves, meters, backflow preventers, controllers, sprinkler heads, points of connection to the water system and other such equipment.  These exact locations shall be indicated on the "As-Built Record Drawings" to allow easy location.  The As-Built Record Drawings shall be prepared by the Landscape engineer/architect.

The plans shall clearly show existing and proposed streetlights, utility poles, utility vaults and fire hydrants.

501-2.06 The plans shall be prepared on mylar or similar material on sheets sized to 24 inches X 36 inches.

Title sheet shall identify the development, contain a vicinity map, a key map (scale 1 inch = 200 feet), signature blocks for the Landscape Architect and the Kern County Public Works Director.

The balance of the drawings shall be drawn at a scale not less than 1 inch = 20 feet.

Where shrubs or trees are to be planted, the sight distance lines, per Plate No. T-7 shall be overlaid on the plans to show that the plants and other improvements do not interfere with clear zones.  See Division One, Chapter VIII, Section 108-1 Landscaping, for sight distance requirements.

Chapter II. Irrigation System

Sec. 502-1 General Design Notes

502-1.01 All electrical wiring, controls, and devices shall be U.L. listed, and so labeled.  Other approval organizations will be subject to review and approval prior to installation.

502-1.02 The landscape system shall be designed to properly function from service pressure without the use of pumps.

502-1.03 Sprinkler heads shall be selected to limit the amount of overspray on walls, sidewalks, or pavement.

502-1.04 All sprinklers and quick coupling valves shall be installed using double swing joints.

502-1.05 A master irrigation plan shall be submitted for phased development.

502-1.06 Irrigation system shall be designed to minimize the number of meters and backflow devices.

Sec. 502-2 As-Built Drawings

502-2.01 Provide a complete "As-Built" record set of prints which shall be corrected daily and show every change from the original drawings and the exact "As-Built" locations, sizes, and kinds of equipment. The "As-Built" prints shall be a set of cronar or similar mylar material. All work shall be in waterproof, red ink and applied to the mylar by a technical pen made expressly for use on mylar material in a neat and complete legible manner.

502-2.02 The As-Builts shall be dimensioned from two permanent points of reference, i.e., building corners, sidewalks, or road intersections, etc., and accurately show the location of the following items:

1. Connection to existing water lines.
2. Connection to existing electrical power and irrigation controller.
3. Gate valves, remote control valves, quick couplings and related equipment.
4. Routing and/or directional turns of sprinkler pressure lines and control wiring (dimension max. 100 feet along routing).

Sec. 502-3 Controller Charts

Provide three controller charts for each controller supplied, one is to be attached in the controller and the other turned over to the County in the Operation and Maintenance Manuals. Chart attached to controller shall be laminated to prevent weather damage.

The chart shall indicate the area controlled by the automatic controller and shall be the maximum size which the controller door will allow.

Sec. 502-4 Operation and Maintenance Manuals

Prepare and deliver prior to completion of construction, two (2) hard cover three (3) ring binders containing the following information:

502-4.01 Index sheet stating landscape Contractor's address and telephone number, list of equipment with contacts for manufacturer's representative.

502-4.02 Catalog and part sheets on all material and equipment installed.

502-4.03 Complete operating and maintenance instructions on all major equipment.

Chapter III. Materials

Sec. 503-1 PVC Pipe and Fittings

503-1.01 Pressure Main Line Piping and Fittings:  Sizes two and one half (2-1/2) inches or larger shall be P.V.C. Class 200 Ring Tite or approved equal.

503-1.02 Pressure Main Line Piping and Fittings:  Sizes two (2) inches and smaller shall be Schedule 40 P.V.C.

503-1.03 Non-pressure laterals shall be minimum thickness Schedule 40 P.V.C.

503-1.04 P.V.C. nipples shall be Schedule 80 with molded threads.

503-1.05 All pipe and fittings shall conform to specific requirements as follows:

1. P.V.C. Pipe:  Manufactured from virgin polyvinyl chloride compound in accordance with ASTM D1784 or ASTM D2241, Cell classification 12454B.
2. P.V.C. Fittings (solvent weld or thread):  Standard weight, schedule 40, side gated, injection molded P.V.C. complying with ASTM D1784, cell classification 13454B, including threads when required.

Sec. 503-2 Electrical (Low Voltage)

503-2.01 Wiring sizing shall be a minimum of #14 direct burial AWG-UF, 600-volt wire, insulation thickness 3/64 inch, utilizing low density high molecular weight polyethylene insulation.  Wiring shall be color coded with the common wire to be white and all others in different colors.  An extra wire for every six (6) stations shall be looped in each valve box and housed in a box.

503-2.02 Splices, where necessary or permitted, shall be waterproofed using connectors which are UL 486D compliant.

503-2.03 All wiring placed under concrete or pavement shall be placed in a sleeve with pull boxes at each end.

Sec. 503-3 Gate Valves

503-3.01 Gate valves three (3) inches and smaller:  ASTM B62 brass body, 150-pound saturated steam rated; with screwed joints; non-rising stem; screwed bonnet, solid disc.  Provide with handwheel.

503-3.02 All gate valves shall be installed with schedule 80 unions to allow easy removal and placed in an approved valve box.

Sec. 503-4 Backflow Prevention Units

503-4.01 Backflow preventer shall be designed to operate on a "reduced pressure" principle; equipped with gate valves, “Wye” strainers of 125# class brass with 40 mesh monel screen and field test cocks acceptable to the water purveyor and the Environmental Health Services Department.

503-4.02 Prior to acceptance, the backflow prevention unit must be tested, and the test results submitted to, and approved by, the Environmental Health Services Department.

The backflow preventer shall be protected by a water protection unit mounted to the concrete slab and shall have adequate insulation blanket attached to the unit.

Sec. 503-5 Automatic Controller

Automatic controllers shall be the fully automatic operation type capable of independently operating the number of stations indicated.

503-5.01 Wall mount type in a housing with locking hinged cover.

503-5.02 Fuse and chassis ground all controller components.

503-5.03 The controller shall be mounted inside a stainless steel, vandal-resistant and weather-resistant enclosure. The enclosure shall include a predrilled backboard with 117-volt duplex outlet.  Metal conduit shall run from the 117-volt supply to the controller housing.  All power within the housing shall be properly phased.

503-5.04 Controller must be UL approved. Each valve shall be controlled by a separate station.

503-5.05 The electric meter may be installed in the above cabinet or a separate, approved vandal-resistant enclosure.

Sec. 503-6 Remote Control Valves

503-6.01 Valve type shall be spring-loaded, packless diaphragm activated, normally closed type with plastic body, equipped with adjustable flow control. 

503-6.02 Valve solenoid shall be 24-volt A.C. 45-watt maximum, 500 milli-amp maximum surge, corrosion-proof, stainless steel construction, epoxy encapsulated to form a single integral unit.

503-6.03 Provide bleeder valve to permit operation in the field without power at the controller.

503-6.04 All valves shall be installed with Schedule 80 unions to provide for easy maintenance.

503-6.05 Identification tags shall be attached to each remote-control valve, showing the number that corresponds with the controller sequence. Tags shall have the station number displayed with one-half (1/2) inch letters.

Sec. 503-7 Small Lawn Sprinkler Heads

Heads shall have screw adjustments.

Nozzles shall rise a minimum of six (6) inches.

Sec. 503-8 Rotary Sprinkler Heads

Rotary sprinkler heads shall be gear driven with minimum six (6) inch pop-up sprinkler heads.

Part circle heads shall have variable arc setting capability.

Sec. 503-9 Quick Coupling Valves

503-9.01 Type: Heavy-duty, brass construction, with stainless steel internal valve spring, using a three-fourths (3/4) inch valve key, and shall have a locking rubber cover.

503-9.02 Quick Coupling Valves shall be spaced no more than 100 feet apart or 50 feet from either end of landscape sections.

503-9.03 All Quick Coupling Valves shall be installed in approved round valve boxes.

Sec. 503-10 Small Shrubbery Sprinkler Heads

12-inch minimum pop-up type body shall be used. Heads shall be fully adjustable.

Sec. 503-11 Valve Boxes

503-11.01 Valve boxes shall be fabricated from a durable plastic material with UV inhibitors, resistant to weather, sunlight and chemical action of soils.

503-11.02 Gate valve boxes shall be round plastic boxes with an overlapping, lockable lid.

503-11.03 Remote control valve boxes shall be rectangular plastic boxes with an overlapping, lockable lid.

Sec. 503-12 Installation - General

503-12.01 All plastic pipe and fittings shall be installed in accordance with manufacturer's instructions for same.

503-12.02 Line Clearance:  All lines shall have a minimum clearance of six (6) inches from each other and from lines of other trades.  Parallel lines shall not be installed directly over one another.

503-12.03 Pressure lines shall have a metallic detector tape placed above them in accordance with manufacturer's recommendation.

503-12.04 Provide minimum coverage as follows:

Pressure supply lines (two and one half - (2-1/2) inches and smaller):  18 inches

Pressure supply lines (three (3) inches and larger):  30 inches

Non-pressure lines:  12 inches

Control wire:  18 inches

All wire and pipes under concrete or paving shall be at least 30 inches deep and sleeved.

503-12.05 All lines placed under paving or concrete shall be contained in a Schedule 40 P.V.C. sleeve.  The size of the sleeve shall be the minimum size which will allow the interior pipe or control wire to be freely removed and replaced.

Sec. 503-13 Field Quality Control - Adjustment of the System

503-13.01 The Contractor shall adjust all sprinkler heads and valves for optimum performance and to prevent as much as possible any overspray onto walks and roadways.

503-13.02 Testing of Irrigation System

Test all pressure lines under hydrostatic pressure of 150 pounds per square inch and prove watertight.  Testing of pressure main lines shall occur prior to installation of electric control valves, quick couplers or any other equipment that might prevent a proper test from being performed.  All piping under paved areas shall be tested under a hydrostatic pressure of 150 pounds per square inch, and proved water-tight, prior to paving.  Pressure in lines shall be sustained for not less than two (2) hours.  If leaks develop, replace joints and repeat test until entire system is proven watertight.

Sec. 503-14 Plant Material

503-14.01 Soil

Engineer shall submit to the County for approval a soil nutrient report; this requirement may be waived if the County has on file acceptable information to indicate that it is not warranted.  The report shall contain recommendations of soil amendments, fertilizers, as well as an indication of the soil's suitability for the purpose intended.

503-14.02 Plants

Turf will only be allowed under certain circumstances and if in compliance with MWELO, this must be approved by the Director of Public Works.  Trees shall not be a type which have a lot of surface roots or drop fruit or are a maintenance problem.  Trees when planted near concrete or paving shall be planted with root guards.  All plants/trees must be chosen from WUCOLS Database (Water Use Classification of Landscape Species).  Trees which exceed a four (4) inch diameter trunk at 10 years growth shall not be placed in the right-of-way without specific approval from the Director of Public Works or his representative. No trees shall be planted within 20 feet of a streetlight pole base.

Sec. 503-15.01 Multi-Use Trail Fence

Trail fence shall be heavy duty two rail white vinyl fence designed for agricultural uses, or an alternative approved by the Engineer. Fence rails shall be nominal two (2) inches x six (6) inches x 16 feet ribbed type, with minimum 0.11-inch wall thickness, installed with a minimum 24” bury at eight (8) feet on center. Use aluminum inserts at all end, corner and gate posts (both latch and hinge sides) or fill with concrete. See Plate No. L-15 for details.

Sec. 503-16.01 Stamped Concrete

Stamped or imprinted concrete shall require proposed design provided and approved with Landscape Plans.  Design mix shall include design of stamp or imprinting, color and other relevant specifications.  If vapor retarding membrane is not used, the based shall be moistened.  Concrete shall be constructed with the use of forms in accordance with ACI 347. Concrete shall be placed in accordance with ACI 301, 302 and 304. If using non-integral color, apply color hardener prior to application of pattern.  Apply hardener at rate by that recommended by the manufacturer, evenly to the surface of the fresh concrete by the dry-shake method. If applied in two or more shakes, float after each shake and trowel concrete only after final floating. While concrete is still in its plastic state, apply the tool/texture pattern to the surface of the concrete. Property tamp tools into the surface to achieve the required texture, with uniformity of pattern and depth of stamping. Release materials shall be applied to the troweled surface prior to stamping/imprinting. Place curing compound on exposed concrete surfaces immediately after finishing in accordance with the manufacturer's instructions. If required per design, apply secondary stain treatment and apply finish sealer per approved design. Immediately after placement, protect concrete from premature drying, excessive temperatures and mechanical damage.

Chapter IV. Maintenance

Sec. 504-1 Maintenance

Maintenance of the system is the responsibility of the Developer until such time as the maintenance entity/CSA has collected sufficient funds to operate and maintain the system.  Prior to the entity/CSA beginning to maintain the system, the Developer shall replace all plants which are not in healthy condition, readjust all sprinklers and make all repairs to the system.

A one (1) year’s maintenance bond is required prior to acceptance of the landscaping by the maintenance entity.