Imperial County Municipal Code § 90302.04 Landscaping standards—Commercial uses

The purpose of this chapter is to insure that all development is aesthetically pleasing and compatible with the surrounding area by requiring the provisions for adequate landscaping in connection with new development and the expansion of existing development, as well as, changes in use. The purpose of the requirements contained herein is to define the standards for the design, installation, and management of landscaped areas in order to utilize available plant, water and land resources, to the greatest benefit of the people of Imperial County. Skillful planting and irrigation design, appropriate use of plants, and intelligent landscape management can assure landscape development that avoids excessive water demands and that is less vulnerable to periods of severe drought.

(Prior code § 90302.00)

Landscaping shall be provided in accordance with the minimum conditions set forth herein, and shall meet the water conservation requirements also set forth herein.

Specific project approved landscaping requirements shall supersede these standards.

(Prior code § 90302.01)

The following standards shall apply to landscaping in mobile home parks and recreational vehicle parks.

A. A minimum of ten percent (10%) of the total developed lot area shall be landscaped. This ten percent (10%) is in addition to other required open space areas.

B. Set back areas between streets and the perimeter fence of a mobile home/R.V. park, excluding approved driveway entrances and such other approved access points and public sidewalks, shall be landscaped. Within these areas trees shall be planted no further than fifty (50) feet apart and no closer than five feet from the edge of sidewalk. No material that will grow to a height of more than twelve (12) inches shall be planted between the curb edge and sidewalk.

C. Within the interior of the mobile home/R.V. park at least one tree per space shall be required.

D. Within each planter or landscaped area an irrigation system and live landscaping shall be provided and continually maintained.

E. Ornamental or landscaping rock and gravel areas, artificial turf, or other areas covered with artificial materials shall be considered hard surface and not qualify as part of the ten percent (10%) landscaping minimum requirement.

F. Landscaping materials including trees, shrubs and ground cover should be the type suitable for the climatic conditions of the county of Imperial and shall be low volume water use plants.

G. Minimum tree size or shrub size to be planted for any new development shall be of the five-gallon capacity or larger.

(Prior code § 90302.02)

The following standards shall apply to landscaping for industrial/manufacturing uses:

A. Minimum of ten percent (10%) of the developed lot area shall be landscaped.

B. Along any interior property line abutting a residentially zoned lot, parcel or area, trees shall be planted at least every twenty-five (25) feet in either individual planters or a maintained median planting area.

C. Along any interior property line abutting commercially zoned lots, parcels or areas, trees shall be planted at least every fifty (50) feet.

D. Within each planter or landscaped area, an irrigation system and live landscaping shall be provided and maintained.

E. Planters or landscaped areas shall be provided within off-street parking areas at a minimum of five percent of the total parking area.

F. Ornamental or landscaping rock and gravel areas, artificial turf, or other areas covered with other artificial materials shall be considered hard surface area but may be credited toward the minimum ten percent (10%) landscaping requirement.

(Ord. 1415 § 74, 2006)

The following standards shall apply to landscaping in commercial development areas, recreational development areas, and institutional development areas:

A. A minimum of ten percent (10%) of the total developed lot or parcel area shall be landscaped.

B. Along any interior property line abutting residentially zoned lots, parcels, or areas, trees shall be planted at least every thirty (30) feet in either individual planters or continual median type planter.

C. Planters and/or landscaped areas shall be provided within all off-street parking areas at a minimum of five percent of the total parking area.

D. Within each planter or landscaped area, an irrigation system and live landscaping shall be provided and maintained.

E. Ornamental or landscaping rock and gravel areas, artificial turf or other areas covered with artificial materials shall be considered hard surfaces and may not be credited to the minimum ten percent (10%) requirement.

F. Any commercial development abutting a sensitive receptor, as determined by the planning department shall be landscaped with trees spaced at no more than twenty-five (25) feet on center and shrubs, vines etc., equally spaced between the trees.

G. All trees and shrubs planted shall be a minimum of five-gallon capacity or larger.

(Ord. 1415 § 76, 2006)

The following standards shall apply to landscaping in multi-unit residential developments.

A. A minimum of fifteen percent (15%) of the total developed lot area shall be landscaped. This fifteen percent (15%) is in addition to any required park or open space area.

B. Front and street side yard setback areas, excluding driveway entrances, maneuvering areas and public sidewalks, shall be landscaped.

Within these areas trees shall be planted no further than thirty (30) feet apart and no closer than five feet from the back of the sidewalk. No plant material that will grow to a height of more than twelve (12) inches shall be planted in the street right-of-way or between the curb edge and sidewalk.

C. All interior open space area shall be landscaped with live landscaping, which shall be maintained.

D. Planters and landscaped areas shall be provided within all off-street parking areas, not less than ten percent (10%) of the total parking area required for the development.

E. Within each planter or landscaped area, an irrigation system and live landscaping shall be provided and maintained.

(Prior code § 90302.05)

The following standards apply to landscaping of single-unit residential developments.

A. A minimum of twenty percent (20%) of the total developed lot area shall be landscaped.

B. The front and street side yard setback areas, excluding approved driveway entrances and public walkways, shall be landscaped.

Within this area, trees shall be planted no further than thirty (30) feet apart and no closer than five feet from the back side of sidewalks. No plant material that will grow to a height of more than twelve (12) inches shall be planted within the street right-of-way or between the curb edge and sidewalk edge.

(Prior code § 90302.06)

No landscaping or irrigation system required to be provided by this chapter shall be installed until a landscaping plot plan has been submitted to and approved by the planning department. No final inspection or inspection approval for the development shall be granted by the county until the adequate landscaping is provided.

(Prior code § 90302.07)

All required landscaping shall be maintained to meet the intent of this chapter and state law.

(Prior code § 90302.08)

These requirements herein shall be applicable to all new and rehabilitated landscaping for industrial, commercial, and institutional developments; to multifamily residential common areas, and to all housing developments. Homeowner provided landscaping for single-family residences and duplexes are excluded.

(Prior code § 90302.09)

To assure that the purpose of this chapter is carried out, improvement plans and building permits will not be issued until a submittal of a landscaping plot plan conforming to the specific provisions of this chapter has been approved.

(Prior code § 90302.10)

The board of supervisors of Imperial County ("board") or its designee may authorize conditional exceptions to any of the design and improvements standards in this chapter, unless state law specifically states that an exception cannot be granted. Such exceptions may be granted if the board finds, in writing, that the proposed design or improvement is in substantial compliance with the purpose and intent of the standard to be expected.

(Prior code § 90302.11)

This division is enacted by the county of Imperial pursuant to the requirements of the state of California (Gov. Code 65591 through 65000). The board of supervisors adopts this chapter and finds that this is a state mandate to comply with the county water conservation landscaping requirements.

(Prior code § 90302.12)

The following shall be submitted to the county of Imperial planning and development services department, for review and approval:

A. Landscaping Plan. The planting plan shall be drawn on substantial paper (drafting cloth or blueline) in a clear and legible fashion.

1. A scale of no smaller than one inch = ten (10) feet shall be used.

2. Plan. The planting plans shall accurately and clearly identify:

a. Landscape materials, trees, shrubs, groundcover, turf, etc. Planting symbols shall be clearly drawn and plants labeled by botanical name, common names, container size, spacing and quantities of each group of plants indicated;

b. Property lines;

c. Streets, driveways, walkways, and other paved areas;

d. Building and structures including elevation if applicable;

e. Natural features — rock outcropping, existing trees, shrubs, etc. — to remain;

f. Tree staking, soil preparation details, and any other applicable details.

B. Irrigation Plan. The irrigation plan shall be drawn on substantial paper (drafting cloth or blueline) in a clear and legible fashion.

1. The scale shall be equal to that used for the planting plan.

2. Plan. The irrigation plan shall accurately and clearly identify:

a. Flow rate and P.S.I. at the point of connection;

b. Coverage of all components of the irrigation system, including main and lateral lines;

c. Valves;

d. Controllers;

e. Heads;

f. Quick couplers;

g. Head precipitation rates;

h. Meter size;

i. Moisture sensor devices;

j. Rain switches;

k. Backflow prevention device.

C. Sloped Areas. Sloped areas shall be indicated by contour lines (this may be shown on grading plan).

D. Soil Tests. A soils report may be required to be prepared by a soil testing company and submitted with the plans. Soil samples shall be collected after grading operations are conducted and prior to the installation of landscape materials. Soil samples shall be sufficiently numerous to account for any soil variations that may be present in the planting areas. At a minimum, the following shall be included:

1. Soil infiltration;

2. Soil texture test;

3. Cation exchange capacity;

4. Soil fertility including tests for nitrogen, potassium, phosphorous, pH, organic matter and specific conductance (E.C.).

Amendments shall be added to correct for problems as noted by the soils report. A copy of the soils report shall be attached to the irrigation schedule which will be delivered to the owner and controller operator.

E. Water Use. Estimated plant water use calculations for each planting area shall be submitted with the planting plan.

F. Irrigation Schedule. An annual irrigation program with a minimum four-season water schedule shall be required for both the plant establishment period and established landscape. The water schedule shall include run time and frequency of irrigation for each station. The total average planted area precipitation shall not exceed thirty (30) inches/year for established landscapes (see Section 90302.15). A copy of the schedule shall be delivered to the owner.

(Ord. 1415 § 78, 2006; prior code § 90302.13)

A. Irrigation systems shall be designed so that the application rate does not exceed the infiltration rate of the soil, and will minimize overspray and runoff. The designer shall refer to Section 90302.18, and the results of the soil tests to meet these design criteria. In general, low volume sprinkler heads; drip emitters and pressure compensation bubblers shall be used throughout the system.

B. Irrigation stations shall be separated (e.g., drip vs. overhead spray systems). Additional control valves shall be installed to account for different site specific characteristics (i.e., full sun/full shade, level/sloping, shrubs/lawns, street trees, etc.).

C. Maximum sprinkler spacing for both turf and non-turf areas shall be fifty percent (50%) of the diameter of the throw. (Example: thirty (30) foot diameter nozzle should be no more than fifteen (15) feet apart). Spacing of sprinklers shall take into account on-site wind conditions.

D. All irrigation systems shall be operated by an automatic controller. At a minimum, each controller shall have a rain shutoff operation, a fourteen (14) day calendar, two independent programs, and three cycles/day capabilities.

E. The irrigation system shall be designed to allow a complete watering cycle within a fourteen (14) hour period.

F. All turf areas shall utilize either pop-up rotary impact heads or spray heads with a minimum riser height of five inches.

(Prior code § 90302.14)

A. Water Use Criteria. All landscapes shall comply with the following water use criteria:

1. The maximum amount of water that can be applied per year to any landscape shall average no greater than thirty (30) inches of supplemental water.

2. The planted area shall balance the water demands of different plant species to create an overall landscape which requires a moderate amount of water. For design purposes, planting area shall be defined as low use, medium use, or high use areas (refer to Section 90302.19 for a list of low, medium and high use plants). Water use values (Table I) below reflect the relative water use of each type of planting area. To check a landscape design for compliance, multiply the water use value by its respective planting area.

Example: Assume a two-acre landscape plan consists of twenty percent (20%) high use plants (turf), fifty percent (50%) medium use plants, and thirty percent (30%) low use plants.

Since the sum of water use factors is less than the area (two acres), the design is acceptable. If the sum of the water use factors exceeded two, the design would not be acceptable, and the designer would be required to substitute some high use species with low or medium use species to reduce the sum of water use factors to two or less.

Table I

Water use calculations including plant key, and planting area shall be shown on the planting plan according to the format in the following example:

Assume a landscape design involves two thousand six hundred (2,600) square feet of planting area. The planting area consists of six hundred (600) square feet of Cistus purpureus (CP), six hundred (600) square feet of Nerium oleander (NO), four hundred (400) square feet of Pittosporum tobira (PT), Juniperus horizontals (JH), and Liquidamber styraciflue (LS), and one thousand (1,000) square feet of turf.

Water Use Calculations Water Use Factor

1. Turf Selections and Use. Turf shall not be permitted in planted areas ten (10) feet or less in width, or in medium strips.

2. Non-Turf Selections.

a. Plants selected for use in non-turf areas should be well suited or adaptable to the climate of this region. Plants shall be grouped according to their water needs and irrigated separately. Species of different water needs may be grouped (i.e., low with medium and medium with high) but the highest water use value of the two shall be used to determine compliance with the ordinance. Low and high use species may not be used in the same irrigation area.

b. A minimum of three inches of an organic mulch shall be placed in shrub areas on the soil surface after planting. Nonporous materials shall not be placed under the mulch.

(Prior code § 90302.15)

Upon completion of the installation of the landscaping, the designer shall certify that the landscape complies with all county water conserving landscape requirements. Certification shall be accomplished by completion of a certificate of compliance on a form approved by the planning and development services department. Failure to submit a complete and accurate certificate of compliance will delay final approval of the project.

(Ord. 1415 § 80, 2006)

A. For each subdivision with three or more model homes, the developer shall submit a landscape plan and install landscaping for one model home which incorporates the county's water conserving landscape requirements. The intent of this requirement is to demonstrate to prospective home buyers the feasibility and aesthetic qualities of water conserving landscape design.

B. Signs identifying aspects of the landscape design and irrigation shall be placed around the model. These signs should be clearly marked on the landscape plan for the model. The following criteria shall be used in developing and placing the signs.

1. Front Yard Sign Identifying Model. A sign, large enough to be visible from the street and sidewalk (at least two feet by two feet) shall be located in front of the model home. The sign shall indicate that the model is landscaped with water conserving plant materials and irrigation systems.

2. Other Exterior Signs. A sign shall be placed within the landscaped area identifying the irrigation system used, the different sub-areas of the landscape, and any other features that contribute to the overall water-conserving theme.

3. Interior Signs or Displays. A drawing, or combination of drawings, shall be displayed inside the model providing a schematic of the landscape. These drawings shall include a key identifying the plants in the yards. It is suggested that this schematic also be printed on a one-page handout to be available at the model or the sales office. The drawings could be a simplified rendering of the landscape plan itself, using common names rather than the Latin names for the plants. The drawing(s) should be colorful and easy to read.

Literature describing water conserving landscapes shall be available to individuals touring the model.

(Prior code § 90302.17)

Infiltration Rate (IR) Inches/Hour

Note: Rates based on full cover. These figures decrease with time and percent of cover. Derived from USDA information.

(Prior code § 90302.18)

A list of plants that are commonly used in landscape designs with water requirement classifications of low (L), medium (M), or high (H), is available from the planning and development services department.

The list however should not be considered a complete list of plants that can be used in landscape projects. The list is provided to assist the landscape designer in choosing species of appropriate water demands to meet the requirements of this document, and to group species of similar water demands to facilitate efficient irrigation. To use species other than those listed, the designer may provide the county with information indicating the water requirement of the species. Information may include the listing of a plant in an acceptable reference stating its water requirement characteristics, comparing it to a species in the plant life, field data etc. Acceptable references include the "Sunset Western Garden Book"; "Trees and Shrubs for Dry California Landscapes," by Robert Perry; and "Water Wise Gardening," E.B.M.U.D.

(Ord. 1415 § 82, 2006)

Unless the context specifically indicates otherwise, the meaning of terms used in this chapter shall be as defined in this section.

"Amendment" means any material added to the soil to alter the pH or improve the physical properties of the soil.

"Application rate" means the rate of irrigation (inches per hour or gallons per minute) at which water is applied by an irrigation system.

"Automatic control valve" means a valve in an irrigation system which is activated by an automatic electric controller via an electric control wire.

"Automatic irrigation system" means an irrigation system that can be controlled without manual manipulation and which operates on a pre-set program.

"Contour" means a line drawn on a plan which connects all points of equal elevation above or below a known or assumed reference point.

"Controller" means an automatic timing device with enclosure, which signals automatic valves to open and close on a present program.

"Coverage" is a general term, used with respect to the spacing of sprinkler heads, which defines the manner in which water is applied.

"Cycle" in irrigation, means the complete operation of a controller station.

"Drip irrigation" means low volume irrigation.

"Grading" means earthwork performed to alter the natural contours of an area to be planted.

"Infiltration rate" means the rate (inches per hour) in which water moves through soil under natural conditions.

"Irrigation system" means a complete connection of system components, including the water source, the water distribution network, and the necessary irrigation equipment.

"Median" means a planted area which separates two roadways or divides a portion of a road into two or more lanes.

"Mulch" means materials such as bark or sawdust placed on the soil surface to retain moisture, retard weed growth, or prevent erosion.

"Overspray" means water which is discharged from a pop-up or spray head which lands outside of the planting area.

"P.S.I." means pounds per square inch gauge water pressure.

"Percolation" means the movement of water through soil.

"Permeability" means the quality of a soil, which allows water and air to pass through it.

"Planting area" means the parcel area less building pad(s), driveway(s), patio(s), deck(s), walkway(s) and parking area(s). Planting areas include water bodies (i.e., fountains, ponds, lakes) and natural areas.

"Planting plan" means a plan showing the features, contours, and dimensions of a plot of land, along with the location and dimensions of elements to be constructed.

"Point of connection" means point at which the irrigation system is connected to the public water system. This location is normally identified by the point at which a water meter is located or will be installed.

"Precipitation rate" means the amount of water, in inches per hours, discharged by a group of sprinkler heads.

"Rain shutoff" means a feature of an automated irrigation system, which interrupts the normal irrigation cycle when it detects a significant amount of rainfall.

"Rehabilitated landscape" means any planting area(s) in which landscape materials are replaced or modified. Examples include a change of plants or groundcover, installation of a new irrigation system, and grading modifications.

"Runoff" means water which is not absorbed by the soil to which it is applied. Runoff usually occurs when water is applied at too great a rate or when water is applied to a steep slope.

"Station" means a position on an automatic irrigation controller, which indicates the control point of automatic irrigation valves.

"Tensiometer" (or "moisture sensor") means an instrument for measuring the moisture content of the soil and capable of interrupting the cycle irrigation when excessive or adequate moisture is detected.

"Toe" or "slope" means a horizontal section located at the base of a slope.

(Prior code § 90302.20)