Model Water Efficient Landscape Ordinance (MWELO) Compliance

Projects in California that require a building permit, plan check or design review and have a landscape area component of 500-sf or more must adhere to the more stringent of either the State's Model Water Efficient Landscape Ordinance (MWELO) or a comparable local ordinance.

Under the State's model ordinance, projects with a landscape area of 2,500 square feet or less may comply with the prescriptive measures described in MWELO Appendix D.

These prescriptive measures regulate four items:

(1) Compost (2) Plant Material (3) Turf (4) Irrigation Systems

While not an engineering task per se, Alaco will work with a project owner to prepare a basic prescriptive MWELO plan for permit approval in conjunction with preparing a site / grading / drainage plan. Alaco will otherwise coordinate with a project owner's landscape professional for more extensive landscape / MWELO plans.

Compost

Unless conditions would not warrant, compost should be cultivated into planting areas to a depth of six inches at a rate of at least four cubic yards per 1,000 square feet (approximately a 1½ inch layer before mixing).

Area : Compost

(SF) : (CY) | (CF)

1000 : 4.0 | 108

900 : 3.6 | 97

800 : 3.2 | 86

700 : 2.8 | 76

600 : 2.4 | 65

500 : 2.0 | 54

400 : 1.6 | 43

300 : 1.2 | 32

250 : 1.0 | 27

200 : 0.8 | 22

100 : 0.4 | 11

50 : 0.2 | 5½

25 : 0.1 | 3

9 : 0.037 | 1

1 : 0.004 | 0.1

Plant Material

• Climate adapted plants

Except for edibles and areas using recycled water, climate adapted plants that require occasional, little or no summer water (average WUCOLS plant factor 0.3) are to be planted in 75 percent of residential planting areas and 100 percent of non residential plant areas.

Plant factor (PF), also known as species factor (ks value), ranges from 0.1 to 0.9 and are divided into 4 categories: Very Low (<0.1), Low (0.1-0.3), Moderate (0.4-0.6), High (0.7-0.9).

Plant characteristics can be queried in the WUCOLS Database for specific California cities.

• Mulch

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 where mulch is unwarranted.


• Plant Debris

In addition to California requirements, an Alameda County Waste Management Authority 2008 ordinance (applicable throughout all of Alameda County), prohibits disposal of plant debris in county landfills.

Turf (Lawn)

(A) Turf is not allowed in non residential areas and must not exceed 25 percent of the landscape area in residential areas.

(B) Turf must not be planted on sloped areas that exceed a 1 foot elevation change over a horizontal distance of 4 feet.

(C) Turf is prohibited in parkways less than 10 feet wide, unless the parkway is adjacent to a parking strip and used to enter and exit vehicles. Any turf in parkways must be irrigated by sub-surface irrigation or by other technology that creates no overspray or runoff.

Irrigation Systems

(A) Automatic irrigation controllers are required and must use evapotranspiration or soil moisture sensor data and utilize a rain sensor.

(B) Irrigation controllers shall be of a type which does not lose programming data in the event the primary power source is interrupted.

(C) Pressure regulators shall be installed on the irrigation system to ensure the dynamic pressure of the system is within the manufacturers recommended pressure range.

(D) Manual shut-off valves (such as a gate valve, ball valve, or butterfly valve) shall be installed as close as possible to the point of connection of the water supply.

(E) All irrigation emission devices must meet the requirements set in the ANSI standard, 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.

(F) Areas less than ten (10) feet in width in any direction shall be irrigated with subsurface irrigation or other means that produces no runoff or overspray.


For non residential projects with landscape areas of 1,000 sq. ft. or more, a private submeter(s) to measure landscape water use shall be installed.



Local Resources in Alameda County

Waste Management Earth Care locally sourced and produced 100% recycled compost and mulch: San Leandro / Livermore

Plant Nursery Map (Click "View larger map" for more info) . . .