MWELO: Model Water Efficient Landscape Ordinance Triggers

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A small yard can carry a landscape compliance requirement even when most of the property is concrete and building. I start with the landscape work itself. If I use the entire lot size, or choose a threshold before identifying the kind of project, I can send the job down the wrong permitting path.

The practical consequence is simple. A mistaken area or project classification changes the documentation I plan for. Catching that during estimating gives me time to coordinate the design. Catching it after installation can mean changing work that is already finished.

The Model Water Efficient Landscape Ordinance establishes California's baseline requirements for water efficient landscapes. The California Green Building Standards Code connects landscape water efficiency to building code compliance. A more stringent local ordinance can apply, so I check the reviewing agency's requirements before treating a statewide threshold as the complete answer.

I have the 2 main project triggers together on the chart. For new construction, the statewide landscape area trigger is 500 sq. ft. or more. For rehabilitated landscaping, the trigger is 2,500 sq. ft. or more. These provisions apply to projects requiring a building or landscape permit, plan check, or design review.

The words or more matter. Exactly 500 sq. ft. reaches the new construction trigger. Exactly 2,500 sq. ft. reaches the rehabilitation trigger.

Imagine 2 separate projects, each with 600 sq. ft. of landscape area. One is new landscaping associated with a new home. The other is renovation of an existing landscape. Assume both require local review and neither has an applicable exemption. The new landscape reaches its statewide size trigger. The renovation does not reach its statewide rehabilitation size trigger. The area is identical, but the project classification changes the result.

That second project still needs a local check. Falling below a statewide size trigger does not erase local landscape requirements or water waste rules.

I also avoid calling landscaping rehabilitation merely because a house already exists on the property. For mixed work, such as a new accessory dwelling combined with changes to an existing yard, I have the reviewing agency confirm the project classification and the area being evaluated. I do that before I price the compliance work.

My memory connection is short: classify the work, then compare the area. New construction starts at 500. Rehabilitation starts at 2,500.

This chart separates the landscape area from the rest of the property. I include irrigated planting beds, turfgrass areas, and water features such as ornamental ponds in the landscape area calculation. I leave out building footprints, driveways, sidewalks, patios, decks, and other hardscape. Existing non-irrigated native vegetation and open space designated for non-development are also excluded.

A gravel walk is still a walk. Its ability to pass water does not turn it into an irrigated planting bed. Likewise, the absence of lawn does not make a project disappear from the ordinance. Irrigated shrubs and an ornamental pond can still contribute landscape area.

I add the qualifying areas across the project. A front planting bed and a side planting bed do not each get a separate size allowance merely because a walkway separates them.

Suppose a hypothetical new home has 300 sq. ft. of irrigated planting in front and another 300 sq. ft. along the side. Together, that is 600 sq. ft. of landscape area. The driveway does not count, but it also does not divide this project into 2 independent 300 sq. ft. projects.

I keep the area takeoff with the plans. That lets the designer, installer, and reviewer work from the same quantity. It also gives me something specific to revise if the owner expands a planting bed before construction.

Once a project reaches a trigger, I have a second decision: how will it demonstrate compliance?

For a qualifying smaller new landscape, the prescriptive option uses specified design and installation requirements instead of the performance path's water budget calculations. Think of a checklist that the entire design must satisfy. Choosing that option does not remove the need for plans, documentation, or approval.

For the 600 sq. ft. new landscape, I would check whether that option fits the proposed design and local requirements. It is below 2,500 sq. ft., the size boundary associated with the smaller-project option. I would not promise the option on a project exactly at the boundary without confirming the reviewing agency's current requirements.

The performance option uses a water budget and supporting design documents. Estimated water use must stay within the allowed amount. A covered project above 2,500 sq. ft. needs the performance option under the statewide framework.

The distinction I want you to keep is between being subject to the ordinance and choosing a way to comply. A project can require compliance without requiring the same package as every other project. I confirm the accepted path before the landscape subcontractor orders materials.

I put 3 prescriptive soil requirements on this chart because they are easy to mix up during estimating. The compost rate is at least 4 cu. yd. per 1,000 sq. ft. Incorporation depth is 6 in. The mulch layer is at least 3 in. on applicable exposed planting soil.

Those are separate measurements. 4 cu. yd. is a material quantity for a stated area. 6 in. describes how deeply that compost is incorporated into the soil. It does not mean installing a 6 in. blanket of pure compost.

The compost requirement has soil test exceptions. I check the applicable soil information and approved requirements before ordering or directing tilling. I do not invent an exception because the soil looks good.

For a simple estimate, imagine the 600 sq. ft. planting area qualifies for the prescriptive option and requires the standard compost rate throughout. 600 is 0.6 of 1,000. 4 cu. yd. multiplied by 0.6 gives 2.4 cu. yd. of compost. That is the calculated minimum quantity for the stated area and rate.

Mulch is the surface treatment. The minimum 3 in. layer applies to exposed planting soil, with specified exceptions such as turf and situations involving groundcovers or direct seeding where mulch is contraindicated. I check the approved planting requirements rather than spreading the same material over every surface.

The physical connection is useful: organic matter incorporated into soil helps it retain water, while mulch on the surface helps reduce evaporation. Pouring the compost on top and calling it mulch does not accomplish the specified incorporation work.

For supervision, I check the compost quantity and incorporation before the finished surface hides the work. I retain delivery records and verify what was actually installed. A receipt can support the quantity delivered; it does not establish the depth of incorporation. That distinction matters when preparing the completion documentation.

The same attention to location applies to irrigation. Under the prescriptive requirements, a landscape area less than 10 ft. wide in any direction needs subsurface irrigation or another method that produces no water waste, runoff, or overspray.

Overspray means water lands beyond the intended watering area. Runoff means applied water flows away from the landscape instead of being absorbed there. A narrow bed beside a sidewalk can have either problem, or both.

Imagine an 8 ft. wide planting strip where the sprinkler throws water onto the adjacent concrete. Reducing the watering time leaves the spray pattern unchanged. I need the irrigation design corrected so the water stays within the intended area, using a compliant method. Subsurface drip can be one suitable approach; the requirement is not permission to ignore the rest of the irrigation design.

The prescriptive requirements also call for an automatic controller using weather information or soil moisture data, together with a rain sensor. A clock that simply repeats the same schedule is not the same specification.

I verify pressure regulation against the irrigation equipment manufacturer's operating range. I also check the manual shutoff near the water supply connection. For a General B supervisor, the useful question is whether the installed equipment matches the approved design and works as intended. A box labeled efficient is not the whole inspection.

I handle the paperwork in the same order as the work. During planning, I confirm the local ordinance, project classification, measured landscape area, and compliance path. Before installation, I coordinate the required plans and approvals. During installation, I retain the records needed to support completion.

At closeout, I verify the required completion package with the reviewing agency. I do not assume a few delivery receipts replace that package. I want the installed landscape, the irrigation operation, and the submitted information to agree.

That is the connection to general building supervision. Landscaping may arrive late in the schedule, but its design and documentation decisions belong much earlier. If I wait until the final inspection to ask which path applies, I have lost the easiest opportunity to correct the scope.

Keep the sequence: classify the project, measure the landscape area, check the local rule, then coordinate the compliance path and installation. That is how the threshold becomes a usable field decision.

I made an audio practice quiz specifically for this episode's landscape triggers, area calculations, and field checks. The questions are read aloud, and you answer by tapping. I designed it for studying on the go; save the tapping for when you are safely stopped if you are driving.

Go to the description below this video. You will see a link that says PassTheCSLB. Tap it. It will take you straight there.

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