Yes, permeable resin-bound surfacing can be part of a Los Angeles stormwater design, but only as the top layer of an engineered infiltration section that LA Sanitation and Environment (LASAN) accepts in a project's Low Impact Development plan. Laid over an old slab, it is a finish, not a stormwater control.

The rules shifted in 2024. Ordinance No. 188125 narrowed which projects need LID plan check, so many smaller jobs, including most ADUs, no longer trigger it. That leaves two separate questions for an owner or designer: does this project need LID at all, and if not, is a permeable surface still worth building to cut runoff and possibly reduce the Measure W parcel tax?

LASAN's LID ordinance after the 2024 threshold change

Post-construction stormwater rules in the City of Los Angeles flow from the Los Angeles Regional Water Quality Control Board's Regional Phase I MS4 Permit, Order No. R4-2021-0105, adopted July 23, 2021. LASAN is the City's lead agency for that permit and runs the LID Program under Los Angeles Municipal Code Section 64.72.

Ordinance No. 188125, effective April 2, 2024, brought the City's thresholds in line with the state permit. The earlier ordinance applied LID to projects that added, created or replaced 500 square feet or more of impervious area. The lowest trigger is now 2,500 square feet in an environmentally sensitive area, and the program otherwise focuses on larger developments. Where LID applies, a signed LID Plan Check Clearance is needed before building permits are approved, and LASAN checks the work again at Certificate of Occupancy.

Measure W, the Safe, Clean Water Program, adds a countywide angle: a parcel tax of 2.5 cents per square foot of impermeable area within the LA County Flood Control District. The County's credit program reviews improvements that capture or treat stormwater, with applications and biennial recertification due December 31. A resin-bound section over a real infiltration base is worth asking about. A resin overlay on concrete is not, because the slab underneath still sheds the water.

Alluvial valleys, hillsides and a short, intense wet season

Los Angeles gets most of its rain from a few winter storms, then goes months with almost none. That favors a base sized to take a storm's volume quickly and drain it down over the following days. The long dry season also lets dust and debris settle into the surface, so vacuum sweeping before the first storms belongs in the maintenance plan.

Ground conditions change block by block. Parts of the San Fernando Valley and the coastal plain sit on alluvial deposits that can infiltrate well, while hillside lots, clay pockets, mapped liquefaction areas and old fill on former industrial land can make infiltration unwise. These are calls for the project geotechnical engineer: test infiltration rates, check slope stability and foundation setbacks, and decide whether the section needs an underdrain or a liner. Where infiltration is ruled out, a permeable surface can still drain into a lined reservoir or biofiltration, but it should be documented that way, not as infiltration.

Where a permeable resin-bound surface fits in LA's building stock

Resin-bound earns its place where a decorative finish and drainage are both wanted. The strongest candidates are places where hardscape is already being rebuilt and the owner wants it to soak up rain:

Courtyards, motor courts and paseos in larger multifamily and mixed-use projects, where LID applies and room for planters is tight.
Plazas, school yards and campus walkways replaced as part of institutional redevelopment.
Driveways and patios at Westside and Valley homes, where owners want to cut runoff and may apply for a Measure W tax credit. The tax itself still counts paved and hardscape areas.
Restaurant and hotel terraces that need a jointless decorative finish that also drains.

Public sidewalks and streets are different. Work in the public right-of-way needs separate City permits and approval of the surface material, so plan on private property unless the City agrees otherwise.

Getting a resin-bound section through LASAN plan check

Start by confirming with LASAN whether your project falls under the ordinance at all. If it does, the civil engineer selects and sizes the BMPs and shows the permeable section on the LID plans with infiltration test results, base depth, any underdrain or liner, and a maintenance plan. Expect reviewers to treat the permeable area as an infiltration BMP that has to be justified, not as landscaping.

Resin Rock supplies the system and does not install it: UV-stable resin binder, natural stone aggregate blends, trims and the Rock Crete permeable sub-base. Our technical data sheets give your engineer product data for the submittal, and we can match you with an approved installer, usually within 24 hours. Contractors who want to install the system can apply for our California installer training.

Before you specify permeable resin-bound in Los Angeles

Confirm with LASAN whether Ordinance No. 188125 puts your project under LID plan check.
Get infiltration testing and a geotechnical review before choosing an infiltrating section.
Screen for hillside, liquefaction and contaminated-fill constraints that call for a liner or underdrain.
Keep resin-bound on private property unless the City approves it for the right-of-way.
Ask the Safe, Clean Water Program about a parcel tax credit before the December 31 deadline.
Write a maintenance plan that includes vacuum sweeping before the rainy season.

Common questions about permeable resin-bound in Los Angeles

Does my ADU or small remodel in Los Angeles need LID compliance?

Often not anymore. Since Ordinance No. 188125 took effect on April 2, 2024, most small projects, including most ADUs, fall outside the LID program. The lowest trigger is now 2,500 square feet of new or replaced impervious area in an environmentally sensitive area. Confirm with LASAN for your parcel, because location and scope both matter.

Will a resin-bound driveway lower my Measure W parcel tax?

It might, but nothing is automatic. The tax is 2.5 cents per square foot of impermeable area, and the County counts driveways, pavers and other hardscape as impermeable, so a new surface does not by itself lower the tax. Any saving would come through the County's separate credit program for improvements that capture or treat stormwater, after it reviews the design. A permeable section over an open-graded base has a case. Resin laid over the old concrete does not.

Can resin-bound go over my existing concrete patio?

Yes as a finish, no as a stormwater measure. Over a solid slab, rain passes through the resin layer and then runs off the concrete underneath, so it should not be shown as an LID BMP or claimed toward a credit. For stormwater value, the slab comes out and the section is rebuilt on a permeable base such as Rock Crete over an engineer-designed stone reservoir.

Official sources for Los Angeles

Local rules change. We last checked these sources in October 2026. Confirm current requirements with the reviewing agency before you design, and treat this page as a starting point, not engineering or permitting advice.

Permeable Resin-Bound Surfacing in Los Angeles, CA