Skip to main content
CityRuleLookup
🌍 Environmental Rules/Stormwater Management

Stormwater Management: Topanga vs West Covina

How do stormwater management rules compare between Topanga, CA and West Covina, CA?

Topanga and West Covina have similar restriction levels.

Topanga, CA

Los Angeles County

Some Restrictions

Unincorporated LA County falls under the LA County MS4 NPDES permit. The LACFCD operates one of the largest flood protection systems in the world, including 14 dams and 80,000+ catch basins. Low Impact Development standards apply to new construction. The district captures and infiltrates 270,000+ acre-feet annually.

View full Topanga rules β†’

West Covina, CA

Los Angeles County

Some Restrictions

West Covina enforces stormwater management under the LA County MS4 permit and NPDES requirements. Construction projects must implement BMPs. The city participates in the San Gabriel River watershed programs.

View full West Covina rules β†’

Key Facts Comparison

FactTopangaWest Covina
MS4 PermitLA County NPDES-
LID RequiredFor new development-
LACFCD14 dams, 80,000+ catch basins-
Annual Capture270,000+ acre-feet infiltrated-
Permit-LA County MS4 / NPDES
BMPs-Required for construction projects
Watershed-San Gabriel River
Authority-LA Regional Water Quality Control Board

Highlighted rows indicate differences between cities.

Topanga FAQ

What can go into storm drains in LA County?

Only stormwater. Illicit discharge of chemicals, wash water, paint, oil, or other pollutants is prohibited under Title 12 and the MS4 permit. Storm drains flow directly to rivers, ocean, and groundwater.

What are LID standards?

Low Impact Development standards require new development to capture and treat stormwater on-site through features like bioswales, permeable paving, cisterns, or rain gardens. They apply to new construction and major renovations.

How do I report illegal dumping into storm drains?

Call the LA County illegal dumping hotline at (888) 846-0800. For active spills or hazardous discharges, call 911 or the LA County Fire Department hazmat line.

West Covina FAQ

Do I need a stormwater plan for my project?

Generally required for new construction and major renovations that increase impervious surface area. Small residential projects may be exempt.

What is an illicit discharge?

Any non-stormwater substance entering the storm drain system, including paint, oil, chemicals, or sediment. Report violations to West Covina public works.

Want to add a third city?

Use our full comparison tool to compare up to three cities.

Open Comparison Tool