Los Angeles County, California, USA
#00214
Case study of
#00199 Stormwater capture and managed aquifer recharge funded by a dedicated impermeability levy
Implementer
Los Angeles County Flood Control District (Safe Clean Water Program) and LADWP
Timeline
Since Nov 1, 2018
Location
Description
Measure W, the Safe Clean Water Program, passed in November 2018 with ~69% voter support, creating a ~$280M/yr parcel tax on impermeable area, hypothecated to stormwater capture and quality projects. By 2024 more than $1bn had been invested. LADWP captures over 83,000 acre-feet per year on average; a single storm event yielded up to 5.5bn gallons. The transferable piece is the financing instrument: taxing the pavement that causes the runoff, with proceeds locked to stormwater capture and quality infrastructure. Governance reforms were adopted in 2024–25 to speed spending and tighten accountability after project delivery lagged revenue collection.
Metrics
6Funding
Lessons learned
- A hypothecated tax on impermeable area passed with nearly 70% support: linking the charge directly to the cause of runoff made the levy politically sellable.
- Money is not the bottleneck: delivery lagged revenue collection, and governance reforms were required within six years of passage — structure the program management and permitting pipeline before funds accumulate.
- Stormwater capture at this scale (~83,000 acre-feet/yr) is a meaningful supplement but remains under 10% of regional demand; plan it as a risk buffer, not a primary supply replacement.
Sources
1Documented Jul 24, 2026