Measure W — LA County's Safe, Clean Water Program
Los Angeles County voters passed Measure W in November 2018, taxing impermeable surface at 2.5 cents per square foot to fund stormwater capture across the Flood Control District's 88 cities. Nearly $1 billion has gone to almost 500 projects since 2020. A public portal maps every one — but the capture volumes it reports are modelled from designs and self-reported by grantees, not metered.
📊 Impact
Funded projects are projected to capture nearly 60,000 acre-feet of extra stormwater a year, a modelled figure rather than a metered one. The programme's 2023 oversight review found no methodology to stop captured water being double counted, and counted only about 30 acres of pavement removed countywide against 27.5 acres newly added.
🎓 Lesson
Los Angeles built the accounting layer before the measurement layer: it can show you every funded project on a map, but the acre-feet beside them are modelled from designs, and its own oversight review could not rule out double counting.
Sources
📎 Cite this project
1001 Smart Cities (2026). “Measure W — LA County's Safe, Clean Water Program” — Los Angeles, United States. The Smart City Atlas. https://1001smartcities.org/projects/la-stormwater-capture/ (last verified 2026-07-26). Data: CC BY 4.0.
The underlying data is free to reuse with attribution — see the open data page.
🔗 Related projects
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