Measure W — LA County's Safe, Clean Water Program

🤖 AI-generated summary · 🔎 Last verified 2026-07-26

This overview was generated with AI from the public sources listed below and checked against them before publication. It has not had a complete human fact-check — treat it as a starting point and follow the sources.

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A portal maps almost 500 funded projects, but the capture volumes beside them are modelled, not metered. The county's own review counted 30 acres of pavement removed against 27.5 newly added.

Outcome🔄 Ongoing

Evidence🏛️ Official

what does this mean?

The strongest source is the operator's or the city's own reporting — an official report, dataset or press release. It grades who did the looking — not how well the project went. All four grades →

Run byLos Angeles County Flood Control District, administered by LA County Public Works

Scale🗺️ Regional

Cost≈$285M a year from the parcel tax; ≈$1bn committed to ~500 projects since 2020

FundingLos Angeles County Flood Control District parcel tax (Measure W)

Part of 1001 Smart Cities — 1,167 documented projects · 🏙️ 12 more in Los Angeles · 💧 Water guide · 🌱 Environment projects

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.

Live 📅 since 2018

📊 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.

🌱 Environment Water Flood resilience GIS & cadastre

Sources

↗ Safe Clean Water LA — About Us (authority)Programme's own page: about $285 million a year from the special tax; 50% Regional Program, 40% Municipal, 10% District administration. Note the site also cites 'over $670 million for more than 100 projects', a narrower Regional-Program count than the countywide ~$1bn/~500 figure.

↗ SCW Portal — map, dashboard and reporting module (authority, the data layer)The public project register: per-project records, benefit metrics, expenditures and bid/award schedules. The companion Watershed Planning Tool states its figures represent modelled and user-reported benefits.

↗ Ballotpedia — LA County Flood Control District, Measure W (reference)Vote of 6 November 2018; 69.5% in favour against a two-thirds threshold. Its '$0.25 per square foot' summary is a factor-of-ten error; the rate is 2.5 cents.

↗ LAist — how to lower the new stormwater tax, 30 July 2019 (press)Carries the rate sentence-level: 'It's a 2.5-cent tax on every square foot of impermeable surface of your property', and names the county Flood Control District as administrator.

↗ LAist — the stormwater programme has a long way to go, 16 February 2023 (press)Reports the oversight review: no methodology to prevent double counting of captured water; 6 of 101 funded projects create new green space; ~30 acres of pavement removed against 27.5 acres added.

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↗ LA County Supervisor Horvath — Board adopts changes to expedite the programme, 19 March 2024 (authority)Nearly $1 billion invested in almost 500 projects since fall 2020; projects 'capture nearly 60,000 acre-feet annually of additional stormwater' — stated as a projection. The motion itself is the Board acting on slow delivery.

↗ LADWP — Stormwater Capture Master Plan (authority, separate City programme)Boundary source: the City utility's own 2015 plan, distinct from Measure W. Its capture figures are explicitly modelled — 'modeling conducted as part of this study showed that on average, the centralized facilities that exist today capture nearly 30,000 acre-feet of stormwater annually.'

↗ Pasadena Now — stormwater project targeting Eaton Fire runoff, 12 March 2026 (press)2026 currency: Jefferson Park infiltration gallery funded by Measure W local return plus a $191,180 SCWP grant, pre-design from December 2025, 567-acre drainage area including Eaton Fire burn land, up to 38.5 acre-feet a year; the $16.4M for design and construction is not yet secured.

Continue exploring

Compare this project

🇩🇰 Copenhagen's Cloudburst Management Plan · Copenhagen Two billion-scale programmes of hundreds of small projects: Copenhagen builds to shed rainwater, LA County taxes pavement to keep it. 🇹🇭 Bangkok's Million-Tree Register · Bangkok Both publish a public object-level register that undercuts its own headline: Bangkok's million was 35% trees, LA's acre-feet are modelled. 🇺🇸 CleanStat Street Cleanliness Index · Los Angeles Both mark their own homework: the crews grading LA's streets work for the department that cleans them, the acre-feet come from grantees.

Explore the wider context

🏙️ Urban digital twins compared 📖 Digital twin 📖 District metering area (DMA)📖 Flood early-warning system

📎 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.

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