United Utilities' Storm-Overflow Monitors and Live Spill Map in Manchester
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.
22 sourced claims on this page, none individually verified yet — turn on “Sources in the text” to see each one.
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In 2025 a monitor counted 50 sewage spills from Aspin Lane into Manchester's River Irk; in 2026 the overflow was sealed. Another on the same river spilled 92 times, with no improvement logged.
what does this mean?
The strongest source is an independent non-academic evaluation: an audit office, a government or EU review, or an NGO. It grades who did the looking — not how well the project went. All four grades →Part of 1001 Smart Cities — 1,216 documented projects · 🏙️ 8 more in Manchester · 💧 Water guide · 🌱 Environment projects
United Utilities, the stock-market-listed company that runs water and sewerage across North West England, has an event duration monitor on every one of its storm overflows, including the relief points where central and north Manchester's combined sewers spill into the Rivers Irk and Medlock in heavy rain. The monitors record how often and for how long each overflow discharges. Every year the company returns those figures to the Environment Agency, which publishes them overflow by overflow, and since April 2024 it has also shown each overflow's status on an interactive near-real-time map; companies aim to transmit a discharge within an hour. An overflow that spills more than 30 times in a year has to be given a reason in the return. The operator is a regional private utility, not the city council.
📊 Impact
In 2025 the Aspin Lane overflow on the River Irk, on the edge of the Green Quarter and NOMA district, spilled 50 times for a total of 35 hours (its long-term average is 53 spills a year); the return gives the reason as hydraulic capacity and marks an Environment Act improvement as ongoing. In 2026 United Utilities invested £1.3 million to disconnect surface water from the combined sewer there and sealed the overflow off. On the same river the Rochdale Road/Collyhurst overflow spilled 92 times, for 415 hours, with no improvement action in the reporting period. Across the North West the company reported a 22% reduction in spill numbers in 2025 and credits 129 interventions at 125 Greater Manchester overflows with preventing 4,225 activations; these are its own figures. The regulators' view is harsher: the Environment Agency rated the company four stars for 2023 and two stars, 'requires improvement', for 2024, when its 347 sewerage pollution incidents were rated red; and an Ofwat enforcement case opened in 2024 was still unresolved at 31 March 2026, with a possible penalty the company puts at around £100 million. No source measures water quality in the Irk after the overflow was sealed.
🎓 Lesson
A monitor on every overflow turns a sewer's failures into a public count per pipe, and the count can carry a rule: more than 30 spills in a year and the company has to explain itself to the regulator. The monitor does not decide which pipe is fixed. In Manchester one overflow on the Irk was sealed off in 2026 after a year of 50 spills, as part of the company's wider programme, while another on the same river logged 92 with no improvement action. The regulators' consequences arrive at company level and slowly: Ofwat's case, opened in 2024, was still open in 2026.
Sources
Show 3 more sourcesShow fewer
📅 How old is the evidence?
Two clocks, kept apart: when this entry’s sources were published, and what has happened to its record in the atlas. Documented span: since 2019. 7 of 8 sources carry a publication date, from 30 April 2024 to 17 August 2026.
When the sources were published
- Utility Week · pressUtility Week — Three water companies launch live sewage discharge maps (30 Apr 2024)
- UK Government (GOV.UK) · national governmentEnvironment Agency — United Utilities EPA data report 2024
- United Utilities · utilityUnited Utilities — Response to environmental information request EIR-738 (20 Mar 2026)
- Environment Agency · national governmentEnvironment Agency — Event Duration Monitoring: Storm Overflow Annual Return 2025 (dataset and documentation) · updated August 2026
- United Utilities · utilityUnited Utilities — United Utilities cuts storm overflow spills across the North West (26 Mar 2026)
- United Utilities · utilityUnited Utilities Group PLC — Preliminary full year results for the year ended 31 March 2026 (30 Apr 2026)
- United Utilities · utilityUnited Utilities — United Utilities completes Manchester sewer improvement scheme (17 Aug 2026)
Show your work What this page rests on and what it can’t tell you · all 22 claims with their sources · the forensic record
Evidence file · public beta 22 addressable claims, 8 source dossiers, one permanent baseline. The file is unreviewed — an AI-assisted structural migration, not a human or expert endorsement. Every revision keeps a permanent copy under revision history.
Inspect the claims, one by one — verbatim text, sources and caveats for all 22
The text below is copied verbatim from the published record. Each claim names the source dossiers that carry it; caveats stay attached to the claim they qualify.
clm-71a34d7df22999bf
descriptive
United Utilities, the stock-market-listed company that runs water and sewerage across North West England
Sources carrying this claim
clm-b70d86284754032b
descriptive
has an event duration monitor on every one of its storm overflows
Sources carrying this claim
clm-15445329ef5a0bd2
descriptive
including the relief points where central and north Manchester's combined sewers spill into the Rivers Irk and Medlock
Sources carrying this claim
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descriptive
The monitors record how often and for how long each overflow discharges.
Sources carrying this claim
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descriptive
Every year the company returns those figures to the Environment Agency, which publishes them overflow by overflow
Sources carrying this claim
clm-60af3a159ce79f37
quantitative
since April 2024 it has also shown each overflow's status on an interactive near-real-time map
Sources carrying this claim
clm-442e0f91bf06691f
descriptive
companies aim to transmit a discharge within an hour
Sources carrying this claim
clm-b017400ab404c402
quantitative
An overflow that spills more than 30 times in a year has to be given a reason in the return.
Sources carrying this claim
clm-48f6508092259b3f
descriptive
The operator is a regional private utility
Sources carrying this claim
clm-65d5835808d6273e
quantitative
In 2025 the Aspin Lane overflow on the River Irk, on the edge of the Green Quarter and NOMA district, spilled 50 times for a total of 35 hours
Sources carrying this claim
clm-15566676a4fbbbeb
quantitative
(its long-term average is 53 spills a year); the return gives the reason as hydraulic capacity and marks an Environment Act improvement as ongoing
Sources carrying this claim
clm-83238e8a9b61f026
quantitative
In 2026 United Utilities invested £1.3 million to disconnect surface water from the combined sewer there and sealed the overflow off.
Sources carrying this claim
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quantitative
On the same river the Rochdale Road/Collyhurst overflow spilled 92 times, for 415 hours, with no improvement action in the reporting period.
Sources carrying this claim
clm-401a48fe052b5433
quantitative
Across the North West the company reported a 22% reduction in spill numbers in 2025
Sources carrying this claim
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quantitative
credits 129 interventions at 125 Greater Manchester overflows with preventing 4,225 activations; these are its own figures
Sources carrying this claim
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quantitative
the Environment Agency rated the company four stars for 2023 and two stars, 'requires improvement', for 2024
Sources carrying this claim
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quantitative
its 347 sewerage pollution incidents were rated red
Sources carrying this claim
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quantitative
an Ofwat enforcement case opened in 2024 was still unresolved at 31 March 2026, with a possible penalty the company puts at around £100 million
Sources carrying this claim
clm-182ed027687d03a2
quantitative
more than 30 spills in a year and the company has to explain itself to the regulator
Sources carrying this claim
clm-a5344da661cac9dd
quantitative
In Manchester one overflow on the Irk was sealed off in 2026 after a year of 50 spills, as part of the company's wider programme
Sources carrying this claim
clm-c52b647885dba0ae
quantitative
while another on the same river logged 92 with no improvement action
Sources carrying this claim
clm-3f6aae82657b262c
quantitative
Ofwat's case, opened in 2024, was still open in 2026
Sources carrying this claim
Forensic record — source dossiers, gaps, hashes and the exact revision this page renders
This layer records what is known about each source, what is still missing, and the exact snapshot this page is rendering. A missing date, archive or hash stays visible as missing.
Awaiting operator and domain-expert review; publication of this revision implies neither.
sha256:38c9c9b8059ac9a2603d7a22fd5e9390d772450a72c07053a5b999bd57e332a0
- 22
- of 22 claims mapped
- 8
- source dossiers
- 7
- publication dates recorded
- 0
- archives linked
- 0
- exact locators
- 0
- content captures hashed
Governance facts carried by the record
- Operator
- United Utilities Water Limited (regional private water and sewerage company for North West England); annual returns reviewed and published by the Environment Agency
- Actor types
- utility, national-government
- Funding model
- utility
- Funding description
- United Utilities; the Aspin Lane overflow removal cost £1.3 million and forms part of the company's 2025–30 investment programme. No budget for the monitoring itself located.
- Cost
- Not recorded
- Ownership
- Not recorded
- Decision rights
- Not recorded
- Exit conditions
- Not recorded
8 source dossiers
Environment Agency — Event Duration Monitoring: Storm Overflow Annual Return 2025 (dataset and documentation)
- Stable source ID
src-cf77377d65bb73d5- Publisher
- Name not classified · environment.data.gov.uk
- Type / language
- web-page · language not classified
- Published
- 2026-03-26
- Updated
- Not recorded
- Source last checked
- No source-level check date
- Record last verified
- 2026-10-16
- Dossier created
- 2026-10-16
- Retrieved copy
- No local capture recorded
- Archive
- No archived copy linked
- Content hash
- No captured content hash
- Locator
- Descriptive only — not page/paragraph exact
Open the recorded source note
The regulator's dataset of every monitored storm overflow in England for 2025, with its documentation. United Utilities' sheet lists ASPIN LANE CSO 281CJ (River Irk): 50 counted spills, duration 35:04:00, long-term average 53, data from 2019, reason 'Not asset maintenance - Hydraulic capacity', 'Env Act (SODRP) improvement ongoing'; and the Rochdale Road/Collyhurst CSO (River Irk): 92 spills, 415:26:00, 'No improvement action in reporting period'. The documentation defines the counts and the single-year high spill frequency threshold of more than 30. The workbook notes it was updated in August 2026 after a re-submission by another company.
Environment Agency — United Utilities EPA data report 2024
- Stable source ID
src-45332543d2906e2d- Publisher
- Name not classified · gov.uk
- Type / language
- web-page · language not classified
- Published
- 2025-10-23
- Updated
- Not recorded
- Source last checked
- No source-level check date
- Record last verified
- 2026-10-16
- Dossier created
- 2026-10-16
- Retrieved copy
- No local capture recorded
- Archive
- No archived copy linked
- Content hash
- No captured content hash
- Locator
- Descriptive only — not page/paragraph exact
Open the recorded source note
The Environment Agency's annual assessment of the company: four stars ('Industry leading company') for 2023 and two stars ('Company requires improvement') for 2024; 347 sewerage pollution incidents in 2024, rated red, against 216 in 2023; 2,270 active storm overflows, all with event duration monitoring commissioned.
United Utilities — United Utilities completes Manchester sewer improvement scheme (17 Aug 2026)
- Stable source ID
src-519d30ab9a5d9102- Publisher
- Name not classified · corporate.unitedutilities.com
- Type / language
- web-page · language not classified
- Published
- 2026-08-17
- Updated
- Not recorded
- Source last checked
- No source-level check date
- Record last verified
- 2026-10-16
- Dossier created
- 2026-10-16
- Retrieved copy
- No local capture recorded
- Archive
- No archived copy linked
- Content hash
- No captured content hash
- Locator
- Descriptive only — not page/paragraph exact
Open the recorded source note
Company announcement: £1.3 million spent disconnecting surface water drainage from the combined sewer at Aspin Lane, on the edge of Manchester's Green Quarter and NOMA district; enough surface water removed to prevent the storm overflow from operating, and the overflow sealed off; work began in June and finished ahead of a 19-week schedule; part of the company's wider programme to improve rivers.
United Utilities — United Utilities cuts storm overflow spills across the North West (26 Mar 2026)
- Stable source ID
src-766162f954d9c0c0- Publisher
- Name not classified · corporate.unitedutilities.com
- Type / language
- web-page · language not classified
- Published
- 2026-03-26
- Updated
- Not recorded
- Source last checked
- No source-level check date
- Record last verified
- 2026-10-16
- Dossier created
- 2026-10-16
- Retrieved copy
- No local capture recorded
- Archive
- No archived copy linked
- Content hash
- No captured content hash
- Locator
- Descriptive only — not page/paragraph exact
Open the recorded source note
Company announcement on the day the Environment Agency released the 2025 figures: a 22% reduction in spill numbers (16,974 fewer) and 27% in duration across the North West; across Greater Manchester, 129 interventions at 125 storm overflows that the company says prevented 4,225 activations.
- Claims linked
United Utilities Group PLC — Preliminary full year results for the year ended 31 March 2026 (30 Apr 2026)
- Stable source ID
src-c3911a1e0c0c2a6c- Publisher
- Name not classified · unitedutilities.com
- Type / language
- pdf · language not classified
- Published
- 2026-04-30
- Updated
- Not recorded
- Source last checked
- No source-level check date
- Record last verified
- 2026-10-16
- Dossier created
- 2026-10-16
- Retrieved copy
- No local capture recorded
- Archive
- No archived copy linked
- Content hash
- No captured content hash
- Locator
- Descriptive only — not page/paragraph exact
Open the recorded source note
Stock-exchange results statement. Under contingent liabilities: the water company remains subject to the enforcement case Ofwat opened in 2024; a penalty could reach 10 per cent of relevant wastewater turnover, around £100 million; no provision recognised; no firm timeframe for conclusion; a parallel Environment Agency investigation into permit compliance is ongoing.
Utility Week — Three water companies launch live sewage discharge maps (30 Apr 2024)
- Stable source ID
src-5c1f0e2b9e012068- Publisher
- Name not classified · staging4.utilityweek.co.uk
- Type / language
- web-page · language not classified
- Published
- 2024-04-30
- Updated
- Not recorded
- Source last checked
- No source-level check date
- Record last verified
- 2026-10-16
- Dossier created
- 2026-10-16
- Retrieved copy
- No local capture recorded
- Archive
- No archived copy linked
- Content hash
- No captured content hash
- Locator
- Descriptive only — not page/paragraph exact
Open the recorded source note
Trade-press report by Ruth Williams: Northumbrian, United Utilities and Yorkshire have launched interactive near-real time digital maps of storm overflows in their regions ahead of bathing water season, showing locations and ongoing operations.
- Claims linked
United Utilities — Response to environmental information request EIR-738 (20 Mar 2026)
- Stable source ID
src-f779ebd75e1bcf00- Publisher
- Name not classified · cumbria.unitedutilities.com
- Type / language
- pdf · language not classified
- Published
- 2026-03-20
- Updated
- Not recorded
- Source last checked
- No source-level check date
- Record last verified
- 2026-10-16
- Dossier created
- 2026-10-16
- Retrieved copy
- No local capture recorded
- Archive
- No archived copy linked
- Content hash
- No captured content hash
- Locator
- Descriptive only — not page/paragraph exact
Open the recorded source note
The company's reply to an information request (about an area of the Wirral). Explains the data flow: near-real-time data detected by event duration monitors goes to each company's cloud storage and on to the map and the national Stream hub; companies aim to transmit a discharge within an hour; raw telemetry is unvalidated.
- Claims linked
United Utilities Better Rivers — What is the storm overflow map?
- Stable source ID
src-56f915b5c842f64f- Publisher
- Name not classified · unitedutilities.com
- Type / language
- web-page · language not classified
- Published
- Not recorded
- Updated
- Not recorded
- Source last checked
- No source-level check date
- Record last verified
- 2026-10-16
- Dossier created
- 2026-10-16
- Retrieved copy
- No local capture recorded
- Archive
- No archived copy linked
- Content hash
- No captured content hash
- Locator
- Descriptive only — not page/paragraph exact
Open the recorded source note
The company's description of its map: interactive and near real-time, including all its storm overflows.
- Claims linked
Known limits of this file
- Publisher names and source languages have not yet been classified; domains are recorded without guessing.
- Existing source notes are descriptive locators, not page- or paragraph-exact citations.
- A missing archive, publication date or content hash is shown as null rather than inferred.
- The project-level evidence grade ranks the strongest source in the entry; it is not a truth score for every claim.
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📎 Cite this project
1001 Smart Cities (2026). “United Utilities' Storm-Overflow Monitors and Live Spill Map in Manchester” — Manchester, United Kingdom. The Smart City Atlas. https://1001smartcities.org/projects/manchester-storm-overflow-monitoring/ (last verified 2026-10-16). Data: CC BY 4.0.
The underlying data is free to reuse with attribution — see the open data page.
