The supply-area layer every postcode on these pages resolves against measures 16 regional companies of public water supply, per the water industry's own Water Company Boundaries layer (UC2) (19 September 2026, read 20 September 2026).
Source: the water industry's own Water Company Boundaries layer (UC2) β dated 19 September 2026, read 20 September 2026Water company boundaries Β© Water UK, licensed under CC BY 4.0
Who publishes this
TapWaterData is based in the United States. This section of the site is written for readers in this country, in this country's units, against this country's own regulator β but the people who build it are not here, and that is worth knowing before you weigh anything on the page.
What that means in practice is that nothing here rests on local knowledge. Every statement is traceable to a document published by a water company or by a public body, and the page prints the address of that document and the day somebody opened it.
How a figure gets onto a page here
A source is read once, whole, and kept: the bytes are committed to the repository that builds this site, so a figure can be checked against the document it was taken from rather than against a memory of it. A parser turns that document into rows, and a row that cannot be read is set aside and counted rather than guessed at.
The figure is then printed with the publisher's name, the address it came from and the date it was read, and it is described using the regulator's own published scale. Where a publisher contradicts itself, the page withholds the figure and says that the publisher's own document disagrees with itself.
What this section will not do
It will not estimate. If a supplier publishes no figure for an area, the page says so instead of interpolating one from a neighbouring area, from geology, or from an average of the places that did publish.
It will not ask a supplier's website one address at a time in order to rebuild a dataset the supplier has chosen not to publish. Where a figure exists only behind such a lookup, what this site holds is a bounded sample, and the page says which it is.
And it will not describe water as fit or unfit to drink on its own authority. That judgement belongs to the regulator named below, against standards the regulator publishes itself.
Every source these pages use
| Source | What it gives these pages | Licence | How often it is published | Read |
|---|---|---|---|---|
| Office for National Statistics β ONS Postcode Directory (May 2026) | Which district and small-area code a postcode sits in. Every supply-area lookup joins through it, and no coordinate is ever derived from anything else. | Open Government Licence v3.0Contains OS data Β© Crown copyright and database right 2026Contains Royal Mail data Β© Royal Mail copyright and database right 2026Source: Office for National Statistics licensed under the Open Government Licence v.3.0 | on no published schedule β the publisher announces none | Source: Office for National Statistics β ONS Postcode Directory (May 2026) β read 19 September 2026 |
| Water Company Boundaries (UC2), published by Water UK on the water industry's shared data portal | Which company supplies a postcode, and the supply areas each company publishes for itself: 16 regional companies. | Creative Commons Attribution 4.0 (CC BY 4.0)Water company boundaries Β© Water UK, licensed under CC BY 4.0 | on no published schedule β the publisher announces none | Source: the water industry's own Water Company Boundaries layer (UC2) β dated 19 September 2026, read 20 September 2026Water company boundaries Β© Water UK, licensed under CC BY 4.0 |
| The water companies' drinking water quality results, on the water industry's shared data portal | How many sample results each company publishes, and where: 46 datasets from 13 of the 16 regional companies, each with its own count of results. | No licence statement was recorded when this was read. It is a public map service the industry publishes, read as published. | on no published schedule β the publisher announces none | Source: the Stream ArcGIS organisation β every service it publishes, enumerated β dated 20 September 2026, read 20 September 2026 |
| South Staffs Water β water quality zones (town β zone table) | The supply zones this publisher lists, and the codes it publishes them under. | No licence statement was recorded when this was read. It is a water company's own publication, read as published. | on no published schedule β the publisher announces none | Source: South Staffs Water β water quality zones (town β zone table) β dated 20 September 2026, read 20 September 2026 |
| South Staffs Water β sitemap.xml (one URL per zone page) | The supply zones this publisher lists, and the codes it publishes them under. | No licence statement was recorded when this was read. It is a water company's own publication, read as published. | on no published schedule β the publisher announces none | Source: South Staffs Water β sitemap.xml (one URL per zone page) β dated 20 September 2026, read 20 September 2026 |
| Cambridge Water β sitemap.xml (one URL per zone page) | The supply zones this publisher lists, and the codes it publishes them under. | No licence statement was recorded when this was read. It is a water company's own publication, read as published. | on no published schedule β the publisher announces none | Source: Cambridge Water β sitemap.xml (one URL per zone page) β dated 20 September 2026, read 20 September 2026 |
| South Staffordshire Water β supply-zone water quality reports | 35 supply zones, read from the company's own annual zone reports. | No licence statement was recorded when this was read. It is a water company's own publication, read as published. | once a year | Source: South Staffordshire Water β supply-zone water quality reports β dated 31 December 2025, read 20 September 2026 |
| Yorkshire Water β Water quality report for 1st January 2024 - 31st December 2024 | 4 supply zones from 6 postcode lookups of the company's own checker β a bounded sample, not a published list. | No licence statement was recorded when this was read. It is a water company's own publication, read as published. | once a year | Source: Yorkshire Water β Water quality report for 1st January 2024 - 31st December 2024 β dated 31 December 2024, read 20 September 2026 |
| Environment Agency β the weekly report on dry weather and drought in England | Which water companies have a temporary use ban in force in England, and the area each covers, as the Environment Agency lists them each week. It covers England only and states no date a ban began. | Open Government Licence v3.0All content is available under the Open Government Licence v3.0, except where otherwise stated Β© Crown copyright | on no published schedule β the publisher announces none | Source: Environment Agency β dated 11 October 2026, read 11 October 2026 |
| The Gazette β water companies' statutory ban and removal notices | Each temporary use ban a water company gives statutory notice of in The Gazette, and each notice removing one, in England and Wales alike. These pages link a company's ban notices beside its status so you can read the area and the dates each one states; they print no start or lift date of their own. | Open Government Licence v3.0All content is available under the Open Government Licence v3.0, except where otherwise stated. | on no published schedule β the publisher announces none | Source: The Gazette, notice 5228870 β dated 9 October 2026, read 11 October 2026 |
| The water companies' own hosepipe-ban notices | Each company's own wording, read from its own page: 16 read this cycle, of which 3 answered with something that is not a notice; 2 not asked, because the company's site refuses automated readers. | No licence statement was recorded when this was read. It is a water company's own publication, read as published. | on no published schedule β the publisher announces none | Source: Affinity Water β dated 11 October 2026, read 11 October 2026 |
| Environment Agency β Event Duration Monitoring, storm overflows | The statutory annual return: spill count, duration and monitor availability per outfall, across 6 published return years. | Β© Environment Agency copyright and/or database right 2025. All rights reserved.The Environment Agency's catalogue record for this dataset declares no licence β its licence id, title and address are each empty β so its copyright notice, carried beside every figure these pages take from it, is the only permission statement it makes. | once a year | Source: Environment Agency β Event Duration Monitoring: Storm Overflows Annual Returns β dated 20 September 2026, read 20 September 2026 |
What we do not have
Everything about Scottish Water
We hold no drinking-water data for Scotland. Every source this site reads β the water companies' published quality results, their supply-zone hardness reports, the regulator's supply-zone notices and the Environment Agency's storm-overflow return β covers England and Wales only. Scotland's drinking water is regulated separately, by the Drinking Water Quality Regulator for Scotland.
Read: Scottish Water β the source that names it as the public supplier β dated 19 September 2026, read 19 September 2026
Everything about Northern Ireland Water
We hold no drinking-water data for Northern Ireland. Every source this site reads covers England and Wales only, and Northern Ireland's drinking water is regulated separately, by the Drinking Water Inspectorate for Northern Ireland.
Read: Northern Ireland Water β the source that names it as the public supplier β dated 19 September 2026, read 19 September 2026
Compliance monitoring for the companies that publish none
3 of the 16 regional companies publish no drinking water quality results on the shared data portal the others use: South East Water, Thames Water, Wessex Water. Their results are absent here, not zero, and no page in this section treats them as companies with nothing found.
Read: the Stream ArcGIS organisation β every service it publishes, enumerated β dated 20 September 2026, read 20 September 2026
Hardness figures from the regulator
The regulator publishes the scale water hardness is described against and no values at all, so every figure here is a water company's own. 15 of the 16 regional companies publish no bulk per-zone list either, which is why most of this country has no hardness figure on this site.
Read: Drinking Water Inspectorate β Water Hardness / Hard Water ("Water Hardness (mg/l CaCO3)") β dated 20 September 2026, read 20 September 2026
A bulk register of supply zones β looked for at www.dwi.gov.uk
2,222 URLs across the 16 children, 2,220 distinct. TWELVE contain the string 'zone', and they are NOT all incidental: 5 are ozone chemistry, 1 is a nitrate groundwater PROTECTION zone, 1 is the pesticide 'bentazone' (a substring, not a zone at all), 1 is a private-water-supply feasibility study β and FOUR are real water supply zone ENFORCEMENT NOTICES naming three companies. So the regulator does publish some zoneβcompany data. What it does not publish, anywhere in its advertised URL set, is a LIST: no zone register, no zone dataset, no zone download.
Read: Drinking Water Inspectorate β every URL the regulator advertises, via its own Yoast sitemap index and ALL 16 child sitemaps it lists (post, page, research, case-study, imprvmnt-programme, guidance-document, report, category, topic, case-study-topic, imprvmnt-programme-water-comp, imprvmnt-programme-parameter, imprvmnt-programme-type, region, guidance-document-regulation, guidance-document-country) β dated 20 September 2026, read 20 September 2026
A bulk register of supply zones β looked for at services-eu1.arcgis.com
203 services, of which none has 'zone' in its name. The field search covers a subset, and says so: the 69 services whose names match water-quality/drinking/DWI/supply/boundary were opened, giving 42 layers, and across those 42 layers there are 32 distinct field names β NONE matching zone, supply, area or WSZ. Every result is located by census small area (LSOA) instead. All 203 service names were read; the fields were read for the 69 that could plausibly carry a zone, and the remaining 134 (reservoir levels, consumption, storm-overflow returns, annual performance tables, survey forms) were not opened.
Read: the water industry's shared data portal β whether the drinking water quality datasets this site already reads carry a supply-zone column β dated 20 September 2026, read 20 September 2026
A bulk register of supply zones β looked for at data.gov.uk
1,812 hits, whose top match 'Water Supply Zones 2014' is OpenDataNI β NORTHERN IRELAND only, and therefore outside the England & Wales scope every source in this split covers. Re-run for 'drinking water inspectorate': 203 hits, none an England & Wales zone registry.
Read: data.gov.uk β a published England & Wales water supply zone dataset β dated 20 September 2026, read 20 September 2026
Anglian Water's own hosepipe-ban notice
The company's page could not be read when it was checked, so no status on these pages rests on it. An unread page is never treated as one saying there is no ban.
Read: Water Company Boundaries (UC2) β dated 19 September 2026, read 20 September 2026Water company boundaries Β© Water UK, licensed under CC BY 4.0
Southern Water's own hosepipe-ban notice
The company's page could not be read when it was checked, so no status on these pages rests on it. An unread page is never treated as one saying there is no ban.
Read: Water Company Boundaries (UC2) β dated 19 September 2026, read 20 September 2026Water company boundaries Β© Water UK, licensed under CC BY 4.0
DΕ΅r Cymru's own hosepipe-ban notice
The company's site refuses automated readers, so its page is not asked, and no status on these pages rests on it. A page we do not read is never treated as one saying there is no ban.
Read: Water Company Boundaries (UC2) β dated 19 September 2026, read 20 September 2026Water company boundaries Β© Water UK, licensed under CC BY 4.0
Wessex Water's own hosepipe-ban notice
The company's site refuses automated readers, so its page is not asked, and no status on these pages rests on it. A page we do not read is never treated as one saying there is no ban.
Read: Water Company Boundaries (UC2) β dated 19 September 2026, read 20 September 2026Water company boundaries Β© Water UK, licensed under CC BY 4.0
Scottish Water's own hosepipe-ban notice
The company's page could not be read when it was checked, so no status on these pages rests on it. An unread page is never treated as one saying there is no ban.
Read: Scottish Water β dated 19 September 2026, read 19 September 2026
The storm-overflow record, outfall by outfall
The Environment Agency's annual return publishes a row for every monitored storm overflow, across 6 published return years, and what this site holds of those per-overflow rows is a sample rather than a whole return. The per-company totals the same returns publish are on this section's storm-overflow pages; the individual outfalls are not, and no page here ranks one company's own outfalls against each other.
Read: Environment Agency β Event Duration Monitoring: Storm Overflows Annual Returns β dated 20 September 2026, read 20 September 2026
Who regulates water in the United Kingdom
Drinking Water Inspectorate (DWI) enforces the UK drinking water quality regulations in England and Wales. Nothing on these pages is our own standard: where a figure is described, it is described in that regulatorβs own published terms.
Telling us we are wrong
If a figure here disagrees with your own supplierβs publication, we would rather hear it than not. Every page carries the source it came from and the day it was read, so a correction can name both.
The dates above are the days these sources were read, not the day this page was built. Last source read: 11 October 2026.