What this is
This site publishes the working documents of an independent evidence programme concerning a single stretch of the tidal and freshwater Thames. It is not a campaign site and it does not ask you to accept a conclusion.
The purpose is narrow and practical: to assemble what is actually known about this reach of the river from official monitoring, published datasets and public records; to identify clearly where that evidence is thin, contested or absent; and to set out proportionate asks of the bodies that hold statutory responsibility for it. The material below is organised into two zones — the evidence base itself, and why it matters in the wider national picture. Everything is versioned, dated, and revised as new information is obtained.
- Sourced. Figures and claims are referenced to the dataset, publication or public record they came from, with a provenance tag.
- Provisional. Material is published at working-draft stage and marked with its version and date, not held back until it is final.
- Corrigible. Where a body identifies an error in this evidence, the correction is made and recorded.
Zone 1 · The evidence base
Evidence
Eight self-contained evidence pages, each built directly from primary data and every figure tagged with its provenance — RAW-PULL (data we downloaded and parsed), PUBLISHED (quoted from an official source), DERIVED (our inference from a stated rule) or ACCESS-BLOCKED (public in a browser but unreachable by automation). Read, cite and share them freely.
-
Evidence
Water quality
Dissolved oxygen, ammonia, phosphate, nutrients and temperature at Teddington Weir (freshwater) and Richmond (tidal) — 2,432 observations from the EA Water Quality Archive. Oxygenated but eutrophic above the weir; fish-stress oxygen sags below Mogden.
Working page · RAW-PULLOpen →
-
Evidence
Sewage & storm overflows
Mogden sewage works (permit CNTD.0085): storm-tank discharge hours and counted spills to the tidal Thames, 2020–2025. 2024 was the worst year on record — 471.7 hours across 50 spills. Duration only; no volume is published anywhere.
Working page · RAW-PULLOpen →
-
Evidence
WFD status & compliance
Water Framework Directive classifications for the river and tidal bodies: below "good" for three cycles, sewage discharge named as a reason on both, and the chemical objective relaxed to 2063 citing "disproportionate burdens".
Working page · RAW-PULLOpen →
-
Evidence
Fish & aquatic ecology
A 32-year Richmond seine-net series, the collapse of the Critically Endangered European eel (12 in 1993 to none after 2019), and an honest audit of how thin the mainstem ecological evidence really is.
Working page · RAW-PULLOpen →
-
Evidence
Birds & biodiversity
142,070 NBN Atlas records: 19,469 waterbird records across 23 species, indicator species (eel, smelt, quagga mussel) and the effort-versus-population caveat that means these counts are context, not proof of cause.
Working page · RAW-PULLOpen →
-
Evidence
Bathing water
England's first designated river bathing water at Ham & Kingston (designated 15 May 2026): the E. coli and intestinal enterococci samples now coming in, and why no formal "safe to swim" classification is due until about 2029.
Working page · PUBLISHEDOpen →
-
Evidence
Accountability & context
The regulatory record: Ofwat's record £122.7m penalty (May 2025), 523 pollution incidents and a bottom 1-star rating in 2024, and ZSL's long-term State of the Thames temperature and oxygen trends. Fines proven; charges kept distinct from convictions.
Working page · PUBLISHEDOpen →
-
Interactive
Cross-correlations
The interactive flagship: where the strands meet — storm spills, dissolved oxygen, season and ecology — shown together, with correlation held carefully apart from causation and every asserted link flagged as such.
Interactive · mixed provenanceOpen →
Zone 2 · The wider picture
Why it matters / In the news
The reach does not sit in isolation. A five-year sweep of 88 catalogued news items — from Thames Water's finances and record penalties to the Water (Special Measures) Act 2025 and the local Teddington abstraction saga — sets out why this evidence matters and what is at stake for the river and the people who use it. Legal status is stated with care: "charged" and "alleged" are never presented as "convicted"; regulatory fines are kept distinct from criminal convictions.
-
News
Why it matters / In the news
The national and local context in one place: the biggest stories of the last five years, the regulatory reforms now under way, and how the Teddington-to-Richmond reach fits the wider story of water in England.
Awareness zone · 88 sourced itemsOpen →