Tryweryn reservoir scheme
E900770
The Tryweryn reservoir scheme was a controversial mid-20th-century project by Liverpool Corporation to flood the Welsh village of Capel Celyn to create a water supply reservoir, becoming a lasting symbol of Welsh nationalist grievance.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Tryweryn reservoir scheme canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T11038644 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Tryweryn reservoir scheme Context triple: [Llyn Celyn, createdBy, Tryweryn reservoir scheme]
-
A.
Clywedog Reservoir
Clywedog Reservoir is a large man-made lake in mid-Wales, created for water regulation and recreation amid scenic upland surroundings.
-
B.
Claerwen Reservoir
Claerwen Reservoir is a large upland water reservoir in mid Wales, known for its impressive dam and scenic surroundings within the Elan Valley.
-
C.
Garreg Ddu Reservoir
Garreg Ddu Reservoir is a scenic man-made lake in the Elan Valley of mid-Wales, known for its distinctive submerged dam and role in supplying water to the city of Birmingham.
-
D.
Pen-y-garreg Reservoir
Pen-y-garreg Reservoir is a scenic man-made lake in the Elan Valley of mid Wales, known for its historic stone dam and role in the region’s water supply system.
-
E.
Cantref Reservoir
Cantref Reservoir is a man-made lake in the Brecon Beacons of South Wales that forms part of the water supply system for the city of Cardiff.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Tryweryn reservoir scheme Target entity description: The Tryweryn reservoir scheme was a controversial mid-20th-century project by Liverpool Corporation to flood the Welsh village of Capel Celyn to create a water supply reservoir, becoming a lasting symbol of Welsh nationalist grievance.
-
A.
Clywedog Reservoir
Clywedog Reservoir is a large man-made lake in mid-Wales, created for water regulation and recreation amid scenic upland surroundings.
-
B.
Claerwen Reservoir
Claerwen Reservoir is a large upland water reservoir in mid Wales, known for its impressive dam and scenic surroundings within the Elan Valley.
-
C.
Garreg Ddu Reservoir
Garreg Ddu Reservoir is a scenic man-made lake in the Elan Valley of mid-Wales, known for its distinctive submerged dam and role in supplying water to the city of Birmingham.
-
D.
Pen-y-garreg Reservoir
Pen-y-garreg Reservoir is a scenic man-made lake in the Elan Valley of mid Wales, known for its historic stone dam and role in the region’s water supply system.
-
E.
Cantref Reservoir
Cantref Reservoir is a man-made lake in the Brecon Beacons of South Wales that forms part of the water supply system for the city of Cardiff.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
controversial public works scheme
ⓘ
infrastructure project ⓘ reservoir construction project ⓘ |
| associatedWith |
Capel Celyn
NERFINISHED
ⓘ
Llyn Celyn NERFINISHED ⓘ Welsh language activism ⓘ growth of Welsh nationalism in the 1960s ⓘ |
| beneficiary |
Merseyside region
ⓘ
city of Liverpool NERFINISHED ⓘ |
| controversialFor |
being approved by UK Parliament despite Welsh MPs voting against
ⓘ
destruction of a Welsh-speaking community ⓘ ignoring Welsh local opposition ⓘ |
| country | United Kingdom ⓘ |
| developer |
Liverpool City Council (historical Liverpool Corporation)
NERFINISHED
ⓘ
Liverpool Corporation NERFINISHED ⓘ |
| historicalSignificance |
catalyst for debates on Welsh autonomy and devolution
ⓘ
key event in modern Welsh political history ⓘ |
| impact |
contributed to the rise of Plaid Cymru
ⓘ
galvanised support for devolution in Wales ⓘ inspired political activism in Wales ⓘ |
| languageContext | affected predominantly Welsh-speaking community ⓘ |
| legalBasis | Act of Parliament authorising Liverpool Corporation to build reservoir ⓘ |
| locatedIn |
Tryweryn valley
NERFINISHED
ⓘ
Wales ⓘ near Bala ⓘ |
| memorializedBy |
memorials at Llyn Celyn
ⓘ
slogans such as "Cofiwch Dryweryn" ⓘ |
| oppositionFrom |
Plaid Cymru
NERFINISHED
ⓘ
Welsh nationalist movement NERFINISHED ⓘ local Welsh communities ⓘ most Welsh Members of Parliament ⓘ |
| parliamentaryApproval | obtained via private bill at Westminster ⓘ |
| purpose | water supply for Liverpool ⓘ |
| result |
creation of Llyn Celyn reservoir
ⓘ
destruction of Capel Celyn village ⓘ displacement of residents of Capel Celyn ⓘ flooding of Capel Celyn ⓘ submergence of farmland and chapels in Capel Celyn ⓘ |
| startDate | 1950s ⓘ |
| symbolOf |
Welsh nationalist grievance
ⓘ
cultural and linguistic loss in Wales ⓘ lack of Welsh self-government ⓘ perceived English domination over Wales ⓘ |
| timePeriod | mid-20th century ⓘ |
| typeOfImpact |
cultural impact
ⓘ
environmental change ⓘ social displacement ⓘ |
| waterSource | River Tryweryn NERFINISHED ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Tryweryn reservoir scheme Description of subject: The Tryweryn reservoir scheme was a controversial mid-20th-century project by Liverpool Corporation to flood the Welsh village of Capel Celyn to create a water supply reservoir, becoming a lasting symbol of Welsh nationalist grievance.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.