Garreg Ddu Reservoir
E237073
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.
All labels observed (5)
| Label | Occurrences |
|---|---|
| Garreg Ddu Dam | 3 |
| Garreg Ddu Reservoir canonical | 3 |
| Garreg-ddu Reservoir | 2 |
| Craig Goch Reservoir | 1 |
| Garreg Ddu Reservoir (downstream via system) | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T2115145 — 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: Garreg Ddu Reservoir Context triple: [Rhayader, hasNearbyReservoir, Garreg Ddu Reservoir]
-
A.
Ladybower Reservoir
Ladybower Reservoir is a large Y-shaped drinking-water reservoir in the Upper Derwent Valley of Derbyshire, England, known for its distinctive plughole spillways and surrounding Peak District scenery.
-
B.
Howden Reservoir
Howden Reservoir is a large man-made lake in Derbyshire’s Peak District, known as part of the Upper Derwent Valley chain of reservoirs supplying water to nearby cities and popular for its scenic surroundings and outdoor recreation.
-
C.
Abbeystead Reservoir
Abbeystead Reservoir is a man-made lake in Lancashire, England, known for its scenic setting within the Forest of Bowland and its role in regional water supply.
-
D.
Derwent Reservoir
Derwent Reservoir is a large man-made lake in Derbyshire, England, best known for its scenic surroundings in the Peak District and its historical association with the World War II "Dambusters" training flights.
-
E.
Foziling Reservoir
Foziling Reservoir is a major multipurpose water conservancy project in Anhui Province, China, known for flood control, irrigation, and water supply within the Huai River basin.
- 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: Garreg Ddu Reservoir Target entity description: 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.
-
A.
Ladybower Reservoir
Ladybower Reservoir is a large Y-shaped drinking-water reservoir in the Upper Derwent Valley of Derbyshire, England, known for its distinctive plughole spillways and surrounding Peak District scenery.
-
B.
Howden Reservoir
Howden Reservoir is a large man-made lake in Derbyshire’s Peak District, known as part of the Upper Derwent Valley chain of reservoirs supplying water to nearby cities and popular for its scenic surroundings and outdoor recreation.
-
C.
Abbeystead Reservoir
Abbeystead Reservoir is a man-made lake in Lancashire, England, known for its scenic setting within the Forest of Bowland and its role in regional water supply.
-
D.
Derwent Reservoir
Derwent Reservoir is a large man-made lake in Derbyshire, England, best known for its scenic surroundings in the Peak District and its historical association with the World War II "Dambusters" training flights.
-
E.
Foziling Reservoir
Foziling Reservoir is a major multipurpose water conservancy project in Anhui Province, China, known for flood control, irrigation, and water supply within the Huai River basin.
- F. None of above. chosen
Statements (38)
| Predicate | Object |
|---|---|
| instanceOf |
man-made lake
ⓘ
reservoir ⓘ |
| accessibleFrom |
Elan Valley
ⓘ
surface form:
Elan Valley Visitor Centre
|
| basinCountry | United Kingdom ⓘ |
| constructionMaterialOfDam | masonry ⓘ |
| country | Wales ⓘ |
| hasFeature |
stone road bridge over dam
ⓘ
surrounding hills ⓘ tree-lined shores ⓘ |
| hasInfrastructure | aqueduct to Birmingham ⓘ |
| hasNearbyActivity |
birdwatching
ⓘ
cycling ⓘ |
| hasStructure |
Garreg Ddu Reservoir
self-linksurface differs
ⓘ
surface form:
Garreg Ddu Dam
|
| hasType | upland reservoir ⓘ |
| hasViewOf | Elan Valley ⓘ |
| impounds | River Elan ⓘ |
| knownFor |
scenic landscape
ⓘ
submerged dam ⓘ |
| locatedIn |
Elan Valley
ⓘ
Powys ⓘ mid-Wales ⓘ |
| locatedInProtectedArea |
Elan Valley Estate
ⓘ
surface form:
Elan Valley Estate SSSI
|
| managesFlowTo | Caban Coch Reservoir ⓘ |
| near |
Caban Coch Dam
ⓘ
Claerwen Reservoir ⓘ Pen-y-garreg Reservoir ⓘ
surface form:
Pen-y-Garreg Reservoir
|
| operator | Dŵr Cymru Welsh Water ⓘ |
| partOf |
Chew Valley water supply system
ⓘ
surface form:
Birmingham water supply system
Elan Valley Estate ⓘ Elan Valley reservoirs ⓘ
surface form:
Elan Valley Reservoirs
|
| purpose |
drinking water supply
ⓘ
water regulation ⓘ |
| river | River Elan ⓘ |
| usedFor |
angling
ⓘ
recreation ⓘ walking ⓘ wildlife observation ⓘ |
| waterSupplyFor | Birmingham ⓘ |
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: Garreg Ddu Reservoir Description of subject: 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.
Referenced by (10)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Craig Goch Reservoir
this entity surface form:
Garreg Ddu Dam
this entity surface form:
Garreg-ddu Reservoir
this entity surface form:
Garreg Ddu Dam
this entity surface form:
Garreg Ddu Dam
this entity surface form:
Garreg Ddu Reservoir (downstream via system)
this entity surface form:
Garreg-ddu Reservoir