O'Shaughnessy Dam

E145604

O'Shaughnessy Dam is a concrete arch-gravity dam in Yosemite National Park that creates the Hetch Hetchy Reservoir, supplying water and hydroelectric power to the San Francisco Bay Area.

Try in SPARQL Jump to: Surface forms Statements Referenced by

All labels observed (1)

Label Occurrences
O'Shaughnessy Dam canonical 3

Statements (49)

Predicate Object
instanceOf concrete arch-gravity dam
dam
architectEngineer Michael Maurice O'Shaughnessy
associatedHydroelectricSystem Hetch Hetchy Power System
authorizedBy Raker Act
basinCountry United States of America
surface form: United States
constructionStartDate 1919
controversy inundation of Hetch Hetchy Valley
country United States of America
surface form: United States
creates Hetch Hetchy Valley
surface form: Hetch Hetchy Reservoir
crosses Tuolumne River
elevationAtCrest about 1,158 meters above sea level
about 3,800 feet above sea level
height about 139 meters
about 430 feet
impounds Hetch Hetchy Valley
length about 175 meters
about 575 feet
locatedIn California, United States
surface form: California

Tuolumne County
surface form: Tuolumne County, California

United States of America
surface form: United States

Yosemite National Park
locatedWithinProtectedArea Yosemite National Park
material concrete
namedAfter Michael Maurice O'Shaughnessy
nearbyCity Groveland, California
Manteca, California
openingDate 1923
operatedBy San Francisco Public Utilities Commission
opposedBy John Muir
Sierra Club
ownedBy San Francisco County
surface form: City and County of San Francisco
partOf Hetch Hetchy Power System
surface form: Hetch Hetchy Project

Hetch Hetchy Power System
surface form: Hetch Hetchy Regional Water System
purpose flood control
hydroelectric power generation
municipal water supply
RakerActSignedBy Woodrow Wilson
regionServed San Francisco Bay Area
reservoirCapacity about 360,000 acre-feet
about 444 million cubic meters
reservoirName Hetch Hetchy Valley
surface form: Hetch Hetchy Reservoir
riverBasin Tuolumne River
surface form: Tuolumne River basin
suppliesWaterTo Peninsula communities in the San Francisco Bay Area
San Francisco
San Francisco Bay Area
parts of Silicon Valley
typeOfDam arch-gravity dam
waterSource Sierra Nevada snowmelt

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: O'Shaughnessy Dam
Description of subject: O'Shaughnessy Dam is a concrete arch-gravity dam in Yosemite National Park that creates the Hetch Hetchy Reservoir, supplying water and hydroelectric power to the San Francisco Bay Area.

Referenced by (3)

Full triples — surface form annotated when it differs from this entity's canonical label.

Tuolumne River hasDam O'Shaughnessy Dam
Hetch Hetchy Valley hasLandmark O'Shaughnessy Dam
Hetch Hetchy Valley impoundedBy O'Shaughnessy Dam