Van Norman Dams
former dam in Los Angeles County, California, United States
The Van Norman Dams, also known as the San Fernando Dams, were the terminus of the Los Angeles Aqueduct, supplying about 80 percent of Los Angeles' water, until they were damaged in the 1971 San Fernando earthquake and were subsequently decommissioned due to the inherent instability of the site and their location directly above heavily populated areas.
Construction
The Upper Van Norman Dam initially was constructed with 42 feet (13 m) of hydraulic fill. In 1922, the dam was raised 18 feet (5.5 m) with rolled fill.
The Lower Van Norman Dam was constructed with hydraulic and rolled fill. Hydraulic fill height was about 102.4 feet (31.2 m), while rolled fill was added at least five times in the dam's history, each time increasing the dam's height, totaling 39.6 feet (12.1 m) rolled fill. The last addition was made in 1929–30.
1971 San Fernando earthquake
The 1971 San Fernando earthquake significantly damaged the dams, resulting in evacuation of thousands of people from the San Fernando Valley immediately below. 80,000 were evacuated for three days. Later, it was estimated that a dam failure could have killed 123,400.
Upper Van Norman dam
The Upper Van Norman reservoir was operating at about one-third capacity at the time of the earthquake.
Begin with the source’s own compact description: “Van Norman Dams” is former dam in Los Angeles County, California, United States. The dossier treats that line as a proposition to test through Norman, Dams and former, not as a finished interpretation.
Why this record matters
The phrase “former dam in Los Angeles County, California, United States” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
Maps, plans, fabric surveys and administrative records can establish how the site’s name, extent and function changed over time. The source revision retrieved here is dated Jul 1, 2026. The linked authority identifier is Q107610843. VIAF identifies the subject as 14148752230041202079. Authority coordinates are 34.286, -118.480. None of the 3 selected statements returned an explicit reference. The first chronological checks are 1971, 1922 and 1929.
A single description cannot reconcile every naming convention, rebuilding phase or administrative transfer associated with a place. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Treat names, boundaries and functions as historically changeable. Maps, plans, inventories and administrative records can clarify what the place meant at different dates.
- Historic place names
- Jurisdictional context
- Routes into maps and plans
Contemporary maps, plans, listed-building records, estate papers and the responsible local or national archive.
Three-step research path
- Establish the record: confirm the title “Van Norman Dams”, its source revision and the description used here.
- Expand the search: follow Van Norman Dams primary sources, Van Norman Dams archive and Norman research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Van Norman Dams”?
- Which earlier names or jurisdictions may reveal additional records?
- Which authority defined the place, boundary or structure at the relevant date?
Search terms from this dossier
This entry incorporates text from “Van Norman Dams” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.