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,[5] 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.

The Upper Van Norman Dam initially was constructed with 42 feet (13 m) of hydraulic fill.

[8] The Upper Van Norman reservoir was operating at about one-third capacity at the time of the earthquake.

[13] Reconstruction was proposed, but abandoned after geologic evaluation showed the inherent instability of the dams' foundations.

[16] During the 1994 Northridge earthquake, the Lower Van Norman reservoir area was again severely damaged, but as then it was in use only as a holding basin, the consequences were minor.