Definition
Mulholland Dam is a concrete gravity dam located in the Santa Monica Mountains of Los Angeles County, California, United States. It impounds the Upper Hollywood Reservoir and forms part of the Los Angeles Department of Water and Power (LADWP) water‑supply system.
Overview
Constructed in 1924, the dam was originally designed by civil engineer William Mulholland to increase the water storage capacity for the growing city of Los Angeles. The structure lies within the Hollywood Hills near the intersection of Mulholland Drive and Sepulveda Boulevard and is accessible via the Mulholland Scenic Trail. Following the 1928 failure of the nearby St. Francis Dam, Mulholland Dam underwent extensive safety retrofits, including the addition of a concrete buttress and a reduction of the reservoir’s operating level. The dam continues to serve primarily for municipal water storage and, to a limited extent, flood control.
Etymology / Origin
The dam is named after William Mulholland (1855–1935), an Irish‑born engineer who was instrumental in developing Los Angeles’ early water infrastructure, most notably the Los Angeles Aqueduct and the original Los Angeles Reservoir system. The name “Mulholland” therefore reflects his direct involvement in its planning and construction.
Characteristics
| Feature | Details |
|---|---|
| Dam type | Concrete gravity dam |
| Height | Approximately 151 ft (46 m) above the foundation |
| Length | About 700 ft (213 m) crest length |
| Crest elevation | Roughly 1,040 ft (317 m) above mean sea level |
| Reservoir name | Upper Hollywood Reservoir |
| Reservoir capacity | Approximately 1,300 acre‑feet (1.6 billion L) |
| Construction period | 1923–1924 (initial); major safety modifications 1929–1930 |
| Owner / Operator | Los Angeles Department of Water and Power (LADWP) |
| Primary purpose | Municipal water storage; secondary flood control |
| Safety features | Post‑St. Francis retrofits include a concrete buttress, spillway enlargement, and reduced maximum pool elevation |
Related Topics
- St. Francis Dam – another Los Angeles water‑storage dam whose 1928 collapse prompted widespread dam‑safety reforms, influencing upgrades to Mulholland Dam.
- Upper Hollywood Reservoir – the water body formed by Mulholland Dam, supplying part of the city’s municipal water needs.
- William Mulholland – civil engineer and key figure in Los Angeles water development; his legacy includes several infrastructure projects bearing his name.
- Los Angeles Department of Water and Power (LADWP) – the municipal utility that owns and operates Mulholland Dam.
- Dam safety regulations in California – legal and engineering standards governing the design, inspection, and retrofitting of dams, especially after historic failures.
- Concrete gravity dam – a dam type that relies on its weight to resist the horizontal pressure of stored water; Mulholland Dam is an example of this design.