1924 Littlerock-Palmdale Dam on Little Rock Creek near Palmdale, CA

(HAER; Satellite)

"Significance: When built the Littierock Dam was the tallest reinforced concrete multiple arch dam in the world. For over fifty years it has provided water for the South Antelope Valley and contributed to the valley's economic development." [HAER_data]

Heritage Documentation Programs, NPS posted

Detail view of reinforced concrete arch-rings comprising dam's upstream face.

Little Rock Creek Dam

Little Rock Creek

Littlerock, Los Angeles County, CA

Other Title: Little Rock Dam, Palmdale Dam

Survey Number: HAER CA-8

Photographer: Jet Lowe, September 1981

SIGNIFICANCE

When built the Littlerock Dam was the tallest reinforced #concrete multiple arch #dam in the world. For over fifty years it has provided water for the South Antelope Valley and contributed to the valley's economic development. When constructed in 1922-24, the Little Rock Creek Dam was the second highest multiple arch dam in the world, second only to that built in Tirso, Italy, at the same time. The Little Rock Creek Dam was the highest reinforced concrete multiple arch dam of the period, with the Tirso Dam of masonry-reinforced concrete construction. Sited adjacent to the very active San Andreas Faultline, the dam is a superlative example of the innovative and artistic design work of internationally-acknowledged #engineer John Samuel Eastwood. The Little Rock Creek Dam has provided water for the South Antelope Valley for nearly 70 years. Little Rock Creek Dam was listed on the National Register of Historic Places - NPS in 1976.

LEARN MORE

See the rest of the Historic American Engineering Record (HAER) documentation of the Little Rock Creek Dam in the HABS/HAER/HALS Collection in The Library of Congress at http://www.loc.gov/pictures/item/ca1230/

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ryono
"The dam is 124 ft [38m] high from foundation to crest and spans 576 ft [177m] across the canyon, forming a reservoir with a capacity of 3,700 acre⋅ft. The reservoir has a surface area of 108 acres and receives water from a drainage area of 63.7 sq mi on the north slope of the San Gabriel Mountains. A formerly popular recreation spot, the dam, reservoir, and vicinity used to receive about 300,000 visitors each year, but since 2015, the facilities have been closed to the public."
The downstream side was filled with roller-compacted concrete in 1994. It was also raised 12' (3.7m) and a new spillway was added.

 HAER CAL,19-LITRO.V,1--1
1. General view of dam looking west, showing both the downstream buttresses and the upstream arch-rings. The spillway is on the far end of the dam. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

HAER CAL,19-LITRO.V,1--28
28. DOWNSTREAM (NORTH) ELEVATION, DETAIL OF EAST HALF SHOWING OUTLET PIPES. 

HAER CAL,19-LITRO.V,1--29
29. WEST END OF DAM, LOOKING SOUTHEAST, SHOWING DOWNSTREAM FACE OF SPILLWAY.

This view allows us to see more of the depth of the buttresus.

HAER CAL,19-LITRO.V,1--30
30. LOOKING UP AT DAM FACE FROM OUTLET PIPES DISCHARGE POINT.

 

HAER CAL,19-LITRO.V,1--35
35. VALVES AT OUTLET PIPES DISCHARGE POINT, ABOUT FIFTY FEET NORTH OF BASE OF DAM.

HAER CAL,19-LITRO.V,1--61
61. 'LITTLEROCK DAM - LOOKING FROM LEFT TO RIGHT ABUTMENT-SPILLWAY DISCHARGING.' No date; probably 1960s. Photographer unknown.

Eric Zirkelbach posted
~1992, Winter, after a heavy bout of rains, I drove to the Dam and took a roll of film and my Minolta 35mm with 50mm lens. The best thing about the Dam, is you could come and hang out with a crowd of 4-wheelers, or come during the week and decompress alone. I had the site to myself and wandered around that day...

When I accessed the satellite map, the dam was spilling a little water. But they don't appear to be using the outlet pipe.

Satellite

avpress, Photo courtesy of Palmdale Water District
In 2022, a 12-year sediment removal project started. The project was delayed for decades because they discovered the endangered arroyo toad in the area. The amount of sediment to be removed increased from 1.12m cu.yd. to 1.7m cu.yd. because of that delay.