Big Tujunga Dam
title: "Big Tujunga Dam" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["los-angeles-county-department-of-public-works-dams", "arch-dams", "los-angeles-river", "san-gabriel-mountains", "angeles-national-forest", "dams-completed-in-1931", "historic-american-engineering-record-in-california", "1931-establishments-in-california"] topic_path: "technology/web" source: "https://en.wikipedia.org/wiki/Big_Tujunga_Dam" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::data[format=table title="Infobox dam"]
| Field | Value |
|---|---|
| name | Big Tujunga Dam |
| image | Big tujunga reservoir.jpg |
| image_caption | View of the dam and reservoir from upstream |
| coordinates | |
| country | United States |
| location | Angeles National Forest, Los Angeles County, California |
| opening | |
| owner | Los Angeles County Flood Control District |
| dam_type | Concrete arch |
| dam_height | 208 ft |
| dam_height_foundation | 244 ft |
| dam_length | 830 ft |
| dam_crosses | Big Tujunga Creek |
| spillway_type | Concrete-lined overflow |
| spillway_capacity | 90000 cuft/s |
| res_name | Big Tujunga Reservoir |
| res_capacity_total | 5960 acre feet |
| res_catchment | 82 mi2 |
| :: |
| name = Big Tujunga Dam | name_official = | image = Big tujunga reservoir.jpg | image_size = | image_caption = View of the dam and reservoir from upstream | image_alt = | location_map = | location_map_size = | location_map_caption = | coordinates = | country = United States | location = Angeles National Forest, Los Angeles County, California | status = | construction_began = | opening = | demolished = | cost = | owner = Los Angeles County Flood Control District | dam_type = Concrete arch | dam_height =208 ft | dam_height_thalweg = | dam_height_foundation=244 ft | dam_length = 830 ft | dam_width_crest = | dam_width_base = | dam_volume = | dam_elevation_crest = | dam_crosses = Big Tujunga Creek | spillway_count = | spillway_type = Concrete-lined overflow | spillway_capacity = 90000 cuft/s | res_name = Big Tujunga Reservoir | res_capacity_total = 5960 acre feet | res_capacity_active = | res_capacity_inactive= | res_catchment = 82 mi2 | res_surface = | res_elevation = | res_max_depth = | res_max_length = | res_max_width = | res_tidal_range = | plant_operator = | plant_commission = | plant_decommission = | plant_type = | plant_turbines = | plant_capacity = | plant_annual_gen = | website = | extra =
Big Tujunga Dam is a 244 ft concrete arch dam in Los Angeles County, California, spanning Big Tujunga Canyon northeast of Sunland, in the foothills of the San Gabriel Mountains. Completed in 1931, it provides flood control and groundwater recharge for the San Fernando Valley.
Its reservoir is called Big Tujunga Reservoir, and collects runoff from a watershed of 82 mi2. Although it is located inside the Angeles National Forest, public access to the lake is forbidden. The water is usually kept at a low level, in order to protect against winter floods. The name of the dam is derived from a Tongva village name.
Description
The dam is 208 ft high from the riverbed, 244 ft high from the foundations, and 830 ft long. It has a width of 138 ft at the base, tapering to 8 ft at the crest. The storage capacity is 5960 acre feet at the spillway, with a minimum pool of 1210 acre feet to prevent sediment and debris from entering the dam's outlets.
After the completion of Hansen Dam downstream, the importance of Big Tujunga Dam for flood control has decreased; however, it is still directly responsible for protecting about 4,600 residents living in the floodplain of Big Tujunga Canyon. In addition, the dam conserves about 4500 acre feet of runoff per year for drinking water and groundwater recharge purposes. This saves the city of Los Angeles about $2,250,000 annually due to the cost difference between local and imported water.
Because of the small storage capacity of the reservoir relative to the size of its watershed, frequent dredging is required to remove sediment from behind the dam. Most of the sediment is compacted and stored at the Maple Canyon Sediment Placement Site located less than 1 mi west of the dam. The 2009 Station Fire, which burned some 87% of the Big Tujunga watershed, caused more than 2 million cubic yards (1.5 million m3) of sediment to flow into the reservoir, all of which subsequently had to be removed.
History
::figure[src="https://upload.wikimedia.org/wikipedia/commons/7/77/DOWNSTREAM_ELEVATION_VIEW_OF_BIG_TUJUNGA_DAM,FACING_EAST.-_Big_Tujunga_Dam,_809_West_Big_Tujunga_Road,_Sunland,_Los_Angeles_County,_CA_HAER_CAL,19-SUNL.V,1-1.tif" caption="Big Tujunga Dam appearance before seismic retrofit"] ::
Aside from the village of Tujunga or Tuxunga (means "old woman's place" in both the languages of the Tongva and Fernandeño), the former Fernandeño (Native American) village in the area of the dam and Big Tujunga Canyon was called Muxúnga, which means "place of shooting" in the Fernandeño dialect of the Tongva language. The name comes from the verb muxú, which means "shoot him."
The dam was completed in 1931 by the Los Angeles County Flood Control District, at a cost of $1.2 million ($ in dollars). It was originally planned as one of several flood control dams inside Big Tujunga Canyon and was thus referred to as Big Tujunga Dam No. 1 until the larger Hansen Dam was completed in 1940 at the mouth of the canyon, eliminating the need for the other dams.{{cite web |url=http://ussdams.com/proceedings/2008Proc/57-72.pdf |title=The Sustainability of Experience — Investing in the Human Factor |publisher=United States Society on Dams |work=28th Annual USSD Conference |year=2008 |page=59 |access-date=2011-10-16}} During the Los Angeles flood of 1938, the dam was able to stop a huge debris flow of boulders and uprooted trees, sparing much of Sunland, Tujunga and Glendale from destruction.
In 1976, the dam was recognized as in danger of failure from earthquakes (the San Andreas Fault runs nearby) and the reservoir's level was temporarily restricted to about 25% of capacity.{{cite web |url=http://ladpw.org/wrd/reservoir/BIGTFINALISMNDJan52006-final.pdf |title=Big Tujunga Dam Seismic Upgrade |publisher=Los Angeles Department of Public Works |date=2006-01-05 |access-date=2011-10-16 |url-status=dead |archive-url=https://web.archive.org/web/20101217105433/http://ladpw.org/wrd/Reservoir/BIGTFINALISMNDJan52006-final.pdf |archive-date=2010-12-17 |url=http://dailynews.mycapture.com/mycapture/folder.asp?event=1289840&CategoryID=26369 |title=Big Tujunga Dam Seismic Retrofit Project completed |work=Daily News |date=2011-07-21 |access-date=2011-10-16 |archive-url=https://web.archive.org/web/20120425052250/http://dailynews.mycapture.com/mycapture/folder.asp?event=1289840&CategoryID=26369 |archive-date=2012-04-25 |url-status=dead
References
References
- Suntree, Susan. (2020). "Sacred Sites: The Secret History of Southern California". University of Nebraska Press.
- (Apr 2006). "Final Environmental Assessment: Big Tujunga Dam". Federal Emergency Management Agency.
- (2012-02-13). "Bracing for Impact at Big Tujunga Dam". International Water Power & Dam Construction.
- "Big Tujunga Reservoir Sediment Removal Project Frequently Asked Questions". Los Angeles County Department of Public Works.
- "Ethnohistoric Overview for the Santa Susana Pass State Historic Park Cultural Resources Inventory Project".
- Bartholomew, Dana. (2011-07-21). "Dam renovation expected to help cut water costs". Los Angeles Daily News.
- Carlsen, Robert. (2011-12-05). "Big Tujunga Dam". ENRCalifornia.
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