Hansen Dam
The Hansen Dam is at 1,000 feet elevation in the watershed and was completed in 1940 by the Army Corps of Engineers. It was designed and built to control flood flows in the lower urbanized watershed and can hold 74,100 acre-feet of water before spilling. It captures the water, sediment, and other material from the Big and Little Tujunga Washes (<<link). During extended large rain events or exceptionally rainy seasons, such as the '04/'05 winter, there may be significant flow going through the upper spillway vents. On January 8, 2005, flows in the lower Tujunga Wash were measured to be 9,800 cubic feet per second (cfs). The maximum flow that can leave the Dam and enter the lower Wash is 20,800 cfs (PWA, 2002). The lower spillway is the primary and usual source of water for the lower Tujunga Wash. Click on the linked words to read more about the Dam and flow and storage information online.
Looking North across the impoundment toward Big Tujunga Looking South at the Spillway
 Looking South from the Dam toward the percolation basins |
 Hansen Dam and impoundment soon after construction |
 Shallow lake develops in 1950s, used for recreation |
 Excavated lake upstream of dam |
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Topics
Storm Events of Winter '04/'05
Links
Army Corps of Engineers (ACE) site for Hansen Dam
This site includes information about the dam, operations, and impoundment. It also has pictures of the dam at various stages of its evolution. You can also see daily ACE reports on Hansen stages etc. and read a background document put together by the ACE.
Citations
Philip Williams & Associates, Ltd. 2002. Tujunga Wash: An Investigation
of Channel Hydraulic Conditions and Potential Restoration Alternatives.
A report to WaterCycle LLC and The River Project.