This is the Morris Dam, located up Highway 39 above Azusa in the San Gabriel Canyon in Southern California.
The dam was built in the 1930s by the City of Pasadena for water supply purposes. It was dedicated in 1934 by Herbert Hoover.
Morris Dam, along with the Cogswell and the San Gabriel Canyon Dams upstream, is part of a chain of dams that add 85,000 feet of storage capacity to LA County water supplies. They also provide valuable flood protection for downstream cities.
Here’s what it looks like from the air. San Grabriel Canyon Dam is in the middle; Morris Dam is creating the reservoir downstream reservoir pictured towards the right hand side of this picture (below):
A lot of sediment flows down the San Gabriel River. I am not kidding. If you travel up into the mountains, you can see how the soil is just sloughing off the mountains …
When first built, Morris Dam was capable of storing about 39,300 acre-feet; however, sedimentation has reduced the capacity by about 29%, giving the reservoir now a capacity of about 27,800 acre-feet.
The new valves will allow more flexibility in matching the downstream needs of conjunctive use facilities; or, in simpler words, water can be held back at Morris Dam until downstream spreading grounds, which are used to replenish groundwater basins, are available to receive the water.
This is the ceremonial valve (below). It is ceremonial because, while it does work, the guys will really just punch a button on the computer to open the valve from their spiffy digs in the new control house.
There’s a boat to go out on the reservoir on …Here is one interesting piece of trivia. Morris Reservoir was used as a secret torpedo research station during World War II. By some accounts, it was still used as such as late as 1990. The torpedoes were rolled down the concrete slide that you see across the reservoir to see if they’d sink or swim. You can read all about it here: Torpedo Test Site Launched New Arms Era
For more information:
- Morris Dam upgrades improve L.A. County’s water preservation, management efforts, from the San Gabriel Valley Tribune
- Torpedo Test Site Launched New Arms Era, from the Los Angeles Times, 2003
- For more on flood control and other aspects of the water resources management at Los Angeles Department of Public Works, watch the video below and/or visit the Water Resources Page at LADPW