Excavation begins at Success Lake
Work will increase flood protection and capacity
Excavation work began Tuesday at Success Lake to remove silt and sand that has been deposited by the Tule River over the last 50 years, and the end result will be a return to its original storage capacity, and more depth and space for recreation.
Calvin Foster, Southern Operations Area manager for the U.S. Army Corps of Engineers, describes the work as a maintenance project that has been years in the making.
“This week we will see some material moved, something that we’ve been looking at and considering for a number of years,” he said. “It’s a project that does a couple of things. Not only will it protect space in the reservoir, it will provide a very valuable material that’s needed for construction in this area.”
That valuable material is sand, which is used in making cement aggregate and road base materials for paving projects.
Mitch Brown General Engineering of Porterville, who was the successful bidder for the contract, is hoping for large quantities of the material, which they will move out of the lake and take off site for processing at their facilities directly below the dam near Bartlett Park.
The five-year project began in an area north of Success Lake Campground, in a large silt pool where a pond usually forms this time of year. Crews will begin near that pond and work north, excavating 10 to 15 feet of material, and no trees will be removed during the project.
Success Dam was completed in 1961 as part of the Flood Control Act of 1944, which authorized the creation of a system of dams and levees to provide flood protection for the Tulare Lake basin area of the southern San Joaquin Valley.
It was designed to create a reservoir to hold 80,000 acre feet of water — 75,000 of which would remain empty between October and April for flood control space.
Engineers allowed for a buffer of 5,000 acre feet in anticipation of the inevitable deposit of silt and sand from the lake’s tributaries, which gradually reduces storage capacity as it occupies space intended to hold water.
“On the average, we lose 80 acre feet of space a year to silt intrusion. So we’ve lost a couple thousand acre feet of capacity to silt intrusion in a very short period of time,” said Foster. “The project we’re undertaking is to remove material and protect that space. Actually, we now believe that the amount of material removed could actually double that, so we could actually gain space.”
Foster said that removing silt and sand from the bottom of the lake has been discussed for years, but never done before now.
The project was first suggested in the late 1980s when Foster was on a recreation committee with Tulare County, when they were exploring the possibility of a spillway raise project.
“I knew of the silt pool and the fact that if we did nothing that someday that it would be silted in, and we would lose the ability to have carry over water,” he said. “So I recommended to the team that we take a close look at excavating this material out and try to protect this space.”
Foster said that at one point the excavation contract was almost awarded once before, but it fell through the cracks.
“It’s a project that I’ve been very interested in, and working with my manager, we put it back out there, got the environmental re-addressed and put it into play,” he said.
There is also increasing interest in revisiting the spillway raise project, which was strongly considered in the past, and even had a groundbreaking ceremony in 1993, but was put on hold due to safety concerns that USACE had about the dam.
Those safety concerns have now been resolved, however, and Foster said that the project is again gaining traction, and many local groups are hoping for its completion. The project would raise the dam’s spillway by 10 feet, increasing the lake’s capacity to 110,000 acre feet.