Santa Anita Dam Project Nearly Complete in Wake of Tree Controversy

By Jim E. Winburn

The massive conveyor belt starts at the Santa Anita Dam and takes sediment to the spreading grounds near the area in Arcadia where trees were torn down 18 months ago. -Photo by Terry Miller

As Public Works nears completion of its sediment project for the Santa Anita Dam, residents and activists continue to question the county’s intentions for demolishing the 11-acre Arcadia Woodlands a year and a half ago.
Following the removal of nearly 180 coastal oaks and 70 sycamores on Jan. 12, 2011, the Department of Public Works has kept busy moving residuum from the dam to middle and lower sediment placement sites. Moving dirt, according to county officials, makes both flood control and water conservation possible for the neighboring populations of Arcadia and Sierra Madre.
According to Bob Spencer, Chief of Public Affairs for the L.A. County Public Works Department, the water program for the two cities depends on cleaning all the mud and debris out of the reservoir to benefit the storage for water.
But this problem of sediment removal quickly becomes a problem of where to put it all. And this raises the very question over the need to remove a pristine 11-acre woodland to store tons of this sediment.
“It is a problem that belongs to everyone in the county, and the whole question is what are we going to do with it 20 years from now? It’s got to go somewhere. It can’t stay here,” said Spencer, who recently gave this reporter a tour of the Santa Anita Placement Site.
City of Monrovia Planning Commissioner Glen Owens, who is also founder of the Big Santa Anita Canyon Historical Society, also knows the site well. Owens contends that the department may have moved some dirt to that location, but not enough to warrant the removal of the trees.
Before the trees were cut down, environmental activists claimed that the site could already accommodate all the sediment from the Santa Anita Dam without removing the trees.
“They made a tragic error on this thing with the oak trees,” said Owens. “They did not need to do it, and I don’t think you’re going to find that they have much (sediment) to put on (the site) where they took the trees out.”
Owens bases his claim on the amount of dirt that can be stored on the middle sediment placement site, where the trees were bulldozed. He said that the county “failed to disclose to the people,” though he admits to it being part of the environmental impact report “in a low-key manner,” that officials were supposedly setting the area up as a disposal site for debris basins across the San Gabriel Valley.
“They were saying it was a regional site, but nobody put the dots together. The people of Arcadia don’t really want a dump in their backyard,” said Owens, who claims that the trees were cut down on the premise that flood control needs to get rid of 500,000 cubic yards of sediment in the dam, but says “they come up way short.”
“So the point being is if they sold this thing to the people that they had to get rid of 500,000 cubic yards, then now they’re coming out and there’s only maybe 300,000 yards, somebody ought to hold them to task on that,” Owens said.
Spencer disagrees with Owens, saying, “The residents were told that the sediment … would first be used to finish the lower sediment placing site. That way we can go ahead and get that planted and landscaped. And what is left will be used for the middle sediment placement site, where the trees were vacated.”
Spencer said this is the start of a multi-year process where the flood control facility needs room to remove sediment out of the dam and the spillway for future winter seasons. “It was never ever the department’s intent to put 500,000 cubic yards of sediment onto the middle sediment placement site,” he said. “And that was well understood.”
According to L.A. County Department of Public Works representative Keith Lilley, who responded to questions through an email with Spencer, the development of the middle sediment placement site was required for future needs, as well as the current dirt removal project. “Without this Middle SPS, there would not be capacity for future sediment placement from either emergency or planned sediment removal projects from the facilities served by the Santa Anita SPS,” Lilley wrote.
Lilley also explained that large debris inflows to debris basins must be removed immediately during storm season to protect communities from subsequent storms. “There must be capacity available for these emergency cleanouts,” he responded. “This Middle SPS will serve our sediment management needs for the area for many years to come.”
According to Lilley, the contractor for sediment removal from behind the dam has removed nearly 330,000 cubic yards, approximately 125,000 cubic yards in 2011 and 205,000 cubic yards in 2012. In fact, “With the storm season starting Oct. 15, the contractor is required to remove the conveyor prior to this date to allow for flood control operations at the dam,” said Lilley. “It is anticipated that the conveyor system will be finished removing sediment within the next week.”
Once the Contractor has removed the conveyor from the reservoir, he will be conducting final grading of the fill areas with the stockpiled material, completion of drainage structures, and finalize work on the riser structure at the dam, according to Lilley.
It’s also important to note that the removal of sediment from the dam, built in 1927, was ordered by state safety officials to meet seismic safety standards, according to the department.
However, despite any type of necessity that may account for the destruction of those trees, Spencer himself admitted, “It wasn’t something we looked forward to doing.”
He recalled how residents and environmentalists demonstrated their anger and disgust once they realized that the trees on the site were to be uprooted. It was not something that he or his department looked forward to. “I was there, and it wasn’t an experience I wanted to go through,” Spencer said. “What can you do for the sake of those trees? This massive facility here could have been shut down.”
Note: As a follow up to this article, this paper will continue its update to the Santa Anita Dam’s flood control facility with coverage of the site’s plans for revegetation, which include planting, irrigation, and biological monitoring for the lower sediment placement site.

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