By Rachel Young, March 21, 2014
Confronted with over 200 lengthy submitted comments and an expert
action committee formed by the City Council, the project manager of the
Devil’s Gate Dam sediment removal project said at a meeting this week
that the County is considering ways to make the project “better.”
As it stands, the proposed removal will involve one truck per minute,
six days a week for five years.
The Los Angeles County Flood District
says it must remove 4 million cubit yards of sediment, enough to fill up
the Rose Bowl four times, from the Devil’s Gate Reservoir to protect
the county from a potential flood.
While no one argues the need for sediment removal, the method of the
proposed project, outlined in the draft environmental impact report, has
not sat well with Pasadena residents or council members.
“Looking at something like 5 years of 200 trucks per day and then you
look at the other proposal to the south to build a tunnel through
Pasadena, the picture you get is a dystopia here in this beautiful city
that we have,” Councilmember Steve Madison said.
The public comment period for the draft environmental impact report
closed in January and Los Angeles County is now faced with sorting
through the comments and answering every comment in the final report.
“We’ve taken those comments and were looking at ways to make a better
project, we’re working on our response to comments. But before we
finalize that document we have a number of steps, one of which is to
address some misinformation and lack of information in terms of this
design criteria and sediment history,” Principal Civil Engineer for Los
Angeles County Flood District Keith Lilley said.
Lilley presented an update to both the Pasadena City Council and Supervisor Michael Antonovich at a joint meeting on Wednesday.
“We don’t think our standards are overly conservative, but we do want the right information,” Lilley said.
Council members had formerly questioned Lilley about the need for the
project and likelihood of a storm big enough to break the dam threshold
and cause a flood. Lilley reported back that two storm events within
the last century have been large enough to cause concern—the storms of
1969 and 1938.
“What various folks here are asking, including Tim Brick, is to take a
step back to look at the overall program to determine whether scraping
it out and trucking it out is really the long term management and
solution for the county in terms of the impact on your budget and the
future environmental impacts around the region,” Councilmember Terry
The City of Pasadena currently has a working group of six experts on
sediment removal brainstorming an alternative plan to the County’s
proposed project. The group will look at providing the appropriate level
of flood control, but also seek to lessen the impacts on the park as
well as adjacent neighborhoods.
By April the working group expects to have a recommendation for the
City Manager that will focus on six areas of suggestion for the
County—hydrology of the sediment behind the dam and downstream, wildlife
and habitat in Hahamongna, lowering neighborhood and recreational
impacts, and the long-term maintenance plan.
“We spent a Saturday with Dr. Norman Brooks, a Caltech Professor with
expertise in sediment transport, that was a very informative day for
us,” Director of Public Works Siobhan Foster said who is taking part in
Arroyo Seco Foundation President Tim Brick brought in his own expert
from Germany. Last week Dietrich Bartelt of the German hydrology firm,
DB Sediments visited Pasadena. Bartelt has been tracking the Devil’s
Gate sediment program from Europe and submitted comments to the County’s
draft environmental impact report.
“In Europe they have standards on things like this and they have
standards for upgrading rivers, and so the sediment management is now
becoming part of the whole best management practice for looking at
rivers in Europe,” Brick said. “He has a whole approach toward sediment
management in rivers and reservoirs that uses a more environmentally
friendly approach, and it’s based on kind of a slow, steady release of
sediment through natural stream processes.”
Viewing sediment as a key part of river dynamics and health,
Bartelt’s uses equipment like dredging equipment in order to try to move
the sediment naturally through the stream system.
“The sediment in Devil’s Gate Dam was build up for almost a hundred
years, so we would prefer that they develop an ongoing and slow program
that removes the sediment from the base and over a longer period of
time, say 10 to 15 years that would dramatically reduce the impacts on
the neighborhoods, less trucks, less traffic, less pollution from the
trucks and noise,” Brick said.
Brick said that when Bartelt spoke with Keith Lilley in a meeting, he
voiced interest in these natural methods for other dams and facilities,
but probably not for Devil’s Gate Dam.
“We hope that through Pasadena’s strong stand and the entire
community’s voice and all of that, that the county will actually come up
with a more ongoing, a continuing program. We want really a long term
program here that will make sure that we don’t have this kind of
sediment build up in the future,” Brick said.
Brick said it is so difficult to grab the attention of the county who
oversees 14 dams and 162 debris structures, but he said this working
group stands a chance at having a voice.
“Were tremendously grateful for the open and cooperative
communication that exists between us and the county on this matter,”
Bill Bogaard said.
Once the County has responded to all the questions and comments on
the draft environmental impact report, a final document will be drafted
and communication will continue to inform the City of Pasadena and
“Michael were looking forward to receive a report in April,”
Supervisor Antonovich said to the City Manager at the conclusion of the