Aug 20, 2011

Temporary flood-control measures expected to ensure Rose Bowl safety

By Janette Williams, Staff Writer

Work has started to move sediment and green waste from the face of the Devil s Gate Dam. The work will
stay within the work area, which is about 100 feet from the dam face, whereit will be trucked out.
(Walt Mancini / Staff Photographer)

PASADENA - Unless there's a “100-year storm” this winter, the Rose Bowl and Brookside Golf Course will be protected from potentially devastating mudflows by removing 25,000 cubic yards of sediment from Devil's Gate Dam, City Engineer Dan Rix said Wednesday.

Concerned officials from the Tournament of Roses Association and the Rose Bowl Operating Company met this week with city and county public works staff for assurances that the stop-gap measure will work.

“I brought the issue up,” Dennis Murphy, a five-year RBOC member, said Wednesday.

“I was concerned that if we had 23 days of rain that the basin may fill up and overflow and damage our two assets,” he said, referring to the city-owned Rose Bowl and golf course. “We're spending $152 million on one, the Rose Bowl, and we don't want to see it damaged.”

But the larger issue, Murphy said, is how quickly the interim measures will be followed by the main flood-control project planned in Hahamongna Watershed Park above Pasadena.

“We'll just have to say our prayers there's no big (storm) event in the next couple of years,” Murphy said.

An environmental impact report, which is expected to take about two years, is under way on the project to take 1.5 million cubic feet of debris from the dam.

The removal, which was to have started next month, originally got an emergency exemption from California Environmental Quality Act requirement after record amounts of Station.

Fire debris washed in during the winter storms of 2009-10.

Rix said the meeting with Project Manager Keith Lilley and other county public works officials was reassuring.

“I think everyone seems to be feeling a little better now they're more educated about the interim project, as far as what the goals are to help protect the downstream area from potential mudflows,” Rix said.

“We'll meet again in September after the county consultant completes the evaluation of the mudflow that could come through in the worst-case scenario, a 100-year storm,” he said. “We've had some 50-year and some big storms in the last 10 years, and it's always the worst scenario after a fire event like we've had, and having a very intense storm.”

Alex Aghajanian, who represents the tournament on the RBOC, said they were primarily concerned about public safety and the environment.

“We know the Station Fire was a horrific event that caused great environmental injuries,” Aghajanian said.

Storms still have the potential to wash down “heavy flows of debris” for the next few years, he said, and that's a worry.

Drainage channels, including one above Brookside that's just below the dam, have the potential to fill up and spill on to the golf course, he said.

Minimizing such threats until the EIR is approved and the major project can go ahead is critical, Aghajanian said.

“It's not the 12 inches of rain, it's the ferocity of the storm that brings the rain down the canyon, and the debris, such that the dam can't be drained,” he said.

However, he said, everyone is “on the same page” that the temporary measures are likely to see the lower Arroyo Seco through the winter.

Work on removing sediment and “green waste” from the dam face started Aug. 8, county spokesman Kerjon Lee said.

The sediment, separated from the “tree trunks, broken (tree) limbs, decomposed leaves and organic material,” is being spread out to dry about 100 feet from the dam face, Lee said.