2nd Phase of Project to Dredge Silt From Wetlands Nears End

Construction workers this week will wind up the second phase of a $10-million project to remove 1.5 million cubic yards of silt now choking off the life of the 752-acre Upper Newport Bay Ecological Reserve, one of Southern California’s last surviving coastal wetlands.

About 20 men and 20 trucks, bulldozers and other construction equipment have been working six days a week since late May to dig a basin seven feet through the sediment carried by San Diego Creek into the upper reaches of the bay.

Dam to Be Opened

Late next week, salt water will again flow into the upper bay after workers open a dam that has separated it from the lower bay. Shortly afterwards, a second dam will be opened, allowing San Diego Creek to flow into the upper bay.

The basin excavation is part of a plan to restore the tidal action in the bay and improve the water quality in both the bays and also to create a viable mud flat habitat for the animals and plants.

While area residents and conservationists were initially alarmed when they saw bulldozers digging deep into the ecological reserve, they are now supporting the excavation.

“Many people thought it was going to be a disaster,” said Frank Robinson, a founding member of Friends of Newport Bay. “But it’s like a serious operation . . . it’s going to be better afterwards.”

Sat Tamaribushi, an Irvine Co. representative on a committee overseeing the excavation, said, “It’s going to be quite attractive in comparison to what was out there before.”

For 15 years, silt from the San Diego Creek has been a problem for the area, which is a unique salt- and fresh-water wetlands habitat for more than 1,200 species of wildlife.

Silt From Far Away

Studies show that an average of 50,000 cubic yards of sediment are carried to the bay each year from construction sites and agricultural lands as far away as Tustin and Orange and from undeveloped areas in the county.

Tamaribushi said some of the silt was carried from industrial areas, but “most of it comes from the natural process of the mountains wearing down and rainfall bringing dirt from the hills.”

The remains of an abandoned saltworks added to the stagnation when a dike holding the silt back from the bay was destroyed during 1969 storms.

More sediment was added to the upper reaches of the bay when flood control channels funneling storm water into San Diego Creek were improved.

Until 1980, people argued over what to do about the bay but didn’t do a thing about it, Tamaribushi said. “Then they decided to compromise and say, ‘Let’s get the job done.’ ”

Tamaribushi said a coalition of the state, the county, the cities of Newport Beach, Irvine and Tustin, and the Irvine Co., decided to work together on a plan to clean up the bay.

$10 Million Price Tag

The committee worked out a plan for the work, which will end up costing about $10 million, Tamaribushi said.

The first phase, completed in 1983, involved creating two basins in the channel of San Diego Creek and cost $3.3 million, he said.

Phase two, which will be completed next week, cost $3.7 million, of which the state paid 75% and the Irvine Co. 20%, with the rest paid by the coalition. The excavation created a basin in the upper reaches of the bay, just west of Jamboree Road.

Phase three, set to begin next year, will involve underwater dredging to create a new basin in the upper bay.

The projected cost of the third phase is $3.6 million, Tamaribushi said. The state has provided $2.7 million for the project due to the efforts of state Sen. Marian Bergeson (R-Newport Beach).

Don Simpson, coordinator of the project, said the dredging would not stop all the silt from coming into the bay.

“The silt will still be coming to the bay and will have to be cleaned every six to seven years,” Simpson said.