Restoring the 77-year-old Colorado Street Bridge in Pasadena will cost $26.3 million, almost $6 million more than expected when the bridge was closed last year, city engineers say.
"Some of the work being done is unique," said Alan Charmatz, a principal engineer with Pasadena's Public Works Department. "Nobody's ever attempted to restore a historic, concrete arched bridge at the same time as an earthquake retrofit."
The higher price tag arose after two construction bids were returned in July, both higher than budgeted for the project, he said.
The project will take 2 1/2 years to complete once work begins, possibly later this year, Charmatz said. The soonest the bridge could be reopened is mid-1993.
When the project was proposed in 1988, it was estimated at $15.8 million. With $12.7 million from the Federal Highway Administration, the city expected to make up the difference.
But public works officials were unpleasantly surprised in May, 1989, when engineering consultants De Leuw Cather & Co. of Pasadena completed design drawings with a new estimate of $20.4 million.
Faced with the shortfall, city officials scurried to find other money and got $3.7 million from the county Department of Transportation.
The city then advertised for bids. Kiewit Pacific Co. of Santa Fe Springs said it could do the work for $21.7 million, and Steve P. Rados of Santa Ana estimated $23.2 million. Neither bid included $2.6 million for a project contingency fund and $2 million for construction engineering costs to oversee the project, both of which were in the $20.4-million estimate, Charmatz said.
City staff members and the consultant reviewed the project to determine whether the job could be cut back but concluded that it could not be, Charmatz said.
The frail and crumbling Colorado Street Bridge was considered an advanced engineering feat, the highest concrete bridge in the world, when it opened in 1913. It was saved from demolition in 1951 after a community letter-writing campaign and has become one of Pasadena's most visible landmarks.
Under the rehabilitation project, the bridge will be brought up to earthquake safety standards. Concrete surrounding the bridge's 11 arches will be stripped away from the first level of steel reinforcing bars and repoured.
The historically accurate restoration will include replacing the concrete urns that once lined the bridge and refurbishing 48 lampposts along its sides.
All the work will be done within a restricted area to minimize the impact on the Arroyo Seco park below, Charmatz said.
Because of the novel work and conditions, the contractors submitted higher than usual bids to protect themselves from unforeseen costs, Charmatz said.
Fewer contractors submitted bids than expected, he added, because of the passage in June of Proposition 111, a state gasoline tax that will fund government construction projects statewide. With more routine work anticipated, developers shied away from the complex Pasadena bridge job, Charmatz said.
City Engineer Dave Barnhart is now asking for an additional $3.8 million from the county. He also hopes to reduce construction engineering costs by about $900,000, Charmatz said. The city would then have to provide the additional money.