Old bridge, new cost estimates

Engineer studies and public review sessions over the fate of
Healdsburg’s Memorial Bridge continue to inch along this summer,
leading to an eventual final project choice by the City Council
next month.
Following an update session held last week at City Hall, a
formal public hearing on final proposed projects to replace, repair
or retrofit the old bridge will take place Thursday, Aug. 26.
Following that final public testimony, the City Council has
tentatively set a target date in early September to select a
“locally preferred project.”
Updated cost estimates presented last week by city consultants
Omni-Means set a cost range of $10 million to $48 million for 12
project concepts still being studied.
The wide cost variance includes everything from minimal
structure and safety repairs to the existing 89-year-old bridge to
converting the old bridge to a bicycle/pedestrian-only crossing
while building a new adjacent 540-foot long, 54-ft. wide vehicular
bridge.
The city hopes a final selected project will win federal highway
and bridge grants to pay for as much as 88 percent of the total
project cost. Without such federal or state funding, no project is
likely to go forward for quite some time, City Engineer Mike Kirn
and other city officials have said.
The bridge is qualified for funds under the California Highway
Bridge Program. However the Omni-Means consultants have said the
state and federal officials are likely to favor only an “economic
superior” project that includes a thorough “life cycle cost
analysis.”
The existing steel-truss bridge built in 1921 is too narrow to
meet modern safety standards. Many of its structural and other
safety conditions have been rated as unsafe, functionally obsolete,
and in need of seismic retrofitting.
Late last year the city undertook the latest bridge studies
after receiving $2.8 million in state funds to update engineering
and environmental measurements for either the replacement or
rehabilitation of the bridge.
After hearing outspoken support to save the bridge, City Council
members pledged that the study would provide an “unbiased” report
on both saving the old bridge and replacing it.
In a set of final studies, the Omni-Means consultant team will
next rank each of the 12 project concepts, applying weighted scores
on such criteria as public safety, right-of-way impacts, cost,
historic preservation, funding capability and environmental
sensitivity, among others.
The criteria and weighted factors were partially set by public
testimony from previous workshops and two town hall meetings on the
project.
At last week’s public session, several bridge neighbors raised
concerns over increased traffic and other impacts a new bridge or
realignment might cause.
While viewing the aerial engineering drawings last week, some
citizens urged the consultants to provide more complete street
level drawings of the proposals to better depict the scale and
ground level views.
One of the proposals would add a traffic roundabout at the west
end of the existing bride and two other proposals would link a new
bridge directly to Mason Street or south across Kennedy Lane to
Healdsburg Avenue.
Other concepts still being analyzed include converting the old
bridge to alternating one-way traffic with signal lights at each
end of the bridge to meter traffic.
Replacing the old bridge with a newer steel-truss bridge is
estimated to cost $27, while a “box girder” concrete design would
cost $16.6 million.
Concepts of rehabbing the old bridge for non-vehicular traffic
while building various styles of a new adjacent bridge would cost
between $24 million and $48 million, depending on the alignment,
structure and right-of-way costs.
More than one resident told the consultants last week, that 
most of the proposals looked “economically impossible.”
What is economically possible or impossible will be determined
by Caltrans and federal highway officials when they review the
“locally preferred project” selected by the City Council in
September.
Old bridge advocate Mel Amato, who has previously found
significant errors in Caltrans studies about the bridge, last week
continued to be very skeptic on the latest round of engineering
studies.
“The continued claim that our bridge is deficient is
false,” said Amato after the meeting.
“If our city decides to move forward with a replacement decision
on the bridge based upon the faulty Omni-Means analysis, it will
not hold up to a CEQA court challenge,” Amato said in a written
followup.