WEST SEATTLE BRIDGE: Council’s consultant suggests closer look at repair option, briefing discussion reveals

(SDOT photo, September)

By Tracy Record
West Seattle Blog editor

Some new information today as the City Council got its first comprehensive West Seattle Bridge briefing since August.

The council’s independent consultant suggests a closer exploration of the repair option, it was revealed when City Councilmember Lisa Herbold asked council staffer Calvin Chow to talk about a memo the consultant sent councilmembers Friday. Here’s the memo (also embedded below):

More on that shortly.

Also, Transportation Committee chair Councilmember Alex Pedersen said Mayor Jenny Durkan has invited councilmembers to send her their individual repair-vs.-replace thoughts by week’s end.

And when Budget chair Councilmember Teresa Mosqueda pressed SDOT reps on the timeline for that key decision, director Sam Zimbabwe said that since they’re continuing to plan for both options, a final decision could theoretically wait as long as spring before they started losing time – though the need to seek federal/state funding would require action sooner.

Money is where the council will have the most say on whatever happens; asked about their role in the project, Chow noted, “(The) council always has control of the purse strings.”

Herbold continued to make her leaning clear: “The sooner we restore the bridge, the better, that is the premium value for me.”
She and Pedersen also have had some say as members of the West Seattle Bridge Community Task Force, though she explained to her colleagues that the CTF was not tasked with a consensus opinion, but members were providing individual feedback to the mayor.

SDOT has not taken a public position but Zimbabwe said of the bridge’s closure, “This should only be something that happens once”; the Cost-Benefit Analysis notes prominently that repairing the bridge would mean another closure at some time in the future – possibly even another emergency closure if repairs failed, and eventually a replacement closure no matter what.

Herbold stressed that the Technical Advisory Panel suggested there’s a strong likelihood that repairs would last another 40 years, taking the bridge to its full projected original life span.

Zimbabwe and project leader Heather Marx started the briefing with a recap of what’s happened since the bridge was suddenly shut down March 23rd after detection of rapid crack growth. “We’re coming to the end of the first stabilization efforts,” she said, showing on-bridge images – “these are really BIG things that are happening inside the bridge.” Zimbabwe says each bracket used in the stabilization work weighs a ton, and that each post-tensioning strand is 300 feet long and ratcheted up to 280,000 pounds of tension. This is being done in each of two box girders. Repair would be MORE of the same type of thing, he explained. Of the “post-tensioning,” Marx said, “There’s a huge amount of work that this steel rope is performing for us.”

She summarized what’s going into the decision, noting that “risk” is a huge factor from the department’s standpoint and again stressing that they’re continuing simultaneous planning for repairing or replacement. While repairs would restore cross-Duwamish traffic more quickly, there’s a “significant risk” of an unplanned future closure, she contended.

The SDOT presentation also touched briefly on funding – so far the project has spent $20 million on stabilization and traffic mitigation (the latter is under the Reconnect West Seattle umbrella), and they’ve secured $8.3 million in federal grants. Chow noted that the council has approved $70 million in funding so far and has another $30 million in next year’s budget.

The subsequent discussion is where Herbold brought up the council consultant’s memo (which was not included in meeting-related documents; we obtained it after the meeting). RHC Engineering writes in part:

In general, RHC Engineering believes that additional engineering analysis could be undertaken to better capture the existing bridge behavior and quantify the risks and benefits related to Alternative 2. The CBA attempts to compare all alternatives using a consistent approach to risk and contingencies, this approach may mischaracterize the costs and benefits of Alternative 2.

Unlike Alternative 4 that relies on a planning level concept, there is significant existing information, including original construction drawings, bridge inspection and health monitoring data, load rating and seismic evaluation, and the stabilization work, to support a refined engineering analysis for Alternative 2.

Further analysis has the potential to address risk factors associated with repair, which could affect the cost and performance assessment of Alternative 2, when compared to Alternative 4. As an example of this clarification of risk, SDOT has progressively found that the bridge is technically repairable, and the bridge foundation is solid under a design earthquake event.

We also note that the CBA comparison has some inconsistencies in the assessment of total lifecycle and what future project elements should be compared for the next 75 years of the corridor function. For instance, the replacement schedule for Alternative 2, after 40 years, will be a planned event instead of an emergency event, and managing traffic during the replacement is possible instead of closure.

Alternate 2 is repair; alternate 4 is partial replacement, potentially including the recently proposed “rapid span replacement.”

Zimbabwe said SDOT has seen the memo and stressed that the Cost-Benefit Analysis “doesn’t make the decision for us … it tries to take some level of information for all the alternatives and give us an apples-to-apples comparison.” He said that they have indeed been gathering more information on what repair would entail, via the advanced monitoring that’s been put into place. He also said that in the stabilization work so far, the bridge is responding the way their modeling suggested it would, though he cautioned that they have yet to go through a “full thermal cycle,” to see, for example, what happens in below-freezing temperatures. “If we repaired we’d still have to monitor performance and see how the bridge responds ‘off into the future'” – an ongoing, continuing monitoring effort “making sure we’re still providing a safe connection from a transportation perspective.”

That’s where Herbold noted that both the council’s consultant and the TAP have “high confidence” repairs would last 40 years, less than a 5 percent likelihood of failure. She also noted that repairs ranked highest on the “value index” in the CBA. She reiterated the effects on local businesses and other residents, plus the detour-traffic-choked communities, the longer the bridge stays closed.

Zimbabwe cautioned, “We still don’t know exactly what would be involved in full repair that restores traffic – also, the maintenance costs are not fully known.” The risks raised by repairs, he said, would have to be viewed through the lens of “where our tolerance for that risk is.”

ALSO DISCUSSED: Councilmember Tammy Morales asked if alternatives to repair/replace are being considered, and what the “climate impacts” are. Toward the latter, Zimbabwe said that right now the climate impacts of diverting traffic are having a disproportionate effect on air quality for communities that are “already stressed,” since the bridge is such a critical pathway for “thousands and thousands” of people who have to cross the river. Councilmember Mosqueda said she had spoken with walking/biking advocates whose concerns include safety in getting to the low bridge – possibly improving lighting on. pathways under the bridge and at the existing park/ride lot, for example. Councilmember Morales also asked about use of WMBE – women/minority businesses – and Marx said that was already built into the process. Mosqueda also asked what’s happening to see if the original bridge-builder can be held accountable for the bridge’s early failure; Chow said that should be taken up with the City Attorney. (added) Here’s video of the meeting:

WHAT’S NEXT: As mentioned above, the mayor has asked councilmembers for feedback by week’s end. Next public discussion of the bridge is at the scheduled Community Task Force meeting on November 18th. One other note: Marx said the work toward a Size/Type/Location Study – essential if a replacement is pursued – was getting under way with “the first workshop” today.

48 Replies to "WEST SEATTLE BRIDGE: Council's consultant suggests closer look at repair option, briefing discussion reveals"

  • sna November 9, 2020 (1:01 pm)

    Marx said:  While repairs would restore cross-Duwamish traffic more quickly, there’s a “significant risk” of an unplanned future closure, she contended.This isn’t what the experts have said so I think they need to explain this more

    • Bert November 9, 2020 (2:31 pm)

      My thoughts exactly, SNA! Unless we have an expert saying “significant risk,” Marx and Zimbabwe’s comments come across as pure CYA.

      • sna November 9, 2020 (5:36 pm)

        Not to mention even if you have a shiny new high bridge, it’s going to have 40 year old approaches leading up to it.  In 2062, those approaches are 80 years old and likely nearing end of life and the entire span out to 99 might need replacing.  Another reason to just repair now.  

        • jim November 10, 2020 (6:40 am)

          This is the reason I’m so against rapid replacement

  • Derek November 9, 2020 (1:12 pm)

    Thank god. We’re not waiting 8 years to have a dang bridge. Repair THEN replace in a few years. Really not hard. More jobs, happy constituency. Win-win!

  • Matt P November 9, 2020 (1:12 pm)

    This is the key take away from the presentation.  Repair is the clear choice. “For instance, the replacement schedule for Alternative 2, after 40 years, will be a planned event instead of an emergency event, and managing traffic during the replacement is possible instead of closure. At minimum the closure would be during construction only, not during the planning and engineering phases that could take years”

    • Chemist November 9, 2020 (3:10 pm)

      Even saying a future closure needs to last the entirety of construction presumes they’re replacing the bridge exactly in the same footprint.  If you have 3 or 4 decades to plan for replacement maybe they build a replacement bridge adjacent/north of the low bridge and need to replace the on/off ramps in 2060 anyways.  Requiring the same footprint was a presumption of the cost-benefit analysis.

  • Blbl November 9, 2020 (1:21 pm)

    Maybe a decision in Spring. Let’s let the model see a full “thermal cycle”. Oh my god, I’m getting out of here.  

  • Please fix the bridge! November 9, 2020 (1:25 pm)

    This has been so frustrating to watch. The repair is obviously the right choice for West Seattle. There really is no comparison. And Zimbabwe should be fired for continuing to say they they don’t make a recommendation. Even Mayor Nichols has called them out in the CTF meetings because the process has been “slanted in favor of” alt 4. Maybe they think that bias serves their agency, but it really hurts West Seattleites, our small businesses, spends money unnecessarily and irresponsibly, exposes the communities of Highland Park, South Park, & Georgetown to unnecessary levels of pollution for years longer that necessary, and leads to a toll on the bridge that will disproportionately affect lower incomes. Please Mayor Durkan, help us all by making the responsible decision and putting an end to this crisis in our vulnerable communities! 

    • sna November 9, 2020 (6:21 pm)

      Agreed.  SDOT, for some reason, keeps comparing the worst case of the repair outcome to the most optimistic (to the point of being unbelievable) rapid repair scenario.

    • Meyer November 10, 2020 (10:31 am)

      Write the mayor and write Herbold. Its the only way SDOT will be held accountable

  • Wasted my time November 9, 2020 (1:45 pm)

    So the city council has a consultant too? How come their assessment wasn’t part of SDOTS presentation? Why do they need their own consultant and how much did it cost? This seems like wasted revenue and time if they are going to use their own engineer and make a decision based on their consultants opinion. 

  • Chemist November 9, 2020 (2:05 pm)

    Councilmember Mosqueda said she was visited at her home by folks interested in lower bridge accessibility. Apparently that’s a public feedback method now during work-from-home times.  youtube of today’s meeting

    • WSB November 9, 2020 (2:27 pm)

      Sorry, I haven’t added video yet, had to slam out story after taking notes on entire meeting, getting the memo, and then taking a bit of a break. I don’t know whether that was “march to her house” or neighborhood conversation, her description of it could have applied multiple ways. We haven’t heard of any marches since the Evening March group’s visits (which may BTW recur this week – they’re visiting councilmembers again, starting with Tammy Morales – not a West Seattleite – tonight) – TR

  • zark00 November 9, 2020 (2:11 pm)

    Unreal – their “plan” is to meet again, and talk more, and then do nothing – again. This is ridiculous. 

  • Jann Perez November 9, 2020 (2:26 pm)

    Thank you for hiring an independent consultant with no profit to be made by building a replacement bridge.  The Duwamish is tidal brackash water, not a fresh water lake in upstate NY and VT.  Fresh water lakes are pretty stable with the exception of drought, flood or a heavy freeze.   Tidal brackish water is subject to daily changes in depth, rushing movement of water with moving sediment, and salt corrosion.  And do not be so quick to think that the WA State and federal EPAs are going to rubber stamp the disruption of the river and the bay. The Duwamish and the western banks of Elliott Bay are SuperFund sites.  A replacement bridge is a long range project not a snap construction decison.  A new bridge is likely to have significant cost over runs and to consume Seattle for a decade+. In a word, “Monorail.” 

  • Mj November 9, 2020 (2:57 pm)

    Please fix the bridge!  – agreed and Sam should hold the door open for Ms. Marx as they both need to go.

  • skeeter November 9, 2020 (3:24 pm)

    Repair seems like the clear choice for serving the needs of the city residents.  Replacement seems like the clear choice for serving the needs of city leadership.  This is gonna be a bumpy ride, folks.  

  • AMD November 9, 2020 (3:28 pm)

    The repair could last as little as 5 years (or as much as 40).  Replace is going to continue to be part of the conversation because that is not a long time, in the grand scheme of things.  It seems like the more practical question is: do we want to repair AND THEN replace, or just replace it?  It would be more expensive to do the former, but the added expense would probably be worth it if it meant we’d have at least a partially-usable bridge during construction of the new one.

    • sna November 9, 2020 (6:25 pm)

      The CBA states the risk of repair not lasting 40 years is very low.  And as I stated above, in 40 years the approaches to the high bridge will be close to end of life anyway.  

    • Fix the Bridge! November 9, 2020 (6:33 pm)

      All of the technical experts believe there is a 95%+ chance the bridge will last for 40 years or longer. If they’d maintained the Bridge in the first place we would have never had a closure at all. And now that the Bridge is “stabilized” SDOT would literally be tearing down a drivable bridge!?! We have to stop the throw away culture if for no other reason that our environment can’t handle it anymore. Fixing the bridge is the responsible choice in every regard. 

      • CAM November 10, 2020 (11:11 am)

        Why is it that people believe the experts when they say that repairing the bridge will be a safe fix for 40 years BUT in the same comment don’t believe the experts who indicate that SDOT was maintaining the bridge consistent with expert recommendations. Are you privy to some new information that SDOT did not follow expert recommendations for maintenance of the bridge historically? Or are you just selective of accepting data when it fits your needs? 

        • Chemist November 10, 2020 (4:20 pm)

          Have certified bridge experts reviewed and given official feedback on the maintenance?  I only recall marx and Sam saying they don’t have anything relating the failure to maintenance, but they also say the failed bearing listed in years of surveys was a factor….  And very early they mentioned the added load of the bus lane as a possible contributor.  No other contributing factors have been named specifically but they have been handwaved about.

          • CAM November 10, 2020 (8:29 pm)

            You’d like SDOT from the past to consult experts from the present to ask them why the bridge failed and how to maintain it? No. That’s not what I’m saying and another bad faith expectation of them set by false precedents that would be impossible to achieve. They consulted contemporaneously when they observed the cracking and followed the guidance they were provided. That guidance told them what they were doing was sufficient. 

        • JD November 10, 2020 (8:18 pm)

          STimes published a report in early Summer 2020 which stated that SDOT spent far less money and less time on maintance of the WS Bridge than was advised by independent engineers.  While we have all been complaining about the condition of the City surace streets which include potholes, crumbling asphalt, traffic due to the rerouting of buses (1.5 hours to get from the Edgwater Hotel to my home in WS in the 3900 block of Admiral Way SW at 1:30 PM in the Summer of 2019), etc, we were expecting SDOT to be maintaining other infastructure such as the WS Bridge.  How foolish of us!   What other ticking time bombs is SDOT ignoring?  

  • Smittytheclown November 9, 2020 (3:30 pm)

    Good lord. Repair the damn thing.  If it means intermittent monthly shutdowns to check status (like we do with the tunnel) that’s FINE! 

  • Mj November 9, 2020 (4:12 pm)

    Pfizer’s vaccine is looking very promising, presuming it is things will be getting back to normal by next Fall.  And if SDoT had it’s act together the bridge could be repaired by then!

    • CAM November 10, 2020 (11:13 am)

      No one, aside from internet experts, has ever suggested that was a viable timeline. You’ve stated it repeatedly in different comment sections but that doesn’t make it true. 

  • wetone November 9, 2020 (4:30 pm)

     No leadership. Who’s running this program ? How many consultants are needed ? how much money will they spend before decision is made ?  Problem is no one has the guts to make a call.  Why should Mayor, SDOT or city council worry about anything ?  People passed everything they wanted on election day…… that told them their doing great job with budgets, infrastructure and people are happy with what’s going on in this city.  Even if the bridge was usable soon the Spokane st viaduct from east end of high-rise to I-5 is crumbling away (east bound) needing to be rebuilt/resurfaced again…………..

    • WSB November 9, 2020 (8:41 pm)

      There was only one city measure on the ballot, the transit $ measure, and zero city candidates. There was nothing “telling” anyone in city government whether people are happy or unhappy with them. Next opportunity for that is next year, when the mayor, city attorney, and two citywide council seats are all up for election.

  • L November 9, 2020 (4:31 pm)

    We are all so sick of the endless talk — get on with the REPAIR job please.   

  • dsa November 9, 2020 (4:39 pm)

    So it goes to Repair, fine.  But the true cost of repair is Repair plus Replace, so start saving for that future event.

  • Joe November 9, 2020 (5:48 pm)

    DSA – the true cost of Replace is Replace + 6 years with no bridge. Time is money.

  • Mark Schletty November 9, 2020 (5:57 pm)

    Zimbabwe needs to be gone. Wait til next spring just to decide what to do? This is just more of his do anything to inhibit vehicle transportation philosophy. He has absolutely no business leading a department of transportation.

    • WSB November 9, 2020 (8:37 pm)

      No one suggested waiting until spring. Councilmembers pressed on the question of when will a decision be made and when would it HAVE to be made. and he was very reluctant to name any kind of timetable. They eventually said that the ongoing planning on both pathways – repair AND replace – could go as far as spring before one path or the other would have to be chosen.

  • Joe Z November 9, 2020 (6:08 pm)

    Repair it now.

    No replacement without a full EIS and alternatives analysis.

    No replacement until light rail is complete. 

    • dsa November 9, 2020 (7:09 pm)

      Repair could last that long.  How long have you been waiting for light rail so far?  The end should be near.

  • sna November 9, 2020 (7:24 pm)

    Those of you pushing replacement, just imagine if we elect a mayor next year who has a different set of values with respect to the bridges and cars (eg, someone like McGinn).  It’s not unthinkable at all and would throw the whole thing up in the air and potentially delay a replacement for years. 

  • Ashley November 9, 2020 (8:08 pm)

    Repair repair repair. Why are we still talking about this? SDOT didn’t factor economic loss into ANY of their comparisons. That’s absolutely not a fair way to present data. And yes- they assume the worst for repair but the best for replacement . Sorry but after this nonsense- my bet is on another complete failure by this SDOT team if we allow them to replace. 

    • BBILL November 10, 2020 (12:49 am)

      “SDOT didn’t factor economic loss into ANY of their comparisons. That’s absolutely not a fair way to present data.” You want SDOT to spend a couple years computing the economic losses BEFORE presenting any data?

      • Bronson November 10, 2020 (10:59 am)

        BBILL – We want them to utilize historical data the same way every other model/projection/algorithm is built to come up with an estimate, not ignore it entirely. Not doing so unfairly tilts the table towards replacement. The fact that this is even a discussion at this point is absurd. $47M to repair the bridge for 40 years, with a 95 percent confidence rate in the projection. 40 years is a long-term view and society’s transportation needs by 2062 are likely to be dramatically different. Why saddle us with 6-10 years of no bridge, us and future generations with $1B in taxes, and future generations with a bridge they may not need, at least not in its current configuration. 

  • JVP November 10, 2020 (10:17 am)

    Thank goodness the City Council is recommending more process. Seattle lacks in the process department, we act too decisively. /SNARK

  • CAL November 10, 2020 (2:39 pm)

    SDOT has been ignoring the council of structural engineers
    like the Trump Administration has been ignoring the council of scientists in
    the battle against the pandemic. It is maddening. You will not find a
    structural engineer who believes the structure should be replaced rather than repaired
    unless that same engineer is trying to sell you a new bridge design contract.
    Repairing the bridge is very obviously the most financially and socially
    responsible option. What’s more, they don’t want you to know that the repair
    that is nearly complete could restore service of the bridge.  Instead, they say it won’t “restore
    traffic,” a misleading term because by “traffic” they mean all
    seven lanes (one more than the six it was designed to handle) as compared to
    some fewer number of lanes (2 or three in each direction??) that could be
    possible within weeks – now that the first stage of repair is nearly complete
    (and as noted by Zimbabwe yesterday is performing perfectly in line with the
    engineers’ expectations.) SDOT claims to have expedited restoration of bridge
    service as the highest priority and that cannot be true. They appear poised to
    keep the bridge closed for as long as they can while it serves to help their
    cause. That cause is to sell us a new bridge that we do not need – a massively
    expensive endeavor that will swell their operating budget with new tax dollars.
    The truth behind the viability and sensibility of a repair is becoming harder
    and harder to conceal, however. If decision goes toward replacement, it will have
    no basis in sound judgement but will instead be revealed to be the massively
    self-dealing endeavor that it is. This whole episode is an abomination – from
    the handling of the issue when first discovered, to a forced bridge closure
    that became necessary only after allowing the cracks to grow for too long, to
    the charade of a cost-benefit-analysis in which SDOT shrewdly gamed the
    presentation of results to mislead and conceal the pro-repair conclusions
    reached within it. There are a few heads that need to role at SDOT after this
    is all said and done. But the PR game is up, as evidenced by the comments on
    this post. Repair the bridge.

  • I Have a Bridge To Sell You November 10, 2020 (10:27 pm)

    Repair by 2022 (so we can live to see it, God willing).

    Replace by 2062 (by which point all the actors will be different and bridge technology will be more advanced).

Sorry, comment time is over.