Friday, October 25, 2019

When there are logs in the Ebey Slough, we can’t be a stick in the mud

By Joseph Calabro and Thomas Charlson

If you’re a frequent traveler on US 2 between Everett and Lake Stevens, you may have noticed over the years a large crane clearing debris from under the trestle. Usually once or twice a year, especially after a stretch of heavy rain, you’ll see our crew out there. Well, it’s that time of year again. Rain around the Puget Sound area caused water levels to rise, including in the Ebey Slough. This swept wood, logs and other debris from the shore and pushed it downstream toward the trestle’s piers where a logjam, of sorts, formed.
Logs and debris collects from rising water levels in the Ebey Slough.
So what’s the big deal, you ask? If we leave the logjam unattended, pressure can build against the piers and potentially damage them. The debris can also cause water to swirl and move in irregular patterns, potentially eroding the dikes on either side of the slough, allowing for the possibility of flooding.
Heavy machinery breaks up the debris to relieve pressure on the piers and dikes.

When this happened earlier this month, our maintenance crews jumped into action quickly so to prevent these scenarios. At noon on Tuesday, Oct. 22, we closed the peak-use shoulder lane of eastbound US 2 at the east end of the trestle where we stationed a crane and excavator. The excavator breaks up the debris, the crane moves it to an open channel and a boat crew guides the debris safely downriver, away from the piers. Since this wood debris is naturally-occurring, we abide by environmental regulations and do not remove it from the waterway. Instead, we break up small amounts at a time and push it along with the current. Spotters stand at the trestle’s edge and communicate potential safety risks via a headset to the machine operators, ensuring the heavy machinery does not make contact with the underside of the bridge. Importantly, our crews have not found any damage to the piers or dikes.

The peak-use shoulder lane of eastbound US 2 closed over the trestle.
This is a time-intensive task that required our crews to work around-the-clock Tuesday and Wednesday. With the eastbound peak-use shoulder lane closed across the trestle, drivers saw some delays, especially during the afternoon commutes. As always, we appreciate you planning ahead, giving yourself extra time to travel and slowing down through the work zone.


Woodswalker said...

This mess has a lot of back history...part of which can explain why some of us long-time residents are SO frustrated with WSDOT.

Hop in the Way-Back Machine to when there were public meetings to showcase the new design for the Eastbound US 2 trestle. In the meetings we were told of the great cost savings measures including limiting the number of different lengths of cast pre-stressed concrete beams for roadway support.
In examining the design many of us expressed very high concern with the 3 trestle bents in the main slough channel. Our concern was that they would serve as a strainer and catch river debris that came down the slough during heavier rains. WSDOT’s new Eastern engineer ASSURED everybody that the east channel was a back slough and carried little water and that the river flow geometry would prevent any flood debris from entering the channel.
Those standard length concrete beams that WSDOT saved $100K on back when they rebuilt the eastbound trestle, the design of which required trestle bents in the river channel, are sure costing us now. I am SURE we have spent the $100K many times over just in WSDOT costs to remove debris.

This, in addition to the replacement of a rickety wooden decaying 2 lane structure with a shiny new concrete, earthquake resistant concrete 2 LANE(!) structure drove more frustration. We all knew of the development going on east of the trestle in Snohomish county and were concerned about the traffic delays that a 2 lane structure would entail. We were told at the time that in the 2050 timeframe that WSDOT would start a design for a US-2 cut off from around 41st Street in Everett to around Bickford Ave outside Snohomish. That is not a useable timeframe.

Fast forward to the completed new trestle, Grand Opening ballyhoo and all. The traffic back up was HORRID, worse than before the trestle replacement. WSDOT re-striped the entry lanes, but you can only do so much when you try to stuff 4 lanes of traffic down into two lanes of travel. So WSDOT re-striped the main deck of the trestle, eliminating the breakdown lane and shoulders adding an additional lane of travel...and limited the usage hours...this marginally helped. The trestle was over capacity when it was built and the loading has gone nowhere but up as eastern Snohomish county has grown.

Then it RAINED...and the trestle bents acted as designed, a strainer in the slough channel. WSDOT stationed a crane with a clam bucket and cavalcade of trucks to remove the debris...EVERY SINGLE TIME WE HAD A SUSTAINED HARD RAIN. This has continued unabated through today with the requisite media circus and traffic tieups.

Mark Wallers said...

Fake news mr woodswalker

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