Posted Saturday, November 23, 2024
By Bill Lider
Lider Engineering
One of the most important duties of City government is to protect the health and safety of its residents. Besides the obvious police and fire protection, it is the Public Works department’s duty to assure the safety of its residents, too.
While potholes in public roads can be ignored or put off for a long time, or roads can be closed pending repairs, the rail traffic on the Edmonds waterfront cannot. Every day, tens of thousands of gallons of hazardous, toxic, and explosive materials move up and down the Edmonds waterfront.
We tend to become complacent and ignore this rail traffic, except for the occasional, inconvenient traffic blockage.
Unfortunately, the City owns a Perrinville Creek pipe that is both structurally deficient and hydraulically deficient under BNSF railroad tracks. Stormwater culverts under the tracks are normally owned and maintained by BNSF, with the one exception being the City-owned Perrinville Creek 42-inch ductile iron pipe (DIP) that since the December 2022 storm has conveyed 100% of all the flow in Perrinville Creek.
The City’s pipe was installed under the tracks by the City sometime around 1995. Nobody knows for sure exactly when the DIP was installed because the City kept no records of its environmental decision, design, or construction for the DIP and diversion flow splitter.
So why did the City take on the liability for this expensive, continuing maintenance?
In 1984, the City approved a short plat for a home at the mouth of Perrinville Creek in a FEMA-mapped floodplain. As a part of the short plat, the homeowner was required to construct a berm at 21.5-feet MLLW (mean lower low water) to prevent flooding.
Instead, the homeowner redirected Perrinville Creek through his yard so he and another downstream neighbor could have a water feature in their landscaped backyard with salmon swimming upstream, even though City code makes it the responsibility of the property owners to maintain stormwater conveyances on their private property.
When the downstream property flooded repeatedly because the permit-required berm was never constructed, the homeowners somehow talked the City into constructing a flow-splitting diversion structure in Perrinville Creek, just upstream of their property to prevent flooding. Not only was this structure paid for by the taxpayers, but it also blocked the sediment transport to Puget Sound that helps to nourish the tidelands as well as replenish the beach and now prevents all returning salmon from spawning upstream.
It is now proposed to transport and place this sediment in the Brackett’s Landing Marine Sanctuary, about 2.75 miles south of Perrinville Creek as mitigation. But no environmental work has even commenced to identify how the sediment will be placed in the marine sanctuary without significant environmental harm.
Yet the City is piecemealing or segmenting the environmental analysis to avoid having to prepare an Environmental Impact Statement (EIS) to continue maintenance removal of sediment.
Every year, the City spends tens of thousands of dollars removing sediment that would otherwise be naturally deposited in Puget Sound, at no cost to the taxpayers, if not for the City’s flow splitter. No one knows exactly how much the City spends on the Perrinville Creek flow splitter, because the City does not track its maintenance cost, which is a gift of public funds for two property owners.
As far back as the 1990s, the City’s own consultants had warned that the high-flow bypass DIP was undersized to convey even a 10-year storm. With development in the Lynnwood/Edmonds Perrinville Creek basin over the last 30-years, this pipe today cannot even safely convey a five-year storm.
Yet, in 2012, the City added an additional 125 acres of urban flow into the flow splitter that maxed out the DIP’s maximum stormwater conveyance capacity. This leaves almost no capacity for any Perrinville Creek flow, let alone a 100-year design storm.
A February 2022 Lider Engineering report documented that holes have rusted through the pipe’s exposed outfall. At Lider’s urging, the City finally hired a consultant to video-inspect the DIP in July 2023. This video documented that a hole had opened up in the DIP under the railroad tracks large enough for foundation rock under the tracks to enter the pipe.
Both the City and its video consultant failed to identify this hole. This was either incompetence on the City’s part, or worse, an effort to intentionally cover up this finding of a structurally deficient pipe to avoid a bust in the Public Works budget.
When this foundational rock drops into the pipe, it will create a void under the rails. For a while, the rock above the void will continue to redistribute the rail load, and the loss of rock will not be visible at the surface. But as the void grows larger, the load and vibration of a train passing over the void will cause a sudden settlement resulting in a derailment.
Any train derailment at Perrinville Creek will result in a major catastrophic accident that could easily match the East Palestine, Ohio, explosion – it threatens a large swath of Edmonds. Should an Amtrak train go into Puget Sound water at 40°F, at high tide, in the dark, during a storm, the loss of life will be horrendous.
The cost of triple damages for dozens of wrongful death lawsuits because the City knew, but failed to act to maintain its DIP, will make its replacement cost look like a bargain.
The City’s flow splitter now serves no beneficial purpose. It totally blocks all salmon passage, it blocks sediment delivery to the beach, it must be constantly maintained after even minor 6-month storm events, it provides no flood protection as the City’s pipe is grossly undersized, and is a drain on the City’s taxpayers.
Yet the City still plans to keep this flow splitter, just so that two downstream property owners can continue to have a water feature in their backyards at taxpayer expense.
The City is currently fighting an appeal of its SEPA determination of nonsignificance (DNS) to continue using its fish-killing flow splitter. The appeal, pending a Dec. 4 hearing, would require preparation of an environmental impact statement (EIS) so these issues can be fully disclosed to the public and elected officials.
If the City then determines to accept this risk of an avoidable accident, it will be on the City and its insurance carrier’s responsibility.
I urge every citizen in Edmonds to contact the Mayor’s Office and City Council, tell them to stop wasting the taxpayer’s money, and demand that the City withdraw its DNS and prepare an EIS to remove this fish-killing structure.
Link to Edmonds Beacon article:
https://www.edmondsbeacon.com/stories/perrinville-pipe-under-tracks-could-spell-disaster,105093