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The land shown in yellow is owned by Seattle’s water department. They limit activities on it to protect their 60-inch-diameter Chester Morse reservoir pipeline. The pipeline runs just north of Legacy Square/Gateway Park (left) and beneath the center of the Piazza (lower right).
As crews rush to complete Legacy Square, the Piazza, and the Pavilion, they have to be extremely careful digging in the ground or driving trucks on the site. Seattle’s most important water pipeline system runs straight through the construction site, just a four feet under the surface. Any errant equipment operator who strikes this pipeline could cause a break that could dump 100,000 gallons per minute into downtown Renton, and deprive Seattle of 70% of its water. It’s actually a pair of pipes through the Piazza, one is 52 inches in diameter and one is 66 inches. The 66 inch pipeline is seventeen times bigger in cross-section than the 16 inch pipe that flooded Houser Way and Renton’s 200 Mill Avenue (former City Hall) building last week.
Safely working around this pair of pipelines must remain front and center, as the Piazza work crews have just 46 workdays left to complete this project before the June 2nd Farmers Market. They can’t rush their digging work, or introduce any extra personnel that have not been fully briefed on the pipeline risks.
Here is a wider view of Seattle’s property ownership in Renton, to protect their pipeline
Hre is a 1931 photo of the pipeline in Renton, looking west. Notice it is not very deep.
The pipeline in Renton on South Third Street, looking east. (1931 photo from University of WA)
As the pipeline carries water across Renton towards Seattle, it runs along South 3rd Street until it gets to the Piazza Park. At that point it slightly turns and runs under the Piazza and just north of Gateway Park (future Legacy Square). The pipeline property is used for parking and landscaping in Renton, with no trees planted on top of it. Renton held extensive negotiations with Seattle before building the Piazza in 2000.
This large excavator working on the Piazza is sitting directly on top of Seattle’s water line. If the operator errantly dug more than a couple feet into the ground, and broke the 60 inch diameter pipe, all of downtown could quickly flood. A break could dump 100,000 gallons per minute.
This is a good cautionary reminder of hidden dangers lurking below the surface of downtown Renton. The Piazza work seems to be so far behind the mayor’s deadline for FIFA in June. One wrong dig just a little too deep or in the wrong place would be catastrophic for downtown. Does the city of Seattle Utilities department know about this?
Don’t forget the mole people, their weird king, and the vast empire under Renton they’ll defend to the death,
Can’t wait to move to where adults are running the show. I’m a dem, but at some point this nonsense gets to be too much. Better to be ruled by a wise Turk over a idiot Christian as Martin Luther said.
The Red zones have their own derpy problems. Like HOAs from hell and rolling coal.
If something goes terribly wrong and Renton gets flooded who is liable? Will it be the homeowner who probably has no flood insurance, the equipment operator, the construction company,or the city?
The construction company or the city. Good luck getting money out of them however – the city has infinite money to stonewall and has sovereign immunity. And the construction company would just fold their pocket llc that they setup just for this job.
Can we tax the heck out of Seattle for putting our downtown at risk?
You’ll have to run it by city staff first.
Snicker
Anonymous asked “Can we tax the heck out of Seattle for putting our downtown at risk?”
I’m not saying we could or should do it, but for the sake of science if we had a commodity tax on the water in the pipeline it could sure add up. Seattle delivers 170 million gallons PER DAY through that pipe! If Renton taxed the water at …for example…a penny per gallon, it would amount to 1.7 million dollars per day, or $620 million dollars per year. That would more than triple the City of Renton’s budget.
As a more realistic answer to your question, Renton does charge private franchises (like Comcast) for a license to run utilities in our city, and Renton does tax their services. Our relationship with Seattle Water District is much older and different than these arrangements, and their public water district has been a good partner to Renton’s water utility. While Seattle’s pipeline does present some risks to Renton, their water district has emergency agreements in place with Renton that help ensure we have enough water to drink and put out fires in the event of failure of our own system. We have similar mutually-beneficial agreements with many neighboring jurisdictions. Seattle has also allowed Renton to make reasonable use of their pipeline property for walkways, driveways, parking lots, and green spaces, so long as we’ve protected it from heavy truck traffic and heavy equipment.
When I heard about Houser Way flooding last week, and the former city hall (Mill Avenue Building) flooded, my first thought was that the Seattle Pipeline might have breached. I was very glad to hear it was one of Renton’s lines, and crews were able to repair it fairly swiftly. The broken 16-inch water main totaled some cars and did heavy damage to the Mill Avenue building.
Am I reading this right? In a large earthquake dtr is going to get flooded?
Yes. And it will bankrupt the city. Goodby pensions.
This pipeline’s survival in earthquake is a very legitimate concern Anonymous. Seattle Public Utilities completed a seismic evaluation of their system in 2018, and they have identified areas in Renton where their pipeline should be upgraded. Ideally, their pipeline would contain more slip-joints and other features to allow it to adjust to land that moves from liquefaction, landslides, or faults.
The area where the pipeline runs through downtown (including the Piazza) there is a moderate-high liquefaction risk in a severe earthquake, which could create displacements sufficient to break the pipe. The pipeline segments on Martin Luther King Way and Renton Hill are near landslide zones, which put them in jeopardy.
The Executive summary of the study can be found here.
The Seattle Public Utilities Seismic Planning page can be found here.
Here are some charts from their seismic study.
Can confirm. Building in North Renton wiggled like jello during the Nisquali earthquake.
Yes, I had many friends in Boeing’s 10-85 building in North Renton that felt lucky to get out, as their office was totaled by that earthquake. That earthquake caused a landslide in Renton that blocked the Cedar River and would have produced a flash flood if not for the quick-thinking of two Renton employees that borrowed a nearby contractor’s bulldozer and cut a new river channel by themselves.
Here’s a good four-minute story about the new “Kubota” japanese pipelines that several west coast cities (LA, San Fran, Portland, Vancouver) have begun installing to sustain earthquakes better. This system allows pipe segments to move against each other but prevents them from sliding completely apart. It has been used in successfully in Japan for 40 years.
I hope you will write a blog about the piazza’s renovation. The substantial expenditure of taxpayer money has not yielded satisfactory results. The mayor has described this as an “improvement”, and I believe he should provide taxpayers with a detailed justification. His primary focus seems to be on securing re-election, and it appears that personal financial gain is also a motivating factor. Regrettably, his leadership has been ineffective. Are you contemplating a mayoral run? If not, I intend to discuss this matter with the council members, as I believe any of them, including Carmen, would be a better choice.