FOLLOWUP: Admiral Way sinkhole filled, but mystery remains

(SDOT photo)

As noted in our morning traffic report, the Admiral Way sinkhole is now filled. SDOT had said that crews were doing exploratory work first to see if they could find the cause. So, did they? We followed up today, and here’s what SDOT’s Kari Tupper responded:

Our crews restored two utility cuts and repaired the void (sinkhole) in the 5300 block of SW Admiral Way this week. Several teams of SDOT staff and Seattle Public Utilities coordinated efforts to make this happen relatively quickly. We have completed the paving.

We were not able to pinpoint the source (cause) of the void during our work. These issues can be difficult to diagnose. Crews ran a CCTV camera through pipes and also did other diagnostic tests of water and sewer lines but did not find any water leaks or structural issues with the pipes at this time. It’s possible that groundwater is the source of the issue at this site. We may continue to perform additional testing and/or work at the site in the future and will keep you posted.

We first reported on the sinkhole more than two weeks ago; SDOT covered it temporarily with a steel plate while planning further exploration/repairs. It’s not the first one in that area.

Rumbles September 11, 2020 (9:55 pm)

“Not able to pinpoint the source”’ and 2020 just keeps on throwing the punches!

flimflam September 11, 2020 (10:52 pm)

great solution to a persistent problem

Clinker September 11, 2020 (11:10 pm)

Wouldn’t it be funny if this was responsible for estimation errors in a wide area of CSO sewer flow.

pelicans September 12, 2020 (5:26 am)

There has been a recurrent sinkhole in that area for a long time. It’s been repaired several times over the years. They checked the area’s infrastructure, but did they do anything other than a cursory search of the street’s hydrology? Something else is causing the repeated sinkholes on Admiral. It may be something they cannot control, only repair as it occurs. But, ok, just say so. But Bravo to the city crews who worked so quickly on this! Driving over the visible repair produced not a teeniest bump. Thank you guys and gals!
- Kathy September 12, 2020 (10:48 am)
  
  Right, my hunch is that it is just a persistent underground spring, common in the hilly parts of West Seattle, that has been causing problems in this area for years. I don’t think the patch job is going to solve it, it would have to involve finding the source(s) and creating infrastructure to channelize the water. It’s especially bad in freezing weather when we get slick spots on the sidewalk/road/bike lane as the draining water turns to ice. As long as the sinkholes don’t get big enough to swallow a car, I guess they cheapest option would be to keep repatching.
  - Wendy Ross September 12, 2020 (9:10 pm)
    
    The repair crew foreman told me that other nearby water coming out of the street about 6 houses up from this is “just springs” and ignored my concerns altogether. They were friendly guys though.
    - Barb September 13, 2020 (9:54 am)
      
      I noticed that too. Coincidence? I wouldn’t think so.

Rick September 12, 2020 (3:48 am)

I think the earth is just getting tired of us.

667 September 12, 2020 (8:06 am)

Given the times, probably just a portal straight to hell.

cjboffoli September 12, 2020 (10:06 am)

How interesting that you can have something that removes such a large volume of material and yet still remain undetected.

Wendy Ross September 12, 2020 (9:07 pm)

I live very close by. I have notified Seattle of water running out of cracks in the middle of the street mere feet from this. They have yet to evaluate it. in the meantime, I asked the foreperson to come look at it while they were working across the streets. They supposed it’s just water from something. Which I clearly already knew. They were really nice guys in an awkward position. Our plumber warned us this looked like a potential sinkhole. We told Seattle. That has not motivated Seattle to come check it out.