SR 99 Tunnel Project - Information for Property Owners
The SR 99 Tunnel Project is one of the largest excavation projects in the history of our state. The project’s five-story-tall tunneling machine will remove approximately one million cubic yards of soil by the time it finishes digging the tunnel. The ground naturally experiences movement over time, but digging underground can cause additional movement.
While we do not anticipate significant levels of settlement, as a precaution, we are implementing a comprehensive program to monitor and mitigate any effects of tunneling. The following information is intended to be a guide for property owners above and near the SR 99 tunnel route.
If you have questions, please email us at email@example.com or call our hotline at 1-888-AWV-LINE (298-5463).
Common Questions for Property Owners
When will the tunneling machine be near my building?
Tunneling began near the stadiums in summer 2013, and the tunneling machine is expected to exit near Thomas Street and Sixth Avenue North in late 2014. The machine will dig an average of 35 feet per day. At this rate, it will take about 10 days for the machine to pass underneath one city block. The rate will be slower during the start-up phase.
We will contact you to let you know when the machine will be close to your property. You can also track the machine’s progress online at our Follow Bertha page.
Will I be able to hear or feel the tunneling machine?
It is possible that you may hear some noise or feel slight vibrations while the tunneling machine is near your building. If perceptible, noise and vibrations would last less than one week as the machine passes beneath.
Will my building be damaged during tunneling?
It is unlikely that your building will be damaged during tunneling. The machine was designed specifically for the soil and groundwater conditions beneath Seattle. As a result, we do not anticipate significant levels of settlement from tunnel construction. If any damage occurs as a result of tunnel construction, we will be responsible for repairs.
How is WSDOT protecting structures along the tunnel route?
While we do not anticipate significant levels of settlement, as a precaution, we are implementing a comprehensive program to monitor and mitigate any effects of tunneling. As the tunneling machine pushes forward through the earth, crews will measure the soil it removes while also tracking any ground movement above its path.
Buildings, utilities and streets located above and near the tunnel route will be monitored before, during and after construction. Each building will be surveyed prior to construction to document its interior and exterior condition. Monitors installed on the buildings by our crews will be checked against data from before construction, as well as data from monitors installed outside the monitoring area. If damage does occur to buildings, utilities or streets as a result of tunnel construction, we will be responsible for costs associated with repairs. We will rely heavily on pre-construction surveys and monitoring data to evaluate construction-related damages.
What happens if damage occurs to my building during tunnel construction?
If we receive a report of damage to buildings or infrastructure, we will assess the damage and determine the cause. We will be responsible for repairing damage that occurs as a result of tunnel construction. Our staff in the Seattle project office will handle claims and work directly with property owners to address claims.
Crews have conducted pre-construction surveys that document each building’s interior and exterior condition prior to tunneling. This survey will help building owners and our structural experts quickly determine if any damage occurred as a result of tunnel construction.
To report property damage or discuss any concerns during tunneling, please contact us at 1-888-AWV-LINE (298-5463) or firstname.lastname@example.org. The hotline is answered 24 hours a day, seven days a week.