Sweetwater Ranch

May 2
The City's initial work on the stormwater system in the Sweetwater Ranch neighborhood has revealed some challenges that impact the project.

The goal was to fix the stormwater pipe at the east end of the neighborhood by inserting a slipline pipe into the existing corrugated metal pipe. Unfortunately, due to the extremely poor condition of the existing pipe and the condition of the soil surrounding the pipe, we are unable to proceed with this method.

To complete the project, the City must use a method called guided boring to dig a hole and insert a new pipe about 7.5 feet east of the current pipe and a bit closer to the surface. This method will have no vibration and as a result will have minimal disturbance to your daily routine. Further, steel plates will be used to prevent new sinkholes from developing in the project area. This work is occurring within a utility easement.

Five parcels in the immediate vicinity of the project are impacted, and the City is working directly with those homeowners to document existing landscape and overall conditions. We will do our best to restore their property to the current condition after the work is complete. The project will also include roadway and sidewalk restoration.

Shoreline Construction is continuing to execute this project. There will be minimal disruption due to construction, and work will take place between 7:30 a.m. and 4:30 p.m. The guided boring work and its preparation will take approximately six weeks to complete. Additionally, there will be landscaping, roadway and sidewalk restoration work needed after the guided boring is complete.

April 3
The City of Mill Creek has contracted with Shoreline Construction to repair a section of stormwater pipe toward the east end of 144th Street SE, just past 12th Drive SE. Light construction will begin the week of April 9. Starting the week of April 16, there will be some noise and traffic impacts between 7:30 a.m. and 4:30 p.m.
The goal is to fix the pipe by inserting a slipline pipe into the existing corrugated metal pipe. This entails digging a trench across 144th Street SE. There will be noise impacts from a generator and from the digging work.

The road will always be open in at least one direction, and the City will provide traffic control. Following completion of the pipe work, the City also will provide an asphalt overlay on the street to cover the trench, reconstruct the sidewalk on the south side of the street, and restore the landscape on the properties that have been impacted.

The street will be swept at the end of each construction day to ensure it is kept as clean as possible.

The project is expected to take no more than six weeks.


February 27
In December, the City was made aware that a sinkhole had developed at 1328 144th Street SE in the Sweetwater Ranch neighborhood. The cause of the incident was failure of a corrugated An image of the section of Sweetwater Ranch in the project areametal pipe coupler (point of connection between two pipes) all part of the City’s stormwater system. The City took immediate action to create a stop-gap measure to temporarily patch the pipe and to fill in the hole. Please be assured that while you’ve seen City vehicles and barricades in the area, there is no imminent danger to life or property.

Following the initiating event in December, the City assessed the situation by conducting a CCTV inspection on the stormwater line, as well as on adjacent lines. It was determined that a single section of pipe has failed in the Sweetwater Ranch neighborhood. This runs from a manhole located on the property of the home at 1334 144th Street SE in the Sweetwater Ranch neighborhood to the manhole on the property of the home at 1310 142nd St. SE in the Douglas Fir neighborhood. The City has been working with a design consultant to identify solutions best for this location and to hire a contractor.

The project will be presented to the City Council for approval on March 13.