Water Main Break Repairs and Road Closure Update
Update: 08/27/2025
Crews have made excellent progress on repairing the water main break that caused significant damage to a section of East Mercer Way earlier this month. One lane is now open between SE 76th St. and the north end of Clarke Beach Park, restoring limited access through a section that was previously closed to all traffic. Drivers, bicyclists, and pedestrians should exercise caution and obey the traffic signals as the area remains an active construction zone. Intermittent closures may still be necessary as construction wraps up.
In less than three weeks since the incident occurred, the City is close to completing the emergency project to replace a 220-foot section of damaged water main. Flushing of the system and water quality testing is currently taking place. Water service is expected to be restored to the five impacted residences later this week or early next week once water quality standards are verified.
Roadway repairs are also in progress. City engineers are conducting a thorough evaluation to determine the necessary scope of work, followed by a design phase. Permanent pavement restoration of both lanes should be completed by the end of October.
Update: 08/20/2025
The emergency project to replace a section of water main and repair a portion of East Mercer Way that sustained damage is moving forward. A contractor mobilized equipment to the site earlier this week. After beginning construction preparations, including grinding asphalt and locating utilities, crews started installing the replacement water pipeline. A substantial amount of the pipe is expected to be installed this week, and pipe connections, flushing, and water quality testing are expected to take place next week.
As a reminder, East Mercer Way between SE 76th St. and the north end of Clarke Beach Park remains closed to all vehicle, bicycle and pedestrian traffic for at least the next three weeks while crews are working. Bicyclists and pedestrians should avoid entering the barricaded section of roadway and refrain from moving the barricades for their own safety.
Update: 08/12/2025
Update on East Mercer Way closure and water main break
After a water main along East Mercer Way near Clarke Beach Park ruptured last week, the City of Mercer Island Public Works staff has determined that a larger emergency repair is needed to restore service.
Design and engineering work is currently underway, and a contractor is being mobilized to begin work as early as next week to complete the replacement. The work will occur within the existing roadway closure and will include the replacement of approximately 200 feet of water main due to failed pipe integrity. The five homes impacted by this break currently have temporary water service, and the water is safe to drink.
Due to this construction and structural damage to the roadway, East Mercer Way between SE 76th and the north end of Clarke Beach Park will remain closed to all vehicle, bicycle, and pedestrian traffic for up to four additional weeks, with the possibility of one lane opening to traffic sooner.
The safety of all residents of and visitors to the Island is the City’s highest priority. Although this closure is an inconvenience, bicyclists and pedestrians should avoid entering the barricaded section of roadway and refrain from moving the barricades for their own safety. Large vehicles moving construction equipment and machinery, as well as the compromised nature of the road surface, create dangerous conditions that may not be immediately apparent.
Update: 08/08/2025
City Declares Local Emergency to Address Water Main Breaks
The City of Mercer Island has declared a local emergency due to the impacts of multiple water main breaks along East Mercer Way, which occurred on Aug. 5 and 6, 2025. This emergency declaration, under Proclamation No. 365, was issued because the breaks caused water service outages, flooding, and the closure of a segment of the East Mercer Way roadway, impacting the public's health, safety, and welfare. To address the situation as quickly as possible, the City has invoked emergency powers, which includes the ability to enter into contracts and employ temporary workers outside of normal procedures.
Update: 08/06/2025
Crews worked through the night to repair a water main break near the 8300 block of East Mercer Way. Water service has been restored to approximately 50 affected homes. This break required replacing a section of pipe, which is complex and time consuming to repair. The main has been flushed and the water is safe to drink; there may be some discoloration at first and it should gradually improve. Impacted residents are encouraged to run their water to speed up this process. Contact City of Mercer Island Customer Service at (206) 275-7600 or customerservice@mercerisland.gov to report any issue.
There is a second water main break near the 7700 block of East Mercer Way (near Clarke Beach Park), which is impacting five homes. Crews are on scene and beginning to complete the repair. These five homes may experience intermittent service disruption while the emergency work is completed.
The East Mercer Way roadway between SE 76th St and the north end of Clarke Beach Park sustained damage due to the water main break and will remain closed to all vehicle traffic, pedestrians, and bicyclists. Clarke Beach Park is also temporarily closed. A geotechnical engineer has evaluated the site and has recommended that the roadway remain closed until it dries out and is further evaluated. This road closure is anticipated to be in place for at least a week. See the attached map for recommended detours. The Fred Hutch Obliteride bike ride on Saturday, Aug. 9, whose route had been scheduled to use East Mercer Way, will be rerouted.
Updates will be provided as more information becomes available.
What to do when your water is restored:
City crews have been able to maintain positive pressure throughout the work, isolating the water main and maintaining drinking water standards, so the water is safe to consume. Some cloudiness is expected while the water service is restored. Customers should flush their lines to help clear the cloudiness and possible sediment that may have been disrupted from the work. The most effective way to flush your system is to run *cold* water from the bathtub tap located at the highest part of your home (whatever tub is on the top floor of your home).
