City to address erosion and more at Gene Coulon Park

Renton is looking at ways to combat problems caused by erosion at Gene Coulon Memorial Beach Park.

The Renton City Council approved a contract amendment of $345,300 with PND Engineers to find a solution for a failing bulkhead and public walkway at Gene Coulon Park. Renton Capital Project Manager Betsy Severtsen said the erosion on the retaining wall along a portion of the shoreline walkway on the western side of the swim beach is causing a void in the retaining wall and the walkway to settle.

“It has some safety implications over time because if the erosion keeps happening, the walkway could collapse or settle further and cause some bigger cracks,” Severtsen said. “It also affects the accessibility for people who have mobility impairment because of slopes or cracks in the walkway.”

Severtsen said the parks and maintenance crew have put a temporary plywood barrier against the retaining wall to try to alleviate the erosion in the meantime. The project started with engineers looking for the cause of the erosion, and they found it is primarily caused by the waves and wind at the beach. She said the council approved contract amendments to work on a solution.

Another problem the engineers found was clogged drainage infrastructure that could cause a pipe to burst in the future. Severtsen said they may have the opportunity to clear the pipes with this project. They also found the low walkway allows for wave overtopping, causing slipping hazards. She said this problem is only in the summer because of higher lake levels, and it shouldn’t cause icing in the winter.

Due to natural processes, Severtsen said sediment eroding from the west side of the beach and being deposited on the east side is another factor in the project. One option the engineers may propose is building the walkway back to the way it was before the erosion. Other options she foresees would be to change the pathway configurations on that side of the beach, move the wall away from the water, or shoreline riparian planting.

“They will look at the cost, the change at how recreation could happen in this part of the park and also the environmental benefit,” Severtsen said. “This is a site of juvenile salmon use and also contributes to what regulatory agencies will want to see for a fix for this.”

There will be community engagement this fall at the park to show park users design concepts on their possible solutions. The design process is expected to take about a year, but environmental and regulatory approval timelines are more unknown. She said they are hoping to begin construction in early 2027 at the soonest.

“This area of the park was implemented, I believe, in the early 1980s. There’s been a lot of regulatory changes about what is allowed on the waterfront since that time,” Severtsen said. “The public really loves the park as it is in many ways. We’ll be balancing that recreation need with how we can solve this issue.”