Culvert replacement to be more “fish-friendly”

Outflow of the creek on the downstream side of the culvert
(you can see part of the steel box of the culvert).
Photo by Tracy Furutani

By Tracy Furutani

Culvert replacement in Lake Forest Park will begin with the “L60” culvert on Lyon Creek near the intersection of NE 178th St and 44th Ave NE.

This action was decided by a unanimous LFP City Council vote at their meeting March 26.

The construction is set to begin in June and be completed by September, according to the council’s resolution. 

The governor’s “stay at home” order is not expected to delay the timeline, said city engineer Neil Jensen.

Following a 2017 recommendation of the engineering firm Gray and Osborne, Inc., the city approved replacement of the existing culvert, which city resolutions have described as “structurally deficient” and “undersized.” 

The L60 culvert is the first to be replaced along Lyon Creek because of its adjacency to previously-replaced culverts, and it also being the furthest downstream culvert that was not “fish-friendly,” according to Jensen.

In an agreement with the city, the Lake Forest Park Water District is replacing one of its aging water mains during the culvert replacement, confirmed Alan Kerley, the general manager of the water district.

The L60 culvert is near the intersection of
NE 178th St and 44th Ave NE.
Photo by Tracy Furutani 

The L60 culvert is currently made of steel and quite narrow, whereas the replacement structure will be pre-cast concrete and 24 feet wide, specifically made to be passable by fish. 

The original design proposed the removal of some trees in order to improve the stream itself, but that would have required heavy equipment to do excavations in the stream, which would violate the city’s tree protection ordinance.

“So we’re a community that likes our trees and likes our streams,” said councilmember Mark Phillips, “and in this case [this project] illuminated the possibility there may sometimes be conflicts between the two.”

Redtail, LLC, of Snohomish will perform the construction at a cost of about $1.2 million, which was under the engineers’ estimate. The city obtained King County Flood Control District grants totaling $341,000 towards project construction. The balance is being paid for by the city.