Sylvan Way, one of West Seattle's most vital east-west arterial streets, remains closed while workers replace much of the street's road base after encountering unstable soils under the street when they tried to hook up a sewer line.

A few weeks ago, workers were installing a sewer system for a new 178-unit townhouse development called Sylvan Heights under construction next to Sylvan Way. The housing project's sewer line is supposed to tap into the main sewer line buried under Sylvan Way. But workers encountered soils less stable than expected, so making the connection and repairing Sylvan Way is taking longer than expected, said Gregg Hirakawa, spokesman for the Seattle Department of Transportation. A contractor working for the developer of Sylvan Heights is hauling in materials to rebuild the road base.

Sylvan Way connects 35th Avenue to Delridge Way. The arterial street is expected to be barricaded from Forest Lawn Cemetery to The Home Depot store until early May.

Sylvan Way currently is 22 feet wide. The plan is to widen the street to about 36 feet in the midsection of Sylvan Way, at the planned main entrance to the new housing development. The wider section will run for about 600 feet and provide space for cars to enter and exit Sylvan Heights from either direction, Hirakawa said. The rest of Sylvan Way will remain a two-lane road, he added.

The southwest side of Sylvan Way now has a paved shoulder with concrete curb and gutter.

Tim St. Clair can be contacted at tstclair@robinsonnews.com or 932-0300.