Seattle Public Utilities has a cleanup plan for Saturday that might affect traffic on Dumar Way:

SPU will perform routine ditch and culvert cleaning beginning on the 1700 block of Dumar Way SW [map] in West Seattle on Saturday, April 9 between 8 a.m. and 3 p.m. Maintenance crews will be progressively cleaning along Dumar Way SW, with a single lane closure shifting in conjunction with their workflow. Traffic will be impacted in the area. SPU has scheduled this work on a weekend to reduce traffic congestion. Expect traffic and bus delays.