Photo 4 shows the original route of Springbrook Creek, from left center and under the new Interstate 405 bridges to bottom center. During the Boeing redevelopment of Longacres the creek would be moved to the West ( right ) side of the 405 bridges to allow Oakesdale Ave. to be built under the left side of the bridges. And yes, the roadway underpass has flooded several times since. The entire Auburn - Kent Valley was a natural flood plain until the Howard Hanson Dam was completed in the Green River Gorge above Kanasket, WA. in 1962. This dam required relocation of the Northern Pacific mainline for many miles in the Gorge, however it also ended ( most of ) the yearly flooding and allowed for development of the valley. Clues to this past life exist in the elevated Railroad Right of Ways through the valley, and the high foundations and daylight basements of older homes in the area.
Ironically, the Black River of today is less than a mile long, and serves mostly as the outlet of Springbrook Creek and the Sewage Treatment Plant. The Black River of old was a link between the Cedar River in Renton and the Green River in Tukwila. Construction of the Ballard Locks and the various canals and cuts linking the inland lakes of the area ( Washington, Union, & Portage Bay ) lowered the water level of Lake Washington by several feet, enough to cause the Black River to mostly dry up.