As more people moved along the creek, flooding became an issue.  In the 1930's, the federal government was trying to get Americans back to work and out of the Great Depression.  The Works Progress Administration program employed many Americans, and was responsible for building many structures still around today - the Columbia Gorge Scenic Highway and Timberline Lodge are a couple examples most of us are familiar with.  The rocks that line that the lower half of Johnson Creek were also build by the WPA.  The goal of the dredging, straightening and lining of the creek was to eliminate flooding of streamside properties.  As more development has occurred within the watershed, Johnson Creek responds rapidly to rain events and certainly still manages to flood over the top of the rock walls due to limited water storage and infiltration within the urbanizing watershed area.

Johnson Creek is still developing.  The lower half of the creek has been developed since the early 1900's, but the agricultural and forested areas in the upper half of the watershed are being actively converted to neighborhoods and other land uses that are more impervious (roads, parking lots, rooftops, etc.).