 By removing the original vegetation, rural and urban development of the Johnson Creek watershed induced more rapid storm runoff and expensive floods.As a flood-control measure in the 1930s, the Works Progress Administration of the federal government cleared and lined with rock about 90 percent of the creek between its mouth and Southeast 158th Avenue, about from the mouth, creating an artificial channel to deep and to wide.Although substantially altering the stream and its aquatic life, this channel failed to prevent overflows, the largest of which damaged 1,200 structures in 1964.