In addition to the work of straightening the River des Peres in the Worl's Fair site, similar work was undertaken across the Washington Heights area from Delmar to Lindell. Later, when streets such as Waterman Avenue and Kingsbury Boulevard were opened, brick and stone arches were constructed to carry these streets across the River des Peres. The straight course of the river also aided in the building of the underground sewer and the construction of Des Peres Avenue above it during the early 1930's.
Accelerated run-off caused by newly built artificial sources such as streets and house roofs aggravated the River des Peres flooding situaiton considerably after 1910. The worst such flood occurred in August, 1915, when areas as far away as DeBaliviere Avenue and the northern part of Forest Park were inundated with more than a foot of water. The streets in Washington Heights resembled Venetian canals as shown in contemporary photographs. Placing the River des Peres underground, ending its problems of flooding and offensive sewer odors, was a major project of the City's $87,000,000 bond issue of 1923.