In 1917, landowners along the slough had formed three drainage districts to control floods. They dug ditches, deepened existing water channels, and built levees to keep the rivers and the slough from flooding agricultural, industrial, and commercial property. Hoping to flush the slough with clean water from the river, city engineers created the crosscutting Peninsula Canal. The project largely failed because daily tides reversed the slough's flow and because both ends of the canal were at nearly the same elevation.
