Levees throughout the Yuba-Sutter area protect it from Floods on the Bear River, Feather River, Sacramento River, and Yuba River, with widely varying degrees of effectiveness. Marysville is one of the best-protected areas, surrounded on all sides by seven miles of some of the strongest levees in California, which were repeatedly expanded throughout the 19th century, largely under the direction of W. T. Ellis, Jr. Plumas Lake is one of the worst-protected areas, with levees that have not been upgraded to reflect the steep increase in population there after the land, which was originally the bottom of a lake and then transformed into unpopulated farmland, was built up into a new town.
Some of the levees have roads on top of them; most have walking paths instead, often paved. In many places, there are stairs or paths leading up the sides of the levees. Residents frequently walk, jog, or bike on the levees.
The Marysville Levee Commission was created by an Act of the Legislature on March 6, 1876, as a result of the flood experienced by the City in the previous year.