In about fifty years, the clamshell dredge changed the Delta from a vast wetland into an agricultural, water delivery, and shipping hub. In the late 1880s, these dredges reshaped the waterways to ease ship navigation and reduce seasonal floods. As farming developed, dredges used mud to build large and longer levees to protect fertile lands from larger floods. Levees also helped divert water to irrigate local crops and distant farms. By 1930, the transformation was nearly complete, and much of the Delta's history traces back to the clamshell dredge.