MARINA DEL REY, Calif. — The U.S. Army Corps of Engineers plans to remove about 100 Olympic-sized swimming pools worth of sediment from Marina del Rey’s harbor in an operation set to begin Monday.

The five-month-long dredging effort is expected to remove about 400,000 to 500,000 cubic yards of sediment accumulated along the harbor’s north jetty, where shoaling has impacted navigation for boaters and first-responders, according to the Los Angeles County Department of Beaches and Harbors.

The Army Corps of Engineers will use a vessel dubbed Sea Horse in the dredging effort.

According to county officials, as the Sea Horse dredges, the sediment will be loaded onto a dump scow and deposited in the Pacific Ocean near the shore of Dockweiler State Beach — north of Imperial Highway in Playa del Rey.

The scow is expected to make four to five trips per day, officials said.

County officials expect the 24-hour dredging operation will make certain portions of the harbor entrance impassible for periods of time.

The Department of Beaches and Harbors will post information regarding accessibility to the harbor on social media sites.

About $7.18 million toward the dredging was funded through federal budget appropriations for the project, which aims to ensure safe navigation of the harbor entrance for the U.S. Coast Guard, first-responders and about 4,300 recreational boats docked at Marina del Rey’s harbor.