By J.D. Hardesty
District Public Affairs Office
SAN FRANCISCO, May 21, 2009 – Beach goers may be alarmed by the hopper dredge that started working about half a mile offshore of Ocean Beach this morning as it may appear to be foundering.
The Army Corps of Engineers is placing sand just beyond the surf helping to save one of San Francisco’s most popular beaches and keeping the navigational ship channel safe for entering the bay. People should be informed that it is normal for the large ship to roll to one side while releasing sand from the ship’s hopper.
As a part of the Corps of Engineers annual maintenance dredging, the beach renourishment effort is a continuation of a demonstration project in cooperation with the City of San Francisco and National Park Service to improve beach conditions in the Golden Gate National Recreation Area.
The Essayons is dredging sand out of the San Francisco Main Ship Channel, four to six miles offshore from the Golden Gate. The Corps of Engineers maintains the channel to a depth of 55 feet to provide safe navigation for large commercial vessels entering San Francisco Bay.
“The Corps is using the beach-quality sand it dredges from the shipping channel to create an offshore sandbar so that natural wind and wave action can wash the sand ashore,” said Peter Mull, Corps of Engineers project manager. “We are gathering scientific information which the U.S. Geological Service will analyze to improve our understanding of how natural processes affect the beach.”
This is the fourth year of the demonstration project. In previous years, the sand dredged offshore was disposed of far from the beach at an ocean disposal area south of the channel. This year, however, the Essayons continues to bring those valuable beach-quality sands into the near-shore waters off of Sloat Boulevard.
The goal is to determine whether sands deposited in this near-shore location favorably impact the adjacent beaches, which have undergone severe erosion in recent years. Erosion now threatens the Great Highway and municipal infrastructure.
“It will take several years placing sand at the site to see how effective this is,” Mull said. “The City of San Francisco and the California Department of Boating and Waterways are cooperating with the Corps in the search for long-term solutions to erosion problems.”
The Essayons is 350’ long and 100’ high. She holds 6,000 cubic yards or about 300 dump trucks full of sand. She works 24 hours a day, seven days a week, and will normally be off Ocean Beach every four hours for 20 to 30 minutes. She will continue dredging and relocating sand to the near-shore area just south of Sloat Boulevard off Ocean Beach to about June 1.