Ever since a seaplane carrying Admiral Chester Nimitz struck floating debris while attempting to land in San Francisco Harbor in 1942, the U.S. Army Corps of Engineers has been tasked by Congress with maintaining the navigability of the Bay Area’s waterways.
It’s been an assignment that in the years since World War II has focused on keeping shipping lanes free of objects: any debris floating or submerged that could disrupt or affect the safety of the region’s multi-billion dollar shipping industry.
So when sonar from vessels transiting the nearby Sacramento River’s Deep Water Ship Channel detected a potentially dangerous submerged object, the Corps was once again called to perform a duty that has been its responsibility.
“This could do damage to a large vessel,” said Lt. Col. John C. Morrow, commander of the Corps’ San Francisco District. “We thought it was a shipping container because of the dimensions on sonar and I think it was only a foot buried into the bottom of the channel so you’re talking about a six to seven foot obstruction.”
The Dillard, the San Francisco district’s debris collecting vessel, loaded with 11 crew including seven divers was dispatched to the 43-mile channel that leads from West Sacramento to San Francisco Bay to identify the unknown object and clear it from the federally maintained shipping lane.
It took several days of work in 90-plus degree heat and in water 35 feet deep and so turbid that the divers “we’re literally on their hands and knees feeling around for the object,” said Morrow. “It’s got to be really tough to operate in those conditions.”
Each year, the U.S. Army Corps of Engineers removes more than 1,200 tons of drift hazards from the San Francisco Bay and works to improve the quality of life for the area’s seven million residents by overseeing flood risk management operations, recreation sites as well as enhancing or restoring thousands of acres of habit, wetlands and watershed.
But the importance of the Corps’ dredging and debris removal operations extend well beyond the region.
Cargo traffic along Pacific Rim routes has more than doubled over the past decade, meaning Corps missions such as the one just completed are increasingly important to the safety and commerce of a waterway connecting the port of Sacramento to the West Coast.