In 2004, the Army Corps of Engineers used a giant claw to grab sand from the floor of San Diego Bay and drove it to Imperial Beach.
It dumped the sand near the shore so it would wash up and replenish the beach.
The city of Imperial Beach considered it “opportunistic sand.” The city wanted it because sand makes the beaches attractive to tourists. It was available, so why not take it?
But the sand wasn’t filtered before it was dumped, and it didn’t include any long term monitoring of the environmental impacts of dumping the sand, said Greg Wade, Imperial Beach’s director of community development.
So the city would never know for sure whether it had hurt or help the local environment.
My recent story about IB’s sand scuffle detailed environmentalists’ opposition to a new plan to bring more sand to the city’s beaches.
But not all sand replenishment projects are the same, and the environmentalists don’t oppose all sand projects.
Unlike the Army Corps project, some projects are specifically designed to bring sand to beaches, like one completed by the San Diego Association of Governments 9 years ago. City officials and environmentalists say the project was a success because it identified parts of the bay and ocean where sand was cleanest, and chose them as dredging sites. It sucked the sand up with a hose and ran it through a grate to filter out debris before depositing it on the boat.
It also included a monitoring component. For years after, the agency has kept an eye on the beaches where it dumped sand to evaluate whether any environmental problems resulted from the project.
Officials have even identified positive environmental impacts, Wade said. Without sand, the beaches would be cobble, which don’t accommodate some natural beach activity. The sand provided a spawning area for grunion, small fish that wash up on shore to reproduce in the sand before they catch the next wave back to sea.
It provided places for shorebirds to forage and for clams to live, he said.
Wade acknowledged that anecdotal evidence suggests the sand placed in the near offshore of Imperial Beach in 2004 may have been contaminated, as environmentalists claim. Back then, they said chunks of rock and metal rods washed onshore.
Wade said his office has asked the Army Corps to include more stringent measures to keep debris out of sand this time around. This is especially important because the project again will not include a long term monitoring requirement. The Army Corps has proposed again using a claw to pick up sand, but the city has asked it to use another technique. The Corps hasn’t responded to that request.
The city is waiting to see what requirements for clean sand the Army Corps includes when it asks private contractors to bid on the project, which is supposed to start this fall.
— ADRIAN FLORIDO