Environment & Science

Rains wash trash down Southern California rivers

Trash litters the beach at the mouth of the San Gabriel River after recent storms.
Trash litters the beach at the mouth of the San Gabriel River after recent storms.
Susan Valot/KPCC

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With the recent rains, trash – lots of it – made its way into Southland rivers. You can see the problem on beaches where the rivers meet the Pacific Ocean.

The San Gabriel River straddles the Orange County-L.A. County line as it belches its contents into the ocean. The sand is littered with trash.

Chip bags, quarter-sized bits of plastic foam, even a couple of red Christmas bows. Across the way, a blue shopping cart is lodged in the rocks.

"Storms are the vehicle for mobilizing our trash and bringing it to the ocean," says Long Beach-based sea captain Charles Moore. "They lift up lightweight plastic packaging and plastic trash, convey it to the storm drain system, unless there’s a very effective catch basin insert to block the flow of this material. But L.A. is ahead of Orange County in doing that."

He discovered the Eastern Garbage Patch, a vortex of floating debris in the Pacific Ocean, between Hawaii and California. Moore says that’s where the trash from our rivers ends up.

"A certain percentage of what gets out there will be caught by the California current, swept down past Cabo San Lucas, out into the North Pacific Subtropical Gyre," Moore says. "And there it will remain for goodness knows how long. Perhaps centuries."

Moore says the patch of garbage – stuck in swirling vortices known as gyres – is huge.

"All of the five subtropical gyres, which we now know are polluted with our trash, comprise 40 percent of the world ocean. That’s 25 percent of the surface area of the earth, so it’s a huge system," Moore explains. "And the one that we’ve studied, the Eastern Garbage Patch, people have said that’s one, two, three times the size of Texas, but the gyre itself – the North Pacific Subtropical Gyre, which we know is polluted with hundreds of thousands of these particles of plastic per square kilometer – extends all the way from the Sea of Japan to just off the coast of California."

Moore says that area is larger than the continental United States. He says trying to remove garbage from the gyre wouldn’t do much good because so much more keeps flowing into it.

Last year, 16 cities along the L.A. River added catch basin inserts to catch trash before it hits the river.

Moore says he saw less trash flow out of the L.A. River than the San Gabriel River after the big December storms.

"Walking the banks of the river, it certainly appeared better to me," Moore says. "The L.A. [River] appeared better than the San Gabriel. And there also appeared to be less trash caught by the boom in the L.A. River than in previous years."

Moore hopes Orange County and others upstream will begin to use catch basin inserts along the San Gabriel River, too. But he says that's still a very small step toward cleaning up the giant patches of trash in our oceans.