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Tiny mussels big problem for MWD waterways

March 9, 2012 12:00:00 AM PST
A massive effort is under way to protect the Southern California water supply. The Metropolitan Water District is trying to wipe out millions of tiny quagga mussels, but they multiply in dizzying numbers. Officials are trying to tackle the problem.

Metropolitan Water District divers have been hunting for the quaggas. Millions of the tiny quagga mussels can block water grates and nearly fill water pipes. They have to be washed or scraped off. So far, no other method has been found to get rid of the persistent quagga without affecting water quality. Each quagga can carry thousands of eggs.

"They grow so fast that the pipes start shrinking as they go and then they cut off our ability to deliver water," said MWD General Manager Jeffrey Kightlinger.

It's full-time employment for MWD divers who are constantly in the water going after the persistent and prolific quaggas. If they aren't removed, they can slow or block the water from flowing through the pipes and into the taps of 19 million Southern Californians.

"Two divers in the water, eight hours of diving all day," said MWD diver Matt Wise

Bill Taylor, a Metropolitan Water District reservoir management team leader, showed how the tiny mussels cover the spaces between the protective bars on the power plant next to the Colorado River. In just eight to nine months, the quaggas can completely cover the open spaces between the bars, blocking the water intake.

Anyplace the Colorado River goes, the quaggas go. It's very expensive to control as much as it can be controlled. Apparently they can take over and affect the way we get our water.

"We cannot exterminate them. We can't get rid of all of them. We just need to manage them to the point where we can continue to do our job," said Taylor.

All the scientific knowledge and modern technology hasn't been enough to replace the need to scrape and hose the little mussels from whatever they latch onto. One mussel generates about 1 million eggs a day. They spawn and grow very fast in warmer water.

"We've spent $30 million in the last five years just in scraping out this invasive species from the Ukraine," said Kightlinger.

It is believed the quaggas probably hitched a ride on a ship that went into the Great Lakes and then showed up in California in 2007. That's why boat inspections are so common now - to keep the mussels from hitchhiking to other locations.

"This is the first quagga mussel found in California, and it was about about the size, a little over half-an-inch long," said Taylor.

The tiny mussel now has grown so threatening that it can affect the water supply for millions of people.