Imperial Valley Water Infrastructure Is Infested

Imperial Valley’s entire water infrastructure is infested with Quagga Mussels

By Luke Phillips

An invasive species that has swept across the U.S., from the Great Lakes to the Colorado River, has made it’s way to the Imperial Valley.

Robert Powell, an environmental specialist with the Imperial Irrigation District, says that he is confident that the Imperial Valley’s entire water infrastructure is infested with Quagga Mussels — an invasive species that creates havoc in local ecosystems and can make life difficult for homeowners and recreational boaters.

The first quagga mussels in the U.S. were found in Lake Erie in 1989. The mussels were brought to the U.S. from Europe on trans-ocean ships and quickly established themselves as an aggressive invasive species.

I didn’t take long for the fast-multiplying mussels to spread to the western states. In 2007, quaggas were found in several lakes in Arizona, incuding Mead, Mojave, and Havasu, and in 2008 were found in California at the Imperial Dam near Yuma.

Quagga mussels can cause several problems in our ecosystem. They feed on phytoplankton, an important food source for native species, and also filter water which causes an overgrowth of certain types of plant life. They filtration also creates toxic by-products that raise acidity in the water.

Powell says that the mussels are not causing IID operational problems at the moment, but that could change at any time. According to Powell, some unknown environmental factor in the local area is causing the mussel infestation to move slower than it has in other areas, but Powell also says that the creatures are highly adaptable and could start causing people problems after they get used to their new environment.

“They  do have a tendency to adapt because they have a huge amount of offspring.” Powell said, “It’s pretty likely that we can expect a total infestation.”

Powell says that the IID recently finished a risk assessment study of the problem and is working closely with local farmers by holding workshops to educate them about the infestation.

Powell says that the mussels could also cause serious problems for homeowners who live in the county and rely on cistern systems for their water. Because of the small diameter of pipes serving most county residents, quaggas could easily build up enough to block water flow completely.

“It’s one of my main concerns.” said Powell, “I could definitely see increased maintenance costs (for homeowners).”

Powell says that homeowners who find an infestation in their systems basically have two options: chemical treatment or physical removal.

According to Powell, chemical treatment can be effective, but can also be difficult because of the quagga’s ability to close it’s shell when the environment becomes too harsh for them to survive. Multiple treatments will most likely be necessary. Powell says the only other option at this point is physical removal of the mussels by hydrojetting.

Powell says that the IID is monitoring the situation carefully for new developments and taking steps to protect against more aggressive invasion. The district has several monitoring stations throughout their system that are checked regularly to determine how far the mussels have progressed.

“It doesn’t give us any indication of where the infestations are, it just provides us with an index (of populations).”

The district’s cooling plant at Senator’s Wash has also been switched from raw water (which contains quaggas) to well water as a preventative measure.

“We’re definitely not sitting back.” Powell said, “We’re doing what we can. There‘s no way we‘re ever going to eradicate them completely. We need to look at management strategies, but we are keeping an ear to the issue”

Quagga mussels have also become a nuisance to recreational boaters on the Colorado River system. Quaggas can build up on boat’s propellers, block intake valves and ruin engines. Boaters can also help spread the infestation by moving mussels attached to their vessels from lake to lake. A multi-agency and multi-state education campaign called ‘Don’t move a mussel’ strives to give people a better understanding of the danger the quagga presents and urges boaters to help stop the invasion by pressure washing boats after each use.

As part of the campaign, check points have been set up on highways leading to and from several lakes in Arizona and Nevada and many lakes, including Lake Tahoe,  now require inspections for quaggas before launching.

Powell says that people along the Colorado River system are coping with the problem the best they can, but still have much to learn.

“It’s kind of a big experiment,” Powell said. “All of us on the river are still new to this.”

Steve Chilton

Lake Tahoe is not infested with quagga or zebra mussels! Our partners at Lake Tahoe have instituted the most extensive and effective prevention program in the country and will continue to be dilligent in keeping these invaders out of our Lake.