Water district: Lake Powell quagga mussels not considered a threat to pipeline project

ST. GEORGE —State officials have long said that quagga mussels are a serious problem for boats and bodies of water, but now conservationists claim the invasive species could spell disaster for the proposed Lake Powell Pipeline if it comes to fruition.

Lake Powell, Utah/Arizona, date unspecified | Photo by Brigitte Werner from Pixabay, St. George News

Quagga mussels can clog pipelines and damage boats and have infested Lake Powell and several over bodies of water across the country and cost millions of dollars to remove.

Water conservation advocates say they are a threat that supporters of the Lake Powell Pipeline are taking too lightly because it could bring the mussel infestation to Washington County waters.

Water managers say they’ve been dealing with the mussels for over a decade and have plans in place to keep the mussels from becoming an issue.

Quagga mussels were discovered in Lake Powell in 2012, five years after Lake Mead was contaminated. They have been given the unflattering nickname of the “STD (skiff-transmitted disease) of the Sea” because they are transported from one body of water to another by boats they attach to.

Read more: Plan ahead for decontaminating boats stored at Lake Powell

The quagga mussel can wreak havoc on water infrastructure by plugging up water lines because they reproduce quickly and cluster together. That can affect anything from drinking water to irrigation to water treatment facilities. Utah Division of Wildlife Resources Lt. Scott Daledout previously stated Utahns would likely pay for quagga removal through higher utility bills.

Opponents of the proposed Lake Powell Pipeline claim it could be crippled by the mussels while also bringing an infestation to Washington County waters. Nick Schow, Utah Rivers Council conservation director, called the mussels “a huge elephant in the room.”

Quagga mussels underwater at Lake Powell in 2015. | Photo courtesy of Utah Division of Wildlife Resources, St. George News

Schow and others warn that the mussels will clog the pipeline that would take water from Lake Powell to Sand Hollow 140 miles away. Once there, the mussels could spread across Sand Hollow Reservoir and possibly hop over to nearby Quail Creek Reservoir.

Both reservoirs are free of quagga mussels, and Washington County Water Conservancy District officials say that plans have long been in the works to keep them that way.

“Frankly, we’re not going to let them get that far,” Ron Thompson, general manager of the water district said.

Issues related to the quagga mussels and Lake Powell Pipeline are nothing new, Thompson said, adding that the water district and others involved in the pipeline project have been dealing with the mussels for over a decade.

“This isn’t our first rodeo and we take it very seriously,” Thompson said.

Preliminary designs for the Lake Powell Pipeline include a filtration system, chemical mix and coating to be applied to the intake portion of the pipeline that would keep the mussels at bay, Thompson said.

“It’s easier to treat a pipe than an open body of water,” he said.

Still, the Utah Rivers Council and other conservation groups aren’t convinced.

According to a document cited by pipeline opponents that details the status and strategy of the zebra and quagga mussel management program in Michigan, where the Great Lakes are infested, the mussel’s microscopic larval form – veligers – may be able to pass through filtration systems.

A propeller at Lake Mead is covered with quagga mussels, date not specified. | Photo courtesy of Utah Division of Wildlife Resources, St. George News

“Conventional water screens, in-line debris filters, ultrafiltration, and traveling screens, many of which are now becoming self-cleaning, can be effective in blocking adult mussels and shells, but many still allow passage of veligers,” the document states.

Schow said the idea that quagga mussels aren’t a risky proposition is a “complete fallacy” and that their presence could turn the Lake Powell Pipeline into a disaster in the making.

Thompson is quick to brush off the claims of the Utah Rivers Council and others because they are not being water managers.

“The bottom line is we have plans to deal with it,” he said, adding, “When you’re in charge of supplying water, you really have no room for error.”

In an effort to halt the spread of the quagga mussel infestation, Utah has a strict policy of boat decontamination and inspection of watercraft at certain ports of entry into the state, such as the one on Interstate 15 south of St. George.

“Our biggest risk for the mussels are the boats,” Thompson said.

Besides affecting water infrastructure, quagga mussels remove plankton necessary for some sport and native fish, they damage boat engine cooling systems, and when they die in large numbers they emit a foul odor and their sharp shells can cut your feet as you walk on the beach.

Aside from the quagga mussel issue, pipeline opponents also claim it’s not needed because Washington County has enough water and should focus on conservation; the Colorado River isn’t a reliable water resource long term and is already overtaxed, and the cost of pipeline project itself will be astronomical and cripple the local economy with high impacts fees, property taxes and water rates.

Email: [email protected]

Twitter: @MoriKessler

Copyright St. George News, SaintGeorgeUtah.com LLC, 2019, all rights reserved.

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