Fear of invasive mussel spreads to two Cortez-area reservoirs

Wednesday, Jan. 25, 2017 3:47 AM
The Journal file

In 2010, Narraguinnep Reservoir was closed to trailered watercraft while it was inspected for the quagga mussel contamination. The lake is negative for the invasive species, but there is a concern it is at risk, along with McPhee and Groundhog reservoirs.
Harvey Baker places a tag on a boat at McPhee Reservoir last year after making sure it is drained to prevent invasive species. McPhee now has shorter operating hours to keep mussels out.

Managers of Groundhog and Narraguinnep reservoirs are considering controlling boat access to prevent contamination of the troublesome quagga and zebra mussels.

The lakes are owned by the Montezuma Valley Irrigation Co. and store water for delivery to area farms and ranches. But they are also popular for recreational boating and fishing.

The concern is that the invasive mussels species could enter the lake from infected boats, causing damage to critical irrigation infrastructure.

“We’re looking at different options to keep the mussel out of the system,” said Montezuma Valley board president Gerald Koppenhafer. “Once they get in there, you cant get rid of them, and your yearly maintenance costs go way, way up.”

The non-native mussels attach in layers to pipelines, gates and dam structures, clogging the system. They are difficult to remove, have no predator, and negatively impact the sport fishery.

Boat inspections at both lakes is the preferred solution, along with more educational signs on preventative measures. However, state and local funding for boat inspections is not available at this time, officials said.

Without some sort of boat inspection program, lake officials said banning boats from both lakes may be considered.

Bonnie Candelaria, manager of the Groundhog Lake Campground, said she understands the concern of mussel contamination, but a boat ban would be drastic.

“It would kill my business,” she said. “I don’t think Groundhog is that high of a risk for the mussel.”

Boating and fishing on the lake is very popular in the summer, Candelaria said. Hunting is popular too.

“The fishing has been really good and is one of the primary reasons people visit,” she said.

Colorado Parks and Wildlife manages the fishery for Narraguinnep and Groundhog.

CPW spokesman Joe Lewandowski said Groundhog is considered low risk lake for mussel contamination because of its isolated location. Narraguinnep, adjacent to McPhee, gets more power boats and water skiers and is more of a concern for possible mussel infection.

“Neither lake has ever had boat inspections, and the funding is not there right now to expand the program,” he said.

Quagga and zebra mussels have infected Lake Powell and Lake Mead. Adults can attach to boat hulls and trailers, and larvae can survive for days in the bilge and standing water of power boats.

Boat inspection and decontamination stations are designed to prevent the transfer of the mussels to lakes.

Colorado Parks and Wildlife has been campaigning for boat owners to “Clean, Drain and Dry” boats after leaving any waterway.

McPhee Reservoir is mussel-free, but it’s considered high risk for infection because of its proximity to Lake Powell.

Boat inspections have been ongoing at McPhee, and beginning this year the McPhee and House Creek boat ramps will be gated to prevent boats from entering the lake when the inspection stations are closed.

Prevention is key for both irrigation systems and recreational boating, officials said.

“Once the mussels show up in the lake, we have lost the battle,” Koppenhafer said. “No decisions have been made yet, we’re just beginning the conversation.”