Local marina inspectors are on the lookout for aquatic invaders that could wreak havoc on the Dillon Reservoir.

The town of Dillon describes zebra mussels and other similar species as a direct and immediate threat to the reservoir. The aggressive mussels quickly spread and can cause costly damage to boats and water supply systems.

“We don’t want to see this happen in Dillon. There would be catastrophic results,” said Bob Evans, the manager at Dillon Marina.

The Dillon and Frisco Bay marinas have partnered with Denver Water to provide inspections for every boat before it is launched into the water.

“We train and hire inspectors to make sure every single boat is looked at,” said Neil Sperandeo, Denver Water’s manager of recreation.

“It’s only through the diligence of inspections that we have been able to keep them out,” he said.

The marina managers said they were committed to providing boat inspections to keep the aquatic invaders out, even now, during the busiest time of the season.

“It would be bad for everybody — the recreational boater, the environment and the water resource company,” said Frisco Bay Marina manager Phil Hofer. “We are at the headwaters so if it gets in here it just goes downstream from us. So it’s something we’ve been very proactive about.”

Nearly 20 years ago, non-native zebra mussels were discovered for the first time in North America. The National Oceanic and Atmospheric Association believes they were carried in the ballast tanks of ships from western European ports, and were able to attach themselves to the underwater surfaces of rocks, piers and other structures in the Great Lakes water system.

“They just started to spread,” Sperandeo said.

Zebra mussels reproduce rapidly and have no natural predators in North America. Because mussels can attach to each other when they settle, large clusters occur in small areas. NOAA reports that as many as 700,000 zebra mussels have been found in only one square yard of surface area on boats, pilings and pipes.

“They can attach to boats and other infrastructure, clog pipes and valves and gates and potentially cause millions of dollars in damage to water systems and infrastructure,” Sperandeo said.

The mussels have already made their way into Colorado waters. They’ve been found in Pueblo Reservoir, Lake Granby, Grand Lake, Willow Creek Reservoir, Shadow Mountain Reservoir, Jumbo Lake and Terryall Reservoir.

Frisco resident and boat owner James Latta said he keeps an eye out for mussels on his boat.

“I’ve never had them or seen them in Lake Powell, or Lake Dillon here, but I know they are around some of the lakes down by Denver,” he said.

Latta said he doesn’t mind waiting for inspections before using his boat at Dillon Reservoir.

“They do a good job inspecting here,” he said. “It’s nice that it’s free so the boaters aren’t afraid to get it done, and it only takes about five or 10 minutes at the most.”

Even though the threat of mussels is very real, Denver Water officials said they didn’t want to prohibit recreational boating at the reservoir.

“Denver Water understands how important the Dillon Reservoir is to the economy in Summit County,” Sperandeo said. “Rather than say no boats, we have contracts where we help pay for mussel inspection at the marinas.”

Although any body of water with boat access is prone to invasive species like the zebra and quagga mussels, local water officials said Dillon Reservoir is especially at risk because it is a nationally known destination, with boaters coming in from all over the country.

To help prevent the spread of aquatic invasive species in the reservoir, marina and Denver Water officials ask boaters to be tolerant of inspections. They also urge boaters to remember three words of wisdom, “Clean, drain and dry.”

“Make sure your boat is clean, drain it and keep it dry,” Sperandeo said.

The 100th Meridian Initiative was created to prevent the westward spread of zebra and quagga mussels and other aquatic nuisance species in North America. More information about this effort can be found at http://www.100thmeridian.org.