McPhee Reservoir managers are considering a more aggressive defense to prevent an invasion of the destructive quagga and zebra mussels.
A plan is being considered by local, state and federal agencies to close the McPhee and House Creek boat ramps with locked gates during times when boat inspectors are absent. The new management strategy would go into effect in 2017.
Currently, there are no gates at the boat ramps, and trailered boats can launch after hours when boat inspection stations are unattended.
“It is important to fill the inspection gaps, because the problems and expense of mussel contamination are severe,” said Mike Preston, general manager of the Dolores Water Conservancy District, which manages irrigation at McPhee reservoir.
The non-native, invasive mussels are prolific breeders with no local predators. They attach their hard-shelled bodies in layers onto irrigation canals and equipment, pipes, dam systems, hydro-electric power plants, and municipal water infrastructure.
Their presence causes damage and vastly increases maintenance costs long-term. They negatively impact the lake’s sport fishery by filtering the water and competing for food.
McPhee is considered an at-risk lake for the mussels because of its proximity to Lake Powell and Lake Mead, both of which are heavily contaminated with the mussel.
The mussel and it’s tiny juvenile offspring contaminate new waterways, including rivers, through standing water in infected boats that have not been inspected, drained, dried and cleaned.
Locals know about the problem, and understand the importance of draining and drying their boats, Preston said.
“The worry is a visitor arrives with an infected boat that slips through. It just takes one,” he said.
DWCD, the Bureau of Reclamation, San Juan National Forest, and Colorado Parks and Wildlife signed a memorandum last week to share long-term costs and management for the proposal to improve the McPhee boat inspection program. The program currently costs $85,000 per year to run.
McPhee’s two boat inspection stations typically analyze between 8,000 and 12,000 trailered boats per year since 2009, and the numbers have increased in the past two years.
This year at McPhee, the number of boats needing decontamination went up 40 percent, managers said.
The new plan would limit access for the public such as for boaters wanting to put on early in the morning, or late evening, before and after the boat inspection stations are open. Access during shoulder seasons would also be reduced because inspections stations are open less.
“There would be a push to extend boat inspection hours to accommodate the public,” said Ken Curtis, DWCD engineer.
A one-day survey of trailered boats leaving Lake Powell in 2016 showed that 52 percent of them were coming to Colorado, according to a BOR report.
McPhee managers will be meeting with local governments and the public to discuss issues regarding the proposed plan to gate boat ramps when inspection stations are closed.
“There are issues that need to be worked out,” Preston said.
For example, a boater who returns after the gate is closed could be forced to leave the boat anchored off the dock, and return when it re-opens the next morning to load it on a trailer.
McPhee continues to test negative for zebra and quagga mussels during monthly tests.