Aquatic nuisance species such as zebra and quagga mussels have wreaked havoc on reservoirs and water distribution systems throughout the United States for years. Luckily, Colorado is one of the few states in the nation that remains free of invasive mussel infestations, and West Slope legislators are working to keep it that way. 

Zebra and Quagga mussels are considered among the most destructive invasive species in North America, and experts agree that invasive mussels are an immediate threat to Western states. Without efforts to control them, mussels spread rapidly, fouling boats and equipment, clogging water intakes and increasing the cost of hydropower and municipal operations.  

Management of invasive mussels is also very expensive. According to the U.S. Department of the Interior, the cost of managing Zebra mussels in the Great Lakes region alone is somewhere near $500 million per year.  

Until 2007, the mussels were limited to waterways and lakes east of the Mississippi, but now they have spread westward. In 2016, invasive mussels were found for the first time in Lake Powell.  

Inspections and Interceptions

Colorado Parks and Wildlife is charged with operating the state’s Aquatic Nuisance Species program to prevent, monitor and if needed, eradicate invasive mussels from state waters. Among other things, the program coordinates a network of inspection and decontamination stations operated by  Colorado Parks and Wildlife, the National Parks Service and others.  

Most inspection and decontamination efforts take place at boat ramps around the state, and Colorado is intercepting more and more infested boats every year. Some 54 mussel-infested boats were intercepted in Colorado in 2018. In 2019, that number increased to 86 infected boats intercepted, and 94 boats in 2020.  

Ruedi Reservoir in the Fryingpan River Valley near Basalt had 17 of those interceptions last year — more than any other body of water in the state. April Long, Executive Director of the Ruedi Water and Power Authority attributes the increased intercepts at Ruedi to boats coming from surrounding states and specifically from Lake Powell. 

“Western Colorado reservoirs face increased risks of infestation due to their proximity to Lake Powell,” said Long. “Mussel populations at Powell have been increasing for years and inspections at Powell’s ramps just haven’t kept up.” 

Legislative Muscle

Three West Slope legislators are working on legislation that would increase Colorado Parks and Wildlife’s abilities to inspect and intercept contaminated boats coming from other states. Rep. Perry Will (R—New Castle), a 43–year Colorado Parks and Wildlife veteran who retired from the agency in 2017, joined Sens. Kerry Donovan (D–Vail) and Don Coram (R—Montrose) to introduce House Bill 1226 in the General Assembly.  

House Bill 1226 authorizes Colorado Parks and Wildlife and other peace officers in the state to establish  Aquatic Nuisance Species check stations to stop and inspect a boat or associated equipment traveling into the state. It also prohibits a person transporting a boat in the state from refusing to stop at an  Aquatic Nuisance Species check station and establishes a class 2 petty offense of “failure or refusal to stop at an Aquatic Nuisance Species check station.” 

“Our inspection efforts have been successful to date but we have to do more,” said Will. “Western Slope reservoirs are at risk and the cost of infestation would far outweigh the minimal costs of additional inspections.” 

House Bill 1226 passed out of the House of Representatives unanimously and is expected to draw broad bipartisan support in the Senate.