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Zebra Mussel Information
Zebra Mussel Information

​​​​​Detection ​Timeline​Zebra mussels up close

On September 14, 2022 a single adult zebra mussel was detected on an artificial substrate at Highline Lake by the Aquatic Nuisance Species (ANS) Sampling Monitoring Team. 

On October 21, 2022, 5 additional adult zebra mussels were found on a work boat that had been slipped in Highline for the majority of the summer and an additional single adult was found on the west boat ramp.

On October 23, 2022, 3 more adult mussels were found when the east boat ramp dock was removed from the water. 

On November 15, 2022, 2 adult zebra mussels were found in Mack wash below Highline. 

These subsequent detections are indicative of an established population of zebra mussels in Highline and as a result Highline is now considered “Infested” with zebra mussels. Surveys of the Colorado River and Highline Canal upstream of Highline Lake did not provide any evidence to indicate there is an established population upstream of the reservoir.​

Current Conditions

Starting November 28, 2022, Colorado Parks and Wildlife began lowering water levels in Highline Lake to inspect the pump at the inlet that pulls water from the reservoir into Highline canal for Zebra mussels. 

Over the next few months, Highline Lake will be lowered approximately 30 feet which is an additional 20 feet from the initial lowering that began in November 2022. In addition to lowering the lake to expose areas along and near the shoreline to kill zebra mussels through the natural processes of desiccation and freezing, CPW will apply EarthTec QZ, an EPA-registered copper-based molluscicide, to the lake. For more information, see the January 09, 2023 official press release below.  ​

What to expect for the 2023 boating season: 

  • Boats launching at Highline Lake will continue to be subject to inspection and decontamination protocols prior to launching. All boats must be clean, drained, and dry prior to launching at Highline Lake. 
  • Upon exiting the lake, all boaters will have their boat inspected and decontaminated and will be issued a blue receipt that indicates it was last used on a body of water with a known aquatic nuisance species.
  • Boaters can expect decreased ramp hours and longer exit wait times when boating resumes at Highline in May. 

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