- Reclamation
- Missouri Basin and Arkansas-Rio Grande-Texas Gulf
- Eastern Colorado Area Office
- Aquatic Nuisance Species (ANS) and ECAO
Aquatic Nuisance Species (ANS) and ECAO
Image caption: Zebra mussel on a ruler. Photo credit: Deborah Kornblut/USFWS.
ANS status of ECAO reservoirs
- In August 2026, Colorado Parks and Wildlife announced the discovery of New Zealand mud snails in Carter Lake, near Loveland, Colorado.
- In September 2023, Colorado Parks and Wildlife announced the discovery of rusty crayfish in Lake Granby, south of Grand Lake, Colorado.
- As of August 2026, no quagga or zebra mussels reside in Colorado-Big Thompson or Fryingpan-Arkansas Project reservoirs.
ANS initiatives in the Department of Interior (DOI)
In 2017, DOI announced its initiative, Safeguarding the West from Invasive Species. Developed in collaboration with the Western Governors’ Association and Federal, State, and Tribal representatives, the initiative aims to protect areas in the West from economic and ecological threats posed by quagga and zebra mussels. DOI is revising its Invasive Species Strategic Plan for 2027-2031.
Quagga and Zebra Mussel Action Plan (QZAP) funding
Since 2018, ECAO has invested approximately $2.8 million toward ANS prevention projects, including the construction and maintenance of Watercraft Inspection and Decontamination (WID) stations and traffic controls at boat ramps to safely extend boating hours when inspectors are not present. Partnerships with Colorado Parks and Wildlife (CPW), Larimer County Department of Natural Resources, Estes Valley Recreation and Park District, the US Forest Service, and others are critical to halting the spread of ANS. CPW is the State Managing Agency for ANS in Colorado.
Other funding
To further safeguard ECAO’s project waters, approximately $79,000 is used to sample and monitor all lakes and reservoirs connected to project facilities. Early detection sampling is a critical component in the prevention of new infestations.
Motorized boat inspections at ECAO reservoirs
Colorado is a mandatory boat inspection state to prevent the spread of ANS. Our recreation partners, such as CPW and the Larimer County Department of Natural Resources inspection programs comply with Colorado law. For a map of Colorado ANS inspection stations, visit the Statewide Boat Inspection Stations ArcGIS site.
Larimer County boat inspection information:
Estes Valley Recreation and Parks District boat inspection information:
U.S. Forest Service boat inspection information:
- Green Mountain/Heeney Area
- Ruedi Reservoir
- Lake Granby, Shadow Mountain Reservoir, and Willow Creek Reservoir
- Turquoise Lake
- Twin Lakes
