CDA proposes removing some aquatic plants from Colorado's noxious-weed list

The Colorado Department of Agriculture (CDA) told workshop attendees it plans an administrative-rule update that would remove four "true" aquatic species from the state noxious-weed list and pivot toward education and a watch list approach.

"We're proposing to remove these [four] true aquatic nuisance species from the noxious weed list this year," Patty York, CDA's noxious-weed program manager, said. She identified the species under consideration as hydrilla, giant salvinia, parrot feather and Eurasian watermilfoil and said the change would pair state-level education and laboratory support from CPW with local management options.

York said the proposal reflects practical enforcement limits: many aquatic plants are difficult for county weed managers to observe from public rights-of-way, often require genetic confirmation at a lab, and in some instances eradication is not achievable without aquatic pesticide applications that are controversial and legally constrained. The rule-update work is underway now; CDA plans to formally propose the rule at the end of December and expects the regulatory and public-comment process to run through next legislative session.

CDA is seeking stakeholder input via a survey and noted it had received 52 responses to date, with roughly 52% supporting removal of ANS plants from the noxious list and about 25% reporting no opinion. York said local entities would still be able to add and manage species on their localized noxious-weed lists if they choose.