Aquatic Plant & Algae Management General Permit

We issue the Aquatic Plant and Algae Management (APAM) General Permit to allow chemical treatments for the management of aquatic noxious weeds, native nuisance plants, and algae. These chemicals are limited to a specific list of aquatic-labeled herbicides, algaecides, biological water clarifiers, adjuvants, marker dyes, shading products, and phosphorus sequestration products. They can be used directly into fresh water (lakes, streams, and rivers) or along shorelines, roadsides, dikes/levees, and ditch banks.

The current permit went into effect on April 21, 2021, and expires on March 21, 2026.

Join our email list to receive email updates about this permit.

We've updated our sign template to use more icons to help applicators warn people about any restrictions. 

Permittee resources

For more information, open the boxes below by clicking the + sign on the right side. Collapse them by clicking the - button.

Permit documents

View and download permit documents.

WDFW Restricted Areas for Aquatic Pesticides Map Tool (Treatment Timing Windows)

Map shows specific locations where use of aquatic herbicides is subject to different timing restrictions to protect fish and other priority species. Click image to go to WDFW's map.