Hayden Lake

Treatments for Eurasian watermilfoil control in the Inland Empire CWMA will begin in June.

Treatments include survey and monitoring, aquatic herbicide and diver dredging.

The areas that will receive treatments are:

• Hayden Lake - surveys June 10th through 13th, herbicide treatment June 23rd, diver dredging from mid-July to mid-August.

• Cave and Medicine Lakes - survey June 23rd through 25th, herbicide treatment June 30th.

• Harrison Slough - survey June 23rd through 25th, herbicide treatment July 7th.

• St. Maries River - survey in July, herbicide treatment in July or August.

(Herbicide application to the water requires permits from the State of Idaho and applications are done by a government agency.)

We do not treat over major drinking water inlets or irrigation district pipes.  We do not treat the whole lake with herbicide; only the thick areas of Eurasian watermilfoil will have herbicide applied (see map). 

Posting within a quarter (1/4) mile of an herbicide application is required and it means restrictions will be in place until lifted:

• Do not use the water for human or livestock drinking

• Do not irrigate your pasture or landscape

Swimming and fishing is OK.

To find out when restrictions are lifted, daily updates will be made available on this website OR call 208/446-1295 for a daily recorded message.

If you want more information about our projects, please email us at kcnoxiousweeds@kcgov.us or call our office at 208/446-1290.

To print the map, we also have it available in pdf format, click here.