This page provides information related to current recreation water quality health advisories involving cyanobacteria harmful algal blooms (HABs) and E. coli bacteria. The map is updated with the most current information as health advisories are issued and lifted throughout the season.
Recreation Water Bloom Advisories and Warnings
The map below provides additional information for active health advisories. Click on the marker in the map for updates.
Cyanobacteria Bloom and Advisory Updates
Although Idaho’s bloom season should be winding down, cyanobacteria are still active in many areas. We encourage the public to avoid fishing or hunting where the water is green. Download the USGS field guide for identifying cyanobacteria.
Please remember to wash hands with fresh water or use a wipe after handling fish, lures, and waterfowl. Hand sanitizer does not protect against cyanotoxins. Cyanobacteria can cause serious health issues and even death in dogs.
The table below provides updates for each water body with an active bloom, active advisory, and a lifted health advisory.
|Status Update||County||Waterbody||Advisory Issued||Advisory Lifted|
|Active Bloom||Bonner||Boyer Slough||2021 August 20|
|Lifted||Clearwater||Elk Creek Reservoir||08-04-2021||11-08-2021|
|Active Bloom||Kootenai||Hauser Lake||10-07-2021||11-01-2021|
|Active Bloom||Kootenai||Hayden Lake - near McCleans Bay (where it is shallow with an abundance of aquatic vegetation; including McCleans Bay).||07-27-2021||11-01-2021|
|Lifted||Adams||Hells Canyon Reservoir||08-06-2021||10-08-2021|
|Lifted||Latah||Hordemann Pond - Closed Until Further Notice||07-26-2021||11-08-2021|
|Active Advisory||Canyon||Lake Lowell||08-06-2021|
|Active Advisory||Twin Falls County||Magic Reservoir||08-09-2021|
|Lifted||Nez Perce||Mann Lake||08-13-2021||11-08-2021|
|Lifted||Bonner||Priest Lake Outlet: From Outlet Bay Road (48.4934, -116.8907) to the dam||08-27-2021||09-10-2021|
|Lifted||Bonner||Sagle Slough and Comeback Bay||08-04-2021||11-01-2021|
|Active Advisory||Twin||Salmon Falls Creek Reservoir||08-09-2021|
|Active Bloom||Bonner||Solomon Lake||09-12-2021||11-01-2021|
|Lifted||Latah||Spring Valley Reservoir||07-26-2021||11-08-2021|
|Active Advisory||Fremont||Upper Island Park Reservoir shoreline||09-10-2021|
Report a Health Concern
Idaho’s health agencies are responsible for educating and advising the public on cyanobacteria exposures.
Idaho’s seven public health districts develop public health advisories, in consultation with DEQ, based on lab result analysis. The Idaho Department of Health and Welfare maintains a Harmful Algal Blooms FAQ page and Waterborne Illness page, which contain educational material and general information about potential illnesses from recreational waters and drinking water.
Report a Potential Cyanobacteria Harmful Algal Bloom
Use the link below to provide information about a potential cyanobacteria harmful algal bloom.