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Cyanobacteria Harmful Algal Blooms

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. 

Active Advisories

The table below is a list of active health advisories. When the advisory is lifted it will be removed from this list and added to the Lifted Advisory table. 

County Waterbody Date Issued Dominant Taxa DEQ Contact
Kootenai Black Lake October 7, 2021 Aphanizomenon DEC Coeur d'Alene:(208) 769-1422; Panhandle Health District: (208) 415-5100
Bonner Boyer Slough August 20, 2021 Aphanizomenon (208) 769-1422: Panhandle Health District: (208) 415-5100
Kootenai Cave Lake October 7, 2021 Woronichinia DEQ Coeur d'Alene:(208) 769-1422; Panhandle Health District: (208) 415-5100
Bonner Chuck Slough August 27, 2021 Dolichospermum Health District (800) 878-2364 / DEQ (208) 769-1422
Clearwater Elk Creek Reservoir August 4, 2021 Dolichospermum Idaho North Central District: Tara Macke (208) 799-3100; DEQ Lewiston: Sujata Connell (208) 799-4370
Kootenai Fernan Lake July 28, 2021 Panhandle Health: Katherine Hoyer (208) 415-5108; DEQ: Kristin Lowell (208) 769-1422
Kootenai Hauser Lake October 7, 2021 Dolichospermum DEQ Coeur d'Alene:(208) 769-1422; Panhandle Health District: (208) 415-5100
Kootenai Hayden Lake - North of McCleans Bay (where it is shallow with an abundance of aquatic vegetation; including McCleans Bay). 7/27/2021 Dolichospermum Panhandle Health: Katherine Hoyer (208) 415-5108; DEQ: Kristin Lowell (208) 769-1422
Fremont Henrys Lake September 10, 2021 Dolichospermum DEQ: (208) 528-2695; Eastern Idaho Public Health: (208) 522-0310
Latah Hordemann Pond - Closed Until Further Notice July 26, 2021 Dolichospermum City of Moscow: David Schott dschott@ci.moscow.id.us, (208) 883-7098; Sujata Connell Sujata.Connell@deq.idaho.gov, (208) 799-4370
Fremont Upper Island Park Reservoir shoreline September 10, 2021 DEQ: (208) 528-2695; Eastern Idaho Public Health: (208) 522-0310
Canyon Lake Lowell August 6, 2021 Dolichospermum Dani Terhaar (208) 373-0550
Twin Falls County Magic Reservoir August 9, 2021 Aphanizomenon Twin Falls Regional Office (208) 736-2190
Nez Perce Mann Lake August 13, 2021 Microcystis Lewiston Regional Office (208) 799-4370 / (877) 541-3304
Bonner Sagle Slough and Comeback Bay August 4, 2021 Dolichospermum spp. and Microcystis. September 24 update: surface scum observed along shoreline. During microscopy, DEQ observed Dolichospermum spp. in a high concentration as well as Microcystis. Panhandle Health: Katherine Hoyer (208) 415-5108; DEQ: Kristin Lowell (208) 769-1422
Twin Falls County Salmon Falls Creek Reservoir August 9, 2021 Gloeotrichia Twin Falls Regional Office (208) 736-2190
Twin Falls County Salmon Falls Reservoir August 9, 2021 Microcystin South Central Public Health District 866-710-9775
Bonner Solomon Lake September 13, 2021 Dolichospermum DEQ Coeur d'Alene: (208) 769-1422; Panhandle Health District: (208) 415-5100
Kootenai Spirit Lake August 23, 2021 Dolichospermum - September 3 update: scum was observed and cell counts remains high Coeur d'Alene Regional Office (208) 769-1422 / Health District (800) 878-2364
Latah Spring Valley Reservoir October 6, 2021 Woronichinia DEQ: (208) 799-4370; PH-INCD: (208) 799-3100

Lifted Advisories

Currently, all health advisories issued are active. We will update the Lifted Advisory table when an advisory is no longer active. 

County Waterbody Date Issued Date Lifted
Washington Brownlee Reservoir 08/06/2021 10/08/2021
Valley Cascade Reservoir 08/13/2021 10/08/2021
Adams Hells Canyon Reservoir 08/06/2021 10/08/2021
Bonner Priest Lake Outlet: From Outlet Bay Road (48.4934, -116.8907) to the dam 8/27/2021 9/10/2021

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Water Quality Standards Analyst

Brian Reese
Brian.Reese@deq.idaho.gov
(208) 373-0570

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