Bismarck  (ND Environmental Quality)  Jamestown Reservoir, Wilson Dam, in Dickey County, Schlecht-Thom Dam, and Flood Lake in LaMoure have been added to the list of area bodies of water, on the official advisory list with Blue-green algae blooms that can  produce toxins in the water.

An Advisory means that a blue-green algae bloom is present in portions of the waterbody, and microcystin levels in those areas exceed the public health criteria of 10 micrograms per liter (μg/L). Avoid those areas of the waterbody where the bloom is present. The areas of the lake where there is no evidence of a bloom may still be used for water-based recreation (e.g., swimming, water skiing, kayaking and paddle boarding).

Hot summer weather can contribute to the production of blue-green algae (cyanobacteria) in bodies of water that are used by people, pets and livestock. In some lakes, these blooms can persist into the early fall where they can pose a risk to hunters and their dogs. Blue-green algae discolor the water and can cause foam, scum or mats to appear on the surface. In severe blooms, the water can have the appearance of spilled green paint or green pea soup.

Blue-green algae can also produce toxins in the water called cyanotoxins. People and animals that swallow water containing cyanotoxins can become sick with diarrhea and vomiting. Other symptoms in people include numb lips, tingling fingers and toes; dizziness; or rashes, hives or skin blisters. The most common cyanotoxin found in North Dakota lakes experiencing a blue-green algae bloom is microcystin.

Blue-green algae blooms are extremely variable in terms of when and where they occur. There may be other lakes, reservoirs, ponds or wetlands in the state that are experiencing blooms in addition to those on this list. People should familiarize themselves with what a bloom looks like, and if they see one, avoid it and report it to the North Dakota Department of Health (NDDoH) through the on-line form at

On lakes with an advisory or warning:
• Avoid areas of scum when boating.
• While fish are safe to consume, take the following precautions.
o Rinse hands with non-lake water after landing fish.
o Wash fish thoroughly with tap water before cleaning.
• Contact your health provider or veterinarian if you or your pet become ill after swimming.
For more information contact: Division of Water Quality

Larsen Lake Hettinger August 8
Jamestown Dam Stutsman August 8
Dry Lake McIntosh August 2
Long Lake NWR Burleigh August 2
Blumhardt Lake McIntosh August 2
Wilson Dam Dickey August 2
Schlecht-Thom Dam LaMoure August 2
Flood Lake LaMoure July 29
Patterson Lake Stark July 29
Bowman-Haley Dam Bowman July 29
Devils Lake – Bloom limited to East Bay Ramsey – Benson July 25
Sweetbriar Lake Morton July12
Harmon Lake Morton July 5