Blue green algal bloom in north end of Hayden Lake

Blue-Green Algal Bloom Underway in Northern Arm of Hayden Lake

Our water quality and biotic community monitoring expert is predicting the algal scum buildup that is typical of the late stages of an algal bloom to occur in the next couple weeks. The bloom result should be experienced in the northern arm of the lake but winds could drive the scum elsewhere. The prediction is based on water quality samples collected as part of the Hayden Lake Watershed Improvement District’s monitoring of the lake. Water quality samples collected a foot and a half deep in the waters near Sportsmans Access indicate a buildup of the blue-green algae, Anabaena. This blue-green is of particular concern, because some species produce a toxin. The Department of Environmental Quality has been informed and may issue warnings dependent on the Anabaena species concerned.

The District’s monitoring is specifically designed to detect the early signs of such blooms so these may be addressed by simple chemical additions. Blue-green algal blooms occur in the more phosphorous rich northern arm of the lake during low runoff years like we are experiencing. The low runoff deprives the lake’s waters of the plant growth nutrient, nitrate. The blue-green algal species are capable of fixing atmospheric nitrogen. With all the other nutrient resources left to the blue greens alone these species multiply rapidly into what is referred to as a bloom. A simple small nitrate addition to these waters of the lake can pre-empt this condition maintaining balance in the algal planktonic communities. Unfortunately, the District is just in the process of developing the water quality data base to justify such nitrate additions to DEQ and EPA. These measures cannot be employed this year, but with long term monitoring of the chemical and biotic condition of the lake we hope to manage such incidents in the future.


Blue green algal bloom in north end of Hayden Lake — 3 Comments

  1. Unfortunately, I am committed to help with a baby shower at the Rockin R Ranch for a beloved 4H leader at the same time as the meeting tonight, so am unable to attend. If I were to attend, I would ask about one of the stated “missions” of HLWA which was to go around & remove stray dock debris. Somehow our stretch of lake shore attracts more than it’s share of old dock logs & parts. Our hill is too inaccessible & steep (& my husband works far, far away so it’s just me) – I have no way to haul all that wood away. Is HLWA still planning to go around the lake & clean up that kind of thing?

  2. We are attending a lake party this weekend July 18th in the bay east of Camp Mivodan. We will have children with us who will be swimming. Is the water safe for them to be in??

    • Jeanne – the news release from the Panhandle Health District and Department of Environmental Quality says For health-related questions, contact Panhandle Health District’s Erik Ketner at 415-5224.