Should we open the dam to flush out the milky water?
While the water behind the dam on North Pond is undeniably gross, opening the dam to flush the water is not recommended at this time. While we have not detected the microcystin toxin in the water at the dam, there are other toxins that we can’t test for that may be present (which is why we recommend people stay away from the milky water near the dam, despite the negative toxin tests). Additionally, the water behind the dam has very low oxygen, and may kill fish and other aquatic life downstream.
Note that in 2020, the bloom on North Pond was worse (as indicated by water clarity measurements) and we did not have this occurrence. The tampering of the dam last week possibly concentrated more algae near the dam than would have naturally been there, leading the conditions that we observe now. Opening the dam is far more likely to have unintended negative consequences than it is to help the problem!
Photo from 7 Lakes Alliance