Looking Back at 2026:
A Water Quality Summary

Perhaps the best news of the year is simple: Lake Winnecook remained free of a significant cyanobacteria bloom through our final September 16 monitoring.

One likely contributor was the unusually dry summer. Bangor recorded only 5.44 inches of precipitation from June through August, approximately 46% below normal. Reduced rainfall generally means less stormwater runoff available to carry soil, sediment and phosphorus from the watershed into the lake.

However, rainfall cannot explain the year by itself. Temperature, wind, sunlight, lake mixing, nutrient availability, and the timing and intensity of individual rain events can all influence whether a bloom develops.

The contrast between what we saw at the surface and what we measured at depth may be the most important lesson of 2026. On the surface we enjoyed relatively clear, bloom-free water ... while simultaneously measuring severe oxygen depletion at the lake bottom!

That tells us that favorable conditions during one summer do not mean Lake Winnecook’s underlying phosphorus problem has disappeared.

Why the Alum Treatment Remains So Important
This is also where the alum treatment fits into the story.

The objective is not simply to treat conditions that could support a cyanobacteria bloom. The alum treatment is intended to also address the phosphorus already stored in Lake Winnecook's sediments.

Alum forms compounds that strongly bind phosphorus, helping keep it locked in the sediments even when bottom-water oxygen becomes very low. In effect, the treatment is designed to interrupt the internal phosphorus-loading cycle that our summer dissolved-oxygen measurements help explain.

A bloom-free 2026 is therefore very welcome news, but it does not remove the need to address the lake's accumulated internal phosphorus supply. Improving Lake Winnecook’s long-term health requires reducing the amount of phosphorus available to fuel future cyanobacteria blooms, including phosphorus released from Iron bound bottom sediments.

The 2026 Takeaway
We finish the season with 2.74 meters (9.0 feet) of Secchi clarity, nearly uniform temperatures from surface to bottom, and dissolved oxygen restored throughout the water column as part of fall turnover.

The larger story of 2026 is equally important. The lake can look healthy at the surface while significant changes are occurring unseen at the bottom. Our monitoring documented that progression — from summer stratification, to severe deep-water oxygen depletion, and finally to fall turnover and oxygen recovery.

That’s why continued monitoring, and addressing Lake Winnecook’s underlying phosphorus problem, remains so important.