Lake Erie Hypoxia Forecast

The UWSS will now be posting Lake Erie Hypoxia Reports for 2025 as they become available; these are also received from the (NCCOS). Hypoxia, caused by low oxygen levels in a body water, can be referred to as dead zones, and is inhospitable to many animals.  In the summer the lake stratifies, with warm water on top and cold, dense, deep water below. This part of the lake is typically lower in oxygen levels and has a different chemistry with limited vertical mixing of the cold and warm waters, which further restricts the oxygen levels. The low oxygen water also has different chemistry from oxygenated water, which is problematic for the public water supply. Strong wind events in the summer can cause upwelling, which brings this cold, hypoxic bottom water up to the surface close to shore. This can cause a sudden degradation to the water quality at nearshore drinking water intakes. These events require rapid adjustments to the treatment process in order to maintain drinking water quality. UWSS Inc. continues to monitor these events closely in order to adjust processes quickly in order to continue to provide safe drinking water.  We will be posting regular reports here throughout the 2025 summer season.