Sunday August 30, 2026 Honeoye Lake Water Quality

Terry Gronwall
8 hours ago
3 min read

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There have not been any new blue-green algae blooms reported to the DEC NYHABS map since August 21.

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Surface Water Temperature: ~73.0 F

Water Clarity: ~6.3 Feet

Lake Level: 803.0 Feet above sea level

Lake level is a little below weir level. Evaporation will lower the lake level 0.1 to 0.4 inches per day from this level unless we get more rain soon.

Observations: Sunday (8/30/26), Water clarity was ~6.3 feet the same as last week. An overcast sky reduced the water clarity a little bit. Today’s water clarity was ~1.3 feet higher than it was on August 31, 2025. The surface water temperature was ~73.0 F about a 1.1 F decrease over the last week. The lake’s recent mixing events caused several isolated blue-green algae blooms at the north and south ends of the lake due to the prevailing north and south wind direction between August 16-21 as reported to the DEC NYHABS map. This morning had an overcast sky with a calm wind.

There have been 19 Honeoye Lake near shore blue-green blooms reported to the DEC NYHABS site since June 29. There were 9 new blue-green algae bloom reported to the DEC NYHABS site between August 16-21 due to the recent lake mixing events they are the dark blue circles. There have not been any new blooms reported to the DEC NYHABS map since August 21. See the Honeoye Lake DEC NYHABS Honeoye Lake map below:

We are now in the peak blue-green algae bloom time period across all of the Finger Lakes. The dark blue circles are booms reported in the last two weeks. See Finger Lakes DEC NYHABS map below:

Always use your own visual assessment before making contact with the lake water at this time of year as the blue-green algae situation can change daily if not hourly. Please regularly check the DEC HABs alert map for more detailed updates on Honeoye Lake HABs alerts:

https://experience.arcgis.com/experience/e5dec19912454731a308bbb7af605fb3/

We found about the same amounts of Anabaena (Dolchospermum) (looks like a spring or chain of beads), Microcystis (looks like a group of small round cells), Limnoraphis (looks like a rod), and Aphanizomenon (looks like a leaf) again today. See algae images on the left and below: You should be watchful for Anabaena, Microcystis, Limnoraphis, and Aphanizomenon blooms, all cyanobacteria species, lake wide over the next few weeks particularly when we have 80-90 F days with calm winds. More information on Gloeotrichia and Anabaena which are cyanobacteria can be found at: https://www.honeoyelakewatershed.org/habs

Several research studies have found that most of the phosphorus that fuels Honeoye Lake’s blue-green algae blooms is released from the lake bottom sediments when the lake’s dissolved oxygen level goes below 0.5 mg/L in the deeper parts of the lake breaking the phosphors/iron bond in the bottom sediments releasing phosphorus into the water column. The dissolved oxygen (DO) level near the lake bottom at 9 m (30 feet) was 7.02 mg/L today. This means that additional phosphorus is not currently being released from the lake’s bottom sediments at this time. Today's temperature and dissolved oxygen graphs are on the left.

The lake was isothermal today meaning that the water temperature was uniform from the surface to the bottom. The dissolved oxygen (DO) was also very well mixed. Surface DO was 8.08 ug/L and bottom DO was 7.02 ug/L

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