Water Quality Updates

Water Quality Update for October 15, 2021


Welcome to the final Friday Water Quality Update of the season.


Last week, we reported on a significant bloom event that started on Monday, October 4th - occurring mostly on the west of the lake, which then intensified by Wednesday, October 6th to a lake-wide bloom event. We are sharing results from last week's samples collected by volunteers below. These samples all came back well above the bloom threshold of 25 micrograms per liter of blue green chlorophyll (ug/L) and had the highest levels of the season.


Since last week’s significant bloom event, activity had (for the most part) calmed down, although with yesterday's calm conditions, 8 bloom reports were filed (Thursday, 10/14). Three samples were collected from the east side of the lake yesterday - in Crystal beach, Cottage City, and Vine Valley. All showed significant concentrations of algae.







We want to stress that although we are well into October, there is still the potential for cyanobacteria to reach bloom levels when conditions are right. Sunny or not - on calm days we have been seeing surface accumulations of HABs. From our sampling efforts, we know that when you see surface accumulations of HABs, the levels are high and these blooms have the potential to be harmful to both human and pet health. Please continue to avoid these areas and do not let your pets swim in water that is discolored, showing surface streaks of algae, or has “pea soup” like conditions.


Although this is the final scheduled weekly water quality update, monitoring will continue through a combination of volunteer and watershed staff efforts. We are also staying connected with the water purveyors to learn of any potential drinking water impacts from harmful algae blooms. Routine monitoring of the municipal drinking water systems continues to show that the treated drinking water is safe to drink. The latest weekly results can be found here.


We thank our many CLWA volunteers for their continued support and efforts to monitor the lake in this extended season. You will be hearing more from CLWA and our partners in the future as we put together our season-end report. The Canandaigua Lake Watershed Council will also be hosting a public meeting to share information about the latest efforts to update our current Watershed Plan to meet the DEC requirements for a 9 Element Watershed Plan later this fall / early winter. More information on that event will be coming out in the future.


As always, we encourage you to follow our reports on our website, and on the facebook page for further information.


For those interested in learning more about the formation of HABs and the latest HABs research, consider attending the Harmful Algal Bloom Symposium hosted by the Finger Lakes Institute, NYS DEC, SUNY Fredonia, and Corning on October 28th. More information is posted HERE.


2021 Shoreline HABs Monitoring Program

Sixty-nine trained volunteers around Canandaigua Lake and Watershed staff will be reporting current water conditions from August through the beginning of October. While it is not possible to document every bloom occurring on the lake in real time, trained observer reports help us bring you the most up to date information available.  

View the interactive map here.

Drinking Water and HABs

Learn more about drinking water and HABs HERE.

The six Canandaigua Lake water purveyors (the City of Canandaigua, the Village of Newark, the Village of Palmyra, the Village of Rushville, the Town of Gorham, and Bristol Harbour) are working alongside the Geneva District Office of the Health Department and the New York State Department of Health to monitor the public drinking water for the presence of toxins associated with harmful algal blooms. Samples of the public drinking water are routinely collected and sent to a State approved laboratory on a regular basis during the harmful algal bloom season to determine if toxins are present. Click HERE for the 2019 results.

Previous Water Quality Updates