On Thursday, July 27, a possible cyanobacteria bloom appeared on the shoreline.  A sample was collected and taken to NHDES in Concord.  Based on a positive result, we received the following from NHDES:

A cyanobacteria WARNING (ADVISORY) has been issued for Winona Lake, New Hampton / Center Harbor. The bloom was first reported today 27 July, appearing as green clouds of material along shorelines. See the image attached, taken 27 July. Samples collected and reviewed on 27 July had cyanobacteria (Dolichospermum) in concentrations up to 950,000 cells/mL in areas of highest observed accumulations. Advisories are issued when cell counts exceed 70,000 cells/mL. NHDES advises lake users to not wade or swim in the water during an advisory. Please also keep pets and livestock out. The advisory is not based on a toxin evaluation and is intended as a precautionary measure for short-term exposure.

NHDES will resample in a week. I will reach out to you before then for updates. If you have information on where accumulated material is being observed at that time, please let us know to guide our sampling efforts. Advisories remain active until the bloom subsides.

We will sample again next week and take the sample to Concord.  In the meantime, signs advising people and pets to stay out of the water have been posted at Anchorage Road, the boat launch and West Shore Drive.

2023 Cyanobacteria Sign_FINAL

Below are helpful links from the NHDES website:

• Report a CyanoHAB 
• Healthy Swimming Mapper  
• Frequently Asked Questions