11/20/2025
The November Newsletter went out Yesterday to those on our LOMAC email list.
Hello Neighbors,
We invite you to read the attached LOMAC newsletter dated this November 2025 Vol 9 from the Lake Oscawana Management Advisory Committee (LOMAC) (Town-appointed advisory committee)
It is best to read it in the PDF format, you can visit the LOMAC section of our town’s website to download it directly: http://www.putnamvalley.com/LOMAC (scroll down to find it) – or click the attachment within your own email and start reading as soon as possible.
The Quick Contents of the newsletter are.
â—Ź HEALTH OF THE LAKE â—Ź NYSFOLA / CSLAP â—Ź RAIN GARDEN PROGRAM â—Ź HYDRODYNAMIC SEPARATOR â—Ź FISH MANAGEMENT â—Ź WEEDS / HARVESTER / HAB â—Ź BOATING REGULATIONS â—Ź ANNUAL LAKE OSCAWANA DISTRICT MEETING HEALTH OF THE LAKE
The health of Lake Oscawana remains stable, and our water is safe for swimming. Our limnologist has implemented a new grading system to assess the lake’s overall condition. The Lake Oscawana Surface Water Quality Index rates the lake on four criteria: 1. Average surface phosphorus 2. Average surface nitrogen content 3. Water clarity (measured by Secchi disk) 4. Cyanobacteria bloom activity In 2024, Lake Oscawana scored 8 out of 12 on the Water Quality Index, which our limnologist considers satisfactory and indicative of no serious concerns. A perfect score of 12/12 would reflect low surface phosphorus and nitrogen levels, excellent water clarity, and minimal to no Cyanobacteria blooms. Early 2025 Observations Preliminary reports indicate lower water clarity, possibly due to limited rainfall, low water levels, and human activities such as boating and watershed runoff.
The New York State DEC and Department of Health (DOH) now use an updated, more sensitive method for detecting microbes. The DOH standard for public beaches is 235 bacterial colonies per 100 mL; any readings above that threshold can prompt beach closures. In 2025, Hilltop Beach experienced several closures due to Enterococci bacteria. Our limnologist is conducting additional sampling around Hilltop to locate the source, which may be local. Similar closures occurred at Northview Beach, and Cyanobacteria blooms led to short-term closures at Hilltop and Lookout Manor. While all closures were short-lived, investigations continue. Potential sources of bacteria include both human and animal waste — especially waterfowl. Because source-tracing analysis is expensive, our limnologist is focusing on strategic sampling to help identify likely origins. Water testing confirmed that surface algae (HAB) levels remained below harmful thresholds, with Cyanobacteria counts never exceeding the World Health Organization’s 100,000 cells/mL limit. At a depth of 19 feet (the anoxic layer), the count reached 119,000 cells/mL.
If you notice green patches or algae mats near your beach, please take a photo and send it to [email protected] for review. If swimming areas are closed, the DOH and Town Hall will post updates on the Town of Putnam Valley website.
LOMAC reminds all homeowners to maintain septic systems (pump every three years) and manage runoff from their properties, including monitoring leach fields, to help protect lake health.
To continue to read the Full Version.... you need to download it... LOMAC sincerely thanks all residents, volunteers, and partners for helping protect and improve Lake Oscawana. Together, we can maintain a healthy, vibrant lake for our community and future generations.
Thank you from the
LOMAC Board Members
Please keep informed by signing up for email updates or following LOMAC on social media: â—Ź Facebook: LOMAC page â—Ź Instagram: A recording of the 2025 meeting is available: STAY CONNECTED The LOMAC Newsletter is now electronic-only. If you know someone not on the list, please ask them to sign up Email list for future LOMAC communications
Lake Oscawana Management Advisory Committee (LOMAC) Members: Alan Paley – Chair Jeffrey Coren – Member Steven David – Member Judy Dronzek – Member Jenie Fu – Member Dr. Ellen Friedman – Member John Lafata – Member Supervisor Jacqueline Annabi – Town Board Liaison State of the Lake 20...
