Water Quality Reports

Ongoing monitoring and evaluating lake water quality is critical to the long-term protection of our precious Lake Winona. Our lake participates in the NH Department of Environmental Services’ (NHDES) Volunteer Lake Assessment Program (VLAP) and collects three samplings each summer, once in June, July and August. If you would like to join the Water Quality Committee, please contact Charlie Goodwin, Committee Chair.

2019 NHDES VLAP Recommendations

Lake quality was good in June with phosphorus and chlorophyll levels below the thresholds for mesotrophic lakes, however, historical data suggest the occurrence of late summer algal/cyanobacteria blooms and phosphorus levels have significantly increased in the Hypolimnion suggesting a thick organic layer on the lake bottom that depletes dissolved oxygen resulting in the release of phosphorus bound in the sediments into the water column. This phosphorus is readily available for uptake by algae and cyanobacteria. This highlights the importance of minimizing stormwater runoff, erosion, and sedimentation and deposition of organic material to the lake. Educate lake residents on best practices to dispose of organic material and how to reduce stormwater runoff and shoreline erosion. Identify and catalog areas prone to erosion and prioritize areas for remediation activities. Keep up the great work!

Download the 2019 VLAP Report

2017 NHDES VLAP Recommendations

Recommended Actions: Lake chlorophyll levels (algal growth) has remained above the threshold for mesotrophic lakes since 2010, and this is likely due to the spikes in algal growth typically measured in September during the start of the fall turnover when nutrients from bottom waters become available for algal growth. This highlights the importance of minimizing nutrient inputs from the watershed during the summer months. Several tributaries experienced higher phosphorus levels following a storm event in July, and bacteria levels also spiked. These systems are fed by wetland complexes and the influx of nutrients and bacteria may be a normal occurrence following heavy rainfall. These events may be occurring more frequently and highlight the importance of managing stormwater runoff from lake and watershed properties, and dirt/gravel and paved roads. Encourage lake property owners and those responsible for road maintenance to implement stormwater best practices to reduce stormwater runoff and erosion from their properties. Keep up the great work.

Download the 2017 VLAP Report (individual summary report not produced in 2018)

2014 Lakes Region Regional VLAP Report on Total Phosphorus Levels

Phosphorus is typically the limiting nutrient for vascular plant and algal growth in New Hampshire’s lakes and ponds. Excessive phosphorus in a pond can lead to increased plant and algal growth over time. The median summer epilimnetic (upper layer) total phosphorus concentration of New Hampshire’s lakes and ponds is 12 ug/L. The median epilimnetic total phosphorus concentration for the Lakes region is 8 ug/L.

2014 Lakes Region Regional VLAP Report on Total Chlorophyll-a

Algae are microscopic plants that are naturally found in the lake ecosystem. Algae and cyanobacteria contain chlorophyll-a, a pigment used for photosynthesis. The measurement of chlorophyll-a in the water provides an estimation of the algal and/or cyanobacteria abundance or lake productivity. The median summer chlorophyll-a concentration for New Hampshire’s lakes and ponds is 4.58 mg/m3. The median chlorophyll-a concentration for the Lakes Region is 3.83 mg/m3.

Additional NHDES VLAP Reports for Lake Winona