Chocorua Lake Water Quality —2020 Sampling Season
by Dwight Baldwin
Click on the image above to view a PDF of the entire three-page report. Click HERE to view the data listing from each of the sampling events.
Despite the marked increases in use of Chocorua Lake during the summer of 2020, the quality of the water did not suffer. All the measured parameters show that the lake continues to be pristine (Fig. 1). In fact, the average water clarity was as good as it has been in almost 30 years. This excellent clarity is mirrored in the corresponding low Chlorophyll-a concentrations which is a measure of the suspended algae levels in the water column (Fig. 2).
In summary, the trend of increased water clarity and decreased Chlorophyll-a has continued since 1999 (Fig. 7) when the Berms and Swales project was completed. This improvement in water clarity may be partly due to the natural changes occurring in the watershed, which have lowered natural sources of color in river water flowing into the lake (Fig. 5). But most of the improvement can be attributed to the interception of dissolved nutrients which formerly were washed directly into the lake off of Route 16. Now this water is captured in the swale and allowed to infiltrate into the soil. This in turn has reduced the algae concentrations that in the late 1990s were becoming an increasing problem (Fig. 6).
If you would like to participate in water testing at Chocorua Lake, please sign up via our volunteer form—new volunteers are always welcome! Water is tested 10 or more times a season, an opportunity to be out on the lake in the quiet of morning, with the loons and other early risers.
Thank you to Bob Craycraft and our partners at the NH Lakes Lay Monitoring program administered by the Center for Freshwater Biology at the University of New Hampshire.
Ed. You can read Dwight Baldwin’s lovely description of what it’s like to monitor water quality on the lake for 20 years in our Spring/Summer 2020 Newsletter.)
Banner image: The shadow of a person on the Narrows Bridge falls onto the pristine water of Chocorua Lake. Photo: Juno Lamb