Chocorua Lake Water Quality Report for 2021
by Dwight Baldwin
As swimming season comes around again, we are happy to share the results from our 2021 water quality monitoring program.
As may be seen in the charts below, the water quality of Chocorua Lake remained “Excellent” from Spring through Fall of 2021. The seasonal averages for chlorophyll-a, water clarity, and total phosphorus all fall in the field of excellent/oligotrophic as defined by NH DES aquatic life nutrient criteria. (View the complete Chocorua Lake sampling highlights report HERE.)
Click on the image above to view the complete Chocorua Lake sampling highlights report for 2021.
There was an interesting pattern to rainfall during the 2021 sampling season. The spring and early summer months were unusually dry; but July was unusually wet.
Click on the image above to view the complete rainfall overview document.
High rainfall amounts bring increased inflow to the lake from the Chocorua River and other tributaries. This in turn brings increased loading of nutrients, increased dissolved color brought from the wetlands above the lake and fine suspended sediments. As can be seen in Figures 2 and 3 of “Chocorua Lake 2021 Sampling Highlights,” there was a delay in the response of the lake to the increased inflow. The peak in chlorophyll-a (a measure of suspended algal concentrations) and dissolved color did not occur until middle to late August. The reason for this delayed response is most probably related to the water-storage capacity of the wetlands themselves and their ability to slowly release stormwater that backed up there during this period of high rainfall.
Click on the image above to view the complete Chocorua Lake sampling highlights report for 2021.
So, through the combined efforts of many to minimize the human impact on the water quality in the watershed above Chocorua Lake, the lake continues to be the clear, sparkling, water body that we all treasure. But such purity is always at risk, not only from chemical contaminants but also from the introduction of invasive aquatic species such as Eurasian milfoil. So it is imperative that we all be on the watch!
We’ll be hosting a workshop, “How Healthy is Your Lake? The Importance of Annual Water Quality Monitoring,” in partnership with Green Mountain Conservation Group on Saturday, June 18, from 9-10:30AM. Please join us to learn more about the importance of long-term monitoring on the many lakes in the region, what we can learn from water quality trends about the impact of stressors such as increased usage and climate change, how important community involvement and community science is, and what’s actually involved in becoming a lake monitor. (Hint: it’s a chance to make a commitment to being out on a lake on a beautiful day each month throughout the warmer seasons.) Come early for coffee and donuts!