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Mirror Lake

Current Water Quality Data

Below are heatmap plots showing temperature, dissolved oxygen, and chloride data through our most recent sampling visit. AsRA staff sample Mirror Lake on a bi-weekly basis during the open water season and monthly during the winter. Annually we published a detailed report on the water quality of Mirror Lake. This work is done in close partnership with the Adirondack Watershed Institute

How to read the plots below: The plots below depict changes in the measured parameter over both space (through the water column) and time. The x-axis is time, looking across the plot from left to right gives a sense of how the lake has changed over time. The y-axis is depth in the water column, the top of the plot is the surface of the lake and the bottom of the plot is the bottom of the lake. The colors inside the plot represent the values for the parameter being plotted, a key is on the right side of the plot.

Mirror Lake Temperature

The surface water temperature in 2017 has been cooler than both 2015 and 2016. Additionally, the thermocline has been shallower and the hypolimnion larger. 

Mirror Lake Dissolved Oxygen

Mirror Lake has experienced hypoxic conditions (<2 mg/L) at the lake bottom  in 2015, 2016, and 2017. In 2017 the size and duration of the hypoxic zone is both larger and longer than in 2015 or 2016. Understanding the extent, duration, and cause of hypoxia is important to maintaining the health of many aquatic organisms, including fish. 

Mirror Lake Chloride

Road salt is one of the major threats to Mirror Lake. Stormwater directly enters the lake from over 30 outfalls around the shore. When this salt laden runoff enters the lake it settles to the bottom. This can be observed during both the winters of 2015-16 and 2016-17. That build up of salt persists through the summer if the lake does not turnover in the spring, this phenomenon occurred this year and we expect it also occurred in 2015. The lack of turnover exacerbates the hypoxic conditions mentioned above, threatening the fish and other organisms living in the lake. We are currently working on studying this phenomenon to understand whether the lack of spring turnover is natural for Mirror Lake or the result of the buildup of saltier water at the lake bottom. 

Funding for this work is provided by the New York State Department of State,  Village of Lake Placid, Town of North Elba, IRONMAN Foundation, and Mirror Lake Watershed Association. For more information on our work on Mirror Lake email Brendan Wiltse,


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