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The Science of Saving Our Lake

   
Installation of one of Lake Waramaug's
Layer Aeration system tanks.

From its beginnings in 1975, the Lake Waramaug Task Force has focused on one objective: using science and education to reverse the frightening decline in the lake's water quality. This has been accomplished through innovative thinking that has occasionally defied previously held beliefs; the seeking out of the best minds in the area of limnology; supporting the development of new technologies; and creating and sustaining awareness among those who love and enjoy the lake.

...using science and education to reverse the frightening decline in the lake's water quality.
   
Education on the Effects of Nutrients
The alarming algae blooms of the 1970s were, in large part, the result of a flow of nutrients, primarily phosphorus, into the lake due to the careless use and disposal of potentially harmful farm and household products. Task number one, therefore, was to educate those who lived in the watershed about these harmful effects, the availability of alternative laundry, dishwashing and other products and methods of containing waste. This was accomplished through the media, letters, posters and personal appeals. The response was overwhelmingly positive. We were off to a good start.

Support of New Zoning Regulations
The Task Force also worked successfully with the towns to develop zoning regulations within the watershed which would 1) limit building too close to the shoreline and 2) limit the percentage of impervious surfaces in developed properties throughout the watershed. Impervious surfaces, which include driveways, walkways and athletic facilities in addition to roof areas, reduce the natural filtering effect of the soil and create harmful water runoff into the lake.

In-Lake Restoration Systems
Addressing the problems of the water already in the lake presented the most serious scientific challenge, and perhaps the most spectacular success. By the late 1960's and early 1970's, Waramaug had moved into a serious state of decline — termed "eutrophication" by lake scientists. This was evidenced by massive algae blooms being fed by phosphorus released during the summer from the anoxic (oxygen-deficient) lake bottom.


Bob Frost system at Arrow Point
   
To deal with this problem the Task Force's limnologist, Robert W. Kortmann, Ph.D., designed a unique "hypolimentic withdrawal" system to help contain the lake bottom phosphorus in the deep layer of the lake. Two systems were installed in 1983 — one at the tip of the Arrow Point peninsula, the other at the lake outlet in New Preston. In the following year there was a noticeable improvement in lake water clarity. The system at Arrow Point, named in memory of long-time Task Force board member Bob Frost, had the added benefit of reducing the available phosphorus in the lake by "fixing" it to the lake's abundant natural iron.

In 1989, new Kortmann-designed Layer Aeration systems were installed (see photo above) by the Task Force and suspended in deep water along the Route 45 lake shoreline. These more energy efficient systems allowed the Task Force to replace the New Preston hypolimnetic withdrawal system and greatly expanded the volume of water being circulated and aerated in the lake.

In 2015, two new Layer Aeration systems were installed near Arrow Point to replace the 32-year-old land-based Hypolymnetic Withdrawal System at the Frost Site. Dr. Kortmann then conceived of a new function for this site — the potential cultivation of zooplankton.

Each of these systems also benefit the lake by creating large areas of cold, well-oxygenated water habitat needed by cold water fish and zooplankton, the native natural predator of algae.

   
Biofilter buffer planting off West Shore Road
Other Task Force Facilities
The Task Force has also designed, funded and installed facilities outside of the lake but within the critical watershed area. They include waste catch-basins at a local farm and vineyard, designed to trap and filter harmful pollutants before they can flow into the lake. In addition, a biofilter was installed at an innovative buffer planting site on West Shore Road near New Preston.

Stocking and Seeding
The Task Force developed programs for fish stocking (primarily brown trout) and zooplankton seeding which would be beneficial to the water quality. In one case, the Task Force reversed a long-standing practice of stocking alewives that was determined to be having adverse effects.

The Threat of Invasive Aquatic Species
Invasive plants such as Eurasian Milfoil, Curlyleaf Pondweed and Water Chestnut, as well as Zebra Mussels and some fish, have devastated nearby lakes and present an ongoing threat to Lake Waramaug. The Task Force has developed a plan for prevention, early detection and an immediate response to these threats, including the support of a program to require inspection of all motorboats being launched on the lake that may accidentally introduce invasives picked up elsewhere.

Glossary of Terms


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