Chautauqua Lake Herbicide Report

As everyone around the Lake knows, this year was the second in a row of a DEC-approved herbicide treatment of the Lake. One of the differences is that this year, a focus for treatment was in the historically weed-infested area of Burtis Bay.

As one boater told me: “It was the first time in years that I saw people water skiing in Burtis Bay.” The report of Princeton Hydro, an ecological and engineering consulting company, said it in more scientific language: “Total biomass declined at treatment zones with a marked reduction in the two invasive species…” referring to curly leaf pondweed and Eurasian milfoil.

For the first time this year, a third-party monitor was used in testing both “before” and “after” results. This is a good thing because it gives the public the assurance that the treatment process is being properly performed and evaluated. From a strictly scientific standpoint, it also provides accurate, comparable sampling of water and weed growth so that future decisions relative to the lake can be made with less guess work and more actual data as to what is happening.

Perhaps the best words of summation in the report were the following: “Overall, the treatment was successful at its intent, and data pertaining to this project showed adverse impacts to be minimal.”

There were a couple of observations in the report that I found interesting. The first was that there was some migration of the herbicide treatment and some of that was to the north, in other words upstream from the usual north to south current in the lake. The report said that this was “not surprising in a lake environment…” but it does highlight the fact that we need to know more about how currents in the lake function. Tests at the two public drinking water intakes in the lake (Chautauqua Institution and Chautauqua Lake Estates) indicated that the herbicide treatment did not affect these areas.

A second observation was a pleasant surprise in that “four of the more common native species all increased from pre-to-post treatment conditions.” In other words, retarding the growth of invasive species actually helped stimulate the growth of native plants in the lake.

A recommendation in the study which I found interesting was that “future treatments, if possible, should occur at some of the same areas as in 2019 in addition to new areas. Such an approach would allow for the determination of impacts or benefits from multiple years of treatment.” This could influence the DEC into experimenting with repeat treatments in addition to the “every third year” approach they have been applying thus far.

In short, the report confirms the fact that properly applied herbicide treatment has been effective in reducing the growth of invasive species in Chautauqua Lake. The challenge lies in finding a way to fund this and other lake-oriented activities in the future. Without the prospect of significant state support, we are going to need to rely more on locally-generated money to address the needs of the lake.

Overall, the content of the report was positive. “The treatment was conducted appropriately and within the regulations set forth by permits as issued by the NYSDEC by the contracted applicator, Solitude Lake Management.”

Rolland Kidder is a Stow resident.