LATEST UPDATES

Much work has been done over the past year to reduce or eliminate the nusience vegetation in Quaddick Lake. TREATMENT IS PLANNED FOR JULY 9th. See a map of the treatment areas here.

Attend the annual meeting on July 20th at the Thompson Town Hall to learn what all your Association has been doing since the last meeting.

NUISANCE WEEDS IN QUADDICK LAKE

For many years excessive weed growth has threatened to disrupt the ecological and recreational balance maintained within Quaddick Lake. The encroachment of nuisance vegetation, especially non-native species like variable watermilfoil (Myriophyllum heterophyllum), fanwort (Cabomba caroliniana) and bladderwort (Utricularia) is seriously hindering the spread of wildlife as well as human access and enjoyment of the lake. The ever-present trend of continued development and "cultural eutrophication" emphasizes the importance of a well-rounded plan to manage Quaddick Lake.

Several methods of weed control have been attempted sporadically in the past but, in order to regulate and control the weed growth, an ongoing management program is required. The Quaddick Lake Association has created a Lake Management Committee to focus on comprehensively evaluating available techniques to address this issue and then to educate the community and Association so the membership can determine the best method to use to control the problematic growth as an annual effort. Nuisance Aquatic Vegetation Management (1.8 mb pdf) is a guidebook produced by the State of Connecticut Department of Environmental Protection and Pesticides Management Program, regarding the invasive vegetation issues that are affecting out lake.

One of the primary charters of the Association's Lake Management Committee is to ensure that residents within the watershed area are properly informed about the factors that contribute to weed growth and the options that are viable to control the growth. This website is the primary vehicle to deliver this information. Review some Do's and Don'ts for lake-front Residents.

TREATMENT OPTIONS

In 2001, Aquatic Control Technology, Inc. was contracted to complete a diagnostic assessment of the exotic, invasive vegetation in the lake. The methods determined as viable to effectively control this vegetation in Quaddick Lake are drawdowns, hydro-raking and/or chemical treatments. You can read the entire report here (5.6 mb pdf).

DRAWDOWN

A drawdown is lowering the water level in the winter until the exposed bottom freezes, to kill roots of vegetative places and susceptible seeds of certain rooted aquatic plant species. Drawdowns have been used on Quaddick Lake in the past for rooted plant control, to prevent ice damage and to allow for repair of docks and shoreline areas. View an example of the 3-4 foot drawdown.

Following the Quaddick Lake Association meeting on August 27th 2006, it was determined that the first step in the lake management program would be to lower the lake's water level (drawdown) annually. Divers will inspect the drain pipe's grate to make sure it is clear of debris and then Rawson Manufacturing will begin generating electricity by drawing water through the pipe and over the Red Bridge Dam in early October. This should lower the water level of the lake, until the lake is down about 5 feet in January.

The lake should freeze in early January to an average thickness of 8-10 inches. About 2/3rds of Upper Quaddick will experience significant contact between the ice and the weeds on the bottom of the lake. Over a period of 30 days of surface contact, the ice causes significant damage to the root systems of the weeds within the contact area.

Rawson Manufacturing will stop drawing water from the lake in late March. With good timing and some luck, the snow melting and periodic rains will quickly raise the water level back to its normal condition. This forces the ice off the surface, thus uprooting the weeds frozen in the ice. This also allows for the lake to stay cooler for a longer period of time. The cooler water holds the initial new growth at bay and delays the surge of weeds until later in the summer.

HYDRO-RAKING

Mechanical raking (Hydro-Raking) is a widely used and effective technique for area selective removal of nuisance, rooted vegetation. In some situations the Hydro-Rake is also used to clear accumulations of unconsolidated bottom debris (i.e. decaying leaves, peat, muck). The Hydro-Rake can best be described as a floating barge upon which is mounted a backhoe with several different size and functioning rake attachments. The Hydro-Rake is powered by a Diesel engine which drives the hydraulically operated paddle wheel propulsion system and back-hoe functions. The Hydro-Rake can operate in water as shallow as 1.0 -1.5 feet and can remove nuisance vegetation and bottom debris from variable water depths as shallow as a few inches to a maximum depth of 12 feet. Duration of nuisance plant control varies, but is typically "summer long" for species such as water milfoil (Myriophyllum sp.) to 2-3 years or longer for plants with well developed root systems (i.e. waterlilies, cattails, etc.)

The Hydro-Rake works from the water and can therefore access coves and shoreline areas otherwise inaccessible to conventional machinery. View the Hydro-Rake. Damage to valuable shoreline habitat and waterfront property are avoided with the Hydro-Rake. The Hydro-Rake deposits each rake full (maximum 500 lbs.) of material directly on-shore. Upland disposal of Hydro-Raked material will be handled by the customer in conjunction with the Lake Association and taken to a central collection point where it will be disposed of by the Town of Thompson.

If determined necessary the Quaddick Lake Association makes arrangements with Aquatic Control Technologies to Hydro-Rake beachfronts and shorelines for lakefront homeowners at a discounted rate of $170 per hour. The Association covers the costs of delivery of the machine ($1000) but homeowners are required to contract ACT individually by completing and submitting a sign-up form.

The Hydro-Rake deposited each rake full of material directly on-shore and then permanent disposal of the Hydro-Raked material was handled by the homeowner in conjunction with the Lake Association and taken to central collection points around the lake where it was picked up and disposed of by the Town.

CHEMICAL TREATMENT

The only herbicide that is effective against fanwort is fluridone, commonly called Sonar, and is only available from only one manufacturer. Both weed control companies consulted have agreed that the use of this product will resolve the overgrowth of the fanwort. The good news is that Sonar is harmless to fish, animals and humans. It is used to treat drinking water reservoirs. EPA permissible limits in drinking water are about three times greater than the concentration needed to kill the weeds. It is very effective against fanwort if necessary concentrations are maintained for approximately six weeks…..not an easy task given the flow rate of water through Quaddick, but doable if rains are not too heavy. It will also greatly reduce the milfoil and somewhat reduce bladderwort for the first year. Treatment would be guaranteed for two years for the fanwort, with the expectation that it would be three years or more before fanwort was a problem again. The bad news is that treating upper Quaddick alone costs between 100,000 and $150,000. Adding lower Quaddick, which is beginning to see fanwort and the other weeds in shallower areas, raises the cost to about $175,000. The view of the Lake Management committee is that, if herbicide treatment is required, it would be best to treat both upper and lower sections of the lake. If the problem is kept in check by re-treatment before things get out of hand as they are now, we should not have to spend this amount of money at one time again. One of the treatment companies estimates that ongoing maintenance over the next 10 years will average about $36,000 per year.

In May of 2007, the State of Connecticut awarded the Town of Thompson a bond for $200,000 to be used for Chemical Treatment of Quaddick Lake. The disbursement of the funds will be at the discretion of the Board of Directors and will be used to offset the costs of chemical treatment as well as the purchase and maintenance of water quality monitoring devices.