Work Plan

Twin Island Lake (formerly, Mud Pond) (TWIL) is an approximately 60-acre lake, nestled at the base of Stissing Mountain in the Town of Pine Plains, Dutchess County, New York.  TWIL sits at the headwaters of the Wappingers Creek Watershed.  Its waters flow downstream through a culvert and discharge directly into Stissing Lake (SL) via a wetland stream.  SL has a public boat landing located approximately 150 feet to the east of the wetland stream and a public beach located mid-lake on the eastern shore.  SL, in turn, flows into Thompson Pond, a Nature Conservancy sanctuary (TP), via another culvert and a wetland stream.  Waters flow downstream from TP into the rest of the Wappingers Creek Watershed.

In 2009, Hudsonia was retained as part of a zoning initiative to identify, and conduct an assessment of, all the natural resources in Pine Plains.  As part of its report, Hudsonia determined that TWIL, and the other two lakes are “Priority Habitats” for the Town.  On the basis of the Hudsonia recommendations and other factors, the Town determined that this string of lakes remains an important viewshed for the Town, and imposed zoning laws to protect it.  

In addition to its natural beauty, TWIL has long been known as one of the best places in the area for year-round fishing for wide-mouth bass, bluegill, crappy and pickerel.  It also is a nesting and seasonal lay-over spot for an amazing array of birds, such as American eagles, egrets, osprey, and hawks, and one of its islands is home to an established blue heron rookery, making it an extraordinary venue for birding, especially via kayak.   

In summer 2018, following an unprecedented lowering of TWIL, when its waters were released downstream as a result of work done at the culvert located at the southern tip of the lake, TWIL experienced a sudden explosion of curly-leaf pondweed (Potamogeton crispus), a spike in water chestnuts (Trapas natans), and an aggressive return of Eurasian watermilfoil (Myriophyllum spicatum) (collectively, AIS), which had been successfully controlled after a DEC-approved herbicide application in 2010.  By August 2018, more than 50% of the surface waters of TWIL had become, for the first time, completely inaccessible due to vegetative growth, consisting largely of AIS.  

Concerned lake residents determined that concerted action was needed to try to save this once pristine habitat, and formed Twin Island Lake Association Inc. (TWILA), a New York not-for-profit corporation.  The Mission of TWILA is the “preservation and improvement of the water quality, natural habitat, and general environmental conditions of Twin Island Lake, its shores and its watershed for the benefit of its members, the public-at-large, and future generations.”  

In furtherance of that Mission, TWILA retained lake management expert, Princeton Hydro (PH), in June 2018 to conduct a comprehensive water quality, macrophyte and outlet assessment of TWIL and to make recommendations for addressing, among other things, this rampant infestation of invasive vegetation.  TWILA selected PH because of the organization’s demonstrated track record and established reputation for deploying science-based approaches in developing holistic, ecologically-sound and sustainable solutions for lakes, like TWIL, which sit at the headwater of [ADJECTIVE] watershed and therefore require thoughtful consideration of downstream habitats.

As detailed in its final assessment report dated January 2, 2019, PH confirmed what TWILA members had observed; namely, the presence of these three aquatic invasive species throughout TWIL.  As PH astutely observed in its findings:

“…all three identified invasives have the potential to create extremely dense stands which impair ecological condition and recreational access.  In addition, as many invasive plants may spread through fragmentation or seed dispersal, the presence of these invasives could potentially signal issues for downstream waterbodies.  Water chestnut is a particularly noxious, difficult to control plant, which has the ability to spread rapidly where by it covers the water surface leading to reduced capacity for oxygen diffusion from the atmosphere into the lake.”  (Report at p.11).

PH then concluded:

“The types and densities of aquatic plants in [TWIL] should be managed to achieve reductions or eradication of invasive species and overall reductions in biomass, native or otherwise, which will free up space for recreational access and provide open water habitat for the lakes’ fishery and overall improvements in water quality.” (Id.).

Proposed Remediation Measures for Which Grant Funding is Being Sought

To that end, TWIL is seeking a grant of $_________ from the 2019 Terrestrial and Aquatic Invasive Species Rapid Response and Control Grant, with a $______ match, to fund the cost of the three-year treatment plan recommended by PH as the most effective way to control, and over time eradicate, curly-leaf pondweed, Eurasian watermilfoil and water chestnut. The grant funds and 25% match (consisting of [[cash and]] in kind services) would be used each summer starting in 2019, over a three-year period, for three primary purposes:

  1. two whole-lake applications per summer of SonarOne (at a concentration of 16 ppb), targeting Eurasian watermilfoil and curly-leaf pondweed, with the first application to be applied in late spring/early summer with a second treatment to be applied approximately three weeks later, both by PH, a certified pesticide applicator;

  2. two days in mid-summer and two days in late summer of aquatic harvesting, to be performed by PH, in especially dense patches to clear lanes for boating; and

  3. hand-harvesting of water chestnut to be conducted by lake residents throughout the growing season, which will include a standardized measurement of all harvested plants.  

TWILA’s 25% Match

In an effort to manage the cost of implementing the remediation measures for a three-year period, and to satisfy, in whole or in part, TWILA’s 25% match obligation, TWILA volunteers will support PH’s efforts in the following ways (and as detailed in the Budget accompanying this grant application).

Herbicide Application

  • Sandbagging the culvert at the southern end of the lake

  • Posting treatment signs at public access points

  • Posting notices in local newspapers

  • Taking pre and post-application water samples from TWIL and SL

  • [add others from Beth and PH]

Mechanical Harvesting 

Arrange for the use of a 20 cubic foot roll-off dumpster to be centrally placed along Lake Road, and into which the cleared invasives will be deposited on each of the four days on which aquatic harvesting is scheduled to take place

  • Run at least one work boat from the harvesting site to the dumpster, so that the PH operator can focus solely on the technical aspects of the harvesting.

  • Have at least two volunteers on shore at all times during the harvesting to remove the harvested vegetation from the work boats into the dumpster

Hand-Harvesting of Water Chestnuts and Other AIS

  • On the second Saturday in May of each year, TWILA will hold a meeting of volunteers to train them on how to identify, harvest, use a standard measure to quantify, and safely dispose of water chestnut and other AIS vegetation.  

  • Trained volunteers will hand-harvest water chestnut plants throughout each of the summers; and will hand-harvest and rake the areas around floating docks and along lakeshores in front of lakeside residences. 

  • All trained volunteers will be required to keep track of the services performed and the hours spent in training and in harvesting water chestnut on an association-issued, standardized timesheet, which they will be required to sign and submit to the TWILA Treasurer.

  • All trained volunteers will be required to use a standardized, association-issued mechanism for measuring the water chestnut and other AIS pulled out of TWIL.  

The Anticipated Public Benefits of the Proposed Remediation Measures

The aim of this three-year treatment plan is to control, if not eradicate, Eurasian watermilfoil, curly-leaf pondweed and water chestnut, and thereby begin to restore the lake to its once pristine condition.  While it is not possible to quantify with precision the anticipated number of persons to be served by this work, it is fair to say that the project has the potential to have both local and far-reaching impacts in the watershed.

Local Impact

In addition to the residents who own the 37 parcels which are located on the shores of, or which have a legal right of access to, TWIL, there are two access points, which the public uses to access the lake year-round.  One access point, which is located in the northeastern corner of the lake across from Fire Road, is a .21-acre lot that has a dirt roadway that leads down to the lake and which is used to back vehicles down the roadway to launch boats.  The other access point, which is located in the southwestern corner (just north of Beach Road), is a scenic turn-in just off of Lake Road, that has parking for approximately 4 vehicles. Kayakers and water enthusiasts with other small craft access the lake via an eight-foot path from the turn-around to the lake.  

These two public access points are used primarily by local residents, some of whom also enjoy shore fishing in the spring and summer down at the culvert.  The lake also draws a number of area fishermen, some of whom regularly come from Pleasant Valley and Rhinebeck to fish the lake.  Kayak enthusiasts and birders also come to the lake, often as part of a sojourn to SL and/or TP.  The highest usage months are April through October, and then again in January and February, when the lake is frozen solid enough for ice fishing and ice skating.  In addition, each summer, the local Lion’s Club sponsors a fishing tournament, where contestants can choose to fish three different lakes, one of which is TWIL.   

No one has ever kept track of the number of non-lake residents who access TWIL each year.  Residents who have lived on the lake for years estimate that an average of [10 to 20] persons from the general public access the lake every year, for an approximate total of 90 to 180 visitors.   If awarded the grant, TWIL will set up a mechanism for monitoring the number of visitors who access the lake with greater precision.

In addition to fishing and boating, the lake draws regular foot and vehicular traffic consisting of persons who come to the area to appreciate the viewshed along Lake and Beach Roads.  Indeed, the TWIL viewshed has been showcased as among the “most spectacular views in the US” in a self-guided driving tour promoted by the Dutchess Tourism Bureau.  See Tour 2  [Add estimates from MB research, etc.

It is anticipated that the number of visitors will increase once the Durst organization has completed the development of a __-home residential neighborhood located just [[5 miles]] to the west of Pine Plains, that will include a resort which will be geared to enjoying nature and outdoor activities.  Because significant funding will be made available to neighboring towns, like Pine Plains, which offer a wealth of high quality, outdoor recreational activities, the Pine Plains Town Supervisor has written a letter of support on behalf of the Town Board for the efforts of TWILA to apply for this grant as a means of trying to control the AIS in TWIL, and for preserving this critical viewshed.

Downstream Impacts

Because TWIL sits at the headwater of the Wappingers Creek watershed, the efforts of TWIL to control, if not eradicate, the invasive species in its waters, will have an immediate, concomitant effect of controlling the downstream spread of invasive species in SL, including the infestation of boats which put-in at the public landing, in TP and the rest of the Wappingers Creek watershed.  For this reason, TWILA initiated discussions with the Mayor of Wappingers Falls, which is home to the southernmost body of water in the Wappingers Creek watershed, to explore ways in which TWIL can support the efforts of the Wappingers Falls, the Wappingers Creek Intermunicipal Council and the Cornell Cooperative to manage the watershed, and specifically control the downstream spread of AIS.  [DESCRIBE PILOT PROGRAM]  TWIL has received letters of support from each of these entities.