Beseck Lake is a 113-acre lake located in Middlefield, CT.  There is a public boat launch along the eastern shoreline.  A dam is located at the end of the long, deep cove along the eastern shore. The lake is heavily used for recreation such as boating, water skiing, jet skiing, and fishing. The majority of the shoreline is developed except for a park at the southern end. Beseck Lake's maximum depth is 24 feet with an average depth of 12 feet.

The 2011 CAES IAPP survey was a resurvey from the full vegetative survey done in 2004. The 2011 survey found 20 species of aquatic plants. This is an increase over the 13 species found in 2004. Similar to the 2004 survey, the native plants snailseed pondweed (Potamogeton bicupulatus) and clasping-leaf pondweed (Potamogeton perfoliatus) were codominant in the lake. The invasive plants curlyleaf pondweed (Potamogeton crispus)and Eurasian watermilfoil (Myriophyllum spicatum) have increased since 2004 when only small patches were found. Curlyleaf pondweed was found growing in the shallows around nearly the entire lake. Eurasian watermilfoil was found growing moderately in the northern end and in a dense, large patch in the southwestern end of the lake. The third invasive found was minor naiad (Najas minor). This plant was found in low abundance along the eastern shore in both the 2004 and 2011 surveys. The remainder of the species, all native, grew in sparse patches close to shore. None of these species grew to a nuisance level.