Twin Lake South in Simsbury, 2018

Twin Lake South, Simsbury - 2018

Survey map of Twin Lake South in Simsbury, 2018

2018 Aquatic Plant Survey Map of Twin Lake South

Transect Data | Water Data

Twin Lake South is a public, man-made lake located in Simsbury, CT.  It is 16.3 acres and is deeper than the lake to the north. The deepest point in the lake is 3.5 meters.  The lake is located in the Nod Brook Management Area, land owned and maintained by the DEEP.  The lake is used yearly for field trials for dog hunting.  Various field trial competitions are held on the management area’s land.

CAES IAPP performed the second survey of Twin Lake South in 2018; the first was in 2012. Our survey found 14 species, including two invasives. Eurasian watermilfoil (Myriophyllum spicatum) was found both in 2012 and 2018. However, it was less abundant in 2018. It was still found in the northern and southern areas of the lake, but in smaller amounts. Brittle waternymph (Najas minor) is the second invasive found in 2018 and was not found in 2012. Brittle waternymph is relatively low-lying and usually does not pose a problem. It was only found in a small area in the northeastern corner of the lake. Curlyleaf pondweed (Potamogeton crispus) was found in 2012, but not in 2018. Curlyleaf is an early-season plant, and the 2018 survey took place in September, so it is possible it had died off before our survey.

12 native species were found in 2018, three more species than in 2012. The new species found were arrowhead (Sagittaria species), common duckweed (Lemna minor), southern waternymph (Najas guadalupensis), and watermeal (Wolffia species). Nodding waternymph (Najas flexilis) was the only native species found in 2012 not found in 2018. Pickerelweed (Pontederia cordata) was the most common plant growing around almost the entire perimeter of the lake. The rest of the native species present in both years declined in abundance from 2012 to 2018, the most noticeable being Coontail (Ceratophyllum demersum). Despite the decline, there still remains a healthy abundance and diversity of native species in Twin Lake South.

Species recorded in our 2018 survey of Twin Lake South.
Scientific Names
*Invasive Species
Arrowhead Coontail Pickerelweed Watershield
Brittle Waternymph* Eurasian Watermilfoil* Small Pondweed Western Waterweed
Clasping-Leaf Pondweed Great Duckweed Southern Waternymph
Common Duckweed Green Arrow Arum Watermeal

Other Twin Lake South Surveys: 2012