Ulbrich Reservoir, Wallingford
Ulbrich Reservoir is a 154-acre public drinking water supply. Public access is prohibited. The reservoir is surrounded by forest, and a steep ridge rises from the water to a ridge on the lake's eastern side. The invasive Eurasian watermilfoil (Myriophyllum spicatum) was the most abundant of nine aquatic plants recorded in our July 2005 survey. The species occurred in water from 3 - 13 feet (1 - 4 m) deep all around the lake, although it was most abundant in the lake's south end, where it formed a continuous band along the eastern and western shores. Eurasian watermilfoil extended as much as 175 feet (50 m) from shore in shallow water at the southern end of the reservoir. Eurasian watermilfoil occurred in scattered patches on the east and west sides in the northern half of the reservoir, and it grew densely in a 10 feet (3 m) wide band in front of a dam at the north end.

No other species was nearly as abundant or frequently found. Coontail (Ceratophyllum demersum) occurred in scattered locations around the lake, primarily at the southern end, where it grew abundantly with Eurasian watermilfoil. Water smartweed (Polygonum amphibium) occurred in several locations on the eastern shore and in shallow water at the extreme northwest of the lake. Several other species were recorded in the same area, including duckweed (Lemna minor) and snailseed pondweed (Potamogeton bicupulatus.

Small pondweed (Potamogeton pusillus) and slender naiad (Najas flexilis) were observed in several patches near the shore at the southern end of the reservoir. Both species also occurred among Eurasian watermilfoil along the western shore in the southern half of the reservoir, as did coontail and marsh primrose-willow (Ludwigia palustris).

Species recorded in our 2005 survey of Ulbrich Reservoir.
Scientific Names
*Invasive Species
Common duckweed Slender naiad
Coontail Small pondweed
Eurasian watermilfoil* Snailseed pondweed
Marsh primrose-willow Water smartweed