Halls Pond, Ashford, Eastford
Halls Pond is state-owned, and land along the southern shore is part of Natchaug State Park. A road runs along the northern and northeastern shores, and two homes have been built at the southeastern end of the lake. The area around the 82-acre lake is otherwise forested and undeveloped. The lake has an average depth of 9 feet and a maximum depth of 14 feet. The bases of large trees, which were not removed when the land was flooded, can be seen reaching nearly to the surface of the water, especially in the coves in the southwestern part of the lake. Boat access is by an unimproved ramp on the eastern shore.
Halls Pond has very clear water and supports a community of 16 submerged and floating-leaved aquatic plants. The most abundant species during our August 2005 survey was Robbins' pondweed (Potamogeton robbinsii), which formed an uninterrupted carpet across the lake where water was 1 m or more deep. Other species occurred primarily in small patches in shallow water around the edges of the lake and around 12 small islands.
Species richness was greatest along the northern shore with patches of watershield (Brasenia schreberi), charaphyte (Chara), spineless hornwort (Ceratophyllum echinatum), yellow water lily (Nuphar variegata), western waterweed (Elodea nuttallii), sevenangle pipewort (Eriocaulon aquaticum), greater duckweed (Spirodela polyrhiza), humped bladderwort (Utricularia gibba), golden hedge-hyssop (Gratiola aurea), Eaton's quillwort (Isoëtes X eatonii), small waterwort (Elatine minima), snailseed pondweed (Potamogeton bicupulatus),and arrowhead(Sagittaria species). Occurring in a narrow band of shallow water around the rest of the lake was golden hedge-hyssop, small waterwort, needle spikerush (Eleocharis acicularis), sevenangle pipewort, snailseed pondweed, and arrowhead. Eaton's quillwort and western waterweed also occurred in patches along the east shore with marsh primrose-willow (Ludwigia palustris) while greater duckweed occurred in patches along the south shore. Slender naiad (Najas flexilis) and ribbon-leaf pondweed (Potamogeton epihydrus) were found in patches on the west shore, and ribbon-leaf pondweed was also found on the south shore along with pickerelweed (Pontederia cordata).
Filamentous algae were abundant in one area along the northeast shore, growing thickly on the Robbins' pondweed as far as 75 feet (20 m) from the shore. Shallow water around the lake’s many islands supported scattered plants of golden hedge-hyssop, arrowhead, small waterwort, and needle spikerush.