Assabet River
The Assabet River is a small, long river located about west of Boston, Massachusetts, United States. The Assabet rises from a swampy area known as the Assabet Reservoir in Westborough, Massachusetts, and flows northeast before merging with the Sudbury River at Egg Rock in Concord, Massachusetts, to become the Concord River. The Organization for the Assabet, Sudbury and Concord Rivers, headquartered in West Concord, Massachusetts, is a non-profit organization dedicated to the preservation, protection, and enhancement of the natural and recreational features of these three rivers and their watershed. As the Concord River is a tributary of the Merrimack River, it and the Assabet and Sudbury rivers are part of the larger Merrimack River watershed.
Etymology
The indigenous people of this region first named the Assabet River, though the original meaning of the word "Assabet" is uncertain. Assabet is said to come from the Algonquian word for "the place where materials for making fish nets comes from". Other cited Algonquian meanings include "at the miry place", "it is miry", or "the reedy place".It is also possible to decode the name Assabet in the Eastern Algonquian Loup language spoken by the Nipmuc people who lived and fished on the river prior to European settlement. The word assa-pe-t segments into: assa, "turn back"; pe, a short form of nippe, "water", used in compounds; and a locative suffix, -t, a shorter form of -et after the vowel, so its name in Loup means "at the place where the river turns back". During floods the Assabet River reaches peak height sooner than the Sudbury River, so that at the junction of the two rivers the Sudbury's direction of flow can temporarily reverse.
A Eurocentric interpretation is that the river's name is a corrupted spelling of Elizabeth, or an attempted transliteration of the Nipmuc name. Various historic maps and documents denote the river's name as Asibath, Assabeth, Asabett, Assabet, Elizbeth, Elzibeth, Elizabet, Elizabeth, Elsabeth, Elsibeth, and Isabaeth. The uniform spelling "Assabet" was not adopted until at least 1850. Historic maps up until 1835 mostly label the river the Elizabeth or some variation thereof, but by 1856 maps consistently call it the Assabet. The name's history is further complicated by the fact that the tributary Elizabeth Brook in present-day Stow flows into the Assabet River.
History
lived in what became central Massachusetts for thousands of years prior to European settlement. Indigenous oral histories, archaeological evidence, and European settler documents attest to historic settlements of the Nipmuc near and along the Assabet River. Nipmuc settlements on the Assabet intersected with the territories of three other related Algonquian-speaking peoples: the Massachusett, Pennacook, and Wampanoag.Geography
The Assabet River rises from a swampy area in Westborough known as the Assabet Reservoir. Streams located in the towns of Shrewsbury and Grafton feed the reservoir. From Westborough the river flows northeast, starting at an elevation of and descending through the towns of Northborough, Marlborough, Berlin, Hudson, Stow, Maynard, Acton, and finally Concord, where it merges with the Sudbury River at Egg Rock at an elevation of to form the Concord River.The Assabet's watershed covers. The Assabet marshes in Stow measure about, and the Assabet River National Wildlife Refuge and environs in Stow, Maynard, Sudbury, and Marlborough encompass.
Average and low flow
According to U.S. Geological Survey records the average flow at the gauge in Maynard is per second. February, March, and April flows average greater than per second. July, August, and September flows average less than per second, with some weekly flows averaging less than per second. Five municipal wastewater treatment plants discharge cleaned water into the Assabet River. In summer months this cumulative contribution of more than per day can be more than half of the river's total volume.Human geography
As of 2020 there are nine dams on the Assabet River. Seven dams powered mills: Aluminum City, Allen Street, Hudson, Gleasondale, Ben Smith, Powdermill, and Damonmill / Westvale. The Nichols and Tyler dams are modern dams built for flood control. Damonmill Dam is partially breached so it does not retain water, though it slows flow at flood times. A tenth mill dam—Paper Mill Dam in Maynard—was destroyed by the 1927 flood. As of 2020, 39 road bridges, two Assabet River Rail Trail pedestrian and cycle bridges, the Taylor Memorial Bridge in Hudson, one abandoned railroad bridge in Hudson, and one active railroad bridge in Concord cross the river.The Powdermill Dam was constructed to power the American Powder Mills, a complex of 40 buildings situated on along both sides of the river through the towns of Acton, Concord, Maynard, and Sudbury. The complex manufactured gunpowder between 1835 and 1940. Evidence of 23 recorded explosions during that period remains at a few locations along the river. Acton Hydro Company, Inc., currently owns the dam and is renovating it to generate electricity again. None of the other historic mill dams presently provide hydropower.
Biology
Despite its small watershed area and habitat loss to suburbanization, the Assabet River and greater Concord River basin host many native and naturalized species of trees, wildflowers, aquatic plants, birds, fish, mammals, reptiles, amphibians, crustaceans, and insects. Introduced invasive plants threaten the continued health and presence of native plants along the river.Native and naturalized species
Trees native to the Assabet River area include red maple, silver maple, black willow, river birch, hemlock, and swamp white oak. They are joined by the native shrubs buttonbush, common elderberry, highbush blueberry, multiflora rose, smooth arrowwood, and sweet pepperbush.Wildflowers abound along the Assabet's banks. Blue flag and yellow flag—the latter particularly abundant between Hudson and Stow—grace the riverbanks with color. Other wildflowers present in the area include arrow arum, arrowweed, bittersweet nightshade, cardinal flower, jewelweed, joe-pye weed, pickerelweed, purple loosestrife, swamp loosestrife, swamp smartweed, sweetflag, true forget-me-not, and the poisonous water hemlock. Marsh plants habitating the area include various species of bur-reed, cinnamon fern, common cattail, great bulrush, marsh fern, marsh mermaid weed, reed canary grass, royal fern, soft rush, tussock sedge, and wild rice. Native aquatic plants present on or under the Assabet's waters include common elodea, coontail, duckweed, low watermilfoil, various species of pondweeds, water celery, watermeal, watershield, white water lily, and yellow pond lily.
Given the Assabet's proximity to differing habitats such as forests, pastures, fields, and marshes, a wide variety of birds live in or migrate to the area. The belted kingfisher—the only kingfisher of the northeastern United States—summers and sometimes winters on the lower Assabet. The migratory American yellow warbler, Baltimore oriole, common grackle, common yellowthroat, eastern kingbird, gray catbird, northern flicker, tree swallow, and wood thrush inhabit the area in the springs, summers, and sometimes falls. Other species—black-capped chickadee, cedar waxwing, downy woodpecker, tufted titmouse, and white-breasted nuthatch—live near the Assabet all year round. Some bird species visible from the river inhabit primarily fields, pastures, and old buildings, including American woodcock, barn swallow, bobolink, killdeer, and song sparrow. Bobolinks nest in the grass at Orchard Hill in Stow along the Assabet. The barn swallows feed over the water near Tyler Dam in Marlborough; some of them nest in the grass with the bobolinks while others live in a barn near Orchard Hill. A subset of birds living near or on the Assabet prefer marshy environments, including American bittern, black-crowned night heron, great blue heron, green heron, marsh wren, and red-winged blackbird.
A variety of migratory and nonmigratory ducks habitate the Assabet watershed, including American black duck, blue-winged teal, common merganser, mallard, pied-billed grebe, ring-necked duck, and wood duck. Depending on the time of year, one may see some birds of prey along the Assabet. The osprey is uncommon but may be encountered near the Assabet, especially in Stow and Hudson. The migratory broad-winged hawk is common in the fall, while the red-tailed hawk lives in the area year-round. American kestrels and northern harriers hunt in the area primarily during the fall.
Naturally, multiple fish species inhabit the river. Brook trout, chain pickerel, and largemouth bass are common. The Massachusetts Division of Fisheries and Wildlife stocks brook trout in the Assabet's tributaries, including the above-mentioned Elizabeth Brook, though there are existing natural populations. Chain pickerel live in weedy areas along the Assabet. Largemouth bass thrive in the Assabet Reservoir and in the calm waters before Hudson. Other native fish one may encounter on the Assabet include American eel, black crappie, brown bullhead, golden shiner, northern pike, pumpkinseed, white sucker, white perch, yellow perch, and a few other small species.
Common mammals living near the Assabet include minks, muskrats, raccoons, red foxes, and white-tailed deer. North American river otters are less common but may be encountered along the river. The little brown bat was once abundant in the area before decimation by the fungal disease white-nose syndrome; other bat species remain present in large numbers.
A few native reptile species inhabit the Assabet's waters. Some species—such as common snapping turtle, common watersnake, eastern garter snake, painted turtle, and ribbon snake—are relatively abundant. Other reptiles—Blanding's turtle and spotted turtle—are critically endangered, and though present along the Assabet are rarely seen by humans. Various native amphibians inhabit the Assabet River watershed. Common species include American bullfrog, green frog, leopard frogs, and pickerel frog, all of whose vocalizations may be heard during the spring and summer. Spring peeper, wood frog, and eastern newt also live in the area. At least one crustacean calls the Assabet home: freshwater crayfish of the genus Cambarus.
The Assabet's shaded banks provide prime mating grounds for damselfly and dragonfly species, as they mate near streams and wetlands and lay their eggs underwater. Damselfly species in the area include bluet, black-winged damselfly, eastern forktail, and violet dancer. Dragonfly species mating along the Assabet include cherry-faced meadowhawk and other species of the genus Sympetrum, common whitetail, the migratory green darner, and twelve-spotted skimmer. Aquatic insects plying the Assabet's waters include common water strider, giant water bugs of the genus Belostoma, grousewinged backswimmer and other species of backswimmers, various species of water boatmen, and whirligig beetles of genera Dineutus and Gyrinus.