Fun Facts About The River
Learn some fun facts about the river. Does your drinking water come from the Ipswich River? What activities use the most water? You may be surprised!
About the Ipswich River
What is a watershed?
Where is the Ipswich River located and how large is the river and it’s watershed?
How many people live in the Ipswich River Watershed?
How many people rely on the Ipswich River for their drinking water?
How do people use the Ipswich River?
Wildlife and Habitat
What plants and animals live in the watershed?
How have plants and animal populations in the watershed changed over time?
Are there any endangered, threatened or rare species?
What about beavers? Friend or foe?
What are some of the main issues on the River?
Is the Ipswich River polluted?
Do low water levels affect water quality?
How is water quality measured?
Who’s responsible for measuring water quality?
How do human activities in the watershed affect the Ipswich River?
Learn about the issues that the Ipswich River faces:
About the Ipswich River
A watershed is the land which “sheds water,” or drains, into a particular water body – in this case the Ipswich River. The watershed is also an ecological system, supporting all the life in that area.
Water that falls on the region (as rain, snow, etc.) drains downhill, so hills, ridges and other high points define the boundaries of a watershed. The water flows over the surface of the land and through underground channels (an aquifer) that converge into streams and rivers. As you move downhill and this network of streams and rivers converge and progressively grow larger, eventually reaching the ocean.
Watersheds can be large or small. Every stream, tributary, or river has an associated watershed, and small watersheds join to become larger watersheds.
Watersheds can also be called basins and drainages.
The Ipswich River is located in northeastern Massachusetts, and flows from its headwaters in Burlington, Wilmington and Andover, until reaching Plum Island Sound and the Atlantic Ocean in Ipswich. The change in elevation from the headwaters to the mouth of the river is only about 115 feet over more than 40 meandering miles of river (about 26 miles as the crow flies).
The Ipswich River and its 45 tributary streams cover an area of 155 square miles. The Ipswich River’s tributaries include Bear Meadow, Black, Boston, Emerson, Fish, Gravelly, Howlett, Kimball, Lubbers, Maple Meadow, Martins, Mile, Mosquito, Norris, Nichols, Pye, Sawmill, School and Wills Brooks, Labor-in-Vain and Greenwood Creeks, and the Miles and Skug Rivers.
The Ipswich River estuary, where the river meets and mixes with salt water, is part of the 17,000-acre Great Marsh ecosystem extending up the coast into New Hampshire.
The Ipswich River Watershed is home to about 160,000 people and includes all or portions of 21 towns:
Andover, Beverly, Billerica, Boxford, Burlington, Danvers, Essex, Hamilton, Ipswich, Lynnfield, Middleton, North Andover, North Reading, Peabody, Reading, Rowley, Tewksbury, Topsfield, Wenham, Wilmington, and Woburn.
Of these, only 3, Middleton, North Reading, and Topsfield are entirely within the basin.
The Ipswich River watershed provides drinking water to 350,000 people and businesses in 14 communities including: Beverly, Boxford, Danvers, Hamilton, Ipswich, Lynn, Lynnfield, Middleton, North Reading, Peabody, Salem, Topsfield, Wenham, and Wilmington.
Since the Ipswich River provides drinking water to thousands of people and businesses across the North Shore, this use of the river is most widely known. However, the river, streams, lakes and ponds also provide recreation, including canoeing and kayaking, other boating, swimming and wading, and fishing. The watershed lands provide many other recreational opportunities, including walking and hiking, on- and off-road biking, cross-country skiing and snow shoeing, birding and nature observations, hunting, golf and clamming.
Activities in the watershed affect the Ipswich River in several ways. During rainstorms, pollutants wash into the river from roadways and parking lots, construction sites, lawns, landfills and other “non point” sources.
Clearing land not only exposes soil to erosion, but also results in changes to the water cycle, affecting flows in the river. When land is paved or covered with buildings or other impervious or hard surfaces, the ground cannot absorb water from rain or snow. Instead, the water flows over the ground as runoff. This situation can result in higher peak flows during storm events. At the same time, less water is stored in the ground. This groundwater is what provides continuous flow in a river even when it is not raining. So decreasing groundwater results in less flow in the river during low-flow periods.
Other activities that affect the Ipswich River are water withdrawals for human use, and the loss of water via sewers. These activities reduce the amount of water available for the river.
Wildlife and Habitat
The watershed is home to a wide variety of plants and animals that are native to the area, as well as introduced species. The native forest is dominated by white pine and mixed hardwoods, including red and white oak; sugar, red and silver maple; white ash, hickories and walnuts. Other trees of note include swamp white oak, American elm, Eastern hemlock, Atlantic white cedar and green ash. Junipers, dogwoods, aspens, willows, blueberries and huckleberries, cranberries, wild cherries, viburnums, alders, buttonbush, azaleas, rhododendrons, and numerous other plants make up the shrub layers. There are many wildflowers, grasses, rushes, sedges, ferns, mushrooms, lichens and mosses. More information about native plants is available from the New England Wildflower Society.
Mammals living in the watershed include river otter, fisher, mink, skunk, ermine, weasel, beaver, muskrat, raccoon, grey and red fox, coyote, porcupine, white-tailed deer, woodchuck, chipmunk, grey and red squirrel, opossum, eastern and NE cottontail, snowshoe hare, bobcat, numerous species of mice, voles, shrews, moles and bats. Seals frequent the mouth of the river in winter, and an occasional moose wanders south into the watershed. More information about wildlife is available at Mass Wildlife.
Amphibians include bullfrogs, spring peepers, wood frogs, gray treefrogs, green frogs, leopard and pickerel frogs; salamanders (Jefferson, marbled, spotted, blue-spotted, northern dusky, redback, four-toed, two-lined), red-spotted newt, and toads (American and Fowler’s). More information about amphibians is available at www.frogweb.gov.
Reptiles include painted, snapping, spotted, Blandings, wood, Eastern box turtles and stinkpots, as well as various snakes (Northern black racer, water, brown, ringneck and redbelly; Eastern garter, milk, smooth green and ribbon). More information about reptiles is available at Mass Wildlife.
The current fish community is dominated by generalist species that can tolerate warm water and ponded conditions, as dams have changed habitat available in the river. Three generalist species are redfin pickerel, American eel and pumpkinseed they make up almost 70% of the fish population. Other species currently found in the river include of bluegill, chain pickerel, redbreast sunfish, and small numbers of creek chubsucker, fallfish, yellow perch, white sucker, largemouth bass, golden shiner, yellow bullhead, sea lamprey, swamp darter, green sunfish, brown bullhead, brown trout, brook trout (<.1%), rainbow trout and black crappie. See our Fish and Aquatic Life page for more information.
- Andromous fish
Andromous fish are those that spawn in fresh water but live most of their lives in oceans. Andromous fish once were very abundant in the Ipswich River. However, dams constructed in the 1800’s blocked their spawning migrations. An effort to restore river herring is currently underway, including recent reconstruction of the fish ladder at the Ipswich Dam, and annual stocking of blueback herring. Other anadromous fishes documented historically in the Ipswich River include shad and salmon. See our Fish and Aquatic Life page for more information.
The watershed is home to many invertebrates. In the past, Ipswich River Watershed Association has collected data on macroinvertebrates (“macros”) in the river. Macros are aquatic creatures without a backbone, visible with the naked eye. These creatures serve as good indicators of water quality and river health. They include the larvae of aquatic insects such as stoneflies, mayflies, caddisflies, dragonflies and damselflies, crustaceans such as crayfish mollusks such as freshwater clams and mussels, and other creatures. Visit the US EPA’s page on Benthic Macroinvertebrates in Our Waters for information about these critters.
Historically, the Ipswich River Watershed was home to a number of large predators, such as black bear and wolf, which are no longer found in this region. The lack of predation has allowed explosion of some other species, such as white-tailed deer. Some species, such as New England cottontail, are now extremely rare, whereas the Eastern cottontail has proliferated.
The fish population has been vastly altered. In early colonial times, the Ipswich River was noted for its outstanding spawning runs of salmon, shad and river herring. Alewife harvests were a mainstay of the colonial economy as far upstream as Wilmington, and Wenham Lake was the largest alewife nursery in the region. The construction of dams on the Ipswich River in the 1800’s doomed this fishery.
The river has also lost its population of brook trout, fallfish and other species that depend upon flowing water. These fish cannot survive the low-flow problems of the river. The fish community is now dominated by three fish species that can tolerate warm, ponded conditions: redfin pickerel, American eel and pumpkinseed.
Plant and animal species, which are dependent on wetlands or aquatic habitats, have declined in the Ipswich River Watershed due to the loss of these habitats. Fish, freshwater mussels and other creatures, are also affected.
The following is a partial list of rare species (including endangered, threatened, special concern and watch list) that have been documented in the Ipswich River Watershed: bridle shiner, piping plover, least tern, least bittern, golden-winged warbler, pied-billed grebe, Cooper’s hawk, northern harrier, spotted, blue-spotted, marbled and four-toed salamanders, Eastern pond mussel, spotted, Blandings and eastern box turtles, and a number of invertebrates, including Mystic Valley amphipod, Hessel’s hairstreak, coppery emerald, Kennedy’s emerald, mocha emerald and ringed boghaunter (banded bog skimmer).
Rare plants include dwarf mistletoe, arethusa, seabeach needlegrass, reed bentgrass, variable sedge, broom crowberry, small yellow showy lady’s slipper, slender cottongrass, Andrew’s bottle gentian, New England blazing star, tiny cow-lily, adder’s-tongue fern, pale green orchis, lion’s foot, pod-grass, river bulrush, hall’s bulrush and small burreed.
Certain plant communities, including Atlantic white cedar swamps, quaking bogs and even cranberry bogs, are also rare in the watershed. Vernal pools (explained in more detail below) are also considered threatened habitats.
More detailed information about rare species is available from the Natural Heritage and Endangered Species Program
Beavers are friends. They create essential habitat for many other wildlife, and their low dams are important in enhancing groundwater recharge and maintaining flows during dry periods. Beaver dams, which typically release some flow downstream, are transient features of a dynamic landscape. These dams do not cause the environmental damage that larger, more permanent human-made dams do. Beavers were almost extirpated from North America by trapping in the early 1900s, but are now recolonizing some former territory.
The main problem with beavers is that they share much of the same habitat as humans, thus causing problems with flooded roadways, septic systems and yards. Peaceful coexistence is possible through use of devices such as beaver deceivers, which reduce the ability for beavers to block culverts with dams.
Low flow is the biggest issue facing the river. In 1997 the Ipswich River was designated as one of the “20 Most Threatened Rivers in America”, as determined by American Rivers. In 2003 that designation was upgraded to one of the “10 Most Endangered Rivers in America” due to worsening flow conditions. The Ipswich is still considered a “stressed basin” under the hydrologic criteria developed by the Massachusetts Water Resources Commission.
The Ipswich River has experienced repeated low-flow and even no-flow periods: segments of the upper river have gone dry in 6 of the last 10 years, resulting in fish kills and other ecological damage. See our Low Flow & Floods page for more information.
Other important issues include:
- Changes in river habitat and quality due to the more than 70 dams and 500 road-stream crossings (e.g., culverts) in the watershed.
- The loss of native flow-dependent fish and other aquatic life in the watershed.
- Changes in land use from natural areas into developed parcels and roads, which can segment and eliminate wildlife habitat and increase polluted runoff.
There are some water quality problems in the Ipswich River, but because of a lack of large industrial manufacturing and urban spaces, the Ipswich has been spared some of the poor water quality that has plagued other rivers in the region.
The largest problem remains flow impairment. In the Ipswich River, water quality and water quantity cannot be considered independently. Water quality concerns are compiled by the state and reported on the S. 303(d) list of impaired waters, issued by the Department of Environmental Protection (DEP).
The upper reaches of the river often do not meet water quality standards for dissolved oxygen (DO), especially during low-flow periods. On several occasions during the past 5 years, DO of 0-1 mg/l has been recorded; the state standard is no less than 5 mg/l.
See our Water Quality page for more information.
Reduced flows also result in higher water temperatures in the Ipswich River in summer. Higher water temperatures result in a lack of dissolved oxygen in the water, creating conditions that certain types of fish cannot survive in. Low dissolved oxygen creates an environment for other water quality problems, such as the over nutrient enrichment (eutrophication) due to phosphorus releases from sediments, and possibly conversion of mercury to toxic forms.
Water quality is measured in a number of ways. One way is to use special probes and meters, which are designed to measure concentrations of dissolved oxygen or pollutants. Another way to monitor water quality is to take water samples and use test kits to measure how much of different chemicals are found in the water. Temperature is a very important water quality parameter, which is easily measured with a thermometer. But other water quality measurements are more complicated or expensive to measure; for example, bacterial contamination, hydrocarbons, or metals require a rigorous sampling procedure, careful handling of samples, and expensive laboratory analyses.
IRWA’s monitoring program uses trained volunteers to take samples once each month at 30 sites along the Ipswich River and its tributary streams. Sampling at sites across the watershed provides data to better understand the whole river system. Results are compared with Massachusetts Surface Water Quality Standards, a set of standards that waterways should meet for fishable and swimmable waters. IRWA’s volunteers use thermometers to measure temperature, and DO kits to measure the amount of dissolved oxygen in the river.
Another important aspect of river monitoring is biological monitoring. In the case of the Ipswich River, this includes sampling macroinvertebrates, which are aquatic insects and other creatures (without a backbone) that can be seen without a microscope. These creatures are monitored because their presence or absence gives important information about water quality and river health. IRWA is monitoring macroinvertebrates to learn more about how low-flows affect these organisms, which are essential to the aquatic food web.
The following organizations play a role in measuring water quality in the Ipswich River Watershed:
- Ipswich River Watershed Association
- University of New Hampshire: Water Systems Analysis Group
- Ecosystems Center, Marine Biological Laboratory at Woods Hole
- Massachusetts Department of Environmental Protection
- United States Geological Survey
- Local Boards of Health