Aquatic resources and wildlife habitats in the Watershed are affected by a variety of factors and activities.

We work with our municipal partners, state and local officials, community groups, and experts in the field to seek out and reduce the problems that affect habitat, including:

  • pollutants
  • low water levels
  • direct removal of habitat
  • disturbance of vegetation and soil at the water’s edge
  • exotic, invasive species
  • obstructions (dams)
  • degradation of fish spawning habitat

For more information about our Habitat Restoration Programs, please contact NepRWA River Restoration Director, Sean McCanty, at

Migration Barriers

Barriers to migration, like dams, roads, and poorly designed culverts, have profoundly affected the Neponset River Watershed and its wildlife.

Many of these barriers are out-of-date or outmoded and should be redesigned to accommodate wildlife passage or removed altogether.

  • The once-ubiquitous eastern brook trout struggle to access the headwater springs they need to spawn and the deep cold spots where they wait out the summer heat.
  • The roads that make it easier for us to travel around the Neponset Watershed can be death traps to wildlife.
  • Migrating frogs and salamanders trying to reach vernal pools in the spring have seen major population declines over the past several decades, in part due to migration barriers.
Pine Tree Brook, MIlton

Obsolete Dams

Historically, there were a series of mill dams built in the vicinity of the Baker Dam and the Tileston and Hollingsworth (T&H) Dam for industrial purposes, dating as far back as 1634.

Of the roughly 100 dams remaining in the Watershed, only two were designed for flood control purposes, and the vast majority of the others no longer serve any modern purpose.

A good example of this are the Baker Dam and the Tileston and Hollingworth (T&H) Dam, which have no fish passage facilities and block a number of migratory fish species—most notably Blueback herring and American shad—from reaching 17 miles of historic spawning grounds on the Neponset River and its tributaries upstream.

If the fish could bypass the dams, fish “runs” would be restored in Walpole, Norwood, Westwood, Dedham, Hyde Park, Mattapan, Dorchester, Quincy, Milton, and Canton.

Invasive Species

Invasive species are native or non-native plants and animals that aggressively outcompete or prey on our local wildlife and crops. Once introduced, they spread quickly and can completely disrupt the function and balance of entire ecosystems.

In the Neponset Watershed invasive species are harming many of our natural communities:

  • In the estuary, Phragmites have fully replaced native salt marsh grasses in many areas without providing the same habitat value. Invasive crabs are destabilizing exposed banks and increasing marsh erosion.
  • Several ponds in the Neponset Watershed have been overrun with invasive milfoils and water chestnut
  • Asian clams and carp are found throughout the Neponset River, and their ecological impact is still debated
  • Other common invasive species that can be found in the Watershed include Purple Loosestrife, Reed Canary Grass, Mile-a-minute, Japanese knotweed, Japanese Honeysuckle, Burning Bush, Buckthorn, Multiflora Rose, Garlic mustard, Tree of heaven.
  • Asian long-horned beetles, Emerald Ash Borers, Chestnut blight, and Wooly Adelgid are all introduced pests that are found in the Neponset Watershed. They have been devastating forests all over the eastern seaboard.
Water chestnut pull, Canton