Watershed Planning

APC & Nemasket River Watershed Management and Climate Action Plan

A Watershed Management Plan sets priorities for improving the Assawompset Pond Complex and Nemasket River. A Climate Action Plan extends these strategies to meet future conditions brought about by climate change. This Plan does both!

The integrity of the Assawompset Ponds Complex (APC) and Nemasket River depends on the quality of the surrounding watershed.

We are currently in the final months of preparing a Watershed Management and Climate Action Plan that identifies the key strategies for balancing the essential functions of the APC and Nemasket River, especially in the areas of water supply maintenance, floodwater management, water quality, stormwater infiltration, habitat enhancement, land development, and recreational access.

The plan is designed to incorporate problem statements, goals, strategies and benchmarks of success for both existing conditions and issues and anticipated climate conditions in 2050 (assuming a high emissions scenario). Plan recommendations will include engineered and nature-based solutions for near-term and long-term floodwater mitigation, improved water quality, and consistent water supply in the APC as climate change occurs.

Project Implementation Alert!!

Snipatuit Brook Study

Helping to define watershed boundaries

SRPEDD is supporting the Town of Rochester in exploring the boundaries between the Taunton River and Buzzards Bay Basins. Snipatuit Brook is located in this transitional area. We are teaming with Horsley Witten to study flow direction in the Brook under different environmental circumstances.

Upper Nemasket River Enhancement Planning

From 2019 to 2022 SRPEDD and partners, working with the communities of Lakeville and Middleborough and other stakeholders of the Nemasket River, conducted two parallel planning efforts that assessed opportunities for improving river flow, flood mitigation, fish passage and recreational use along the Upper Nemasket River.

A Hydrology and Hydraulics (H&H) Modeling Study, conducted by Horsley Witten Group, assessed the impacts of several potential management interventions on river flow. During a concurrent stakeholder engagement process, led by CommonPlace Landscape and Planning, the modeling results were shared with the public for feedback and discussion of potential benefits and tradeoffs.

The technical study results, alongside stakeholder feedback, can be used to guide future management that strengthens the resilience of the local community to future floods, improves ecological and hydrological connectivity along the river and enhances recreational opportunities in the region.








Catch us at community events, such as the annual Herring Run Festival in Middleborough (pictured here) to learn more about ongoing restoration work throughout the APC & Nemasket Watersheds.


The Year-One Long Pond Ecoharvester Invasive Weed Pull took place on August 8, 2022, the result of state, regional, and local champions working together.

Group of people representing state, local and regional champions who worked together to obtain the funding and permitting for the invasive weed pull.
Group of people including many of the state, local and regional champions who worked together to obtain the funding and permitting for the invasive weed pull.
A close up view of the ecoharvester as it launches. The ecoharvester has a spinning drum on the front that catches and pulls the weeds, and a conveyor belt that moves them up and into a holding container. Two people are on it - one operator and one turtle spotter.
A close up view of the ecoharvester as it launches.
A sign on the Freetown Beach that says "Beach Closed for weed mitigation work" with a view of the ecoharvester in the background in the pond.
Sign reads: "Beach Closed for Weed Mitigation Work," posted at the Freetown Town Beach.
A close up of fanwort and milfoil - invasive weeds that were pulled from Long Pond
A close up of fanwort and milfoil - invasive weeds pulled from Long Pond.

Why the APC and Nemasket? And why now?

A Regionally Unique and Significant Resource

The APC and Nemasket River play numerous important roles for both the natural ecology and the people of southeastern Massachusetts. The APC is the state's largest natural pond system and is the drinking water source for approximately 250,000 people in the cities of New Bedford, Taunton, and portions of other nearby towns. It is a scenic residential and recreation area for pondside communities, spanning the towns of Lakeville, Middleborough, Rochester and Freetown. Water flows out of the Ponds through one principal outlet - the Nemasket River. The Nemasket is the longest herring run in the state of Massachusetts, with fish making an annual trip from Narragansett Bay, up the Taunton and Nemasket Rivers into their breeding grounds at the Ponds. It is a significant habitat area for fish, birds, wetland and mammal species - now including a resurgence of the loon population!

While the Nemasket and APC are precious in so many ways, the management challenge for this system becomes clear when we consider that water quality and flow are affected by land use throughout their combined 44,900-acre watershed area. In equal measure, the waters of the APC and Nemasket River can have some negative effects on surrounding communities during periods of flood and intense storms.

Bedford Street in Lakeville in an aerial image as it runs north to south along the edge of the Assawompset Pond Complex
An aerial view of the northern end of Long Pond and the eastern edge of Assawompset Pond, intersected by Route 105.
An image of a stakeholder engagement meeting where participants from the Assawompset Pond Complex Management Team give their input into top priorities in the watershed.
The APC Management Team identifies floodwater issues around the Assawompset Pond Complex and Nemasket River

Building on a Track Record of Historic and Recent Work

The need for better stewardship of the APC and Nemasket River, especially in the form of a watershed management plan, is widely articulated across local MVP priorities. The Freetown, Lakeville, and Middleborough MVP Plans all raise this stewardship need as a priority action item. In June 2019, Lakeville, Freetown and Rochester completed a  Regional MVP Addendum. The top environmental action listed is “Update the Assawompset Ponds Management Plan with respect to the MVP process and data; include pond levels, infrastructure, herring run, Long Pond issues, other chronic problems/issues.” This priority is especially relevant for the ponds complex as there are several stakeholders with an interest in managing water levels. The communities surrounding the ponds have a stake in flood abatement, while the water supplier entities have an interest in storing water for potential future drought conditions. This proposed Watershed Management and Climate Resilience plan can promote active management coordinated across stakeholder needs.

Pursuing a watershed management plan at this time also leverages recent work completed in the APC and Nemasket watersheds. In early 2020, a grant from the Division of Ecological Restoration allowed for a reexamination of recent plans, as well as historical studies, reports, and recommendations going back forty years to 1980. The watershed management plan comes as a next step after that effort, and will be informed by an on-going hydraulic and hydrological study of the upper Nemasket, a WMOST model being conducted for the watershed by the EPA to pinpoint possible nature based solutions for addressing climate impacts, and community engagement for solutions along the river.

The APC-Nemasket Digital Watershed Tour

Learn about the important dimensions of the watershed in our kid-friendly video series entitled 'The APC-Nemasket Digital Watershed Tour'. Each chapter walks through a dimension of the watershed, from the uplands, to the role of flora and fauna.

Chapter 1: The Watershed

In Chapter 1, learn about the different dimensions of the watershed, the intersections between human and natural actions, and actions that you can do to protect the watershed on your property and in your community.

Chapter 2: The Uplands

In Chapter 2, learn about the critical role that watershed uplands play in maintaining water quality, providing a home for different animals and plant species, as well as the steps that you can take to protect the uplands.

Chapter 3: The Ponds

In Chapter 3, learn about the roles that the ponds play in regulating water flow and rates of the Nemasket river, serving as a home for mussels and fish, and the steps that we can take to care for the ponds and maintain the water's quality.

Chapter 4: The Nemasket River

In Chapter 4, learn about how the river provides oxygen and a home for animals and plants. Also learn more about human impacts and how you can help prevent toxic pollution and runoff from impacting the Nemasket river.

Chapter 5: Dynamic Equilibrium

In Chapter 5, learn about how the Nemasket River balances the processes of sedimentation and stream flow, and the importance of the cross sectional area accessible to a river. Finally learn about the steps that we can take to ensure the Nemasket has a healthy dynamic equilibrium.

Chapter 6: Floodplains and Wetlands

In Chapter 6, learn about the role that floodplains and wetlands have in storing excess water from storm surges and floods, as well as the impacts that humans have had on the watershed's floodplains and what we can do to preserve these environments.

Chapter 7: Flora and Fauna

In Chapter 7, learn about some of the animal species that call the APC and Nemasket river home, including Mink, songbirds, deer, and raptors! Also learn about the important role that monitoring wildlife species populations plays in maintaining a healthy river by protecting habitats.

Chapter 8: Climate Change

In Chapter 8, walk through the impact that climate change will have on the watershed's ecosystems, water levels, and the impacts that this will have on how community members interact with the watershed. Also learn about some sources of climate change that we can all take steps to address and minimize.

What Climate Change Impacts do we Expect in the watershed?

The most localized climate change predictions in Massachusetts are provided for the major watershed level at Resilient MA. The Nemasket River, Assawompset Pond, Pocksha Pond, and Long Pond are located in the Taunton River Watershed, while the Great Quittacas and Little Quittacas Ponds are located in the Buzzards Bay watershed. With the majority of the ponds area located in the Taunton, we use its figures in the data below. Observed changes are for Massachusetts as a whole.

Days over 90 Degrees


Predicted 2050: +15.2 to 33.5 days

Annual Rainfall


Predicted 2050: +2.56" (spring/winter)

Extreme Weather Events

Observed (since 1958): 55% more heavy precipitation events

Predicted 2050:     +2 days of extreme weather per year

Number of Consecutive Dry Days


Predicted 2050: +1.25 days (summer/fall)

Effects on Herring Migration

Predicted: Shorter run season, with all fish moving closer in time, causing bottlenecks at fish ladders that may turn fish away.

Plan Area Map viewer

The Watershed Boundaries

Explore the landscape of the APC and Nemasket River watershed area. The following map includes datasets that are already known, such as protected open space, ownership, wetland areas, and the like. This map will be updated as the project advances with layers that are created by the project team, where these layers assist in developing action item recommendations.

It's your watershed - please participate!

The Management and Climate Action Plan is to be a collective balancing of objectives across the dimensions of water quality and supply, habitat, recreation, and flood management.


We rely on you, APC community stakeholders across Lakeville, Middleborough, Taunton, New Bedford, Rochester, and Freetown, as our indispensable project partners.

When you sign up for the mailing list, you will receive project updates and notifications, and we maximize our opportunities to hear from you!

Previous Community Meetings

Refer to this page regularly for updates about the time, location, and participation details for our public meetings as we move into Y2 of the project!

Meeting on Floodplain Management

The meeting was hosted at Ted Williams Camp on 9/29/22.
Review the meeting materials here
Workshop recording:

Meeting on Water Quality

The meeting was hosted at Hopewell Park in Taunton on 10/13/22.
Review the meeting materials here
Workshop recording:

Meeting on Ecology and Unique Habitats

The meeting was hosted at the Middleborough Town Hall on 3/23/22.
Review the meeting materials here
Workshop recording:

Meeting on Recreation and Stewardship

The meeting was hosted at Gifford Park in Rochester on 4/13/22.
Review the meeting materials here
Workshop recording:

Meeting on Land Development

The meeting was hosted at the Freetown Council on Aging on 4/27/22.
Review the meeting materials here.
Workshop recording to be posted soon.

Meet Your Plan Open House

This meeting was hosted on July 14th at Ted Williams Camp in Lakeville.

Review the meeting materials here.