3 Rivers

Protected & Clean

Flowing Free

For all to Enjoy

Wild & Scenic

WATERSHED ORGANIZATION
FOR THE SUDBURY ASSABET & CONCORD RIVERS

Our Vision

A watershed with resilient streams and rivers that provide healthy wildlife habitat, water supplies, beauty, education, and recreational opportunities for all. OARS is the voice of the rivers, and is an effective, innovative, and inclusive science-based non-profit organization.

The Rivers

The quiet beauty of the Sudbury, Assabet, and Concord (SuAsCo) rivers in eastern Massachusetts provides an antidote to our modern lives. They form the 399-square mile SuAsCo watershed. The rivers flow north through mill towns and farms, small cities and suburbs, to pass through the Merrimack River in the City of Lowell. Sections were federally designated as Wild and Scenic Rivers in 1999 for their outstanding recreation, ecology, scenic, and historic resources and place in American literature.

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Recognizing Indigenous Stewardship

We would like to honor all the ancestral stewards of this land including the Massachusett, Nipmuc, and Pawtucket Nations. We endeavor to be responsible stewards of their traditional and contemporary territories. We recognize their invaluable efforts by continuing the conservation legacy they started as caretakers of our watershed.

 

The name Assabet is likely from a Nipmuc word for the area’s marshes. The confluence of the Assabet and Sudbury rivers is named Musketaquid, where the waters flow through the grasses.

Diversity and Belonging

OARS is committed to the ongoing work of promoting diversity, equity, inclusion, and belonging within our organization so that all may enjoy and benefit from these rivers.

Enjoy and help our rivers!

River Maps

Recreational guides for Sudbury, Assabet, and Concord rivers are available as a series of single-river maps and as an interactive online map.

RIVER MAPS

Events!

Upcoming events. Explore our opportunities and get involved!

SEE WHAT’S HAPPENING

Dam Removal

Our watershed has over 160 dams. Many are old mill dams in disrepair and result in aquatic weed growth, flooding, warmer water, and degraded wildlife habitat. Learn more about our efforts to let our rivers run clean and free.

DAM REMOVAL

River Science

Read our latest findings on water pollution and work to build climate resilience.

UNDERSTANDING OUR RIVERS’ HEALTH

Report & Pull Water Chestnut

Help us manage invasive water chestnut by using our reporting app to share where you have seen or pulled water chestnuts.

HELP COMBAT INVASIVES

RIVER REPORT CARD

How healthy are your Sudbury, Assabet, and Concord rivers?

READ OUR REPORT CARD
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Upcoming Events

Events Calendar

Three Stones Gallery—Belle Terre

October 23 - November 24, 2024

OPENING RECEPTION Saturday | November 2nd | 6 to 9 PM | 32 Main Street, Concord, MA 01742 | 978.371.1333   Belle Terre, or Beautiful Land, features three artists whose …

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Assabet River Wildlife: Swimming Birds

January 11 - January 11, 2025

Maynard Public Library | January 11, 2025 | 2 PM to 3 PM               Presentation of the Swimming Birds found on the Assabet River, …

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OARS’ WINTER WALK AND TALK

January 25 - January 25, 2025

SAVE-THE-DATE   REGISTER HERE (coming soon)

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Partner Event—Middlesex School Green Summit

April 12 - April 12, 2025

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17th Wild & Scenic Film Festival

April 23 - April 23, 2025

  OARS is once again hosting one of the largest environmental film festivals   WHEN Wednesday, April 23rd WHERE COMING SOON   OARS cordially invites you to join us at …

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Concord River Race

May 04 - May 04, 2025

SAVE-THE-DATE   REGISTRATION COMING SOON

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News & Alerts

River Log

Invasive aquatic species invade Acton Town Hall

November 02, 2024

by Kim Kastens | Nov 2, 2024 | The Acton Exchange On October 22, Town Hall was transformed into a plant identification biology lab, as thirty-five lovers of local ponds …

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Water Chestnut Pull

October 21, 2024

Oct 19, 2024 | ActonTV   OARS partnered with the Town of Acton for a successful community water chestnut pull at Ice House Landing on September 28, 2024, as part …

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PRESS RELEASE: The Sudbury Foundation Awards Over $1,322,000 in Grants

October 11, 2024

by Sonia Shah, Executive Director, The Sudbury Foundation | October 11, 2024   FOR IMMEDIATE RELEASE   October 10, 2024 (SUDBURY, Massachusetts)—The Sudbury Foundation  recently awarded over $1,322,000 in grant …

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Environmental nonprofit OARS worries over water quality at Marlborough’s Hager Pond dam

September 03, 2024

by Tom Benoit | Sept 3, 2024 | The MetroWest Daily News   MARLBOROUGH — An idyllic pond located on the Marlborough-Framingham line has all the makings of a classic …

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Potentially invasive turtle species found in Merrimack River

August 13, 2024

by Peter Currier | Aug 13, 2024 | The Lowell Sun and The Boston Herald   LOWELL—A potentially invasive species of turtle was found in Lowell last week near the …

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PRESS RELEASE: OARS Intern Discovers Invasive Turtle Species in Merrimack River

August 10, 2024

by Sarah Kwan, Director of Communications & Development, OARS | August 10, 2024   FOR IMMEDIATE RELEASE   Lowell, MA—A new invasive species has been identified in the Merrimack River, …

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Fast Facts for 2023

>250

water samples were collected to monitor our river health and provide data for informed decision-making

~24K

water chestnut plants were hand-pulled by the OARS community

~1700

members of the community joined OARS (and growing)

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In memory of Marty Moran of Hudson

Board member, steadfast volunteer, and lover of rivers. We are deeply grateful for all you have done for OARS. Your legacy gift, along with the generous support of the Sudbury Foundation, made the creation of this website possible.