Dams & Culverts

ProblemDams and inadequate road crossings block migration pathways and degrade river habitat. See what we are doing and how you can help

Ipswich Mills Dam

The Ipswich Mills Dam (at the head of tide in downtown Ipswich) is the first of many dams that migrating fish encounter when they enter the river.

For thousands of years, the Ipswich River ran free from source to sea and bountiful runs of migratory fish returned from the Atlantic every year. These migrations helped support local populations of fish and wildlife as well as the region’s human population. Additionally, resident fish (like brook trout and white sucker) and other aquatic organisms were able to migrate within the watershed to maximize their survival.

Times have changed. Roughly 70 dams and 500 crossings (culverts and bridges) now segment the river system. Most of the dams and an unknown-but-large number of the crossings block important migration routes and impair habitat conditions.

These migration barriers are among the major reasons why once impressive fish runs have dwindled in the Ipswich River and elsewhere. River herring used to number in the millions and spawn as far upstream as Wilmington and North Reading. Now their numbers have dwindled to a few hundred annually and they are seldom seen beyond Ipswich’s Willowdale Dam, just a few miles from the ocean. American shad don’t even make it past the tidal zone, as they are stopped by the Ipswich Mills Dam, unable to navigate the fish ladder.

Removing unneeded dams and upgrading problem crossings would quickly restore migration pathways and increase the river’s capacity to support healthy fish runs. Dam removal would restore natural riffles and rapids, restoring the free-flowing character of the Ipswich. These actions would provide important habitats for fish and other creatures, add oxygen to the river’s waters, and offer us beautiful views now buried under several feet of water. There are also significant public safety benefits associated with removing aging dams and undersized crossings that are likely to fail during large storms.

What we do (Dams & Culverts)

  • Educational programs on dams and river restoration – We share information about the effects dams, culverts and other barriers have on river health and highlight how habitat restoration provides an opportunity to make the river healthier for our children and theirs. Check our Event calendar for upcoming programs.
  • Dam removal and fish passage – When possible and practical, migration barriers should be completely removed. In other cases, the dam or crossing can be to upgraded to allow pathways through or around it. We work with communities, businesses, other non-profits, and governmental agencies on  restoration projects to reconnect river habitat. We provide support for these efforts through our Habitat Restoration Program.
  • Road-stream crossing inventory – We are working with partner organizations and volunteers to conduct a comprehensive survey of crossings in the watershed. This effort is part of the UMass Extension regional River and Stream Continuity Project and is funded in part by a grant from the Massachusetts Environmental Trust.
  • Monitor the river and its inhabitants – Our monitoring program tracks key indicators of river health and restoration success including water quality, river herring populations and aquatic macroinvertebrate communities.

How you can help

  • Talk to your friends about river restoration – It takes local champions to build support among their friends and neighbors who might be interested, but less versed in the reasons and methods for restoring a healthy river. So take the initiative! Learn about the issues, ask questions, and talk to your friends about it what you find out.
  • Volunteer 
    • Help with the annual herring count
    • Join your local Stream Team – or start one!
    • Road-stream crossing inventory – Let us know if you would like to get trained to help with the survey
  • Give to the Ipswich River Watershed Association – As a member supported organization, IRWA is only as strong as the community that founded and continues to support us. Please consider becoming a member of you aren’t already. Also, please consider a gift to support our work to protect the Ipswich River and the communities that rely on it.

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