Mill Pond Dam in Durham, NH

The Mill Pond Dam, on the Oyster River in Durham, New Hampshire, is the subject of current debate in the region. The dam, which forms the 9.5 acre Mill Pond (McMenemy 2021), was constructed in 1913 “for philanthropic reasons” by a Durham resident, Edith Onderdonk, in honor of her stepfather (Conley 2014). Today, Mill Pond is used for recreation, including fishing, boating, and ice hockey (NHDHR 2014). In 2000, Mill Pond Dam was inspected by engineers who noted the development of seepage, leakage, and deterioration. In 2017, Mill Pond Dam was found to be out of compliance with New Hampshire Department of Environmental Services (NHDES) Dam Safety requirements and in 2018 the Town of Durham received their most recent Letter of Deficiency related to Mill Pond Dam. A 2020 Feasibility Study developed five preliminary options to address the deficiencies, two of which were chosen for possible action: stabilization or removal (VHB 2020).

 The Mill Pond Dam should be removed.

Mill Pond Dam photograph by Alexandra Evans (Irelan 2019).

The dam should not be preserved at the expense of a healthy river. We are on the homelands of the Abenaki/Wabanaki people who have ongoing cultural and spiritual connections to this area. We acknowledge the land, the waterways and the people who have stewarded it through the generations. The dam is destructive to the ecological integrity of a river that has been stewarded by Indigenous ancestors for thousands of years.

At Durham’s January public hearing, the recent feasibility study was discussed. Comments were heard about the progress made over the years in favor of the dam’s removal. In a public opinion poll about preferences regarding dam removal in New Hampshire, key findings showed that a majority of respondents prefer to remove dams when the alternative is to keep them for maintenance of waterfront property values, preservation of industrial history, or maintenance of lake or pond based recreation (Leuchanka et al. 2019). 

According to Jon Bromley, an environmental science teacher at Oyster River High School in Durham, “The Mill Pond Dam is essentially choking a vein of Great Bay… We’ve altered the landscape in a way that is out of sync with the ways nature wants us to behave” (Lovejoy 2018:9-10). The Durham Conservation Commission had previously voted unanimously (7-0) for dam removal stating in part “we need to speak for the flora and fauna who can’t speak for themselves and recognize the river’s history that started well before the arrival of Europeans.” Further, the Commission stated that all fisheries and wildlife conservation groups supported removal in order to preserve a healthy ecosystem connecting the Oyster River and the Great Bay Estuary. 

The dam includes a fish ladder built in 1974. Scientific studies (e.g. see Waldman 2013) show that fish ladders decrease fish runs and endanger the natural life cycles of the many species formerly abundant in the Oyster River, namely, chad, alewife, herring and salmon. According to Kathleen Blake, Chair of the NH Commission on Native American Affairs, after Exeter removed its dam, “the river is much more beautiful today and has returned to a fully functioning riverine system. For example, the alewives returned that year. When we respect the Earth, we are given respect in return.” The Nature Conservancy states that what they have seen with dam removal is nothing but improvement; rivers are able to restore and heal.

To preserve the dam would require extensive repair, including measures to restore the water quality of the Oyster River, which is one of the town’s main water sources (Lovejoy 2018:10). Removing the dam would be more affordable than restoration (McMenemy 2020; McMenemy 2021), and the cost of removal can be mitigated by federal grants and other available funding sources (Lovejoy 2018:10). Additionally, the potential dangers of dredging up chemical toxins buried in the pond’s sediment can be mitigated by careful engineering and chemical disposal as has been accomplished in 26 states. 

Protecting the river also involves restoring its deep authentic history. Mill Pond Park also features the account of the so-called “Oyster River Massacre” that resulted in the murder over 100 local Euro-American settlers. The commemoration of this event on a state highway marker perpetuates harmful racial stereotypes and prejudices. In fact, historical records explain that the Indigenous people were responding to colonists who had broken treaties, destroyed their farming and hunting grounds, stolen their lands, and extorted control over those who had lived in the region for thousands of years and had tried negotiating their complaints in the English courts. Warfare was their last resort. This narrative needs to be heard.

Whose history should be preserved?

We look forward to preserving the park’s ecology and history. Suggestions for the future include a model fish weir, keeping the dam’s original abutments, and signs naming trees and shrubs in many languages, including Abenaki. 

Example of an Indigenous fish weir
Works Cited

Conley, Casey. 2014. “Dam for all time: 101-year-old Mill Pond Dam granted historic status.” Foster’s Daily Democrat, Jan. 30, 2014. <>

Irelan, Rebecca. 2019. “Watershed Wisdom: Engaging local stakeholders to manage environmental change.” UNH Today: Spark 2019. March 16, 2019. <

Lovejoy, Phoebe. 2018. “Dammed if You Do… Dammed if You Don’t: Should Durham keep the Mill Pond Dam?” Mouth of the River Vol. 4 Summer 2018, pp. 9-10.

Leuchanka, Natallia; Catherine M. Ashcraft, Kevin Gardner, and Lawrence C. Hamilton. 2019. “What to Do With Dams: An Assessment of Public Opinion to Inform the Debate in New Hampshire.” Carsey Research Regional Issue Brief No. 56 Summer 2019, pp. 1-6. <>

McMenemy, Jeff. 2020. “Two choices for fate of Durham’s historic Oyster River Dam.” Foster’s Daily Democrat Nov. 23, 2020. <

McMenemy, Jeff. 2021. “Durham residents split on removing or saving Oyster River Dam.” Foster’s Daily Democrat Jan. 18, 2021. <

New Hampshire Department of Cultural Resources (NHDHR). 2014. “Oyster River Dam added to NH State Register of Historic Places.” <

Vanasse Hangen Brustlin (VHB). 2020. “Oyster River Dam at Mill Pond Feasibility Study–NHDES Dam #071.03.” Prepared for Town of Durham, Nov. 2020. <

Waldman, John. 2013. “Blocked Migration: Fish Ladders on U.S. Dams Are Not Effective.” Yale Environment 360. Apr. 4, 2013. <