The Case for Removing Useless Dams

Over the centuries, tens of thousands of dams have been built across the U.S. to control water for consumption, storage, energy, and recreation. Rarely was any thought given to the effect these dams had on the ecosystem - until relatively recently. Now there is a growing recognition that many dams do more harm than good, and there is a growing movement to restore the health of our waterways by taking down the dams that are no longer useful.

In New Jersey, a partnership has been formed to consolidate information and best practices, and to address the daunting task of dam removal across the state. The partnership recently unveiled NJdams.org, an encyclopedic resource that pulls together the locations, histories, and frequently asked questions about the impact of dams on the environmental wellbeing of the Garden State.

Removal of the Weston Mill Dam in the Millstone River in 2017 brought shad back upstream. Photo courtesy of The Watershed Institute.

Removal of the Weston Mill Dam in the Millstone River in 2017 brought shad back upstream. Photo courtesy of The Watershed Institute.

The New Jersey Statewide Dam Removal Partnership (SDRP) holds regular meetings and workshops to advance its work, most recently at The Watershed Institute, where Executive Director Jim Waltman spoke with CivicStory about the work to be done. Some of the takeaways:

  • There are hundreds of dams in NJ which are bad for water quality, fish populations, and recreational safety.

  • Removing a dam requires funding, investigation of historical and current records, and an often time-consuming process.

  • Removal of even a few dams has already restored populations of native fish like shad to the upper regions of rivers like the Millstone.

  • Removing dams could be part of a larger strategy to make NJ towns more resilient in the face of climatic changes.

Podcast transcript:

Jim Waltman, Executive Director of The Watershed Institute 

Q: What do you think is important for the public to know about dams?

JW: Well we have a lot of them, and they're doing real harm. In the state of New Jersey we think there are some 1,700 dams in our rivers and they're a nuisance. They’re a negative aspect, many of them, in that they change the quality of the water, they impede the migration of fish and in some cases they're very dangerous structures for people that like to recreate on the river. So this is a relatively new idea in the state of New Jersey, that we should look back at these antiquated, old structures and think about ways to remove them. It's been kind of hidden away, quietly harming the ecosystems in the state. There's like 90,000 of them supposedly in the United States. So they’ve been quietly doing damage and now we have an opportunity to restore our rivers, in part, by removing these dams.

Q: Are you saying remove all of them? 

JW: I'm saying there are many of them that serve no positive purpose anymore, that are causing real harm, and there's plenty of those to keep us busy removing them. There are certainly some dams that have been built that still have a very real purpose. There are reservoirs that are supplying important sources of drinking water for people. There are other dams that created recreational lakes and ponds that still have a very real purpose. But there are hundreds that really don't do anything positive for us anymore in society, and those are the ones right now that we're focused on removing. 

Q: Is there any common reason that those hundreds of now-useless dams were built in the first place?

JW: They were really built for a lot of different purposes but the older ones, particularly in this area, were built as power-generating strategies. So there was an old mill, and the old mill was an important part of the economy back then. The gristmill was creating flour from the harvest and those were powered by dams on the river. So we had very smart forefathers and mothers and they found a relatively cheap way to create power. They created an economic benefit, but with a very real detriment. This is a fascinating document written by a gentleman named Johann David Schrupp in the 1700's. He wrote this series of diaries, almost, called “Travels in the Confederation”. This gentleman was traveling around the United States in the early colonies and learning what was going on here. He wrote this section about the Millstone River - so he's here in the late 1700s and he says “these waters contain a multitude of fish: pike, goldfish and suckers, American Shad  - that ran in numberless schools high up this river. But dams of which many have been built in recent years keep back the shad and contribute appreciably to the provisioning of the inhabitants along the banks.” So in the 1700s we already knew: we've created commerce, we've created industry, we’re supporting people's livelihoods with these structures, but they've killed off what used to be a really big part of the life of this river. In this case, in the Millstone River, it was the shad. So you know we’re talking about things that we've known for centuries. I can tell you there are few things that I've been involved in in my 30-year career as a professional conservationist that are as exciting as the opportunity to turn the clock back three centuries and bring back this wonderful natural element to our region.

Q: How much has been done already, in this respect?

JW: There's about 40 or 50 dams, I believe, that have been removed in the State of New Jersey. We've been very focused on the Millstone and Raritan Rivers. The Millstone is a large tributary to the Raritan river. Four dams have been removed just in the last decade, and we're already seeing a response. We’ve got American Shad and the sweep of species - shad, herring, blueback herring, alewife is another fish in the herring family - and they're starting to return to rivers that they've been lost from for centuries. So that's really exciting. Last year we had American shad spawning for the first time in we-don't-even-know-how-long in the Millstone River. Our scientists went out with their colleagues from the US Fish and Wildlife Service and New Jersey DEP and they found young shad for the first time anybody has ever seen that in the Millstone River. That’s really exciting! 

Q: How big an undertaking is it to remove one of these?

JW: It's funny, most of these dams started out life as a structure made from timbers, but over the years had layer upon layer of concrete dumped upon them. In some cases they're reinforced with steel bars. so you know it takes two, three, four days to get them out, even a dam that you look at and think:  “I could get that out myself with a sledgehammer”. It's just this huge truck that goes into the river and it's essentially an enormous jackhammer and just bangs away at the thing for a matter of days, chipping away the concrete, and then they carry the concrete away. Some of these things look pretty small but it's actually quite an undertaking to get them out of there.

Q: How comprehensive are our records, and who owns the properties on which these dams were built?

JW: Those are two very good questions with complicated answers. The records are varied. One of the first steps that we took when we were planning that removal of the Weston Mill Dam on the Millstone River was to hire a historian. These historians went out and reviewed the written record - of which there’s very little - and they investigated the site for evidence of earlier habitation and earlier commerce. They pieced it together. This document, “Travels in the Confederation” that I referenced was something that our historians found. They do a really good job just taking sample cores of an old timber structure beneath the layers of concrete, and they can  date when the structures were built. Dam ownership is an interesting question. In the State of New Jersey, if a dam abuts your property, you own that dam. So there's a lot of dam owners in the state who have no idea that they own dams. When we were first looking at the Weston Mill Dam, it took us quite a while to find the individual who literally owned the dam. He had no idea. That's another reason to remove dams: most of these are old, they’re decaying or falling apart, they may pose a danger. Someone's responsible for their repair and maintenance, and most of those someones have no idea that they're on the hook. If something goes wrong - if a dam blows and it causes damage downstream - the people owning these dams can be liable for that, and be made accountable. 

Q: Can you talk a little bit about the compilation of information that you put on the new website, and who the website is aimed at? 

JW: There’s a new alliance of nonprofits and government agencies that are working together to identify priorities, to investigate and research dams, and the damage they may be causing. The partnership is called the New Jersey Statewide Dam Removal Partnership. We’ve pulled together a lot of information and placed it on a brand new website: NJdams.org. What you can find there on the website is a tremendous amount of information about dams in the state, the process of removing dams, why we have dams in the first place (and they were built with intent), and in which cases those purposes may have expired, essentially. The partnership includes nonprofits like: a national group called American Rivers; the Nature Conservancy, which has a New Jersey chapter; and then more state and local groups like ours, The Watershed Institute; the Raritan Headwaters Association that works a little bit further north of us in the state; the Musconetcong Watershed Association which is a great local group that takes care of and looks out for opportunities to restore the Musconetcong River, which is a tributary to the Delaware River. 

Q: Do you foresee a day when the coalition's work will be done?

JW: Well, I do. It's going to take many many many years. We're still kind of identifying and researching things. I will say that to do anything in the state of New Jersey there is a lot of process, and usually that's a good thing. There was a lot of conversation. Some of these dams are themselves historic artifacts and so there's a process of identifying the history and then a conversation with the state historic trust and local historic commissions. Some of these dams have some sediment that's built up behind them, so we need to investigate the sediment and make sure that there's no contaminants in the sediment, and if there are contaminants there's a special process to remove that and take that to a safe location. There's a lot of different processes involved here. It takes a long time. We started working on the Weston Mill Dam on the Millstone River in about 2008 and the dam was removed in 2017 so that was an almost 10-year experience to remove a dam that's 5 ft tall - or was - it was about a 120 ft wide. To look at it, it looked like a pretty modest structure in a river, but it took 10 years to get it out of there. So there's a long road ahead. But removing dams is a great opportunity to restore our rivers. A lot of things happen when you put a dam in the river. The dam impounds water and when the water pools behind the dam, the water is more likely to heat up, it's more likely to have the oxygen depleted, and you start combining those factors that means the aquatic life - the fish and other creatures within that river suffer accordingly. The dams are an impediment to recreational uses. Towns and cities in our state have found they can build part of their economy around natural outdoor recreation, and see dams as an impediment to that. There's a lot of positive that comes from removing dams, but there's a long process to get to that point.

Q: Are you able to estimate the cost of getting New Jersey to the point of dam removal that you would like to see?

JW: We can't say that we've done that, and I would hesitate to hazard a guess. An individual dam, you're probably looking at $100,000 or more in all of the scientific studies that have to be done, the investigation of the history, the permitting process and then the engineering design. It sounds funny but there's a design that needs to be done to deconstruct and remove things that can be just as complicated as the engineering design was to build it in the first place. And then the removal of the structures at the end is a difficult process. 

Q: And what sources of funding are available? 

JW: One source that has been used quite a bit in the state is something called the Natural Resource Damage Assessment Program, and this is actually a real win-win kind of situation because essentially corporations and others that have been caught polluting the environment are required to do two things: one, to remediate the pollution or the harm that they've caused the environment, but they also have to support the restoration of the natural resources that have been damaged. The first dam that was removed on the Raritan River, the Calco Dam, was part of a large settlement of remediation issue. It involved the historic dumping of pollutants into the Raritan River. People who know the history of that river know that it used to run orange, purple, green, depending on the day or the week or the month. There was a time where we literally poisoned our rivers - intentionally - and that Calco Dam had what we think of as kind of horrifying and impossible today, but the dam had within it a long pipe, and that pipe had a number of holes in it essentially and the dam and this pipe were used to dilute pollution that was coming out of this old plant. Pollution went into this pipe and was spread into the river intentionally. There's an old saying that: “The solution to pollution is dilution”. We don’t typically follow that anymore, but that's what they did. Turn the clock forward decades, and under our current laws, in our current sensibilities, that was an abomination. And so the responsible party, which has changed over the years as the ownership of that site changed, was required both to clean it up and then to compensate, to restore the natural resources that were damaged by that. That pollution killed a lot of fish, so how can we try to restore the fish that were killed by the pollution? Well one thing we can do is take dams out, that then allow these migratory fish to be reconnected to their historic spawning grounds, so over time you know they'll be hundreds and then thousands and hopefully someday hundreds of thousands of fish will be recovered into those rivers, now that they have the spawning grounds open to them again.

Q:  Are there any legislative fixes that are either under consideration now or ought to be?

JW: Well at this point the laws are pretty good. At this point the challenge is to get the funding in place, so that for example with the natural resource damage program that the polluters are held accountable, that the appropriate amount of financial penalty is put in place, and then those funds are used efficiently and smartly to restore the resources have been damaged - whether it be removing dams or restoring wetlands or projects like that. Some would say that the regulations are little overbearing when you're trying to do an environmental restoration. Frankly at the Watershed Institute we're not eager to start streamlining environmental regulations for fear that they could have unintended consequences. But we do have some pretty strong state and national laws. Maybe the most seminal historic dam removal case at the national level happened 20 years ago in 1999 and this was the Edwards Dam in the Kennebunk River in Maine. That was a case where the dam had been federally licensed. This was a big dam on a big river. In order to have their license reupped - that the process to be relicensed by the federal government - the Feds concluded that the cost of that dam vastly exceeded the benefits of having that dam, and the dam owner was actually required to dismantle it and help fund the removal of the dam. So there's some really strong environmental laws at the state and national level and some really strong and creative environmental attorneys that can put these laws to good end. But I think the challenge is really to educate people about the opportunity we have with dam removals to restore components of our natural legacy that have been lost because of these dams. And by educating people, what can come from that is more pressure on our leaders to make sure that we’re funding the removal of these dams.

Q: Are new dams being built? And if so, at what rate and for what purpose?

JW:  In this country we were not really building very many dams and we're certainly not building them in the state of New Jersey. On the international level this is a big concern. Enormous dams at an alarming rate are being built in China, for example, across impossibly large rivers. But it does bring up a real challenge for us as conservationists because you know there are the competing interests. Hydropower, from a climate change perspective, in some ways is a cleaner way of generating energy than a coal-fired power plant. But those large dams have negative implications for climate as well. We impound waters, and we change the flow of sediment, and the sediment accumulates and creates methane release, so it's not so much an issue in this country but it certainly has been an international issue that has raised concerns both for impacts on rivers and these climate changes. 

Q: Is hydropower a consideration in New Jersey at all?

JW: People have talked about it, and there are people looking at ways to generate hydropower that don't or do less damage to a river. I don't know of any cases where they've actually been implemented. The question is: can you harness the power of the river without blocking the river, or without changing the water chemistry in the river, or the biology of the river? I haven't seen it done yet in a way that I'm comfortable with, but it's certainly something people are exploring and people should explore.

Q: Circling back to the question of what does the public need to know about dams, is there anything that public perception could help your efforts?

JW: There's certainly a lot of concern about climate change in the state and certainly nationally, and there's a concern about our cities our towns not being prepared for the inevitable change that's coming, that's frankly already here. There’s an interest in making our communities more resilient, able to bounce back, able to take the punch from big storms from climate change. We think that removing dams is an important part of a broader strategy to make our state more resilient in the face of climate change. Some of these dams impound a lot of water, and that's a dangerous thing for people that live downstream. Some of these dams have impeded the flow of water into their floodplains. In an awful lot of cases, if we look back to the way systems were naturally, there were natural processes that were performing wonderful services to us that we took for granted. There's no better way to handle a storm surge in a river than to allow that river access to a healthy riparian area. So along the banks of of our rivers where we haven't completely developed up to the banks, there's often an area of wetlands or an area that used to be wet, an area of forests and meadows, and when a river is allowed to jump its banks into those areas you have this wonderful natural flood attenuation, this natural flood control. There are places in the state that still have those floodplains available to them, but where the rivers have been disconnected from them. Removing dams is part of the process of reconnecting a river with its floodplain. There's other areas where we’ve built industry or residential communities right along the banks of our rivers and we’re seeing the wrath of nature in the face of climate change making that in an increasingly untenable proposition. Just less than half a mile downstream from where the Weston Mill Dam was removed from the Millstone River is an area called The Lost Valley. The Lost Valley is a part of the town of Manville that has had tremendous harm from flooding, particularly over the last couple decades after Hurricane Floyd that was the first real big wake-up call. But over the last couple decades, through state and federal funding, individuals in harm’s way who have had their homes repeatedly flooding out have had the opportunity to sell their property so they can find a safer place to live. As those homes are removed, there's an opportunity now building to restore what was the natural floodplain. I think we're going to see that over the next fifty to a hundred years we're going to have to do this. There's going to be more and more people who are living in a place that's just untenable. It's just dangerous. We're going to have to find a safer place for them to live, and with that is going to come an opportunity to restore rivers that may have an opportunity associated with it to remove some old dams as well.

Q: Is there anything else that you would like to say that I haven't thought to ask?

JW:  Well in some cases these dams are also very dangerous for people. There have been incidents nationally and within the state of New Jersey where a dam that's no more than 5 feet tall has resulted in deaths to human beings who thought it was safe to swim behind them or to float a boat over the top of them. There can be an incredible back eddy on a downstream side of dam. In some cases people's pets, dogs, have fallen in them and they can’t get out. As we clean up the rivers in this state and across the country, the benefit of the federal Clean Water Act of 1972 is still working for us. The rivers in many cases are getting cleaner. We want to reconnect people with those rivers and we want to have more people enjoying the rivers, fishing in the rivers, boating in the river, swimming in the rivers, but there are certain places that it's very dangerous to do that, and that's because of these dams. So there’s a very real human life and safety component to this issue.

DL: Thanks so much for your work in this area, and thanks for talking with us about it.

JW: It was my pleasure, thank you Donna.