In the first part of our series, we explored the historical significance of dams and the myriad benefits they have provided over the centuries, from hydroelectric power to flood control. We also highlighted the serious environmental drawbacks, such as habitat loss and diminished water quality, as many of these structures age and become increasingly costly to maintain.
In this second part of our series, we dive deeper into the concept of "natural capital and ecosystem services" related to dam removal. We'll examine how restoring rivers to their free-flowing state can rejuvenate aquatic habitats, improve water quality, and bolster biodiversity. Join us as we uncover the compelling reasons behind dam removal and its potential to create healthy ecosystems for future generations.
To understand the benefits of dam removals in the context of natural capital and ecosystem services, let’s first draw a distinction:
When dams come down, both natural capital and ecosystem services can be revitalized primarily by reversing some of the negative effects that were covered earlier. The next sections will elaborate on a few of the most notable of these, and provide a general overview of how they bring value to our society.
Rivers are the lifeblood of ecosystems, and dams are analogous to blockages in the circulatory system, but the connection that dams have to our coastal wetlands isn’t necessarily an obvious one at first glance.
When a dam is removed and natural flow is restored, sediment and nutrients can move freely downstream again, eventually reaching estuaries and coastal areas. This renewed flow rejuvenates many natural processes, including the replenishment of coastal wetlands.
These wetlands rely on a steady supply of sediment to stay healthy and productive. Without it, they begin to erode, especially as sea levels rise. Over time, this can leave coastal communities more vulnerable and degrade the ecological value of the wetlands themselves.
In order to give you an idea of just how much value wetland ecosystems can provide, in 2019, a research team estimated that the planet’s wetlands have a value of $71 trillion per year (in 2024 USD). This represents a pretty significant 43% of the total value of all the planet’s ecosystem services. Similarly, a 2021 study estimated that coastal wetlands save the US approximately $280 million per year from storm damages.
These studies highlight just how vital wetlands are to our society and planet. Imagine the financial and environmental impact if wetlands were to be completely cut-off from their resupply lines. Their immense value would literally erode away, hour-by-hour, year by year, leaving us all the more vulnerable.
Connected waterways are essential for many species, particularly migratory fish like salmon and shad, which need open rivers to reach their spawning grounds.
In 2017, researchers determined that restoring the Columbia River in Oregon to pristine flow conditions could increase the value of its pacific salmon fishery by almost $27 million per year.
On a more local level, by taking part in dam removal projects, Unique Places to Save is helping endangered species such as the Cape Fear shiner return to their native habitats.
Freshwater mussels are yet another major beneficiary. These diverse species are often overlooked yet are critically important due to their ability to filter water. Enhancing habitat for freshwater mussels could potentially save municipalities tens of millions of dollars in reduced water treatment costs.
Mussels thrive in oxygen-rich, free-flowing rivers and rely on specific "host fish" to reproduce and expand their range. Dams disrupt both water flow and fish movement, cutting mussels off from the conditions they need to survive.
Some of the key host fish include:
When rivers are reconnected, so are these essential relationships. By restoring habitat and movement corridors, dam removals support mussel recovery and make ecosystems more resilient to major change.
While putting an exact dollar figure on the value of freshwater mussels remains a challenge for researchers, their ecological importance is clear. There is a solid case for giving them the conditions they need to thrive.
One of the most immediate benefits of dam removal is improved water quality. Dams create often-stagnant reservoirs where water becomes oxygen-depleted and more prone to things like algae blooms. Removing a dam restores a river's ability to self-clean, improving conditions for the benefit of both nature and people.
Water quality improvements are often difficult to quantify due to the complicated relationships between the sources of pollution and the myriad solutions. However, to provide some context, waterborne illnesses in the US result in approximately 7.15 million cases annually, costing $3.33 billion in healthcare expenses. Of these, about 78% are connected to recreational water exposure.
This includes recreation in lakes and reservoirs. With slow-moving water, warmer temperatures, and nutrient-rich conditions, man-made reservoirs are ideal breeding grounds for bacteria like E. coli and harmful algae such as Cyanobacteria.
Climate change is expected to make these problems worse. As temperatures rise and extreme flooding becomes more common the risks associated with algae and bacterial blooms and water contamination will only increase, putting both public health at greater risk.
As we’ve explored in this second part of the series, dam removals offer a bit more than just a cost-effective means of dealing with outdated infrastructure. When properly done, dam removal projects can help sustain and even restore some of the natural systems our society depends on.
But there’s still more to the story...
In the final part of our series, we’ll take a closer look at the social side of dam removals by exploring how restored rivers can strengthen communities, support recreation, and build resilience in the face of a changing climate.
Restoring and conserving land and freshwater ecosystems are essential for protecting our planet’s natural capital, and you can help make a difference. By supporting Unique Places to Save, you’re directly contributing to the protection of natural resources that benefit all of us. Your efforts help ensure these natural systems continue to provide clean water, fertile soil, and habitats for countless species.
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