New Book Aims to Protect and Restore Fish Migrations

Rivers are a critical natural resource and an essential element for the health and survival of billions of people and countless species. Flourishing populations of migratory fish are an important indicator of a healthy, coastally connected river and a robust aquatic ecosystem as a whole. Migratory fish help to maintain a balanced food web, support productive river systems, and provide income for people around the world.

Yet many migratory fish species are severely threatened primarily due to man-made obstacles like dams and weirs, which disrupt the natural flow of rivers and prevent fish migration. When fish can’t reach their habitat, they can’t reproduce and maintain their populations.

Photo Credit: “From Sea to Source 2.0”

A new book, titled From Sea to Source 2.0, explores the challenges that lie behind restoration of fish migration in rivers around the world and provides a practical guide to promoting the protection and restoration of fish migration. The book is a unique collaboration of over 100 international fisheries professionals and supported by river managers, governments, research institutes and NGOs including World Wildlife Fund and The Nature Conservancy. Geared toward practitioners, but also a wonderful resource for the general public, the book is comprised of inspiring stories from nearly every continent on the planet. Click here to download it for free.

“Ultimately our ambition is to contribute in a positive way to making a better world and a positive difference for migratory fish, nature and humans on local and global levels by inspiring new initiatives for and with people all around the world,” as stated on www.fromseatosource.com. “Whether the challenge is simply to increase access to spawning habitats through connectivity improvements for salmon, or to maintain the livelihoods for hundreds of millions of people dependent upon fish and fisheries in the great rivers of Asia, Africa and South America, we hoped our book would help to achieve these goals.”

Princeton Hydro’s Dam Removal Expert Laura Wildman, P.E. and Fluvial Geomorphologist Paul Woodworth are proud contributors to the book, helping to write the dam removal chapter, creating a dam removal flow chart for the book, and providing multiple photos utilized in the book. Princeton Hydro is also listed as a contributing sponsor.

“We’re so proud to be part of this incredible project with so many partners globally,” said Wildman. “We envision that this book will provide a valuable resource and inspiration for those in countries and regions where the importance of restoring riverine connectivity is newly gaining momentum. We hope it will help emphasize the importance of finding balanced and environmentally informed solutions when proposing additional utilization of public trust resources such as rivers.”

Approximately 40% of all fish species in the world reside in freshwater ecosystems, contributing economic and ecological benefits and value. It’s critical that we support efforts that aim to protect migratory fish species, reconnect rivers, sustain fish passage, and preserve free-flowing rivers through removing unnecessary dams, reconnecting floodplains, managing our water use, and managing hydropower for sustainable rivers.

Education and awareness building are key first steps in protecting rivers. From Sea to Source 2.0 seeks to inform, educate and inspire those who want to know more about how to meet the challenges of restoring fish migration in rivers around the world.  The book is regarded as a crucial resource in the ongoing fight to protect and preserve the enormous value of our waterways.

Get your free copy here.

Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of a dozens of small and large dams in the Northeast. To learn more about our fish passage and dam removal engineering services, visit: bit.ly/DamBarrier.

Conservation Spotlight: Restoring Fish Passage on the Noroton River

For thousands of years, river herring swam from the Atlantic Ocean through the Long Island Sound and up the Noroton River to spawn each spring. Then, they returned to the ocean until the next spawning season.

Back in the 1920s, President Dwight D. Eisenhower’s administration began connecting the country through a massive interstate highway system. As part of the infrastructure plan, hundreds of thousands of culverts were built across the U.S. with the intention of moving water quickly and efficiently. While that goal was met, many migratory fish and other aquatic organisms could not overcome the culverts’ high-velocity flows, shallow water depths, and perched outlets. This infrastructure prevented them from reaching their native migratory destinations.

By the late 1950s, Interstate 95 cut through Connecticut’s coastal rivers, and culverts were installed to convey river flows. Alewives, American Shad, Blueback Herring, and other native fish species were unable to navigate the culverts. Their populations dwindled to the point where Connecticut, along with Rhode Island, Massachusetts, and North Carolina, instituted moratoriums on catching and keeping the valued forage fish.

Along the Noroton River, three parallel concrete culverts, each 300-feet long, 13-feet wide and 7-feet in height were installed, completely blocking upstream fish passage.  In order to restore important fish populations and revitalize the Noroton River, Save the Sound launched a project that reopened approximately seven miles of the river, allowing migratory fish populations to safely and easily travel through the culverts to reach their original spawning habitat upstream.

The project is a collaboration among Save the Sound, Darien Land Trust, Connecticut Department of Energy and Environmental Protection (CTDEEP), Connecticut Department of Transportation, Princeton Hydro, and other partners. For the project, Princeton Hydro lead design engineering and guided the construction of the following elements to restore upstream fish passage:

  • The installation of a concrete weir at the upstream end of the culvert to increase water depths in one culvert during low-flow periods;
  • The installation of concrete baffles to reduce flow velocities and create resting places for fish, and;
  • The installation of a naturalized, step-pool, rock ramp at the downstream end of the project to allow fish to ascend into the culvert gradually, overcoming the two-foot vertical drop present under existing conditions. The rock ramp consists of a grouted riverstone base with large grouted boulders arranged to make steps, with low-flow passage channels, between a series of pools approximately 1-foot deep that create resting places for upstream migrating fish.

Reopening river passage for migratory species will improve not only the health of the Noroton River itself, but will also benefit the overall ecosystem of Long Island Sound. Over the last decade, fish passage projects around the sound’s Connecticut and New York shores have dramatically increased freshwater spawning habitat for the foundational species whose return is restoring a more vibrant food web to the Long Island Sound.

Construction of the baffles and rock ramp were completed in time for the 2018 migratory season. Construction of the concrete weir is on temporary hold for low-flow conditions. On April 26, 2018, project partners gathered for a project celebration and the release of migratory fish by CTDEEP at an upstream location.

“It’s fascinating to feel the change in the flow patterns against your legs as you walk through the baffled culvert knowing that it will now facilitate fish passage through this restored reach,” said Princeton Hydro’s New England Regional Office Director and Water Resources and Fisheries Engineer Laura Wildman, P.E. “It is a very attractive and natural-looking fishway, and we’re proud to have created a design that fits so well into the surrounding landscape.”

Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of a dozens of small and large dams in the Northeast.  To learn more about our fish passage and dam removal engineering services, visit: bit.ly/DamBarrier.

The Plight of Aging Dams, and One Solution

As dams age, the danger to life and property around them increases. If they were to suddenly fail and flood downstream communities and infrastructure, there would be serious loss of property and life. More and more, dam removal has become the best option for property owners who no longer want or can no longer afford the rising cost of maintenance and repair work required to maintain such a complex structure.

The Courier-Post recently published this Commentary piece titled, “The Plight of Aging Dams, and One Solution”, which was written by Princeton Hydro’s Vice President and Principal Engineer Geoffrey M. Goll:

Many of our nation’s dams, while originally intended to provide benefits for mills, water supply and energy generation, are severely aged and unmaintained. Nearly 20,000 of the dams on the Army Corps of Engineers’ National Inventory of Dams – which doesn’t even include many dams that are not inventoried or known about – were built in the 1960s. With expected lifespans of 50 years, these dams have reached their limit. And by 2020, 70 percent of all dams will be over 50 years old. Like roads and bridges, dams also require upkeep, maintenance and eventually removal or rehabilitation.

As dams age, the danger to life and property around them increases. If they were to suddenly fail and flood downstream communities and infrastructure, there would be loss of property and life. The Association of State Dam Safety Officials, the professional organization for dam safety engineering professionals and regulators, estimates there would need to be a $21 billion investment to repair just 2,000 deficient, high-hazard dams. More and more, the removal of dams has become an option for owners who no longer want or no longer can afford the rising cost of maintenance and repair work required to maintain such a complex structure.

For dams like this, removal benefits local economies, and eliminates threats to people and property in local communities. There are also many byproduct benefits, including restoring fish migration routes, improving water quality, restoring floodplain functions and values, and increasing biodiversity.

On Sept. 8, we had the honor of meeting the Secretary of the Interior Sally Jewell during a visit of our Hughesville Dam removal project on the Musconetcong River, located in northwestern New Jersey. This project exemplifies the successes that can be achieved through public-private partnerships, including local communities, state and federal agencies, nongovernmental organizations, and private commercial entities. This is the fifth dam removed on the Musconetcong River by a coalition of stakeholders, led by the Musconetcong Watershed Association. The Department of the Interior (specifically, the U.S. Fish and Wildlife Service) provided funding to remove this very old, out-of-compliance dam.

The success of these partnerships is due to the unique strengths that each organization brings to the table. This project achieved the removal of a flood and safety hazard, and will restore additional river miles for migratory fish, improve water quality by removing the heat sink of the reservoir, and provide additional safe passage for recreation along the river.

It is easy to see why Secretary Jewell chose this site to visit, but the old and outdated dam at Hughesville is far from alone. Across the nation, we need to remove dams like this at a much larger scale – aging dams that no longer are of value to us, but increase the danger to those who live downstream. If we can build on this momentum and start to address the issue of dam safety compliance on a national scale, we can address these threats to American’s safety and strengthen local economies.