A river winds through a thick forest boasting colorful autumn leaves.
Allegheny River A portion of the Allegheny River flows through a Pennsylvania forest near Tidoute. ©: The Nature Conservancy/Brad Maurer

Stories in Pennsylvania

Upper Ohio River Basin

Once a centerpiece of economic vitality fueled by steel, iron and coal, western Pennsylvania is now a leader in advancing innovative and sustainable approaches to social change and environmental health. The transformation has prompted The Nature Conservancy to tap into the Sustainable Rivers Partnership, a national program co-led with the Army Corps of Engineers to modernize water infrastructure systems to improve river health, ensure safety and fuel prosperity.

In partnership with the Army Corps’ Pittsburgh District, TNC has been assessing locks, dams and reservoirs once key to transporting goods, maintaining water quality and reducing floods throughout the region for 150 years.

“The Army Corps of Enginners must consider that aging infrastructure not only refers to the physical age and condition of our facilities but also to the historical purposes for which they were built,” says Colonel John P. Lloyd, who served as Commander of the U.S. Army Corps Pittsburgh District when it forged this partnership with TNC. "Do project purposes, shaped by conditions that existed more than 80 years ago, still align with current and anticipated future needs.”

This planning includes closely examining how flows controlled by dam operations affect natural habitats downstream. The effort will inform recommended river flow targets ideal for supporting fish, mussels and other wildlife now and under a changing climate. The partners are also examining whether locks and dams located on the upper Allegheny and Monongahela rivers remain economically justified for navigation or whether alternatives such as decommissioning or modernization should be considered.

A city surrounded by two rivers and several bridges.
Pittsburgh, Pennsylvania The Nature Conservancy and the U.S. Army Corps of Engineers are working in and around the City of Pittsburgh to reduce the impact of infrastructure on ecological processes. © Creative Commons/Filipe Fortes

Partnering Around Pittsburgh

Seated at the head of the Ohio River and surrounded by the mineral-rich Allegheny Mountains, the City of Pittsburgh was a transportation and industrial powerhouse for nearly two centuries with steel, iron and coal serving as the centerpiece of its economic vitality. However, over the past half century, advancements in manufacturing led to huge shifts in the Steel City’s social and economic foundation. Today, Pittsburgh ranks as one of the nation's top travel destinations and most livable cities, with renowned museums, parks, medical centers and academic institutions. Economically, the city has diversified into becoming a hub for industries ranging from banking to consumer products to technology. 

In response to the changing face of the city, the Corps has consulted TNC about updating water control plans for the 16 reservoirs and 23 locks and dams the agency oversees for navigation, recreation, flood control, hydropower and other purposes. Determining how much and how often water is released has a direct impact on habitat that is critical to fish, mussels, and other aquatic plants and animals downstream.

As part of its work with the Corps, TNC compared current operations at the Youghiogheny Lake and Dam with the river's baseline flows—the magnitude and timing of water volume as if the dam were not in place. Then TNC presented recommendations for modifying water releases to better mimic seasonal cycles. The Corps and TNC continue to seek a balance between modifying dam releases to meet wildlife needs while redefining primary functions of the dam. The partnership also extends to other areas within the Ohio River basin.

White water rushes away from openings in a concrete dam.
Kinzua Dam Water flows from a test release at the Kinzua Dam in Pennsylvania. © The Nature Conservancy/Brad Maurer

Allegheny River Flows

In October 2018, the U.S. Army Corps of Engineers spearheaded a water release from the Kinzua Dam in an effort to mimic nature dependent on the Allegheny River.

“This was an incredible opportunity to further explore ways we can effectively employ man-made infrastructure, in conjunction with natural features, to foster a whole-river system that provides a secure and clean water supply, more hydropower, better flood control measures and healthy habitat for local wildlife," says Colonel Andrew  J. “Coby” Short, who took over the helm as Commander at the Army Corps Pittsburgh District in July 2018.

People ride on a motor boat surrounded by water.
Allegheny River Research TNC scientists and partners study the Allegheny River, near the Kinzua Dam. © The Nature Conservancy

At 325 miles long, the Allegheny River is one of the healthiest rivers in the larger Ohio River system. Together with its tributaries—Conewango Creek, French Creek and the Clarion River—it covers more than 11,500 square miles in Pennsylvania and New York, including one of the Allegheny’s most densely populated reaches for freshwater mussels, including some that are rare and endangered.

Along with TNC, the Western Pennsylvania Conservancy, the U.S. Fish and Wildlife Service and the U.S. Forest Service participated in the October study. Specifically, in conjunction with the release, scientists used sonar to measure the shape of the river bottom to understand underwater conditions for fish and mussels. They implemented a similar study in Tidioute, approximately eight miles from the initial site, to gain additional information about mussel habitat along the river.

Releases from the Kinzua Dam influence almost 200 miles of the Allegheny River. Along with Kinzua Dam, the Army Corps of Engineers operates eight lock and dam systems on the Allegheny River and four other dams in the watershed.

“We don’t know what the bottom of the river looks like. By getting this new data, we can understand the river and the life in it, which will allow us to develop well-informed scientific models to guide releases and other activities that take place in and around the river,” said Brad Maurer, restoration engineer for TNC. “Significant populations of humans and wildlife depend on this river for water, power and habitat, so it’s important that we continue developed new methods to support natural flows.”

Surveying Mussels at Kinzua Dam In 2018, TNC partnered with the Pittsburgh District of the Army Corps of Engineers and the Western Pennsylvania Conservancy to survey the bottom of the Allegheny River. Using sonar, we measured the shape of the river bottom to evaluate and gain a better understanding about native fish and mussels.