How We Work

Ensuring Healthy Waters for People and Nature in Pennsylvania

Our work is organized around flow, fish and floodplains.

The flow of water through Earth’s rivers, lakes and wetlands has nurtured and sustained life since time began. Beneath the surface and along the shores, across floodplains and in wetlands, an abundance of life gathers wherever water is found. Water also nourishes our crops, provides fish to eat, powers our factories and carries goods to market. In our effort to harness our waters, we have disrupted the natural cycles that sustain life. Freshwater ecosystems and species are declining at an unprecedented rate.

The Nature Conservancy is working around the world to protect Earth’s most important freshwater resources. In Pennsylvania, that means focusing efforts on the globally significant Susquehanna, Delaware and Ohio River systems.

The Conservancy knows a healthy river is about the entire watershed, from headwaters to bay, including the river’s tributaries and floodplains.

In Pennsylvania, our freshwater conservation work is organized around three themes—flow, fish and floodplains—that combine attention to place with a whole river perspective. Together, these themes encompass three essential components of river conservation: how water moves through the landscape to create a river’s flow; how uplands and floodplains interact with the river to filter and “store” water, and how habitats connect to support fish and other aquatic life.

By looking at these river systems as a whole, the Conservancy is able to support thriving natural habitats as well as the human communities that rely on them.

Susquehanna River

The Susquehanna River basin drains more than half the state of Pennsylvania on its 444-mile journey from Otsego Lake, New York to the Chesapeake Bay and provides more than half the flow of fresh water into the Chesapeake, the most productive estuary in North America. More than 6 million people rely on the river for their drinking water and hydropower facilities in the basin provide 19 percent of the power in the watershed’s 13-state grid area. But accompanying water withdrawals and dams have created unnatural flow conditions, affecting stream habitat, migratory fish movement and, ultimately, the water quality of the Chesapeake Bay. The Conservancy is working to ensure that native species, such as American shad, and natural communities are sustained as the river provides for human needs.

Protection efforts include:

  • A Conservancy project helped the Susquehanna River Basin Commission revise its water withdrawal regulations to better address the habitat needs of fish, mussels and aquatic animals.
  • Several major dams on the lower river are currently renegotiating their licenses to include adjustments, informed by Conservancy work, that will improve downstream habitat and fish passage effectiveness—especially for American shad and American eel.
  • The Conservancy is working with Chesapeake Bay Foundation and Trout Unlimited to restore stream buffers that will improve water quality and brook trout habitat within the Chesapeake Bay watershed.
The Delaware River

Forming Pennsylvania’s eastern boundary, the Delaware River is the longest undammed river in the eastern United States and one of the last strongholds for migratory fish, including the American eel. The Conservancy is using science to understand how the Delaware River functions as a whole system from its headwaters in New York State to the Delaware Bay, and taking action to allow it to flow as naturally as possible.

Protection efforts include:

  • An extensive study on the flows needed to support fish, mussels and other aquatic animals will inform decisions about water withdrawals and reservoir releases.
  • A mapping effort to identify the forests, wetlands and undeveloped lands within the floodplain and river corridor will serve as a tool to protect natural floodplains and, thus, river functionality. 
The Ohio River

The Ohio and its tributaries are among the hardest working rivers in the state, with a network of 37 dams providing us with hydropower, navigation, water supply, flood protection, drinking water and world-class recreation opportunities. The basin’s waters, including those of French Creek—the most intact remaining watershed in the entire Ohio River basin—remain a lifeline for the most diverse fish and freshwater mussel assemblages in Pennsylvania. The Conservancy is striving to support a healthy ecosystem that meets the needs of people.

Protection efforts include:



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