4 minute read
Kinzua Dam
Warren, Pennsylvania, United States
Simulating spring pulses for ecological benefits. The Kinzua Dam is part of the National Wild and Scenic Rivers System and home to several threatened and endangered mussel species. The implementation of a “spring pulse” in March 2023 on the Allegheny River in northwestern Pennsylvania provided an environmental flow (e-flow) release that delivered ecosystem benefits for areas downstream of the dam. A collaboration between the U.S. Army Corps of Engineers (USACE)–Pittsburgh District, The Nature Conservancy, the U.S. Geological Survey (USGS), the University of Pittsburgh, and other federal and state partners, the spring pulse was the culmination of years of research into “flow targets” that mimic the timing, quantity, and quality of preimpoundment flow regimes. The e-flows provide numerous riverine and riparian ecological benefits, like supporting habitat conditions for vegetation, fish, and mussels; seed dispersal; moisture regimes; sediment distribution; and nutrient delivery. A recent rain event provided the volume of water of the spring pulse, which water managers used to model the pulse’s impacts to the Allegheny Reservoir and downstream reaches of the Allegheny River to ensure no detrimental effects were experienced by either. The increased flows produced by the spring pulse were observed and documented by multiple sampling efforts throughout the event.
Article Cover: The Kinzua Dam released roughly 425 cubic meters of water per second for 8 hours, resulting in 12 million cubic meters of water released into the river. (Photo by Andrew Byrne, USACE Pittsburgh District)
Producing Efficiencies
Implementing e-flows provides numerous ecosystem benefits with few additional costs to normal operations. By using existing information sources and technology, water managers can analyze incoming weather events and then model and account for the impacts on the reservoir and downstream river reach to decide whether a pulse event is possible within authorized reservoir operations. The operations that facilitate the e-flows provide benefits that improve ecosystem function, offer more desirable recreation resources, and contribute to the environmental health and economy of the surrounding areas.
Using Natural Processes
E-flows, such as spring pulses, restore ecological function to the river by reestablishing natural processes associated with more significant flows for sustained periods that were part of the natural flow regime before the construction of Kinzua Dam. As a result, e-flows provide numerous riverine and riparian ecological benefits, such as supporting habitat conditions for vegetation establishment and growth, seed dispersal, moisture regimes, sediment distribution, nutrient delivery, increased aquatic habitat and connectivity for riverine fish and mussels, and fish spawning cues.
Broadening Benefits
The social, environmental, and economic benefits of e-flows provide the natural disturbance necessary for healthy and aesthetically pleasing riparian and riverine settings that enhance social recreational opportunities like water sports, camping, and fishing. Environmental benefits and ecosystem services include more habitat opportunities for freshwater mussels that filter the water and increase clarity and the propagation of riparian plant species that buffer and still high-flow events and provide fish habitat and atmospheric oxygen. Economic benefits include making these areas more desirable locations for those seeking recreational tourism opportunities and providing cleaner water that requires less treatment for downstream uses.
Promoting Collaboration
Since 2014, the project has fostered valuable relationships and remarkable cooperation between federal, state, local, and public partners. Coordination between stakeholders at monthly meetings and workshops was critical in developing an adaptive e-flow management and monitoring plan. Collaboration with numerous stakeholders—among them The Nature Conservancy, the Sustainable Rivers Project, the U.S. Fish and Wildlife Service, USGS, the U.S. Forest Service, the Western Pennsylvania Conservancy, the Pennsylvania Fish and Boat Commission, the Pennsylvania Department of Environmental Protection, and the University of Pittsburgh—has been integral to the success of developing and implementing e-flow prescriptions and monitoring techniques.
