NORFOLK -- On the morning of February 23, 2004 the excitement around Fredericksburg, Va., was palpable – school children, dignitaries, and media from around the world converged along the Rappahannock River to watch an obsolete dam blow open.
Embrey Dam, which impeded the flow of the river for 151 years, had outlived its usefulness for generating power and was no longer needed as a supply of drinking water. It only served as a barrier to migratory fish trying to reach their upstream spawning grounds.
Norfolk District, U.S. Army Corps of Engineers partnered with demolition experts from the U.S. Air Force Reserves and a dive team from the U.S. Army for Embrey Dam’s controlled explosion, which was a real-world, joint training exercise.
Hal Wiggins, who works out of the district’s Fredericksburg field office, remembers the day the dam was razed.
“It was cold and clear with lots of people and excitement leading up to the breach,” Wiggins said. “There was a stage with dignitaries including [former] Senator John Warner.”
Many of the original project delivery team members have retired or moved on to other positions, but for those that remain, the dam removal is still a vivid memory of success.
“It was a great project; having grown up along the Rappahannock River I was happy to see the river flow free, finally,” said Betty Grey Waring, Norfolk District operations branch chief, who worked on the dredging portion of the removal project.
Life returns post dam removal
A decade after the blast, researchers observed migratory fish making a comeback in the headwaters of the Rappahannock and Rapidan River in the Blue Ridge Mountains.
According to a 2012 research report by the U.S. Geological Survey, American eel have returned to their once-natural habitat after the removal of Embrey.
“We’ve known that dams can have significant consequences for movement of shad and striped bass in large rivers, but what we learned in this study is that the effects can reach up into the smallest mountain streams,” said Dr. Nathaniel Hitt, a research biologist with the USGS in a 2012 interview.
According to Craig Seltzer, a retired Norfolk District scientist, the return of the eel meant validation for the dam’s removal
“While we understood that it was possible to return catadromous species -- fish that spend much of their lives in freshwater, but breed in ocean waters, such as the American eel -- to their freshwater stream habitats, we had no conclusive evidence that this could happen,” Seltzer said in a 2012 interview.
Lingering items remain
Though the dam’s removal marked the start of environmental healing for migratory fish, it has also illuminated the problem of sediment runoff and uncontrolled development activities up stream.
Just prior to breaching Embrey, the district removed 250,000 cubic yards of sediment that had collected behind the dam.
Now, the sediment continues to enter the river system upstream and collect downstream around Fredericksburg, below the fall line where the Rappahannock becomes a tidal estuary.
“Prior to removing Embrey Dam, we recognized that sediment had built up behind the dam and the dam was no longer holding back any additional material in the river. Suspended sediments were flowing over it downstream,” said Greg Steele, Norfolk District, planning branch chief. “What we are seeing today is a continuation of the sediment flowing downstream and falling out when the currents slow within the city limits, as had happened prior to the dam’s removal.”
Currently, there is no funding available to research the topic further or to develop a removal and sediment control project, but according to Steele, it doesn’t mean there is a lack of opportunity for future assistance.
“We continue to talk with our partners to identify areas for potential watershed opportunities in not just ecosystem restoration, but also flood risk management and navigation,” Steele said.
A great success
Experts considered the dam’s removal a success, and it demonstrated that the removal of outdated and unneeded dams has more benefits than leaving them in place.
“Having returned 106 miles of river to anadromous fish and other important aquatic species has proven to be a great accomplishment in helping to restore the biological community in the Rappahannock River and its tributaries,” Steele said.