Don't blame the Conowingo Dam for Chesapeake Bay pollution
By Linda Church Ciocci
Aug 22, 2018 at 10:45 AM
Scientists from UMCES and St. Mary's College gathered grass from the bottom of the Susquehanna River, to see how grasses are faring after recently being inundated with floodwaters and sediment. (Kevin Richardson / Baltimore Sun video)
While hydropower‘s value proposition has not been at the forefront of most Marylanders’ minds, recent news around the Conowingo Dam has brought it front and center. Over a century of evidence shows hydropower is a primary driver of clean, renewable energy, and it is time to start recognizing its benefits to the electric grid and the environment.
Conowingo Dam, now in its 90th year, is the perfect example. Throughout its history, it has held firm through its fair share of extreme weather events. But the historic rains that recently caused widespread flooding across Pennsylvania and sent unprecedented amounts of water, trash and other debris surging down the Susquehanna River have put the dam at the center of a long-simmering debate over who is responsible for the pollution entering the Chesapeake Bay.
As another surge of stormwater and pollution flows down the Susquehanna River, requiring Conowingo Dam floodgates to open for the second time in weeks, Chesapeake Bay scientists are concerned about the potential impact on oysters and still watching closely for other impacts.
Recent news reports have wrongly cited the dam as a principal culprit. While blaming Conowingo is convenient, it is wrong and will just make the trash and debris problem worse.
Thoughtful state officials, environmentalists and other stakeholders who have objectively studied this issue know that dams don’t cause pollution or debris. On the contrary, if the Conowingo Dam didn’t exist, all of the same upstream pollution and debris would still flow into the Chesapeake Bay, except that it would do so faster and without any meaningful check.
The dam’s operators have voluntarily removed over 600 tons of debris from the waters around the dam this year alone. It is unrealistic and unfair to expect that Conowingo can hold the massive amount of debris and trash flowing down the 464-mile Susquehanna River and the 27,500 square mile watershed covering three states, especially during flood conditions.
During recent flooding, the Susquehanna River experienced 10 times the water flow for this time of year. The sheer volume of water required the dam’s owners, Exelon Generation, to open crest gates to deal with the high flows, just as the dam was designed to do under such circumstances. In short, the dam did its job.
While the clean-up continues, it’s time to have an honest discussion about the origins of the debris and pollution entering the Chesapeake Bay and how those factors are symptoms of the larger challenge. We need to address this now because, left unchecked, it will get worse because the factors causing this continue to grow, along with the increased frequency of flooding events.
The responsibility for the trash and debris rests with the upstream states. Solving this challenge will require a collaborative, multi-state effort to identify where pollution originates and take steps to stop it at its source. It demands the participation of ordinary citizens, environmentalists, civic groups, academics, corporations, elected leaders and other local organizations to play their part. Most of all, it requires science-based evidence, leadership and serious commitment from every level of government to continue cleaning up the bay and curtail upstream pollution.
After record July rainfall filled Chesapeake Bay waterways with trash and debris, Comptroller Peter Franchot said Maryland was "literally drowning in Pennsylvania’s trash." It's impossible to quantify how much of the detritus actually came down the Susquehanna River, but it was likely a lot.
Given the likelihood of more severe weather and the concern we all share for the health of the bay, it’s important that we begin this discussion with a clear understanding of hydropower’s contribution to preventing debris and pollution from entering the Chesapeake Bay, lowering greenhouse gas emissions and serving as the backbone of Maryland’s clean energy grid.
The Conowingo Dam provides 55 percent of Maryland’s renewable energy -- more than all of the solar, wind and other renewable sources in Maryland combined. It produces 1.6 million megawatt hours of electricity annually – enough to power more than 159,000 households for an entire year -- and prevents 6.5 million tons of greenhouse gas emissions. That’she equivalent of taking 1.2 million cars off the road.
The dam is also an important civic, wildlife and recreational destination. Its two visitor centers attract 250,000 visitors each year, including school groups, to learn about the local ecology. It offers recreational opportunities such as boating, hiking, fishing and eagle-watching, bringing tourists and economic investment to the region.
Blaming the dam diverts attention away from the real problem and hurts the important efforts by Gov. Larry Hogan and others to restore and protect the Chesapeake Bay. That’s a risk we cannot and should not take at a time when these efforts are starting to pay off, with the bay recently achieving its highest water quality rating in 25 years.
If we are going to maintain and accelerate this progress, it will take honest collaboration among everyone who lives and works near the waters that feed the Chesapeake Bay. We need to rise to the challenge. Looking for a scapegoat is counterproductive.