Conowingo

Summer Rain and The Chesapeake Bay

I think we can all agree that water has been dumping into our local waterways and the Chesapeake Bay at an alarming rate this summer. Communities throughout the watershed have seen it with their own eyes, with major flooding events causing destruction of property and even loss of life. Maryland alone has experienced the rainiest and wettest year on record in more than a century, with 43 inches of rain falling in July through August. That is the most it’s rained since 1889. One begins to wonder just how much the precipitation has impacted the Chesapeake Bay.

Photo by Chesapeake Bay Program

Photo by Chesapeake Bay Program

One of the biggest impacts has been on the Susquehanna River. The Susquehanna, which starts in Cooperstown, New York, flows through Pennsylvania, and reaches the Bay in Havre De Grace, Maryland, is the Chesapeake’s largest tributary. The Susquehanna provides half of the Bay’s fresh water and this year river levels have risen to record highs, which in turn has caused major flooding. So much so that Exelon Power, the company that superintends Conowingo Dam and sits on the Susquehanna River, opened the dam’s floodgates multiple times to relieve the pressure building behind the dam. As a result, the dam unleashed nutrient rich sediment and pollution. In the past, the Conowingo Dam was able to hold large quantities of sediment, but the reservoir has reached its capacity, so nutrient and sediment pollution is now making its way over the dam. According to Exelon, the recent amount of debris has been the largest in 20 years. In a statement, Exelon said to have removed 1,800 tons of trash from behind the dam and are still cleaning. When the dam is opened, pollution flows freely down into the Chesapeake, carrying everything from garbage to tree branches and trunks.

In addition to nutrient and trash pollution, the increased water is causing an issue many may not have considered. As an estuary, the Chesapeake receives its fresh water from its rivers and salt water from the Atlantic Ocean. Due to the all-time-high fresh water flow coming in from its tributaries, the Bay has seen a decrease in its salinity. This can pose a threat to plant and animal life, like oysters and blue crabs, which can only tolerate or thrive in certain water conditions.

Photo by Matthew Beziat

Photo by Matthew Beziat

Huge rainstorms have proven time and time again how devastating it can be for organisms on land and under water. With heavy rainfall comes not only stormwater runoff but agriculture runoff as well; the single largest source of nutrient and sediment pollution entering the Bay. The excess of nutrients, such as nitrogen and phosphorus, that enter the Bay power the growth of algae blooms that block sunlight from reaching the underwater grasses. It robs the water of oxygen that plants and animals are dependent on to survive. The Bay’s underwater vegetation, where many blue crabs, fish and shellfish reside, is an indicator in determining the health of the Chesapeake Bay. Healthy underwater grasses provide food and habitat for animals, reduces shoreline erosion and improves overall water quality by slowing down the current and filtering sediment.

It will obviously take time for scientists to measure the full effects the rain has truly had on the Bay. In the meantime, let’s do all that we can to prevent any further damage from stormwater runoff by installing rain gardens, rain barrels, forest buffers, and implementing proper conservation practices. If you see trash, pick it up. It will end up somewhere it shouldn’t.  We can’t control the weather, but we can control our own actions.

Learn more about storm water runoff here.

Taylor Montford is the communications intern for the Choose Clean Water Coalition.

What's With That Damn Dam? The Conowingo Story

What is the Conowingo Dam?

The Conowingo Dam is a large, operational hydroelectric dam in the lower Susquehanna River near the town of Conowingo, Maryland close to the Pennsylvania border. As one of the largest non-federal hydroelectric dams in the United States, the dam has a surface area of 9,000 acres and a maximum length of 4,648 feet. Construction was completed on the Conowingo Dam in 1928 and it opened in 1929. The dam is owned by Exelon Corporation, an American 100 energy company headquartered in Chicago, Illinois.

Photo credit: Chesapeake Bay Program 

Photo credit: Chesapeake Bay Program 

How does it work?

Image Credit: WikideVega, Hydroelectric Power 2014

Image Credit: WikideVega, Hydroelectric Power 2014

The dam was built to generate electricity via hydroelectric power. When water from the dam passes through, propeller-like pieces called turbines spin. This then turns a metal shaft in an electric generator, which is the motor that produces electricity. The more water that passes through the dam, the more energy that is produced!

 

Why is the dam significant to the Chesapeake Bay clean-up?

Over time, the dam has unintentionally acted as a “pollution gate” stopping sediment (and attached pollutants) from going down stream into the Chesapeake Bay. However, at this point in time, the reservoir behind the dam is essentially full and is trapping smaller and smaller amounts of sediment over time. When the region experiences large storms that create strong floods, this scours the sediment and other pollutants behind the dam and sends them downstream into the Bay. Original estimates stated that the dam would not be at trapping capacity until 2030 or 2035, but the dam is approximately 95 percent full right now, and recent assessments have determined the dam is no longer stopping pollution at all.

The Susquehanna River flows south past Conowingo Dam, toward Havre de Grace, Md., on June 27, 2016. Photo Credit: Chesapeake Bay Program 

The Susquehanna River flows south past Conowingo Dam, toward Havre de Grace, Md., on June 27, 2016. Photo Credit: Chesapeake Bay Program 

This poses several significant problems to the Chesapeake Bay cleanup. First, the dollar amount that was considered enough to meet pollution reduction goals, around $19 billion, is not going to cut it. Second, even with full implementation of Maryland’s federally-required cleanup plan, it will not be enough to achieve water quality goals on its own. Because of this, Maryland is currently proposing to test dredge a small amount behind the dam to remove some sediment and determine whether this approach would help to improve the health of the Bay. Third, Pennsylvania is significantly behind their cleanup goals, but with the dam filling up, the Keystone State may be asked to do more. This issue may inevitably cause tension between the states about who is responsible for the extra pollution reduction because of the sheer cost of additional reductions.

You might be wondering what Exelon is planning on doing to support the removal of built up sediment and attached nutrients from behind the dam. The short answer is - nothing…yet. However, Exelon cannot operate the dam without a license from the Federal Energy Regulatory Commission (FERC). FERC's current license for Conowingo was issued in August 1980 and expired in September 2014; Exelon is currently operating on a temporary annual license. Exelon has filed an application with FERC for a renewed long-term license. This offers us a rare opportunity to require Exelon to reduce some negative impacts of the dam and support the health of the Chesapeake Bay.

From my perspective, the Chesapeake Bay cleanup was and will always be a team effort among all of the jurisdictions - Virginia, Maryland, West Virginia, Delaware, Pennsylvania, New York, and the District of Columbia – and the federal government. We need to come together as a community to determine the  most effective and least burdensome course of action; one that leads us to a cleaner rivers and streams flowing into a healthy Chesapeake Bay. 

Photo Credit: Chesapeake Bay Program

Photo Credit: Chesapeake Bay Program

What can you do?

President Trump’s FY2018 proposal to cut 31 percent of EPA’s budget would eliminate the Chesapeake Bay Program and the people who coordinate it. Considering the impacts of Conowingo, it is more important than ever to keep the cleanup on track, including the crucial federal investments that improve local water quality. Please contact your Member of Congress and tell them how important the Bay restoration effort is to you!

To learn more, please visit the Chesapeake Bay Program's website.

Chante Coleman is the director of the Choose Clean Water Coalition.