Time is Now to Get Facts Right & Act on Conowingo Dam

October 10, 2014 Update: New website launched to get the facts: www.ConowingoDam.org 

Lower Susquehanna Riverkeeper Michael Helfrich at Conowingo Dam
Lower Susquehanna Riverkeeper Michael Helfrich at the Conowingo Dam

Conowingo Dam is a large hydroelectric dam on the Susquehanna River, near the Maryland/Pennsylvania Border. The drainage area behind the dam is more than 27,000 square miles and extends to Cooperstown, New York.  Conowingo Dam is owned and operated for profit by Exelon Corporation.

Exelon’s current license for the Conowingo was issued on August 14, 1980 and expires in September 2014. They have applied for a new 46-year license from the Federal Energy Regulatory Commission (FERC).  They have also asked the State of Maryland to approve the license application (by issuing a Section 401 Water Quality Certification under the Clean Water Act).  This decision will affect the Chesapeake Bay for generations to come.

Conowingo vs. Local Water Quality

Some in Maryland are pointing to Conowingo as an excuse not to implement local measures to reduce stormwater pollution. Their reasoning goes something like this: “If the Susquehanna River is putting so much pollution into the Bay, whatever we do locally won’t make a difference.” That is simply untrue. While flow from the Susquehanna certainly is a major driver of water quality in the main stem of the Bay, local impacts are far more important to most rivers, creeks, and streams. Polluted stormwater runoff from developed areas and farm fields, failing septic systems, and other local sources contaminate our rivers, creeks, and streams throughout Maryland, resulting in toxic algae blooms, high bacteria leveals, and water contacts advisories.

Let’s not use Conowingo as an excuse – let’s use it as an opportunity. We now have a chance to act with the FERC relicensing process that won’t come around again for 46 years. If we can require Exelon to remove at least some of the sediment from behind Conowingo, and reduce the threat of a catastrophic event, we can enhance and secure our local efforts to reduce pollution and improve water quality. Addressing all sources of pollution is the only way we can make true progress in our fight for clean water.

Conowingo and Sediment

Over the course of its life, the Conowingo Dam has trapped nearly 200 million tons of sediment, nutrients and other pollutants behind it. This sediment consists of 85 years worth of upstream runoff from the Susquehanna River watershed, including everything from farm fields and construction sites to residential lands. The ability of the dam to store any more sediment is almost at capacity – it’s just about full.  What happens then?

When the dam can no longer store sediment, it will simply continue down the river and into the Bay. More importantly, during a tropical storm or other large rain event, the raging river flow over the dam can scour the sediment stored behind the dam. This can, as in 1972 with Hurricane Agnes, deliver a catastrophic amount of sediment to the Bay – far more than there would be in a big storm if the dam was not there. When too much sediment enters the Bay, it clouds the water, and impacts natural resources like oysters and underwater grasses. The nutrient pollution that accompanies the sediment will cause algae blooms and dead zones.

To adequately protect the health of the Chesapeake Bay, Maryland agencies and other scientists need more information to assess the impact of the sediment behind the dam.  A recent study by the Lower Susquehanna River Watershed Assessment left several unanswered questions. While scientists are conducting additional monitoring and modeling, some experts question whether this will provide sufficient information to allow Maryland to reliably protect the Bay during the largest storm events.

Provisions in the federal Clean Water Act give the state of Maryland a once-in-a-generation opportunity to require Exelon to meet state water quality standards.  If the scouring of sediment and nutrients from behind Conowingo Dam impairs water quality and causes damage to the Bay’s habitat and living resources, Exelon is responsible for fixing the problem.

Other Impacts

Conowingo Dam also severely impacts migratory fish species such as American shad and eel.  The construction of two fish lifts and previous programs to capture and truck fish above the dam have done little to address the mortality rates and migration problems.

There are also a host of other concerns to address in the re-licensing ranging from recreational areas and facilities, to boating safety, to optimal flow regimes for aquatic life.

Opportunities To Get Involved

On July 30, 2014, FERC issued the draft Environmental Impact Statement (EIS) for public comment. The purpose of the EIS is to assess the environmental and economic effects of continuing facility operations and (should) make recommendations for reducing negative impacts.  The EIS currently reflects virtually none of the recommended measures by Waterkeepers Chesapeake and Lower Susquehanna Riverkeeper, intervenors in the relicensing proceeding, that were included in our previous comments to FERC.  Comments are due on the EIS by September 29, 2014, and Lower Susquehanna Riverkeeper and Waterkeepers Chesapeake will be submitting comments.

Often, one of the most significant steps in the FERC relicensing process is the Section 401 water quality certification that Exelon must receive from Maryland. This section of the Clean Water Act allows affected states to evaluate the potential for dams to impact downstream waters and insert conditions in the FERC permit to protect those waters.  Maryland is currently requesting further information and study from Exelon prior to issuing the certification.  When issued, Lower Susquehanna Riverkeeper and Waterkeepers Chesapeake will comment on the water quality certification.