Conowingo Dam is shown during Hurricane Sandy in 2012. Controlled daily releases of water have more adverse impacts downstream than do storms, Garrett Pensell says.
Conowingo Dam is shown during Hurricane Sandy in 2012. Controlled daily releases of water have more adverse impacts downstream than do storms, Garrett Pensell says. (RECORD FILE PHOTO, The Record)

Havre de Grace resident and Tidewater Marina owner Garrett Pensell attended the May 5 congressional hearing on the Conowingo Dam relicensing. He shares his thoughts about the relicensing and the dam's effects on the downriver ecosystem, economy and public safety.

Conowingo Dam's relicensing process thus far has effectively been carried out behind closed doors. The antiquated requirements for public notification have proven once again to be woefully inadequate in generating any meaningful level of local citizens' input.


Last Monday's Congressional field hearing was, unfortunately, more of the same. One tiny, non-ADA accessible conference room was stuffed beyond capacity with politicians, bureaucrats and their fleet of assistants and PR representatives. There were but a few local citizens present, most of whom could be found crowding together just outside the doorway. Public comment was not invited at this particular hearing.

As such, it should be no surprise that there are significant local issues which are barely a part of the discussion. The issue of sediment coming over the dam may warrant receiving the lion's share of attention, debate and study, but it is far from being the only one. It is, however, quite likely the most expensive issue to address.

The daily cycling of water flow levels is the most important and persistent issue directly affecting the local economy, public safety and the natural environment. One glance at the NOAA stream flow graphs at Conowingo nearly always reveals a dramatic sawtooth pattern.

Exelon is only bound to adhere to a very low minimum flow requirement, and it is only applicable during part of the year. As a profit-seeking enterprise, Exelon uses that to its maximum extent, turning the water "on" when they can sell it at the highest possible rate and "off" when they can't. In the warm season, this generally translates to minimum flow levels at night and much higher flows during the day, when our air conditioners are working hard and power is selling at a premium.

The plants and creatures that live downstream of the dam have evolved over many thousands of years to adapt to large changes in seasonal flow. They are quite capable of surviving and thriving during the many floods we face. However, they are not equipped to deal with the random and dramatic daily variations they are facing today.

Although it is rarely discussed, this undoubtedly adds greatly to the well-documented stresses on the populations of shad, herring, smallmouth bass, American eels, map turtles and other fish and amphibians. The most significant local fish kill in recent memory was a school of the protected river herring believed to have been trapped in a rocky pool and suffocated when the flow rate was suddenly reduced. Historically, there have been a number of such events, some of which directly led to establishing the minimum flow requirements during the 1960s.

The impacts of Conowingo's routine daily water release practices on boater safety and the local tourism economy have also been largely ignored. Currently the only available information for the public on future water flow levels is calling the "Conowingo Spill Hotline" (888-457-4076). In today's information age, this "system" is embarrassingly archaic. It is updated once a day at roughly 5 p.m. and only provides a loose "forecast" which covers the following 12 a.m.-12 p.m period.

So, let's say you want to plan a trip on the lower Susquehanna for tomorrow (forget about two to three days hence). Sorry, you will have to wait until after 5 p.m.-ish to get a projection of what you might expect. Going out for a quick paddle or fishing trip after work? You better make sure you call before 4:30 p.m. or you won't have any clue if the water flow will be doubled or cut to nothing while you are out in the middle of the river.

This would all be bad enough, but the accuracy of these "forecasts" leaves a great deal to be desired. I have spent many years comparing these recordings to personal observations as well as the USGS and NOAA stream flow data. The only thing consistent is the inconsistency. I have usually had better luck ignoring the recording, looking at the graph from yesterday and presuming that the next day will look somewhat similar. As if all this weren't enough, Exelon steadfastly refuses to update the "hotline" when their plans change during the current forecast period. Is this really too much to ask?

Anecdotally, the majority of boating rescues and accidents above Port Deposit have occurred as a direct consequence of unexpected rapidly-rising water flow. There are countless tales of anchors getting stuck, boats getting flipped, pinned on rocks or swamped, or paddlers unable to get back to their put-in location. These accidents could be eliminated or greatly reduced.

If you take a look at the NOAA stream flow graphs a bit further up the Susquehanna (Harrisburg, Pa., for instance) you will see some interesting contrasts.

Not only are the flow rates gentle curves, following the natural drainage pattern of the river basin, but you will also see that there are projections for the flow that run three full days toward the future. Why can't the same be provided at Conowingo?

The only rational explanation is that the daily flow pattern at Conowingo is manipulated to its maximum extent in order to play the energy and financial markets. I believe we should insist on a more natural, predictable river flow pattern, real time reporting and at least the same three-day projections that our upstream neighbors currently enjoy.

If we can't avoid some daily cycling of flow rates, at least we might be able to raise the minimums or set a percentage limit on the variation per 24 hours. The benefits to our local ecosystem, boater safety and tourism will far outweigh the costs of selling a portion of the kilowatts at non-peak hours.