Effects of Hurricane Irene and Tropical Storm Lee

By TOM LEIGH and TIM JUNKIN Notes on the River
18 September 2011

Drenching rains from remnants of Tropical Storm Lee produced the second-largest water flows from the Susquehanna River into the Bay since Hurricane Agnes in June 1972. Flows from Agnes were measured at more than 1 million cubic feet per second. A major snow melt in 1996 caused a flow of more than 900,000 cubic feet per second. The peak flow from Lee was more than 750,000 cubic feet per second. This condition required that all of the floodgates on the Conowingo Dam be opened. Sediment, nutrients and bulk trash that had collected behind the dam for years were released into the Susquehanna.

These loadings comprise a direct injection of pollutants into the Bay. To add insult to injury, more than 500 million gallons of diluted sewage washed into bay waters in Maryland alone and an estimated 200 million gallons poured in from Washington D.C. In addition, runoff from farms awash in livestock manure and fertilizer containing nitrogen and phosphorous, and the flow from city and suburban streets, lawns, and rooftops contributed more nitrogen and phosphorous, as well as garbage.

These conditions create a pollution cocktail that produces the summer’s annual "dead zone," (this year the largest on record.) Dead zones (caused by algae blooms that feed on the excess nutrients) develop every summer and generally end in the early weeks of fall. This year Hurricane Irene caused a premature mixing of the normally stratified oxygen depleted and oxygen rich layers, essentially removing the dead zone at least temporarily.

A major concern, however, is that these recent events could cause a secondary dead zone to form, or perhaps produce one next year that will exceed this year’s record breaker. Eventually we will accurately gauge the impact of these storms, but what we must appreciate now and going forward is that our behavior is more to fault than that of Mother Nature. The majority of debris and pollution we see right now is a result of how we use land in Maryland and how our neighbors use it upstream. This underscores why it is so important that Maryland provide leadership to all of the Bay states in reducing pollution loads. The citizens of Pennsylvania and New York, after all, don’t enjoy the hundreds of miles of interlacing river and Bay shoreline as we do. They don’t benefit from the blue crab and oyster harvests; nor are their lives filled with the colors, textures, and magical music of the Chesapeake. If we in Maryland don’t set the example, don’t make the necessary sacrifices and provide the leadership required to restore our rivers, how can we possibly expect that the citizens of states with a less direct connection will do the same.

Another storm with another name will impact the Bay in the future this is inevitable. We can, however, reduce the impact by working hard to reduce the loadings from every source in the watershed so that the next onslaught will be less damaging to our efforts to bring about a Bay-wide restoration.

Tom Leigh is the Miles-Wye Riverkeeper and Tim Junkin the director of the Midshore Riverkeeper Conservancy (www.midshoreriverkeeper.org).