What did we accomplish?
Recently, one of American Rivers’ blog readers responded to a previous post about how dams are removed with remarks about how the 2009 removal of the Harmony Junction Dam forever changed Connoquenessing Creek. Let’s take a close look at what American Rivers and our partners accomplished by removing this dam.
The Harmony Junction area has a long history, beginning with the Harmonites, a religious sect that settled the area around 1800. They built a community along Connoquenessing Creek known even today as Harmony, and they constructed a dam and a flour mill on the creek. Sometime in the early 1900’s, the Harmonite Dam was submerged when a new, larger dam was built just a few hundred feet downstream. This new concrete dam provided water supply to the area, as well as hydroelectric power for the Pittsburgh Short Line Railroad.
In the mid-20th century, the concrete dam was abandoned for both water supply and hydropower, leaving Jackson Township responsible for the two dams. The new one was beginning to deteriorate and was contributing to local flooding. The old one was submerged at all but the driest times of the year. PA Dam Safety regulations require any dam, whether or not it is currently in use, to be inspected and maintained. If a dam isn’t providing a useful purpose (i.e., providing water supply or power) then there’s little motivation to spend money on keeping it in good repair.
While the two structures contributed to the industrial history of Harmony Junction and the Harmonite settlement, there is also the much older, rich history of the landscape. The history of Connoquenessing Creek predates the written history. Our current stream drainage pattern, of which Connoquenessing Creek is a part, emerged after the last glaciers retreated, some 10,000 years ago. The stream, carrying meltwater from glaciers, cut its way across the landscape, carving its channel to join the Beaver River. It flowed unimpeded, meandering to create wetlands and floodplains, for over 9,700 years until the Harmonites settled the area. They constructed a dam, one that changed the river’s flow pattern, created a pool that heated up in summer sun, and blocked native river fish from moving upstream to cool, rich spawning areas. The newer concrete dam only made the pool area larger and warmer, and increased the flood risk to local residents. This man-made infrastructure interrupted natural processes, altering millennia of natural history, disconnecting natural habitat, and negatively impacting water quality.
Indeed, the Porters Cove area sustained substantial flood damage during Hurricane Ivan in 2004, and subsequently, 43 flood-damaged residential structures were bought out through the Flood Risk Reduction program of the Federal Emergency Management Agency. Based on a visual assessment of flooding in 2010, equivalent to the 2004 event, less than 10 homes would have been inundated during Hurricane Ivan had the dams not altered the natural flow of Connoquenessing Creek.
Though dams create favorite swimming holes, they are incredibly dangerous. It is not the size of the dam that causes danger. Because of their symmetry, even small dams like those at Harmony Junction create treacherous currents that are nearly impossible for even the strongest swimmers to escape. For this reason, dams are known as “drowning machines.” Recently, a young swimmer was lost at a Pennypack Creek dam in Philadelphia, and in 2012, a jet skier lost her life when she was washed over one of the navigation dams near Pittsburgh. In the past three decades, five people have drowned at the Sunray Dam on Conewango Creek. If there were no known deaths at the Harmony Junction dams, then the community was unusually fortunate.
We accomplished a great deal at Harmony Junction. By removing the dams, we restored Connoquenessing Creek’s natural history and eliminated a significant public safety hazard. We reconnected habitat for resident fish, which need access to headwaters for spawning and rearing habitat just as much as migratory fish. Smallmouth bass fishing is better now that the creek has been restored, according to local anglers. In addition, we commemorated the cultural history of the dam by carefully salvaging logs and other artifacts, which are now being curated by the Butler County Historical Society, from the Harmonite Dam.
American Rivers has featured the Harmony Junction Dam removal project along with others in our recent documentary Restoring America’s Rivers. This video provides additional information about the benefits of dam removals in general, and about this project specifically.
Removing dams that are no longer providing a useful purpose is the single most important thing we can do to restore rivers for the benefit of nature and people.