Pennsylvania Watersheds at Risk: Ecological Degradation

One study in 2013 found that one fifth of the fracking wells in PA pulled water from streams with drainage areas under 100 km2 (38.6 mi2). This study found that further protections are needed for 3rd order streams and smaller, and requested that more stringent water withdrawal practices were adopted. We were motivated by this study to look at fracking withdrawals within watersheds containing small streams and from protected waters.

In this study, “Small Watersheds” are defined as watersheds containing no higher than 4th order streams because these are most at risk of water withdrawal harming the ecosystem. By looking at watersheds containing small ordered streams, we eliminate instances where small drainage areas contain large streams or rivers within their watershed, which is a caveat of using spatial water data.

There are 1,451 watersheds at the watershed scale (HUC 12) across PA. Of these, half (715) contain protected waters, classified as High Quality (HQ) or Exceptional Value (EV). These are protected under PA Code Title 25 Chapter 93 Water Quality Standards because they represent the highest water quality in the state and are supposed to be pristine and free from pollution. These streams were tested and permitted as having reached these designations as part of the PA Clean Streams Law. These protections require stringent considerations for point source and non-point source pollution to prevent degradation of high quality habitat.

By limiting harmful practices, designations are supposed to preserve already suitable habitats for sensitive, migratory, and rare species, including cold-water fish species. Two thirds of all HUC 12 PA watersheds (972) were Small Watersheds, with a mean drainage area of 75.7 km2 (29.2 mi2). Almost half of these Small Watersheds (470) are home to designated HQ or EV waters.