Contributed by Joy Bergey

As a respite from January with its many cold gray days, I think back to a warm, sunny morning in August when I had the pleasure of Jessica Slade’s company as she led a tour through the Arboretum’s lovely restored wetlands. Jess serves as the Arboretum’s McCausland Natural Lands Horticulturist, and oversees staff and volunteers in this important reclamation work. Here are my recollections of my summer day in the wetlands. 

The area has become a nursery for wildlife and important native plants.  Some of the species we observed that morning include:  

  • Buttonbush, a great pollinator plant for bees and butterflies,
  • Black willow, host to many benign caterpillars,
  • Speckled and hazel alder trees, which have a symbiotic relationship with nitrogen-fixing bacteria, giving them a special adaptation to soil that is usually wet, and
  • Black gum, which provides fruit for our birds, and brilliant red fall color.

At the wetlands, we saw painted turtles sunning themselves on fallen logs that poked out from the water. The pond also has snapping turtles and red-eared sliders. (The painteds and snappers are native.) Along with the expected deer, squirrels, and chipmunks, staff spotted a mink in 2017.

We heard the delightful croaks of bullfrogs, and saw many birds: tree swallows, a kingfisher, red-wing blackbirds, and several species of raptors.

The Arboretum staff actively manages the water level in spring and fall to encourage migrating shore birds to stop by and feed. Lowering the water level results in the creation of temporary mudflats, which stop-over species such as lesser yellowlegs and solitary and spotted sandpipers dig into for invertebrate meals.

Alas, there are plenty of invasive plants that Jess and her crew wrestle constantly to control: comfrey, with its seductively pretty pink flowers; porcelain berry (a relative of wild grape), reed canary grass, and of course phragmites, among others. (The cattails around the wetlands are native but are cut periodically to keep them under control.)


Project History

This emerging view in the second half of the 20th century was that water was best moved quickly on its way–out of sight, out of mind.  Civil engineers built culverts under roads and rerouted urban streams and creeks to rush through cement sluiceways along to the next waterway, where it was somebody else’s problem to deal with. Especially in the suburbs, water-absorbing lands were replaced with buildings, roads, and parking lots. Even the source waters for the Wissahickon were paved over, covered by the parking lot at Montgomery Mall.

But we’ve all paid the price as flooding and dangerous, rushing stormwater has increased over the years. All that water has to go somewhere, since it can no longer soak gently back into the land, refreshing the aquifers and springs that are ultimately the source of much of our drinking water.

Scientists have come to realize that it’s better to allow these natural buffers to exist, restoring floodplains whenever possible.  Severe storms with their raging waters are now increasing in frequency and intensity, thanks to climate change. Slowing down rushing waters running through the Arboretum, or even through a backyard, means the impact will be lessened on the next property downstream. Every restored wetland is important. 

If you live in this area, you’re likely aware of the dangerous flooding that can occur along the Wissahickon, and then along the Schuylkill River into which it flows, and even along the Delaware River, as the Schuylkill and other rivers dump their storm waters into it.

The Morris Arboretum has been on the leading edge of righting these unintentional wrongs (for example, installing pervious parking lots in 1986), recognizing the importance of slowing down water and giving it a chance to seep back into the ground. It was in 1997 that Aboretum staff started work to restore the lovely two-acre pond that now exists, helping to mitigate flooding.

Every waterway in this area ultimately flows into the Delaware River, and so we’re all living in the Delaware River Watershed. It’s a gift: 15 million people get their drinking water from the Delaware and its waterways. The Arboretum’s re-creation and care of Paper Mill Run helps contribute to keeping the Delaware River Watershed and its lands safe and clean.

The Arboretum is grateful to the U.S Environmental Protection Agency and the State of  Pennsylvania for providing funding for this restoration project, as well as the many volunteers (including twelve from the EPA) who helped with the initial plantings.

The next time you visit the Arboretum, take a stroll around the wetlands. It’s an easy walk from the lower meadow, with lots to see every time of the year.