It took three years and $7.7 million to reverse a century’s worth of damage to Nine Mile Run, a tributary of the Monogahela River and the backbone of one of Pittsburgh’s historically beleaguered urban watersheds. For decades, industrial pollution from nearby slag piles had leached into the stream, while sewage and debris deposited by frequent stormwater events further degraded water quality.
“It used to be that this stream was basically just a straight shot to the Mon,” said Dave Carr, a volunteer with the UpstreamPgh’s Frick Park Urban EcoStewards program. “Water would just rush through here, and just take everything with it.”
By the time the U.S. Army Corps of Engineers was finished with it in 2006, the daylighted portion of Nine Mile Run in lower Frick Park had been transformed from a smelly, toxic drainage ditch into a meandering natural stream lined with native flora and replete with wildlife habitat. At the time, it was the largest watershed restoration project in the U.S.
A decade-and-a-half later, that massive investment has paid off. Water quality has improved and life has returned to the watershed — most strikingly, with the appearance last month of a beaver thought to have migrated upstream from the Monongahela. It’s at least the second beaver sighted in the area in recent years, and one of the most encouraging signs yet of an ecosystem gradually regaining its natural balance.
Happy Friday from @Pittsburgh’s Frick Park!
Meet “Castor” the newest park resident!
Beavers are a great sign of ecosystem health! And not to worry, your @PghPublicSafety Park Rangers are keeping an eye on this one!@radworkshere pic.twitter.com/YnzwDHkoMT
— CitiParks: Pittsburgh Parks & Recreation (@CitiParks) January 6, 2023
The presence of beavers, nature’s hydrologic engineers, can help make streambanks more resistant to erosion while countering the over-accumulation of vegetation in places where it shouldn’t be. But beavers are late to the party: Urban EcoStewards have been doing this kind of work, and more, ever since the restoration work concluded.
“Most of the things I’m doing now are with invasive plant species,” Carr said. The neighborhood resident and longtime volunteer has been battling poison hemlock along Nine Mile Run for years, and believes he finally has a handle on it.
Carr was with a group of EcoStewards at an October workday event in Frick Park, gathering data and tending to streamside maintenance needs under the supervision of UpstreamPgh’s Aaron Birdy. Birdy told us the original restoration work was critical, but it’s the ongoing efforts of volunteers that have kept the watershed on the path to recovery ever since.
“We have many dedicated volunteers who come out every week, or month, on their own time,” Birdy said, “to maintain the natural diversity and ecology that was established during the Nine Mile Run Ecosystem Restoration project back in 2006.”
The Urban EcoStewards program began as an initiative of the Nine Mile Run Watershed Association, which rebranded as UpstreamPgh in 2021, in partnership with the Pittsburgh Parks Conservancy and Allegheny Cleanways. Learn more about it here.