Flood Prevention Could Include Converting Blighted Route 51 Properties Back To Forest

May 25, 2016

Saw Mill Run courses through the wooded valley of Seldom Seen Greenway in the southern neighborhoods of Pittsburgh on Monday, May 23, 2016.
Credit Matt Nemeth / 90.5 WESA

In 1910, Frederick Law Olmsted, Jr., then one of the nation’s foremost landscape architects, outlined a plan for Pittsburgh. It detailed his thoughts on how city leaders should handle development around Pittsburgh’s major roadways and rail corridors.

Olmsted’s take on the proposed Sawmill Run Valley:

“The Sawmill Run valley offers a park and parkway opportunity which should not be neglected until commercial development becomes a serious stumbling block to its realization. And Sawmill Run itself, when it is no longer used as an open sewer, will be an additional element of park value.”

But that vision of Saw Mill Run never came to be. Today, the stream winds beneath a busy roadway known as Saw Mill Run Boulevard, or Route 51, that’s lined with dozens of derelict homes and businesses.

Traffic races along Saw Mill Run Boulevard on Monday, May 23, 2016.
Credit Matt Nemeth / 90.5 WESA

“If you drive along Route 51, you will see a proliferation of used car lots. You will see much property that’s being used as boarded-up warehouses. You will see properties that basically there’s no other use for other than storing gravel and stone on,” said Lisa Werder Brown, director of environmental initiatives and projects for the Saw Mill Run Watershed Association.

 “We have allowed development to happen in places it probably shouldn’t have happened," she said.

Large tracts of impervious concrete surfaces along the floodplain can't absorb rising water during heavy rainfalls. The stream gurgles up, flooding homes and businesses and overloading the city's aging sewer system.

The waters of Saw Mill Run flow slowly beneath a railroad bridge near Route 51 in the Overbrook neighborhood of Pittsburgh.
Credit Matt Nemeth / 90.5 WESA

Saw Mill Run Flooding Is Not A New Problem

Flooding woes along Saw Mill Run were enough to prompt a 1996 federal government buyout of about 25 properties of a former South Pittsburgh neighborhood that no longer exists – Ansonia Place.

A nearby, primarily German neighborhood was abandoned decades earlier because of similar flooding. Now that area is woodland, part of the 122-acre “Seldom Seen Greenway” now owned by the city.

That rejuvenation is the crux of Werder Brown’s vision for most of the Saw Mill Run watershed: to remove any existing development and infrastructure that's abandoned or underused and return the land to the forest.

It’s not a pipe dream, she said. 

Land trusts elsewhere are starting to acquire properties that were previously developed, tear them down, remove their parking pads and convert them back to forest. That's an option for Pittsburgh, too, she said.  

Organizers of the Saw Mill Run Watershed Association say they want to buy out blighted properties along Route 51 and convert them to 'passive green space' such as this pathway in Seldom Seen Greenway on May 23, 2016.
Credit Matt Nemeth / 90.5 WESA

A Natural Solution To Historic Flooding Problems

The Saw Mill Run Watershed Association is working with the U.S. Army Corps of Engineers to identify which of the 1,000-plus blighted properties along Route 51 and Library Road it should try to buy first. Data collected include zoning information, property ownership, possible tax delinquency and proximity to existing green space.

“And the other thing the corps is looking at is hydrology – so, which areas would absorb the most water?” Werder Brown said.

When all that information is gathered, it will be processed through a 'matrix' that will sort it into a list of properties that the watershed association should try to buy first to make the biggest impact. Werder Brown said she knows some property owners might not want to sell, and that’s okay. This project would take place piecemeal over many years.

Once enough properties are purchased, they’d be turned over to the Allegheny Land Trust, which aims to keep plots of land in a natural state in perpetuity. Vice President of Land Protection and Capital Projects Roy Kraynyk said he’s eager to get started.

“This project needs to happen. It just needs to happen," he said. "If it doesn’t happen, it’s just going to get worse and be more expensive down the road.”

But Kraynyk warned that if people really want to solve the flooding problem in the Saw Mill Run valley, they’ll look beyond the floodplain, up toward the forested hillside properties.

“Is the zoning hearing board granting variances to allow someone to disturb steep wooded slopes that exacerbate runoff problems, flooding problems, so on and so forth?” Kraynyk wondered.

He said Pittsburgh and the smaller municipalities along Saw Mill Run must all play a role in protecting woodland properties in the floodplain and on the hillsides and keeping them healthy by removing invasive plants and vines. 

“If we start today, or in the near future, and just make an incremental change and start to eradicate the vines, in 25, 50 years, we’ll be in a very, very different place in terms of the urban forest health,” he said. 

The U.S. Army Corps of Engineers is expected to finish its study of properties late this summer.