Who’ll Stop the Rain: Green Infrastructure in Schenley Park

Big, green things are in the works in Schenley Park and the Panther Hollow Watershed.

If you’ve been near Bartlett Playground in Schenley Park lately, you might have seen some of our progress on a nearby hillside, which right now looks a little like

woz-leavingkansas

Soon, though, the area will look something like

Is that the Cathedral of Learning off in the distance?

Instead of a field of poppies, though, a lush, textured, and completely native meadow will be springing up this summer. The meadow will be replacing a swatch of non-native, monochrome grass as part of a larger effort to revitalize the Panther Hollow Watershed.

You may be asking yourself: Why remove a field of grass? Doesn’t grass absorb rainwater, keeping it out of our sewer system?

Answer: Yes and no. Grass does absorb a bit of rainwater. But with its shallow roots and often compacted soil underneath, it can almost as hard as a slab of concrete for water to penetrate. On this hillside between Bartlett and Beacon Streets, towards the upper sections of the Panther Hollow Watershed, we see a stellar opportunity to reduce environmentally-taxing maintenance (read: mowing), establish a walking path, and capture rainwater in the ground rather than having it run right into our sewer systems.

bartlett before

The grass to by phased out between Beacon and Bartlett Streets

bartlett after

A concept drawing of what this area will look like after, complete with wildflower meadow and walking path

Like many older cities, Pittsburgh has a combined sewer system in which both stormwater and sewage flow in the same pipe. The system is prone to overflows, with rainfalls greater than ¼ inch triggering large quantities of untreated sewage to discharge into our rivers. By increasing the amount of water retained in the soil throughout the watershed, we’re keeping rainwater out of the park streams and City sewers. This project is the first stage of a plan to reduce the volume of water flowing through the watershed.  This summer and fall, infiltration trenches and berms will be created along the street. Combined, these projects will remove an estimated 1.7 million gallons of water from the combined sewer system.

As the grass on the hillside along Beacon Street dries out, we ask that everyone stays on the marked path so that the meadow seedlings have a chance to really take hold. The seed mix that we’re using can handle the foot traffic anticipated for the Vintage Grand Prix. Until then, excuse the look of this meadow-in-progress and look forward to a ‘low-mow’ biodiversity magnet and an overall green improvement in Schenley Park!

This project is done in collaboration with the Allegheny County Sanitary Authority (ALCOSAN), Pittsburgh Water and Sewer Authority (PWSA), and the Department of Public Works (DPW).

Thank you to the generous funders who are making this project come to life. We’d like to thank Allegheny County Conservation District, Dominion Foundation, Western PA Conservancy, Foundation for Pennsylvania Watersheds, and The Pittsburgh Foundation for their support!

Four Unsung Spots #1: Schenley Pool Meadow

We’re starting a new series on the blog today called Four Unsung Spots in the Parks. These are places in our park system that either get a lot less traffic or that people might have overlooked on their regular hiking or biking routes. We’ll do a spotlight on one place in each of the four regional parks over the coming weeks, so check back often!

Coming up with an “unsung” spot in Schenley Park is fairly difficult, because Schenley isn’t really the park you visit when you’re looking for some genuine solitude.  But I thought I’d shine a spotlight on one of the Conservancy’s lesser-known projects of the past few years, a huge patch of wildflowers known as the Schenley Park Pool Meadow.

Before and After: the lawn in 2006; a summer evening in 2008.

Before and After: the lawn in 2006; a summer evening in 2008.

The meadow is pretty much where you’d expect–right past the fence that borders the swimming pool.  Like a lot of our meadow sites, it was previously used as a lawn before the Conservancy created the meadow in 2007.  Here are just a couple of reasons we love meadows as opposed to lawns:

  • Meadows are beautiful to look at and provide visual interest for park users.
  • Meadows increase the park’s overall biodiversity by introducing many different native plant species into the park and providing habitat for insects, birds, and other wildlife.
  • Lupine

  • Meadows require a lot less maintenance than lawns, which require frequent mowing.  Because the plants in meadows are native to Western Pennsylvania, they have adapted to the weather conditions of the area and grow well with little assistance from us.
  • Meadows soak up a lot more storm water, reducing flooding and erosion in the park.  Our rule of thumb is to look at how tall a plant is and estimate a 1:1 relationship between its height above-ground and its depth below-ground.  Imagine how small one blade of grass is compared to a big black-eyed susan.  Now imagine how much deeper the black-eyed susan’s root system is, and therefore how much more water it can soak up.

And this meadow will hopefully eventually have the added benefit of providing a natural cover for the graffiti that’s all over the wall under the Charles Anderson Bridge.

Volunteers Grace and Beth battle the horseweed.

Volunteers Grace and Beth battle the horseweed.

With any new project comes a set of challenges, though, and the pool meadow’s chief menace has been horseweed.  Although it’s native to the U.S. and not as noxious as some of our enemy plants in the forest, it spreads easily via many windborne seeds and thus is not the kind of plant you want competing with your other meadow natives.  With the help of some of our reliable volunteers, we’ve cut the horseweed population lower each year, and hopefully that’s making it easier for the other plants to grow.

And there’s lots of great plants to see: in the springtime, wild lupine sends up purple stalks, and July brings an explosion of bergamot and ox-eye sunflowers that gives way to black-eyed susans in the fall.  Every year I come across something new and unknown and find myself doing image searches when I get home to try and ID the latest mysteries.

The Schenley Park pool officially opens this weekend, so when you’re done taking a dip, stop off by the meadow and take a look.  (In July you won’t be able to miss the show, but its charms are a little more subtle right now!)  Then check out Wildflowers of Western PA for help identifying all the cool flowers you spot in the meadow!