Sunday, January 11, 2015

PHL - The Water Isn't Fine, But It Is Getting Better...

The restoration of Schenley Park's aging grande dame, Panther Hollow Lake, has several components in play. For openers, PHL is in need of some immediate TLC, especially dredging and controlling the runoff from the hillsides that surround it, and those issues are at the top of the FOPHL's "to do" list.

Our lake lady could stand some cosmetic improvements, too, like signage, park benches, a picnic table or three and improvement of the walking path that girds its shores. In the long run, a convenient access point with park-and-walk ease is part of the plan, although claiming a spot by Phipps and hoofing to Lake Schenley via the Visitor's Center back steps is a straight-shot approach. Bartlett Street is another good entry, involving a 3/4 mile stroll to the waters. Still, a Boundary Street gateway would be ideal.

Steps behind the Visitors Center (credit: Jon Buckley)

The Pittsburgh Parks Conservancy has made their top priority water quality, and that's certainly a crucial step in restoring the Lake to its old glory. PHL was never exactly filled with Perrier; up until the eighties it was loaded with arsenic and lead, thanks to petrol runoff from the streets and the mill's soot dropping into the Hollow.

The good news: a Pitt Geology School study in 2012 found that lead and arsenic concentrations in lake sediments have decreased over the last several decades. But two major problems remain: sedimentation caused by runoff and a high e-coli count, as documented in a 2007 study by CMU's WaterQUEST program. Both are concerns that the PPC is currently addressing, particularly runoff issues.

The Conservancy has returned the stream beds to their original meandering courses and built retaining pools and natural "slow water" barriers, which help trap sediment. That's important; sediment carries pollutants, and the further upstream the gunk is deposited, the more time and space Mother Nature has to filter out the contaminants before they get to the lake.

PPC has also encircled the Hollow with rain gardens and infiltration ditches to capture runoff, notably along the Hollow Trail, the Golf Course and the Beacon Street meadow. With those interventions, a hard rain is stored as part of the water table and seeps into the lake rather than gushing into it, allowing the feeder streams to provide a steady flow to the lake instead of operating in feast-or-famine mode. It's also an effective method to cut down on runoff and sedimentation spikes.

Panther Hollow Run (credit: Pittsburgh Parks Conservancy)

The City's Public Works gang have also helped the cause by recently cleaning out the overflow gutter along the lakeside so that the water from storm events can be diverted rather than rushing, with its sediment load and flooding potential, headfirst into PHL.

The one issue that hasn't been tackled yet is e-coli contamination. The glen is home to plenty of wildlife such as deer, geese, ducks, squirrels and even pooper-scooperless pooches. They consider the Hollow to be their private loo, and you can guess where the waste gets flushed every time it rains. The Hollow also has a couple of century-old sewer lines that run beneath the lake area into a main at Junction Hollow. As of 2007, no smoking gun for leakage or back-up was found, but that's an issue that needs monitored, too.

There is no easy or obvious engineering solution for this problem other than putting critters in diapers and making sure that the pipes under the lake haven't sprung any leaks. The Conservancy provides periodic lake monitoring until a feasible technological work-around comes to light, and hopefully the PW&SA is doing its due diligence on the Hollow's pipeworks.

Where the deer and the antelope play... (credit: Rich Tenney)

So the lake waters have gradually been mediated to a degree. But it's been a painfully slow process, and we'd hate to see the patient die while waiting for the cure. The major players proved with the Nine Mile Run project that when there's a will, there's a way, and we'd like to see some of that urgency shown for PHL.

The FOPHL believes that while the watershed projects have been largely successful, it's time to focus on the main character, the lake itself. Cleaning the feeder system is smart long-term policy, but just part of the answer as long as runoff flows unabated into the lake crevasse.

Our short-term agenda is to have PHL dredged, restoring it to its usual 7-12' depth (it's half that now, at best) while removing at least a decade's worth of pollutants, and that requires municipal action. Stemming the hillside runoff is the other half of the equation. Additional trees, greenery and slow water engineering along the slopes bolstered by infiltration ditches at the bottom of the ravines should do the trick, and this job falls primarily into the hands of PHL's stewards (us included).

It's a rocky road; the Parks Conservancy has committed to a watershed first, lake last action plan while the City is struggling to find discretionary money for projects like lake dredging. But we feel quite strongly that PHL needs attention now, and hope to become the catalyst to draw some overdue lake love from its caretakers.

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