16 January 2021

This winter Panther Hollow Lake in Schenley Park rose to flood level in late November, remained flooded for almost two months, and fell suddenly last week. Here’s the story of the rise and fall of Panther Hollow Lake.

Panther Hollow Lake, which is actually the size of a pond, was built around 1904 by damming the fresh water of Panther Hollow Run and piping its outflow into the buried combined sewer of Four Mile Run, the creek that used to receive it. Underneath Junction Hollow, the big pipe passes beneath a neighborhood called The Run on its way to the Monongahela River.

For decades that combined sewer pipe has been too small to handle heavy rain so sewage backs up in The Run, dangerously flooding streets and basements. In 2019 as part of the Four Mile Run Stormwater Project, a smart valve was placed in the lake’s outflow pipe to hold back fresh water during heavy rain events, then release it slowly after the danger passes. In this way Panther Hollow Lake rises and falls a little to protect the downstream neighborhood.

Normally the water level is low enough that the concrete-step edge is visible as shown at top left and on 19 Nov 2020 below.

But the valve malfunctioned or clogged in late November. By 25 November water was climbing the edge and by 4 December the lake was obviously flooded (top photo at right). An alternate channel kept the water from rising further but you couldn’t walk around the lake until someone beat a path above the water line.

On Wednesday 13 January I circumnavigated the still-flooded lake. The next day someone fixed the valve and the lake began to fall rapidly, cracking and levering ice around the edge.

Here’s what it looked like on Friday 15 January 2021, back to normal water level.

The ice was still settling and cracking when I stopped to record the sound last Friday. Listen to it pop and groan. You can also hear a Carolina chickadee and a song sparrow at the end.

Read more about the Panther Hollow Watershed and the origin of Panther Hollow Lake in this March 2018 blog by Krissy Hopkins: From Hill to Hollow The Evolution of Panther Hollow Watershed.

And, yes, a stream is called a “Run” in Pennsylvania, northern West Virginia, eastern Ohio and western Maryland. See how many names people use for the same thing: at: Another Name for a Run in a Hollow.

(photos by Kate St. John)

Note: Derek Watkins has a map of Generic Terms for Streams in the Contiguous U.S., generated from GNIS data, that shows the places where people use different words for Creek including: Branch, fork, run, brook, kill, stream, bayou, swamp, slough, wash, cañada, arroyo, rio. (map here) Watkins did not include regional pronunciations such as “crick” because the data he used from GNIS spells it “creek.”