Bags in the trees seem to whisper debris

Idon’t know where you go to see trash hanging from trees, but I have a spot in Pittsburgh to recommend. I can’t take any credit for the find. I saw a post from the Nine Mile Run Watershed Association about how the unusually high level of rain in recent years has wreaked havoc in and around our streams.

“For years, the accepted average amount of rainfall in Pittsburgh was 37.7 inches,” Brenda Smith, executive director of the watershed association, wrote. “But in 2017 we had 40.6 inches, and last year the total was an extraordinary 57.8 inches. This year, we are on track to exceed even that total, having already had 45.2 inches of rain.”

I like rainfall stats as much as the next nerd, but what really caught my eye were the photographs. Perhaps plastic bags and other trash hanging from trees should not be so compelling.

“Bags in the trees seem to whisper debris” is not something Maurice Chevalier ever sang about. Nonetheless, like a car wreck, it drew me.

I met Mike Hiller, assistant director of the watershed association, Thursday morning at what is perhaps Frick Park’s least inviting entrance. It’s hiding at the southern end of Regent Square, where a South Braddock Avenue

sidewalk seems to be heading under the Parkway East. It doesn’t get that far because some intentional debris is at the end of that walk, where Nine Mile Run pours from a large culvert.

It doesn’t take much rain to make “this is like a raging rapid of a bathtub right here,” Mr. Hiller said. Water can shoot from the culvert “with pretty tremendous velocity.”

Nine Mile Run flows west and then south, under the parkway to Duck Hollow and into the Monongahela River. The two- mile stream was nicknamed “stink creek” before its restoration by the U. S. Army Corps of Engineers between 2003 and 2006. Now a wetland habitat has been recreated in lower Frick Park, and Nine Mile Run went having almost no fish to nearly 30 varieties, from white suckers to smallmouth bass.

But the watershed is roughly 6 1/ 2 square miles, which include the streets of Wilkinsburg, Edgewood, Swissvale, Regent Square and Squirrel Hill. When people toss litter on those streets, that gets flushed into the storm sewers, then into Nine Mile Run, then the Mon, then the Ohio. Theoretically, some slob’s flotsam could even reach the Gulf of Mexico.

Ms. Smith wrote that in the more than 11 years she has worked for the association, conditions never have been worse in and around the restored stream, the only possible exception being a June 18, 2009, storm.

“This time, there is not just a single storm system to blame,” she said. “Instead, what you are seeing is a graphic manifestation of how climate change is impacting our region.

“It’s pretty simple. Warmer air holds more water vapor, and eventually that will find its way to earth as snow, sleet, rain or hail. And as anyone who hasn’t been living in a cave knows by now, our temperatures are getting warmer, both here in Pennsylvania and globally. Worldwide, the five warmest years on record were the past five years — and the 20 warmest occurred over the past 22. The warmest year on record for the earth’s oceans was 2018.”

Others will say these intense, prolonged downpours are entirely due to chance. Ten years from now we’ll have more data — and the same arguments. Nobody likes saying they’re wrong. But right now, even a tenth of an inch of rain can cause the run to overflow its banks, Mr. Hiller said. When that water ebbs, trash stays stuck in the trees and shrubbery lining the banks.

A lot of work went into restoring this stream. It was given a more meandering path to slow it down, rocks were brought in for the same reason, and the banks were planted to soak up more rain and stem erosion. The association also has sold or given away about 2,000 rain barrels in the watershed, diverting hundreds of thousand gallons of rainwater from the sewers each year ( alas, a relative drop in the Allegheny County Sanitary Authority bucket).

In comparison, not throwing trash in the streets wouldn’t seem to take much effort at all. Empty water bottles and plastic bags aren’t heavy. Yet litter continues apace. ( Feel free to sigh heavily here.)

Volunteers for a pop- up cleanup of the stream are meeting at 5: 30 p. m. Tuesday, Aug. 20, at the soccer field near the Lower Frick Park parking lot. It’s possible to avoid the water, but shoes that can get wet are a good idea. The association will provide gloves, trash bags and light snacks. There is, of course, a rain date: Aug. 21.