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It’s not every day you see emergency rescue boats navigating Northeast Philly to rescue residents on the flood-swept streets like they did last week.
But maybe every few decades.
The massive flooding that befell the far Northeast and parts of lower Bucks County on July 13 was cast in various once-in-a-generation terms. Meteorologists called it a 100-year storm. Philadelphia officials went further. Citing the intensity of the rains, the city said Thursday the weather event was “in the range of what would be considered a 1,000-year storm.”
In the summer of 1982, the area found itself in similar straits.
Then, as now, “100-year-storm” was the most common headline. Those monikers are based on probabilities, experts explained. A so-called 1,000-year storm means it has a 0.1% chance of occurring every year. That doesn’t mean it couldn’t happen more often, and with climate change, the frequency is growing.
Ray Kruzdlo, senior service hydrologist at the National Weather Service in Mount Holly, said the tri-state region gets hit with two to three major flooding events a year, spread out across southeastern Pennsylvania, New Jersey and Delaware. Where the rains fall — and how fast — makes all the difference.
Typically, the short window of heavy rains like those in Northeast Philly, accumulating 6 inches in a matter of hours, can be the most dangerous. Certain amounts of rainfall can cause flooding even in the most porous parts of New Jersey.
“Even in sandy soils, we’ve had 10-inch rainfall and it can’t handle it no matter what,” Kruzdlo said.
The deluge of last week damaged more than a thousand homes and businesses, displacing hundreds of residents. In the city, more than 500 properties were affected. As recovery efforts carry on with the federal government stepping in to help, this might feel familiar to NE Philly residents over a certain age.
In June of 1982, it rained for nearly eight hours, with the sky dropping millions of gallons of water on parts of the city. Nowhere was hit harder than the Red Lion Village apartment complex along Byberry Creek.
A stream that flows into the larger Poquessing Creek, it’s the usual drainage route, but Byberry was no match for this event, and water poured over its banks and right into the residential complex.
The Red Lion Village apartments sat at particularly low altitude — so low that some residents on the ground floor reported “about 8 feet of water in their homes at the height of the flood,” according to the Philadelphia Daily News.
“The residents of Red Lion Village, in fact, were virtually guaranteed to be flooded at some point, even without 100-year-level rains,” the Daily News reported in 1982.
But the damage was no less devastating. As with this July’s deluge, pictures of rescue boats pulling people out of submerged buildings and rescuing dogs from the rain tides landed on front pages.
Other parts of Northeast Philly suffered similar wet shock. Hundreds were displaced. Two people died.
Rising sea level contributes to the possibility of damaging floods. Two years ago, Philly had one of the wettest winters in a century and a half, a National Weather Service spokesperson told Billy Penn at the time, with nine flood warnings issued in just six weeks.
So especially these days, massive flooding doesn’t necessarily mean it was a 100-year storm, or even a 1,000-year storm.
“The federal government as well as USGS has been getting away from calling it 100-year flood or rainfall events,” said NWS specialist Kruzdlo, “because it does cause confusion.”