50 Years Ago Agnes Set Benchmark For Worst Eastern U.S. Flood On Record

Elmira, New York during Tropical Storm 
Agnes flooding, June, 1972

At this point 50 years ago today, the Middle Atlantic States were just beginning to pick up the pieces of what was easily among the worst floods the region had ever experienced.  

The culprit was ex-Hurricane Agnes, an early season tropical system that seemed like not that big a deal until it got halfway up the U.S. East Coast.

Agnes dumped up to two feet of rain on eastern Pennsylvania. The storm killed 128 people - 48 in Pennsylvania alone.  More than 115,000 houses were destroyed or damaged, and more than 360,000 people were forced to evacuate.

It was at the time the most expensive tropical storm in U.S. history.  That record would stand for more than a decade.

Tropical Storm Agnes was more proof that a hurricane need not be strong to unleash havoc. And, former hurricanes can stir up major trouble long after the winds associated with them have died down.   

The spring of 1972 had been wet in the Middle Atlantic region.  That primed the pump for what would happen next. 

Hurricane Agnes splashed ashore as barely a hurricane on June 19,1972.  It caused the usual damage from storm surges, and spun off a couple dozen tornadoes that damaged at least 2,000 structures.

As tropical systems do after landfall, Agnes weakened quickly and the worst seemed over. However, the stage was being set. A cold front over the Great Lakes pulled in some moisture from Agnes, prompting more heavy rains ahead of the main show. That was enough to completely saturate the ground ahead of the main show.   

Which was a bit of a surprise. 

When tropical storms moves off the Southeast Coast, especially early in the hurricane season, they usually continue on to the northeast, out to sea, no longer being a bother to anybody.  Agnes, though, got pulled northwestward by a trough of low pressure pushing southeastward from the southern Great Lakes through Ohio and into Virginia.   

Then, there was nothing coming in from the west to push the remnants of Agnes out. It sat and spun pretty much over Pennsylvania and southwestern New York and just rained itself out. 

With such a wide area receiving 8 to 15 inches of rain, with, as noted, amounts up to two feet, rivers went on a rampage. 

Ground zero was the Susquehanna River, especially around the State Capitol of Harrisburg and the city of Wilkes-Barre. The river crested at 32.8 feet, a full 15 feet above flood state. Of that $3.1 billion in damage from Agnes, $2 billion of that was in the Susquehanna River basin. 

The areas around Corning and Elmira, New York were just as hard hit.  

That water was unbelievable. At the time, I remember news footage of people shoveling mud left behind from flood waters out of second floor windows. 

Flood control efforts since Agnes has spared much of the region from similar or worse storms than that 1972 deluge. Flood walls were raised substantially along the Susquehanna River.  

As the Washington Post notes, Tropical Storm Lee in 2011 caused a crest along that river at Wilkes-Barre even higher than that of Agnes. But flood walls installed after Agnes spared that city and Harrisburg from too much damage.

Other towns aren't so lucky. In the age of climate change, deluges like that from Agnes become more likely. 

Ellicott City, Maryland was devastated by Tropical Storm Agnes floods in 1972.  Turns out that was just a preview of what was to come a few decades later. Six big floods followed in Ellicott City after 1972, including two even stronger inundations in 2016 and 2018. (Just on Wednesday, Ellicott City narrowly escaped another big flood).  

I also recall at the time that Agnes gave Vermont a good scare. Many forecasts had it moving further north and east, putting the Green Mountain State in a huge flood danger But, as we know now, Agnes set its sights on Pennsylvania, southwestern New York and other states in that region.

Since it had been quite a wet month in the Green Mountain State, we were lucky that the rains from Agnes weren't that bad. We only had a few tropical showers in Vermont from Agnes.  Rutland  and Burlingtom ended up picking up about an inch of rain over three days from Agnes. Woodstock got about 1.5 inches of rain.

Vermont's turn for severe flooding would come just a year later. On June 30, 1973, after a wet month, up to 7.5 inches of rain poured down on central and southern parts of the state, causing one of the worst floods in history. 

Record or near record flood crests hit the Black, Ottaquechee, White and Ompmpanoosac rivers. Total flood damage in 1973's Vermont flood was $64 million or $421 million in 2022 dollars.  

Videos

This video is pretty cheesy, but still gives you a glimpse of how bad Agnes got in Pennsylvania's Wyoming Valley.  Click on this link if you don't see the video image on your device:

Some good still pictures in this vide of the flooding from Agnes in Pennsylvania. Click on this link to view, or see below: 

Super 8 mm footage of the flood and aftermath of the Agnes flood around Wilkes-Barre, Pennsylvania. Notice the mud lines up to the eaves of single floor houses in some neighborhoods. Click on this link or view below: