PITTSBURGH – When the rivers around Pittsburgh begin to freeze, a committee of experts assembles to respond.
Think of them as the “Avengers™ on Ice”, except instead of forming a musical about defeating intergalactic foes, the group strategizes how to overcome the impact ice can have on navigation.
Ice blockages at locks and dams can delay navigation and halt industrial operations and economies. Ice can have even more dangerous impacts when paired with rainfalls and rapidly rising waters. In 2018, ice buildup and high water caused six breakaway barge incidents that resulted in millions of dollars in damages.
“The most important thing is that we’re all communicating,” said John Dilla, the chief of the Locks and Dams Branch for the U.S. Army Corps of Engineers Pittsburgh District. “We’re able to share the most relevant information pertinent to any possible risk on the rivers.”
The Ice Hydro Committee meets every week, a gathering that includes the Pittsburgh District, the U.S. Coast Guard, the National Weather Services, the Waterways Association of Pittsburgh, and other navigation partners.
“Cold conditions, with snowmelt and ice on the mainstem rivers, can come together to create this cluster of treacherous conditions on the rivers,” said Megan Gottlieb, the water management unit lead for the Pittsburgh District.
The committee members are better equipped to inform their own stakeholders through their collaboration. Mariners benefit especially to prepare against ice impacts.
“I think, 20 years ago, you wouldn’t have this kind of interagency communication or willingness to share,” Dilla said, explaining that lack of communication would cause significant frustration and pressures on industries that rely on commodities to arrive by water.
“Now it’s wide open. We will share everything we have if it’s going to help somebody make a better decision,” he said.
The committee uses a digital monitoring system to track various data entries from weather forecasts, ongoing navigation reports, and even individual alerts they receive from the public. The group then distributes information further to their key stakeholders through additional communication channels and public notices.
“Mariners and towboat captains can plan better thanks to this information sharing,” he said.
Fortunately, Dilla said the ice risks have been mild so far this winter, but there’s still quite a bit of winter ahead, and not every locking facility is impacted the same. For example, three Allegheny River locks further north are already seeing ice chunks as thick as seven inches, while the ice closer to Pittsburgh is much thinner.
Dilla said the two key factors they watch are temperature and time. If the average temperature reaches below 22 degrees Fahrenheit over 24hours, it is as a strong indication that ice will form.
He also mentioned the Allegheny dams are fixed crest, which means water flows over the top. Therefore, large chunks of ice can keep floating along the Allegheny with minimal obstruction. But once ice reaches the Ohio River, most of those locking facilities have gated dams which stop ice from moving downstream and can cause a major backup.
“Ice that is one inch thick is not a big concern on its own. However, if the same ice begins to stack up, it can quickly build to the point of impacting operations,” Dilla said.
Additionally, he said ice stacking can create an iceberg that can become a big problem.
When ice floats become too large, lock operators pass them through the chamber to clear room for barges. Unfortunately, that can slow down navigation significantly, especially if the ice clogs multiple locks in a row.
Mark Ivanisin, who supervises lock operations on the Allegheny River, credits his lock operators and facility managers for keeping operations going throughout the year, especially in the winter when they fight the elements.
“I don’t know that I could get out every day and do what they do,” Ivanisin said. “They’re out there during the most adverse weather conditions. Even in subzero temperatures, they’re out clearing snow and chipping ice off the walls or conducting ice lockages to make sure chambers stay open.”
Ivanisin and Dilla said they appreciate the unified effort from all their employees and the district’s partnership with other agencies that has grown over the years.
“I appreciate everybody on the committee. When you’re on that call together, you start to understand how passionate everybody is about what they do. Just the way people take ownership of their piece of it and do it the best they can is phenomenal,” Dilla said.