Sediment is pouring into waterways like the Northwest Branch River in Montgomery County, and much of it may end up in the Chesapeake Bay.
Hurricane Sandy's effects will not be limited to residents and real estate on dry ground. As much as 4,500 square miles of Chesapeake Bay will be affected by the hurricane as well.
People who live along the shore will be able to see the effects pretty easily.
"We're going to see a lot of extra trees, stumps, trash working its way into the bay," says Rich Batiuk with the Environmental Protection Agency. "You'll see a lot of mud, a lot of debris, people will see things coming up on their shore lines."
Other impacts won't be so obvious.
"The main risk is due to the heavy rain fall and the possibility that the Potomac and the Susquehanna will have floods that bring a lot of sediment and nutrient pollution down into the bay," says Don Boesch with the University of Maryland.
Sustained rainfall can scour years of sediment into the bay, which could suffocate oyster reefs that the state has spent millions trying to restore. Whether it happens this time, says Boesch, depends on how long the storm lingers over Pennsylvania.
That's not the only thing that could hit the oysters either. Torrents of fresh water may reduce the salinity of the water, which can
kill oysters if it lasts too long. It's unlikely that Sandy will be as
destructive to the bay as Hurricane Isabel in 2003, but nutrients washed
into the bay could spawn algae blooms in Spring and, if the storm
lingers, sediment carried in could suffocate oyster reefs.