The Schuylkill will crest to 20.6 feet tomorrow at 8 a.m., the highest point the river has reached since 2006, according to the National Weather Service. Heavy flooding is expected in the area.
Sergeant Charles Swan of the Whitemarsh Township police department said the damage from the surge should be limited mostly to Elm Street.
"Along the river, we've already notified residents who live on Elm Street. The Spring Mill Fire Company passed out fliers to residents warning them about what could happen and what to do. In Whitemarsh that's about it. Roads are going to be affected and office buildings, but [the office buildings] are built high enough that the water shouldn't cause much damage," said Swan.
The sergeant said that—in addition to Elm Street from Conshohocken to Whitemarsh—Washington Street, River Road, Harts Lane, and Manor Road might be compromised by the surge.
He added though that, in the mind of the police department, the biggest concern isn't the Schuylkill surge, but the threat of continued heavy rainfall tonight.
"At this point a heavy downpour of rain is what we're watching. When the Wissahickon Creek comes up over the road, if we don't have cops on Bethlehem Pike and Germantown Pike, they're not getting there," said Swan. "It could cut the town in two."
According to the Washington Fire Co., the Army Corps of Engineers is releasing water to relieve pressure on Berks County's Blue Marsh Dam. This will cause a 20.6 feet water level in Whitemarsh by 8 a.m. Friday—higher than the Irene-caused surge.
According to the Army Corps of Engineers website, the dam is 1,775 feet long, 98 feet high and can hold up to 16.28 billion gallons of water. It is located outside of Reading.
Stay with Patch for updates.