BETHLEHEM TWP., Pa. – A proposed stormwater flood mitigation plan in Bethlehem Township could cost between $11.8 million and $18.2 million, according to the township’s stormwater engineer.
At Monday’s Bethlehem Township Commissioners meeting, David Petrik presented potential solutions for the municipality’s longtime flooding issues, focusing in on eight main areas in the township. Township officials will now mull over the presentation and decide how to proceed.
There were two recommended options for William Penn Highway and Ohio Street. The first, at a cost of $390,000 would extend a storm main from Ohio Street to the Northampton Country Club. That plan would require approval from PennDOT since William Penn Highway is a state road.
“This would also require an easement from the Northampton Country Club,” Petrik said.
Commissioner John Merhottein asked how likely it was that the Northampton Country Club would approve an easement.
“They use some of the water for irrigation,” Petrik said. “It would be a process to say the least.”
The second option for William Penn Highway and Ohio Street would cost $600,000. It includes the same recommendations as the first option but would also include perforated pipes and open bottom inlets to improve volume control.
One issue, however, Petrik said, is that the area has many karst formations which cause concern about potential sinkholes.
“The trenches would need to be lined, which adds considerable expense,” he said.
Recommendations for Sculac Road and Wilson Avenue call for replacing the existing culvert with an underground pipe system and replacing the outfall to the Lehigh River. That plan would cost $500,000.
Another option would call for the same changes but add the use of corrugated metal pipe for cost savings. That plan would cost $400,000. However, the report found that corrugated metal pipe has a much shorter service life than other alternatives. Also, the pipe would not have much cover due to the proximity of the Lehigh River, Petrik added.
Recommendations to Chetwin Terrace call for the construction of a $3.5 million stormwater collection system throughout the neighborhood.
“This would require further improvements and possible easement to be made downstream,” Petrik said.
According to Petrik since the neighborhood was constructed in the 1950s, further investigation would be needed to ensure no problems are created downstream.
An alternate $4.5 million plan would include the use of perforated pipes and the installation of rain gardens.
Plans for Blue Grillhouse and ABE Auto Salvage call for replacing the trunk line in front of the eatery and the creation of a new conveyance system down Farmersville Road. That plan would cost $450,000. However, it would need approval from PennDOT since it lies on a state road, officials said.
An alternate, $600,000 plan calls for the decommissioning of the existing pipe running under the ABE salvage yard and replacing the trunk line main in front of Blue Grillhouse.
Plans for Walnut and 10th streets call for a $1 million upgrade that would discharge stormwater to Nancy Run through a system of pipes, roadway swales and culverts. However, Petrik said the plan would require a right of way on both sides of Walnut and Turner streets.
Work on Santee Road, Sunset Drive and Easton Avenue would cost $4.7 million and would be dependent upon a collaboration with the township and the city of Bethlehem. Plans include new retention storage to limit flooding on Easton Avenue.
Finally, on the list of eight identified main areas of concern was Willow Park Road. The $1.4 million plan calls for the installation of semi-permanent deployable flood shields on repeatedly impacted properties. Additionally, plans would require the removal of decommissioned bridges on Nancy Run to provide streambank restoration. However, Petrik said, this could require the cooperation of property owners.
Alternate plans call for the purchase of 10 private properties along Willow Park Road identified as “chronically flooded.” This proposal would cost the municipality $6.3 million.