PennDOT’s Bureau of Public Transportation (BPT) hired NTM Engineering to perform a drainage study in the area of proposed improvements to the Keystone Corridor railroad station, in the Borough of Mount Joy. The study’s goal was to identify project effects on runoff to the railway and to evaluate runoff mitigation alternatives. The proposed project entails constructing two 500-foot-long, high-level railroad passenger platforms within the Amtrak right-of-way, a covered pedestrian access connecting stair/elevator towers on either side of the tracks, and two surface parking lots.
NTM reviewed stormwater calculations; utilized SWMM software to investigate the practicability of taking stormwater runoff from East Henry and West Henry Streets that currently drain into Amtrak’s right-of-way and rerouting it through the Borough’s storm sewer network; determined an innovative solution to reduce stormwater runoff utilizing the HydroCAD software; evaluated drainage design alternative concepts; and provided improvement recommendations.
NTM considered mitigating any peak flow increases caused by the project to ensure compliance with the Borough’s stormwater ordinance and Amtrak’s Engineering Specification No. 150 – Stormwater Management Policy. NTM recommended incorporating low impact development practices into the site design to reduce the site’s peak discharge rates and to minimize future flooding risks and damage to Amtrak facilities.