Morrison Hershfield investigated and reported on the feasibility of the demolition and removal of the underpass and the drainage of a newly designed 109 Street at grade.      The detailed design for the demolition and removal of the underpass concrete structure and the drainage of the new alignment of the roadway was completed on time and schedule, and approved by the City of Edmonton.  Construction started four months later.

Within two months, the “Rat Hole” was completely removed from 104 Avenue to 105 Avenue, executed as anticipated and in accordance with Morrison Hershfield’s structural analysis.

 In completing this assignment Morrison Hershfield undertook the following:

• Prepared the feasibility report for using the underpass as a stormwater detention pond
• Produced preliminary design and pre-design report for the demolition and removal of the “Rat Hole” and its impact on existing utilities, traffic and business community and the drainage of the re-aligned 109 Street
• Provided detail design of the demolition and removal of the “Rat Hole”, the decommissioning of 109 Street Subway Pump Station, drainage and aboveground/underground utility relocation
• Conducted a building condition survey along 109 Street and adjacent to the “Rat Hole”, prior to and after the construction completion of the project
• Provided engineering services during construction in an advisory capacity
• Prepared as-built drawing record

The new alignment of 109 Street provided safe conveyance of traffic (through 104 Avenue and 109 Street), shortened travel time to downtown Edmonton, and minimized 109 Street road closure during major rainstorms.

The 5-million dollar project was completed three weeks ahead of schedule, ready for Edmonton’s summer activities.