6.3 Utility Considerations

The infrastructure improvements associated with the PAR construction included the relocation of a 500mm gas distribution main to along the south side of the PAR, immediately adjacent to the proposed Broadway Drain corridor. This necessitated that the adopted channel cross-section be designed in a manner that would ensure a stable north channel bank, and prevent long-term erosion, oversteepening and recession of the north channel bank.

6.4 Property Considerations

In June 2015, after a preliminary design for the Broadway Drain improvements had been prepared, the WDBA received a directive from the Minister of Transport that restricted any of the proposed works from physically impacting Windsor Port Authority (WPA) lands. The preliminary design would have resulted in a slight encroachment of the south channel slope onto WPA lands.

This directive necessitated the redesign of an 89m segment of the Broadway Drain from a trapezoidal earth channel to a retained, rectangular steel-lined channel section. This served to reduce the top width of the channel and achieve the newly-prescribed design constraint. Further details are presented in Section 6.7 of this report.

6.5 Outlet Considerations

As previously noted, late in the design development process, Transport Canada/WDBA imposed a requirement that the Broadway Drain outlet be designed to properly accommodate and coordinate with the proposed infill along the north abutting shoreline. Accordingly, we undertook a comprehensive evaluation of the various design constraints and alternative outlet configurations. A design brief that presents our evaluations and findings regarding this issue is provided in Appendix D.

In summary, we found that a substantial rock jetty would be required to prevent longshore sediment from prematurely fouling the mouth of the new Broadway Drain. This jetty would be aligned with the south bank of the drain, and it should be extended a sufficient distance offshore to prevent formation of a back eddy at the drain mouth.

6.6 Design Alignment & Parameters

Establishment of the final design alignment for the Broadway Drain was dominated by the requirements to locate the drain entirely on lands owned by the WDBA or the City, and to accommodate the proposed alignment of the Perimeter Access Road. In addition to accommodating the physical limits of the roadway pavement, the horizontal alignment needed to account for the installation of new major utilities located within the road right-of-way.

Establishment of the vertical alignment for the Broadway Drain was based largely on the requirement to provide proper outlet for the new sewers from the GHIB plaza that will discharge