A major bridge crossing of the Yukon River was contemplated to provide year-round access to the area north of the river. An intensive assessment of the effects of the bridge on the hydraulic and ice regime at the site was conducted by NHC given the sensitivity of the local residents to the role that ice conditions play in producing floods and the integral part that the river plays in the community.

The work included a brief discussion on the findings of the pervious design reports related to the bridge, a summary of the hydrologic characteristics at the site for both open water and ice-affects events, a description of the channel characteristics based on available cross section and bed material data, a summary of the effects of the bridge on the local channel bathymetry, and a description of the effects of the bridge on freeze-up and breakup severity and winter ice thicknesses.

Also, the effects of the bridge on the mixing of the effluent downstream of the diffuser are also examined along with the response of the groundwater levels in the floodplain near the mouth of the Klondike River to potential changes in river stage.

Finally, the expected design ice loads on the bridge structure were determined on the basis of the historical breakup water levels, measured maximum ice thicknesses and estimated ice strengths, and the local hydraulic characteristics.

The characteristics of the proposed bridge layout were found not to affect critical infrastructure, nor would they adversely affect the timing and/or severity of freezeup and breakup.