Significant creep in the concrete caused variations in the gap between the radial gate and the concrete sealing surface, which the standard rubber seal could not completely bridge. Winter temperatures caused the rubber to lose flexibility, increasing this water leakage, which when frozen, accumulated into an ice buildup that prevented the proper functioning of the gate.

Fine-tuned cross-section of seal to maximize flexibility, in conjunction with a seal positioning system to regulate pre-load deflection of seal along length of radial gate. A polyurethane formulation was used for its low temperature properties, excellent compression set and deflection properties.

Inspections throughout the first winter in operation revealed zero leakage, and no ice build-up along any part of the seal.