INNOVATION January-February 2018

F E A T U R E

cost estimates, for shoreline protection,” says Shelley Ashfield, P.Eng., Town of Comox municipal engineer. “Wedler concluded that approximately half of the foreshore in the study area had ongoing moderate to heavy erosion.” The shoreline in this area historically consisted of active sand dunes. When Lazo Road was built many decades ago, it stopped the natural dune processes, but the sand remained. Wedler’s study found that the sandy ground was eroding. With every winter storm, the edge of the bank encroached closer to the road. By 2011, the road’s shoulder started crumbling in places. Elsewhere, the bases of power poles were exposed. Informal footpaths from the roadside to the beach increased the erosion. A rip-rap wall protecting private property at the beach’s south end may have increased erosion on the beach. “Over time,” says project engineer Andrew Gower, P.Eng., of Wedler Engineering, “the beach, the bank, and the road and other infrastructure next to it had seen considerable erosion— to the point where failure of the road and works was inevitable.” The design plan the company submitted in 2011 proposed a steep, long rip-rap wall like that already in place south of the project area. Although rip-rap is a relatively cost-effective solution for shoreline erosion, Gower had reservations: “Rip-rap walls are not the most environmentally or aesthetically pleasing approach.” And, he says, they cause problems. “They don’t sustain environmental values”—including ecological communities or spawning habitat for fish—“and they can amplify wave forces, scouring, and nearby erosion, which leads to safety and liability issues.” However, by the time the Town of Comox obtained grant funding in 2014 for the work, the foreshore along the project area had changed significantly, and the plan had to be revisited anyways. This presented the town and project team with an opportunity to explore other solutions. A MULTIDISCIPLINARY TEAM AND A CHALLENGING ENVIRONMENT Town staff, Gower, a geotechnical engineer from Levelton (now WSP), and the project archaeologist, who also consulted with the local K’omoks First Nation, had all provided input during the project’s 2011 preliminary design phase. A key resulting recommendation was that a biologist and a wave-modelling and coastal-engineering specialist be added to the team for the project’s detailed design stage. In addition, work done for the preliminary phrase revealed an archaeological site within the project area. A local environmental group had also begun opposing the project. “Because of the archaeological site, we needed an archaeologist,” Gower says. “Because we were dealing with coastal protection, we needed wave modelling and coastal

And, those dune grasses among the driftwood—they’ve just been planted. This stretch of shoreline along Lazo Road may look like it was shaped by wind, waves, and time, but engineers, geologists and biologists worked hard to create that impression. SHORELINE PROTECTION; INFRASTRUCTURE AT RISK “In 2011, the Town of Comox commissioned Wedler Engineering to undertake a study that would assess the condition of shoreline erosion along the 700-metre portion of Lazo Road within the town, and provide preliminary design, including

From top: Erosion had resulted in the edge of the bank encroaching closer to the road. Rather than rip-rap, large logs are anchored to underlying boulders to form a more natural barrier to the waves. The Lazo Road shoreline was studied in detail. Among project challenges were the discovery of an archaeological site and the preservation of endangered native vegetation.

1 8 J A N U A R Y / F E B R U A R Y 2 0 1 8

I N N O V A T I O N