WA

Record-setting rainfall this past week sent Puget Sound’s rivers and streams over their banks, flooding homes in Snohomish County, closing roads and triggering mudslides. The atmospheric river was another blunt reminder of the dangers floodwaters pose to human-made infrastructure, including the culverts that guide waterways underneath the region’s roads. At least one creek’s surge outside Port Orchard overwhelmed a three-foot-wide metal culvert beneath Sunnyslope Road, washing out the road above it. Repairs will take months, closing the thoroughfare indefinitely. Culverts, the artificial pipes that squeeze once-meandering streams through a bottleneck of concrete or metal, exact an ecological toll on species like salmon. But they’re also an increasing liability in an era of climate change. Washington’s transportation network must become more resilient to such flooding in a time of diminished snowpack, heavy rainfall...