When flood PLAIN turns into flood WAY, trails are in trouble. The recent floods in Colorado remind us that our stream-side corridors are vulnerable. Yet in our urban and suburban areas, trails along rivers are the most popular pathways. How do we balance the cost and value of our greenways when they’re covered in brown mud?
It’s clear that manufactured steel bridges can take a direct hit and still survive intact. They may have to be retrieved from some distance downstream, however. How about trail surfaces? Crushed rock is extremely erodible, and asphalt is also susceptible to running water damage.
Concrete can withstand being submerged, as we have seen from decades of annual spring flooding along Denver’s greenways. However, severe undercutting of stream banks can totally wipe out a concrete trail, and then you have big slabs of heavy debris to dispose of.
It’s pretty clear that homes don’t belong in flood plains, but what about trails? Birds, fish, and muskrats– as well as bikers, skaters, and hikers– all love our greenway corridors. Many plants, like willows and cottonwoods, sprout up eagerly after a flood. And as Boulder County Parks and Open Space says, “We WILL be back!”
— Stuart Macdonald
American Trails Magazine and website editor