Drainage Along Swamp Forest Roads Lessons from Northern Europe

Wetland road crossings, especially in peatlands of the boreal forests of the United States and Canada, frequently show patches of dead or low-vigor timber on the upper side of the road. The condition is caused by failure to provide for adequate cross-drainage, with a resulting rise in the level of the water table and drowning out of the timber. The chief problems are lack of a collector ditch on the upper side of the road, culverts set too high, and lack of a discharge ditch on the opposite side of the road. An example is given of proper installation of these road drainage facilities on a forest road in Finland, along with a discussion of the hydrological fundamentals of good and poor provisions for cross-drainage.