For many years fish and other aquatic organisms have migrated through culverts made with corrugated metal pipe (CMP). Installed as long as 50 years ago, many CMP culverts are so significantly rusted and near failure that water and fish have trouble effectively getting from one end to the other. A “fish friendly” solution to these failing culverts that is economically feasible, quickly installed and non-disruptive to the motoring public is imperative. Relining these culverts has always been a possible and popular solution. However, most high density polyethylene (HDPE) pipes have a smooth interior wall. The smooth wall has an extremely low resistance to flow, therefore increasing water velocity and making it difficult for fish and other aquatic organisms to pass through.
New internal structures are comparable to that of CMP, but manufactured with more durable material. Fish and other aquatic organisms now can migrate more easily through their physical environment but with a pipe constructed of HDPE, offering a much longer service life. The interior profiles act as “roughness elements” that decrease the flow velocity and allow for some silt and streambed material to collect inside. Additionally, Snap-Tite can install available baffles to solve depth and velocity problems within a culvert during flow extremes.
In low flow situations, most baffles act as weirs to create small pools of standing water. As the flow increases, the water rises up over the baffles. The baffles help decrease flow velocity while creating resting areas for fish to use during high-velocity water flow occurrences. PRS can help you determine the most cost-effective solution for your culvert project.