What is Outfall?

Definition of Outfall in Construction

Usually the reference to the end of a piping run, culvert or any conduit that is carrying a fluid.

The outfall of a piping system, if storm water, is many times a rip rap swale, a precast outfall, or a structure built of stone or other masonry product. Outfalls can involve energy dissipation of the flowing water. If the outflow is from a heavily running flow, the water will exit the pipe with force. This force, if not properly controlled can cause negative erosion conditions and issues. In this case, the outfall is designed to dissipate the energy of the flowing water, by an engineered layout of baffles and obstacles created to absorb the energy of the water. Also in this type of situation, the creation of a sediment pool is associated with the engineering of the energy dissipater and the outfall. The sedimentation pool or pond is normally at the end of the dissipater and is designed to hold the water in a stagnant fashion, allowing the sediment contained in water to settle out of the mix. Once this sediment has settled out to the bottom of the sedimentation pool, the water runs over an engineered dam or baffle into the stream or water body that the storm water is designed to exit into.