While several types of hoppers exist, they generally have a high velocity stream of mud going through them and a means of mixing either dry or liquid mud additives into the whole mud stream.

Stopping at a stream to cool down I take the opportunity to clean some of that mud off my radiator.

For downstream of homogeneous DAMS, damages caused by rain scouring, storm, ice, stream, animal, swelling, and mud crack must be avoided.