Corrosion and electrochemical material wastage processes take on many different forms. Most of these forms are dramatically affected by the relative flow rates of the reactants in the corroding cell. Some forms of corrosion are termed flow-assisted, flowaccelerated, erosion-corrosion, etc. Old processes, aging infrastructure issues, and an influx of study dollars has brought these corrosion processes to the forefront of the modern world. This manuscript discusses the basics of the flow effects in systems which corrode by water.