The purpose of this Monograph is to describe the basic mechanics of turbulence due to clear water scour at piers. The background of the audiences should have a basic course in fluid mechanics or hydraulics in undergraduate level. The monograph deals with the fundamentals in fluid mechanics emphasizing on the Reynolds and bed shear stresses induced by the flow. It presents concepts of the threshold or beginning of sediment motion. It discusses different factors for affecting scour and its dimensional analysis. It also provides the detailed mechanism of turbulence, which is considered to be one of the most important issues of sediment transport. It furnishes the details of the turbulence measuring instruments that are used in open channels and fluvial laboratories. It also gives a comprehensive review on scour around a circular pier and multiple piers.