Factors Affecting the Efficiency of Hydraulic Flushing in Sewer System for Sedimentation Control: A Review

Hydraulic flushing is a popular and cost effective method for sedimentation control in sewer, especially in European countries. The quick release of large water volume leads to a flush wave with high turbulent flow mimicking dam break phenomenon to flush out the sediment accumulated in sewer. This paper presents a review of the existing literature related to the factors that affecting the efficiency of hydraulic flushing in sewer system. these factors generally can be divided into sewer characteristics, sediment characteristics, flushing device characteristics and environmental factors. Each factor will present certain risks to the sewer flushing system such as flushing failed to happen, frequency of flushing reduced, weak flush waves and amount of flushed sediment reduced. However, limited studies exist in the literature on the reliability and risks assessment of these factors on hydraulic flushing performance. Hence, this paper aims to provide enough information for future works to be conducted on the reliability and risk assessment related to sediment flushing system using decision-making tools in order to have an optimum performance for sedimentation control