The state of knowledge and practice regarding water hammer in the Swedish water and wastewater sector

ABSTRACT Flowchart illustrating a knowledge gap in water hammer assessment in Sweden, linking theory, survey methodology, key findings, and recommended actions to improve practice and education. The theory of water hammer is well developed and can support quantitative assessment in engineering studies. However, in the Swedish water and wastewater sector, water hammer analysis is often overlooked during the design of pressurized pipe networks. Apart from a study from the 1980s, the status of knowledge on water hammer has, to the authors' knowledge, been mapped neither in Sweden nor internationally. Using surveys, this study examines the knowledge within the Swedish utility sector concerning water hammer. The results reveal a substantial and significant lack of expertise among utility engineers. Many utilities do not take water hammer into account during the design, and among consultants, knowledge of the phenomenon is limited. Universities offering civil and environmental engineering programs provide little to no coverage of water hammer. Consequently, a clear knowledge gap exists within the sector on this topic. Improved collaboration between universities and utilities is recommended to ensure that engineers acquire the necessary knowledge. In addition, it is suggested to develop a practical tool for assessing water hammer risks to help utility engineers determine the sufficient level of water hammer evaluation. Ideally, this tool should be incorporated into the primary Swedish publication on water hammer known as VAV P58.