The increase in frequency, magnitude and duration of floods during the past decades has become an outstanding challenge to geotechnical engineering. When dykes or levees do not have a cut-off wall fully penetrating the aquifer, underseepage may occur during high river levels. In such cases, appropriate measures against hydraulic fracture require comprehensive knowledge of failure modes of dams, dykes and levees. The installation of water pressure relief elements at the landside toe zone of dykes and dams has proven successful. The paper focuses on different relief systems based on mathematical approaches, laboratory and field tests, and on site observations. Finally, the hydraulic behaviour of relief drainage columns based on numerous experimental tests and numerical parametric studies is described.