This paper reports a laboratory and numerical study on violent geysers in a vertical pipe. The laboratory geysers produced consists of a few consecutive violent eruptions within a time frame of a few seconds with heights that may exceed 30 m and with characteristics resembling geysers that occur in actual stormsewer systems (e.g., strongest eruption is not the first one but few eruptions later). In general, the present study shows that once the air pocket breaks through the free surface and produces a water spill, the horizontal pipe flow dynamics, in particular the rapidly changing pressure gradient following the first weak eruption, is driving the entire geyser mechanism. This conference paper is based on the following papers Leon 2016, 2018, Leon et al. 2018, and Chegini and Leon 2019.