The future danger of Mt. Kelut (Eastern Java — Indonesia)

The tunnel system of Hettinga Tromp proved that the Kelut dangers can be controlled to such an extend that no great lahars were formed during the eruption of 1951. This eruption, however, destroyed these tunnels. In 1954, a drainage tunnel system was built based on the seepage principle. But till now it has failed to drain the lake completely. The 23.5 million cb.m of water still stored up in its crater lake will form a potential danger during an eventual eruption.