Mt. Ruapaehu is an active stratovolcano is of the Taupo Volcanic Zone, central North Island of New Zealand. Between 1995 and 1996, it underwent a series of eruptions, emitting volcanic ash across the surrounding land, predominantly in an easterly direction, towards the Pacific Ocean.
Along with the ashfall hazard, there were numerous lahars that impacted the region as well. One came within 2 m (6.5 ft) of a ski-lift station on the Whakapapa ski slope on the northern side of Ruapehu in 1995 (Johnston et al., 2000).
The eruptions also produced a large ash-dammed lake, posing the risk of a lahar. The dam was finally breached in 2007, harming no one due to the lahar warning system and structural engineering of the impact highway bridge (Keys and Green, 2008).
The ash dispersal from the eruptions had adverse impacts on agriculture, horticulture, water quality and national power supply as well as local tourism and economics.