Mt Ruapehu's lahar impact on Lake Taupo water quality

A Department of Conservation scientist has said a predicted lahar from Mt Ruapehu's crater lake is not expected to have a big impact on water quality in the Tongariro River and Lake Taupo.

Harry Keys told the Taupo emergency management committee monitoring showed the crater lake was likely to fill to its former level between April and mid-October next year.

Investigations in summer indicated a lahar was not likely to happen until the lake filled 5m past the previous overflow point, probably in 2005.