Franz Josef Glacier is a national icon. It draws international visitors to New Zealand’s South Island and plays a major role in the economy of South Westland. The permanent population is low (270) but on some days there can be up to 2000 mostly international visitors staying overnight in the township. Some of the accommodation (the camping ground, motels and lodge) is on the lee of the stopbanks on the south side of the river.
The Waiho River has been aggrading for some years now (at a rate of 300mm/year) to the extent that the riverbed is now some two metres above the surrounding land.
Stopbanks were constructed about 15 years ago to protect the community from a 1-in-50-year flood event and these are unlikely to provide protection today from a 1-in-10-year event.
The Waiho River is a short-run glacial river on the Southern Fault Line in an area of very high rainfall. Franz Josef is very prone to a catastrophic event either as a result of a flood in the Waiho River or a dam break (from a landslide) in the Calley Gorge upstream from the township.
The community next to the Waiho River, and the south bank in particular, is very vulnerable to a failure in the current flood protection systems. It has been estimated that that if there was a breach in the early morning while several hundred tourists were staying, there could be a large loss of life because of the swiftness of the river and its extremely cold temperature.
Westland District Council has, as a variation in its District Plan, land-use controls that prohibit further development in the areas most vulnerable to flooding in the Waiho flood plain. This however does not address the current properties and businesses. The West Coast Regional Council has installed flood-warning systems up-river from the township. This, along with its civil defence plan, provides some short-term protection to the community.
The Ministry of Civil Defence and Emergency Management and the Ministry for the Environment are working with the West Coast Regional and Westland District Councils towards reducing the risks to people in this area.
Last updated: 17 September 2007