The Waiho River Severe Flood Hazard Policy Unit and Zone comprises land south of the confluence of the Callery and Waiho Rivers which is immediately south of the SH6 Waiho River Bridge. The Waiho River has been aggrading substantially in the last 60 years as a result of complex alluvial processes . The construction of stopbanks has accentuated this problem. At Waiho River Bridge, for example, the average riverbed level has risen by approximately 5m in the last 20 years. The level of aggradation has reached a stage where a damaging flood event is likely to occur in any given year.
The Waiho River Severe Flood Hazard Zone is prone to a catastrophic event either as a result of a flood in the Waiho or a dam break in the Callery Gorge. The short or no flood warning time available, together with the limited resources in the area (Franz Josef is a small community with a permanent population of 264) mean that a safe evacuation cannot be guaranteed. Accordingly, the only secure solution to the problem is to remove the risk by not populating the area. The Waiho Flood Management Committee has consulted with the community and affected parties and plans are underway for relocation or vacation of existing residences and businesses. Subdivision and development are non-complying activities and are extremely unlikely to be approved unless it can be established beyond reasonable doubt that the proposed development will not be subject to natural hazard risk.
220.127.116.11 Waiho River Severe Flood Hazard Zone
A. Permitted Activities
Any agricultural or forestry activity, subject to:
(1) No buildings are permitted in association with these activities;
(2) Compliance with the standards for permitted activities in the Rural Zone as set out in Table 5.7;
(3) Compliance with the general rules in Part 8; and
(4) No modification to or effect on any outstanding natural features and landscapes, or any area of significant indigenous vegetation or habitat (except as specified in 18.104.22.168B) and no modification to or effect on the coastal environment.
B. Discretionary Activities
· The clearance of more than 2000m2 of indigenous vegetation per 5 years, per site, except for land identified by the Council as not containing significant indigenous vegetation or habitats in accordance with Policy 4.9D.
Until a survey to identify significant indigenous vegetation has been completed and is publicly available, areas which are not significant for the purposes of Section 6(c) of the Resource Management Act 1991 and Policy 4.9D of this Plan will not be clear. As an interim measure to help landowners and others to determine whether a resource consent is required for indigenous vegetation clearance or whether the above exemption to Rule 22.214.171.124B applies, the Council will assist with field inspections and ecological assessment. A Certificate of Compliance will be issued where Council determines that the indigenous vegetation or habitat is not significant using the criteria in policy 4.9D and that the area falls within the exemption to Rule 126.96.36.199B.
C. Non-complying Activities
Any activity not specified as a permitted activity.
Note: The provisions of the Waiho River Severe Flood Hazard Zone do not apply to works within the river bed where a landuse consent from the Regional Council is required.
The provisions applying to the Waiho River Severe Flood Hazard Zone are necessary to lessen the risk to the built resource, infrastructure, people and communities associated with the flooding hazards imposed by the Waiho and Callery Rivers.