Background

The floods in 2004 were some of the largest in the Manawatu-Wanganui region in recent times. Post-flood analysis identified gaps in knowledge concerning flood risk. To address this, a flood mapping project to identify and quantify the extent of flood hazard was initiated. This five year project saw significant investment in data acquisition for flood modelling to better provide information to the public and protect people and property.

A series of flood models were developed where key risks were identified, with various annual return intervals (ARI's). Those presented here have a probability of 0.5, meaning that in any given year there is a 1 in 200 chance that it may occur. These models represent a snapshot in time. Subsequent changes to land forms on the flood plains (drains, berms, etc) will affect the utility of these models.

Important: The flood information provided only shows river flooding and does not show all the areas that might get wet during an extreme rainfall or flood event. Areas of ponding from stormwater and other overland flow sources are not included in the model output, and the modelled extent may not cover the full flooded area for a given event. The intended use for this information is as a planning tool and must not be used in isolation. Consultation with Coordinator District Advice at Horizons Regional Council is required for advice at a property level for flood hazard.

The information presented here is a cartographic representation; features shown may not be in their true location. More detail than is presented here is available on request from Coordinator District Advice, Horizons Regional Council.

Terms and Conditions

Please take the time to read the Terms and Conditions as use of the website presumes acceptance by the end user.

  1. This website and the information provided in it are the copyright of Horizons Regional Council. This website is a public service and may be used for personal and business purposes. Users are not permitted to copy or republish any substantial amount of the information from this website without the prior written consent of Horizons Regional Council.
  2. Use of information from this website is entirely at the users own risk. Due care has been taken in providing the information on this website. All information should be considered as being illustrative and indicative only.
  3. Horizons Regional Council does not give and expressly disclaims any warranty as to the accuracy or completeness of the information or its fitness for any purpose.
  4. Horizons Regional Council accepts no liability for any error, omission, or inaccuracy of the information or from any use of or reliance on the information provided by this website.
  5. The user should independently verify the accuracy of any information before taking any action in reliance upon it, i.e. any feature shown on a plan should be physically verified on site prior to any design, construction or other works taking place, property boundaries should be verified by a qualified surveyor.
  6. The user will waive and release Horizons Regional Council from any claims arising from your use of this website or the information provided by it.
  7. The user will indemnify Horizons Regional Council against all claims, loss or damages arising in connection with use of this website or the information provided by it.
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