The Inundation Overlay indicates areas which may be susceptible to localised stormwater flows, stormwater ponding, ponding of other floodwaters or tidal inundation. The overlay is based on historic observed data. The causes of localised ponding are highly site specific but generally relate to the presence of a low lying area where stormwater accumulates or tidal backwater effects prevent drainage.

Tidal inundation may occur at some sites during periods of extra high tides and particularly in combination with low pressure weather systems. In exposed coastal areas wave action is also a factor.

As part of the preparation of Plan Change 29, the Inundation Overlay was reviewed and where modelled flood hazard (river and stream) existed for the Residential, Inner City, Suburban Commercial and Industrial zones, data from the Inundation Overlay was deleted and replaced with either the High Flood Hazard or Flood Hazard Overlay. The Inundation overlay data affecting the Open Space and Recreation, Rural and Conservation zones was not reviewed and consequently has not been amended.

Further information is available by viewing the ePlan

https://nelson.isoplan.co.nz/operative