A TALE OF TWO TOWNS: a Review of Two Taranaki Rain Events 2015

Stormwater Conference

The purpose of this paper is to compare two separate significant rain events experienced in South Taranaki in the winter of 2015; each resulting in devastating but quite different impacts; and so demonstrating the resilience of the communities most affected through the different responses. In both events, and since, South Taranaki District Council continues to play a central role in assisting with the response and recovery for those communities.

In June 2015 a high intensity rainfall event struck the Taranaki region, depositing huge amounts of rainfall in three days over the eastern hills and predominantly pastoral farming country, and resulting in significant runoff via the deeply incised stream valleys draining this area. A civil defence emergency was declared and the small township of Waitotara evacuated, shortly before it was consequently inundated; 8 houses were flooded; the State Highway bridge closed, as well as numerous local roads impacted by hundreds of slips and dropouts. The estimated cost to repair and reinstate the local roads alone is put at $10.25 Million.

In August 2015 the region again experienced a significant rainfall event; this time in the catchment above the Opunake Township on the coastal ring plain; however this event was quite different in nature and duration. The storm occurred overnight; with the main intensity over two hours in the early hours of the morning; highly localised and resulting in significant runoff through previously poorly defined channels and secondary flow paths within the township of Opunake, population 1,335. 18 houses were inundated with a further 71 having sheds and outbuildings and surrounds flooded.

By any measure these were damaging events; the paper will explore the different impacts on our urban and rural communities, against established service levels; and review the Council’s response and damage assessment including cost; and consider subsequent planning for future similar events.

Conference Papers Resource - Conference Papers Stormwater

1.Manning and Mitchell - A Tale of Two Towns (a Winter of Discontent).pdf

1 MB
16 Jan 2017