Protecting Eden Park from flooding during the Rugby World Cup 2011

Eden Park has historically suffered from flooding during major storm events. Flooding occurs as groundwater levels in the underlying basalt aquifer rise in response to infiltration in the upstream catchment. Stormwater drainage in Eden Park itself is constrained by both high groundwater levels and an undersized stormwater network.

A solution to protect Eden Park from flooding in the event of rainfall had to be found. Auckland Council and Beca Carter Hollings & Ferner Limited (Beca) carried out a feasibility study which recommended that a novel groundwater abstraction scheme be taken forward. This was the lowest cost option that could be implemented in the time available. The aim of the project was to draw down groundwater levels to enable surface water to infiltrate into the aquifer, even during large storm events when flooding would normally occur.

This paper reports on the development, commissioning and operational phases of the project. Although designed to operate independently and abstract water to pre-determined levels, many factors could require operator intervention. The paper reviews the actions that were taken, issues that occurred in practice and how these were addressed. It also summarises the overall performance of the scheme during the Rugby World Cup 2011 and the level of protection provided.