Upgrading of Waikato and Hauraki Valley Flood Control Pump Stations

This paper outlines the key issues faced by the ageing pumpstations built through 1960’s to 1990’s to provide flood protection and drainage services in the Lower Waikato, Waihou Valley and Piako River catchments.

Around 120 flood control and drainage services pumpstations are managed by the Waikato Regional Council to provide protection to farmland, townships and businesses across the region. These pumpstations vary in capacity from several tens of litres per second to a several cubic metres per second. They are now requiring significant upgrading to ensure that their useful life is enhanced, operational safety measures are incorporated and the stations are built to current day requirements.

Significant challenges to upgrade these stations include investigating all components requiring upgrading, the varying and poor foundation conditions, integrating operational functions into the upgrade schedule and managing flood risks during construction works.

The paper also outlines the health and safety measures and efficiency considerations that are incorporated into the upgrade of the stations. The upgrading works provide an opportunity for the council as the asset owner to review and where appropriate include any service level changes.

The upgrading will continue to preserve the productive values of the land and assets they protect and will add to the economic outcomes for the Waikato region.

Three to four stations are scheduled to be upgraded each year and successful upgrade works including inlet bay and screen, sump, switchboard and controls, outlet pipes and pump house upgrades have been completed over several years. Lessons from several completed projects with technical issues faced during investigation, design and construction are provided in this paper.