The Otago Regional Council said the work was one of the most significant drainage scheme upgrades on the plains in many years.
Former West Taieri drainage liaison committee chairman Alistair Cameron cut the ribbon at a commissioning ceremony at the pump station, near Lake Waipori, yesterday.
Council engineering, hazards and science director Gavin Palmer said the upgrade was crucial because more than half of the pump station's catchment lay below sea level.
Dr Palmer said the previous pumps had provided great service since 1933, but were nearing the end of their serviceable life.
Investigations began immediately on finding suitable replacement pumps, and specifications were then drawn up.
The upgrade saw two new pumps designed and built in Germany for Taieri conditions.
This followed upgrades to the two other pumps at the station in 2007 and 2008.