A Timely Expansion - Waikato WTP

Continued regional growth and the need to secure the Auckland region’s water supply against drought prompted a fast-tracked project to expand the capacity of one of Watercare’s most strategic assets, the Waikato Water Treatment Plant (WTP), from 75 Megalitres per day (MLD) to 125 MLD. The expansion project planning/design phase commenced in November 2010 with the upgraded 125 MLD treatment capacity being fully realised, on time and budget, in March 2013. An interim stage was included to remove plant bottlenecks and increase the interim plant capacity to 100 MLD, this was achieved, on target, in December 2011 enhancing drought risk mitigation for the 2011/2012 summer and beyond.

A brief discussion of the key project challenges and the strategies successfully employed to mitigate the associated risks are presented. Lessons learned and critical success factors are also described.

The key project challenges can essentially be traced to either the nature of the site or the timeframe within which the project was required to be completed. Site based challenges:

• Brownfield, constrained site
• High degree of expansion integration with the existing plant coupled with the requirement to keep the existing plant fully operational without compromising drinking water standards.

Accelerated project delivery time frame:

• Compressed project timeframe
• Interim capacity milestone requirements

The most important tool that was used to overcome these challenges was the tailoring and control of the project delivery. All aspects of the project delivery including planning, design, construction, commissioning and handover were customised to meet the specific project challenges.