Waiāri Water Supply Scheme : Planning The Water Supply For A Growing City

Tauranga is one of New Zealand's fastest growing cities, with a 14 percent increase in population between the 2001 census and the 2006 census, though that number has slowed to 11% between the 2006 Census and the 2013 Census. This sudden population growth has made Tauranga New Zealand's 5th largest city with a current urban population of 137,900 (June 2017).

This paper outlines the Tauranga City Council’s (TCC) journey to supply and optimise the provision of water for a growing city which has culminated in a need to develop and implement a third water supply scheme.

TCC first identified the Waiāri Stream as the next potential water source for Tauranga City as early as 1995. In 1999, TCC started investigating the Waiāri Stream to service the projected growth of the city’s population, particularly in the eastern parts of Papamoa in earnest.

TCC appointed CH2M Beca Ltd as its delivery partner to provide engineering services for the consenting, design and construction of the intake and water treatment plant (WTP). Land acquisition, the designation of the site, a water take consent for 60Ml/day and other consents were obtained in 2010.

Water demand management measures implemented by TCC through the introduction of universal metering and the global financial crisis led to lower water demands across the city. This led to the project being put on hold in 2012. The project was resurrected in 2016 with the first of three contracts being awarded to procure the construction of the WTP in January 2018. The intended commissioning date is now 2021.

This paper outlines the history of the planning approach used on the project. Studies such as demand, capacity and outage assessments, resilience assessments and decision tools that were used to assist TCC with consenting, decision making and the implementation of the project to achieve the Councils “just in time infrastructure” philosophy are described.