Watercare Services Limited inherited a large number of water and wastewater system assets following the amalgamation of Auckland’s former Councils in 2010. This included a large number of regional assets operated by the former Franklin District Council. None of the Franklin area Water Treatment Plants (WTP) were graded to DWSNZ and the water quality produced by these plants attracted a number of water quality complaints, far higher than all other areas in Auckland. Most of the WTPs were producing at, or above the consented watertake limits and the sources were close to their total allocation limits.
Watercare provided a simple solution to the problem, which was to extend Auckland’s metropolitan water network through Pukekohe and into the rural communities of Patumahoe, Clarks Beach, Glenbrook Beach and Waiau Beach. The programme of work commenced in early 2011 and was completed at the end of 2014. A key driver for this work was to improve water supply resilience in the area.
The execution of this seemingly simple solution required significant engineering effort through a number of discrete elements that were distributed over a large geographic area. Works included constructing over 30km of watermain from the Waikato No.1 watermain through to Clarks Beach, a new pump station at Drury, and bypass arrangement on the Waikato watermain to provide additional security of supply to the area. A new service reservoir was constructed at Clarks Beach and new Chlorine booster plants were installed at Patumahoe, Clarks Beach and Glenbrook Beach.
There were a number of engineering complexities associated with the programme. These were exacerbated by the limited information on the existing infrastructure and its operation. Much of the legacy infrastructure to where the new pipelines were connected required significant reengineering.
Commissioning each element of the works had its own complex challenges. Strategies were put in place and actioned for each phase of commissioning. No water quality complaints were received as a result of any commissioning activity.
This programme of work is an exceptional example of the success of a single, integrated water company serving the Auckland Region. The communities have an improved, resilient water supply receiving A grade water from the Waikato WTP and will cater for growth over the long term horizon.
This paper outlines the extent of the work packages delivered and discusses the strategies employed to ensure that the final solution was implemented with a seamless transition for the customers.