Master planning of wastewater services for the eastern surburbs of Manukau City

With a population of approximately 347,000, Manukau is New Zealand's third largest city and the fastest growing, Much of the wastewater network infrastructure in this area was built between the 1960s and 1980s, with more recent development post-2000.

Watercare Services Limited and Manukau Water Limited operate the bulk and local wastewater networks respectively. The companies jointly commissioned a study to develop a wastewater master plan for the Eastern Suburbs o f Manukau City.

This paper describes the development of this master plan, including challenges associated with the quality and quantity of data and how these were overcome It gives an overview of the options considered for providing increased trunk wastewater network conveyance and will comment on the regional implications of such a development and the phasing of upgrading works. It will also discuss how staff from across the organisations collectively identified issues and the developmen t of solutions.

Primary elements to achieving an integrated master plan were the corroboration of existing data for wholesale and retail systems, identifying individual and common d rivers and identifying constraints to current and future upgrades. This allowed effective prioritisation of existing network problems and those predicted by the demand being placed on the assets for growth.