Affordable wastewater management for the residents of Whangarei was developed through consultation and understanding the community drivers alongside focussed technical investigations to identify a cost effective solution that would meet the community expectations.
Under significant budget constraints, the Whangarei DC engineering team embarked on a number of investigations to develop a more comprehensive understanding of both the catchment and harbour while also listening to the “voice” of the community.
A number of investigations allowed for a better understanding of the environment and provided tools to develop and assess cost effective solutions with this work undertaken in parallel to a substantial consultation program.
With a clear understanding of the community expectations the team at Whangarei were able to use the tools to develop a catchment wide master plan of improvements to the network and plant that would allow for growth, improved containment as well as meet the community expectations.
Solutions implemented included: sewer network treatment and offload systems, sewer capacity and configuration modifications, inline sewer repairs, direct disinfection of primary effluent, and implementation of accurate and timely communication systems specifically around sewer spills.
The capital works programme has taken 5 years to implement at an affordable cost of around $30m. It has exceeded expectations in terms of environmental outcomes. Customer satisfaction has increased from a low of 46% in 2010 to 76% in 2015. The final budget for the work established as part of the master plan is only 20 – 30% of the previously considered network amplification and storage proposed to meet the desired containment standard.