Te whakapiki ake i te kounga o te wai o te Waitematā Harbour water quality improvement

Waitematā Harbour water quality improvement is a joint initiative between our Healthy Waters department and Watercare.

The programme's aim is to:

• reduce wet weather overflows into Waitematā Harbour
• minimise stormwater in the wastewater network.

In the early 1900s, a connected system for stormwater and sewage was established in the CBD and inner suburbs of Auckland, known as the Auckland Isthmus. The system discharged untreated sewage and stormwater straight into Waitematā Harbour. This continued until the completion of the Māngere Treatment Plant in 1960.

The system we have was designed to meet the needs of the early to mid-1900s. These combined networks now struggle to handle the current volume of both sewage and stormwater. This leads to overflow into waterways, particularly during heavy rainfall. Waitematā Harbour then becomes polluted, posing risks to swimming and other recreational activities.

The programme features big improvements to both the stormwater and wastewater infrastructure over the next 13 years.

The biggest improvement is the construction of a public stormwater network, allowing private properties to link their drainage systems to the separate and dedicated stormwater system. This also reduces the burden on the wastewater treatment plant by eliminating unnecessary workload.

Waitematā Harbour water quality improvement is divided into two projects to help manage the stormwater separation works.

Established in 2017, the Western Isthmus Water Quality Improvement programme aims to enhance water quality in Auckland's western isthmus area, mainly focusing on reducing pollution in water areas such as the Waitematā Harbour.

This subprogramme involves extensive infrastructure upgrades to both stormwater and wastewater systems over a 13-year period, in collaboration with Watercare.

The Eastern Isthmus Water Quality Improvement programme focuses on enhancing water quality in the eastern isthmus area, with the main goal of reducing pollution in water bodies such as:

• central city
• Judges Bay
• Hobson Bay
• the Eastern Bays to the Tāmaki Estuary and surrounding areas.

Like its western counterpart, this subprogramme involves extensive infrastructure upgrades to both stormwater and wastewater systems.

Our main aim is to enhance water quality within the Waitematā Harbour through:

• infrastructure upgrades
• collaborative efforts with Watercare
• targeted projects to address wet weather overflows
• making the wastewater and stormwater systems stronger so they can cope with future growth and development.