Waterview separation project

Improving the stormwater system

We are extending the existing stormwater network and creating a separate stormwater and wastewater network.

This project is part of the Western Isthmus Water Quality Improvement Programme and will be delivered in partnership with Watercare.

What the new network will do

The new network will:

• significantly reduce combined wastewater and stormwater discharge in Waterview inlet and Oakley Creek
• improve water quality at Waterview inlet and Oakley Creek
• improve the environment for people, birds and marine life
• increase stormwater network capacity to support future growth in the area
• significantly reduce the risk of flooding to residential and commercial Waterview properties
• rehabilitate the aged stormwater system.

How we will do this

We will use a combination of open trenching and trenchless installation to construct:

• 6.4km of stormwater pipelines
• drainage separation
• new connection points.

What the project will do

The Waterview catchment is currently serviced by aging infrastructure dating back to the early 20th century. The pipes carry both wastewater and stormwater.

Usually, the network carries the wastewater to the treatment plant. However, during intense or prolonged rainfall, the system can overflow and release stormwater – including diluted wastewater – into the inlet.

The project is designed to reduce these overflows from approximately 50-60 spills each year down to 2-5 spills a year. This will improve public health by significantly reducing waterway contamination.

Timeline

• We have completed the preliminary design and are working on the detailed design.
• We have resource consent approval. We will submit a resource consent application for the remaining works (which are more complex) by January 2024.
• We are continuing to consult with affected property owners.
• Construction is expected to commence in 2024 and will take approximately nine years.

How this will affect you

This project involves upgrading some of the private and public stormwater system within the area.

We are carrying out private drainage investigations to determine if properties have either combined or separated pipes, and whether there are any obvious faults in the private drainage.

We are also investigating the public stormwater system to see if pipes need upgrading, upsizing or if new pipes are required.

If we need to visit your property

If we plan to visit your property, we will send you a letter in advance.

The good news is that usually there is no need for you to be home at the time, unless you have a dog or locked gate.

We will tell you if we need to visit for further investigations.

Additional investigations will help us:

• determine whether there are any cracked or faulty pipes
• carry out surveying or geotechnical investigations.

If you have a combined wastewater and stormwater system

If the property has a combined wastewater and stormwater system, we will:

• engage and consult with you further about the proposed work required
• gain your approval before any work is undertaken.

Wherever possible, we will try and locate the public stormwater system on public land, such as within the road reserve. However, this will not always be possible.

In some situations, we may need to locate the new public stormwater pipe and manholes on private property. If this is the case, we will discuss the works with you and request your approval to carry out the work.

Who pays for the works

The cost of both the private drainage and public drainage works is covered by the Water Quality Targeted Rate.

There is no extra cost to property owners.

More information

Find out more about the Western Isthmus Water Quality Improvement Programme.

Email waterviewHW@aucklandcouncil.govt.nz if you have any questions about the project.