Abandoning end-of-life reservoirs

Managing and maintaining the 130 drinking water reservoirs in our network is a big job. We monitor and maintain our reservoirs to ensure they keep our drinking water safe,  remain structurally sound and function as they should. Our reservoirs range in age - some are more than 100 years old and our newest, Omāroro in Mount Cook, opening in 2024. 

Part of managing infrastructure is planning to replace assets when they reach the end of their design life.

After decades of maintenance and thorough assessments, we are starting the process to take four old reservoirs out of service:

1. Alexandra Road Reservoir, Roseneath
2. Kaitangata Reservoir, Eastern Hills
3. Sidlaw Reservoir, Strathmore Park
4. The Track, Plimmerton.

We’re also working on the Highland Park Reservoir in Wadestown. This involves laying new pipes to supply houses which are currently connected directly to reservoir outlet. This will allow us to isolate the reservoir for future maintenance work.

Before we take a reservoir out of service, we need to ensure any live connections are redirected to another water source. Our preparations include modifying pipes and valves ready to bypass the reservoir.

The work required for each reservoir is slightly different.

• Alexandra Road Reservoir, Roseneath - Lay a new pipe to ensure continuity of supply for some properties. Works are within the road reserve and park land.
• Kaitangata Reservoir, Eastern Hills - Install new pipe and valves.
• Sidlaw Reservoir, Strathmore Park - Install flange to stop the pipe.
• The Track, Plimmerton - Disconnect a pipe still connected to the reservoir.

What happens to old reservoirs
The reservoirs identified for retirement will be drained and left in place until we confirm the network is working well without them. Once we’re confident the network is operating satisfactorily without the reservoirs, we’ll start planning to demolish them.