Wastewater that enters our network is mainly water, but it also contains human waste, food scraps, fats, debris and trade waste. Overflows can affect the health of our streams and beaches.

Most wastewater overflows occur in wet weather, but they can occur at any time because of blockages.

Wet-weather overflows

In heavy rain, the volume of stormwater draining from roofs and roads can exceed the capacity of our pipes. Diluted wastewater can overflow into private properties and the wider environment, polluting your property and Auckland’s streams and beaches. Learn more about wet-weather overflows

Dry-weather overflows

The most common cause of overflows in dry weather is a blocked drain. This happens when householders put the wrong kind of waste down the sink or toilet.

• Fat, food scraps, or rubbish such as wet wipes can build up in a pipe. Over time they form large clumps that block the pipe and cause sewage to flow onto your property or on the street. Learn more about how to prevent overflows

• Tree roots can block wastewater pipes. Learn more about trees and roots