Testing planned to help improve Hihi wastewater network performance

The wastewater network in Hihi will undergo testing during November to identify where rainwater and groundwater are entering pipes.

During heavy rain, unwanted water entering wastewater pipes can significantly increase the volume flowing through the network potentially overwhelming wastewater systems. Identifying and addressing these issues will help reduce pressure on the network and treatment plant.

The investigation will use smoke and dye testing to identify where unwanted water is entering the wastewater system, as well as potential leaks and cross-connections.

Residents should not be alarmed if they see smoke coming from manholes, household gully traps, roof gutters or stormwater drains. This is a normal part of the investigation and helps identify potential issues with the wastewater network. Letters are being delivered to affected properties to advise residents of the upcoming work.

Four manholes have been identified as testing points in Hihi, with more than 90 properties connected to the wastewater network through these locations. The testing will help pinpoint potential problem areas and determine where further investigation, repairs or improvements are needed.

The work is part of a district-wide inflow and infiltration programme, which aims to identify and address issues and improve overall performance of wastewater systems. Testing is expected to extend to four more towns soon, with further updates provided as the project progresses.