The main sewer between the Ngaio Town Hall and 45 Waikowhai Street has a history of blockages.  Tree roots intruded into it and it overflowed during heavy rain.  Manholes popped up and spilled sewage into the streams and into some Waikowhai Street properties.  Sometimes it smelled.

Wellington City Council  decided to renew the existing trunk main sewer by diverting part of the wastewater catchment along Waikowhai Street.  This was easier to construct and easier to maintain.

The work involved laying 660m of 600mm diameter concrete pipe, 50m of 630mm PE (plastic) pipes, 57m of 500mm PE pipes, and 15m of 457mm steel pipes.  This was constructed using open trenching.  The work was started in March 2009.

The existing trunk main sewer along the stream will be relined and will now only serve the local catchment. This work should start in December 2009.

Waikowhai Street sewer renewal

(Photo courtesy of Wellington City Council)