A New Zealand infrastructure manufacturing company has found ideas in Japan to minimise damage to waste and waterways in earthquakes.
Hynds Ltd has signed a partnership with Nippon Hume International to trial technology to stop drain covers from floating with liquefaction.
Floating manholes disrupted the sewerage network during the Christchurch earthquakes and contributed to sewage going into the Avon River.
It also caused dangerous and obstructive holes in the roads and footpaths.
Director Aaron Hynds says dispersion valves are retro-fitted inside the manhole, which keep it level with the ground and resilient to seismic activity.
Mr Hynds says his company will begin working with local councils including Christchurch and Wellington in January to introduce the technology nationally.
As many as 5% of manholes in Christchurch will need retrofitting, he says.