Going with the flow

By its very nature, provision of water services involves working in the local environment and Citycare Water Dunedin confronted the ebb and flow of the tides during an emergency repair in Karitane recently.

The water supply to the seaside community is piped from Mountain Road in Hawksbury across farmland and through a swampy section of the Waikouaiti River estuary, so the team had to work up to their elbows in mud around the rising and falling tide, Project Manager Stephen Adam says.

And the time pressure was on as the team tackled the challenging repairs through the changing tide, he says.

The significant pipe failure was in the 100mm diameter supply line across the estuary and it meant Karitane residents had a quarter of their normal water flow, Stephen says.

The break was reported on a Friday and the team planned how to tackle the fix on Saturday, when low tide was around 5pm, he says.

Unfortunately, the repaired pipe broke again further up the line on the Sunday and the team spent Monday undertaking further repairs, Stephen says.

Special attention was paid to some environmental concerns in the estuary. The team was careful about disturbing the crustaceans and fish living in the river and swamp as well as limiting the amount of freshwater being dispersed into the salt waterways, he says.

A large section of the pipe laid for the community by the former Silverpeaks County Council in the 1960s had deteriorated over time.

Around 700 metres of pipe crosses the estuary and 40 metres had to be replaced, Stephen says.

The Dunedin City Council agreed to lay above ground approximately 750 metres of polyethylene pipe around a section of the estuary to avoid the first 350 metres of pipe.

It’s a temporary solution as in coming years the pipes are likely to be replaced with a network following the local roads rather than running through the swamp.