An old box drain has been identified as the cause of a near 2-week delay for workers completing the new storm water mains on Dee Street.

Work came to a halt on 6th April after Invercargill City Council (ICC) Group Manager Infrastructure Erin Moogan announced that contractors had discovered an archaeological feature.

Moogan said archaeologists from New Zealand Heritage Properties had attended the site following the discovery.

“Staff from New Zealand Heritage Properties had assessed the site and found a 19th Century timber boxed drain," Moogan said.

New Zealand Heritage Properties principal archaeologist Amy McStay said the boxed drain was constructed between 1878 and 1900 and would have provided drainage from the roadway and private properties into the Waihōpai River.

Box drains were used widely throughout rural Southland in the early days before clay field tiles became available.

“The drainage was replaced on Dee St in 1900 with earthenware pipes,” McStay said.

“Archaeological remains associated with Invercargill's early drainage and infrastructure network help us understand the local response to drainage, sanitary and environmental challenges as the city grew and in relation to the use of the Waihōpai River,” she said.

Archaeologists will remain on site, while work recommences, as there were still parts of the timber structure to be modified or removed, she said.

This project joins other ICC three waters renewal works including the Kennington wastewater rising main renewal and recent work on Clyde St.