23 February, 2023
Navy divers get drinking water flowing
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An eight-person team from HMNZS Matataua restored Gisborne’s water supply flow, after diving in a severely blocked treatment plant to remove silt.
Leading Diver Shane Gardiner was part of a team of divers and one Marine Technician, with four arriving from Auckland and four others deployed from HMNZS Manawanui this week.
Two water intakes at Gisborne’s water treatment facility were blocked with silt after Cyclone Gabrielle, prompting the Council to tell residents not to use tap water.
The divers utilised Surface Supplied Breathing Apparatus (SSBA) to conduct the work.
“There were a few challenges on site,” said LDR Gardiner. “The team had zero visibility down there. They used their hand to judge how far they could see, and they were putting their hands up right up to the mask, and they couldn’t even see their hands.”
The divers spent nearly two hours over two dives, setting up an ‘airlift’ system. “It’s a pneumatic air system with a venturi effect, similar to how you syphon petrol out of a fuel tank. It drew out all the sludge and excess silt, unclogging the system.”
The team were aware how bad it was for Gisborne. “We knew they had a lot of damage to their water infrastructure. This was the main treatment facility and clearing it will allow Gisborne to go back to full flow, meaning the town and the people will have access to clean drinking water from a very secure source."