A lobbyist is again calling out the group responsible for replacing Rarotonga’s water network with more claims the new $90 million system is not up to scratch.

Te Vai Ora Maori Clean Safe Water Rarotonga group researcher Andy Kirkwood has made the claims after To Tatou Vai (TTV) acknowledged heavy rain in recent weeks had proved challenging for staff monitoring its water intakes.

The past couple of weeks of wet weather had been challenging for “field crews up in the hills monitoring and managing our water intakes”, the water authority said in a social media post.

“When you have a lot of rain it means a great deal of muddy water enters the stream systems.”

The post included photographs of the Avatiu water intake above the weir which illustrate a build-up of silt and mud.

“The build-up of silt and mud can block the flow of water into the chamber causing it to run over the top.

“An excavator is used to clear excess mud/silt and the muddy water is also flushed down stream until there is a lower amount of sediment to allow uninterrupted flow into the chamber to collect water,” To Tatou Vai said in the post.

Te Vai Ora Maori’s Kirkwood says the shortcomings of the newly built Te Mato Vai system are evident in storm conditions.

“Avatiu may be accessible, but Avana or Turangi? Not so much,” he said in a post on their group page.

“The intakes are not remotely monitored, so during storms, conditions at the intakes can only be assessed by TTV staff braving the valley access roads.

“In an earlier flood event, I watched staff use the pipeline to cross the stream, with wading across the stream the only option at the next crossing.

“Remote monitoring and the implementation of upstream diversion system will make the water treatment process more efficient and less-hazardous to manage.”

Kirkwood’s recent calls follow claims he made in November, labelling the system inefficient, as he estimated clearing settling tanks consumed 200,000 litres of water each time sludge was removed from the system.   

It followed warnings from the authority in November that the water situation on Rarotonga was bordering on critical. 

Kirkwood has suggested that pre-filtration would involve construction of retention ponds upstream of the intakes, to allow stream water to slow and sediment to settle prior to entering the treatment facility.

“Vetiver grass can be used to stabilise streambanks in the vicinity of the intake this will reduce risk of bank collapse and trap and hold soil and leaf litter.

“It would require some clearing and periodic maintenance of overhanging trees, but could be an opportunity for youth and community engagement.”

A spokeswoman for To Tatou Vai acknowledged extra work is needed to ensure Rarotonga has clean water.

“None of the intake chambers are blocked, hence why they have preventative measures like getting the excess mud/silt cleaned out which is part of managing the intake/plants.

“Despite the muddy water when there is a lot of heavy rain, To Tatou Vai is able to supply clean water to households.

“The plants and network are working fine.

“The TTV team head up to the hills rain, hail or shine to try and provide our community with clean water, and it can be quite difficult in bad weather.”