Net trial could save choking river

By Aroha Treacher
  • North Island: East Coast

Weed build up continues to choke the Ngaruroro River in Hawke's Bay, a river that the home people of Kohupatiki Marae have been fighting for years to clean up.

Various methods have been tried- the latest is a net the width of the river to catch the weeds.

A 'catch and carry' trial with a net the width of the Old Ngaruroro River, downstream from the Karamū, is a first for the region.

"We've been requesting this for 10 years.  Take the weed out of the river, don't let it clog up and move down- so they've done that," says Aki Paipper of Kohupatiki Marae.

"What this will do- this net will catch the weed and they will extract it from the river so it prevents it from floating out because we have no flow anymore, no velocity in this river so everything that comes down is slow moving."

The trial net was installed to understand the viability and costs of cutting and removing the weeds that build up in the Karamu Stream network during the summer months.

"My understanding to do with rivers [is that] you never put a net across the river- the full width of the river," says Tihau Bishop, Conservation Engineer, "That's what we witnessed today as we came up around the corner and I realised that it had dammed up almost 25m of weed behind it, which means it's an effective dam for fish and wildlife,"

In December last year, the weeds were so thick that around two hundred fish were found dead on top of the weeds.

The net has only just been removed with a draft report of the findings set to be finalised in the coming weeks.