Work is set to begin next month (Feb) on a new channel above Meridian's Manapōuri Lake Control Structure in an effort to better flush nuisance periphytons like toxic algal boom and Didymo from the Waiau River.

The work, estimated to cost between $5-7million, was consented in 2024 and will see 225,000 cubic meters of gravel excavated and moved onto Meridian land.

Meridian said the current channel depth and alignment, and gravel build up, haven’t been as reliable as was intended when the consent condition was put in place in 2012.

Meridian Energy's proposal to redirect water through a new channel above the Mararoa Weir. Photo: Meridian Energy

Meridian said it aimed to provide four or five flushing flows every year, when necessary, to maintain the health of the river.

Lead project contractor, Rooneys, will establish themselves on site from early February, before creating a road for construction vehicles and gravel removal.

Meridian said it was very important that people don’t try to enter their property during construction as there will be heavy machinery in use.

The project will be managed to strict consent conditions to protect water quality, fish and kākahi (freshwater mussels), native sedge plants and nesting birds, they said.

Following completion of works the site will be enhanced with wetland restoration.

Meridian said the project is expected to take around 4-5 months, but due to variable weather conditions and lake levels, the project is allowing a 10-month construction period.

CLICK HERE to read more.