A panel of independent commissioners has granted a 20-year resource consent for the managed opening of Southland’s Waituna Lagoon to the sea, a move hailed by environmental and iwi groups as a major step toward restoring the ecological and cultural health of the treasured wetland.

The joint application—lodged by the Department of Conservation (DOC), Te Rūnanga o Awarua, and Environment Southland—sets out a long-term regime for lagoon openings based on environmental triggers such as water levels, biosecurity, and fish passage.

Environment Southland Chairman Nicol Horrell welcomed the decision, saying it “reflected years of collaboration and a shared commitment to restoring Waituna.”

“The lagoon levels have been high recently and that has caused some concern amongst the community,” Horrell said.

“This decision is timely and means there is certainty for how the applicants, alongside the community, move forward to care for the lagoon.”

Te Rūnaka o Awarua Kaiwhakahaere Pania Coote called the decision “a meaningful step forward in a shared journey of restoration and protection.”

“As mana whenua, Te Rūnaka o Awarua holds deep cultural and ancestral connections to this taonga,” she said.

“We are proud to stand alongside our partners in securing a long-term, collaborative approach to its care.”

DOC Murihiku Operations Manager John McCarroll said the consent “will bring certainty to the co-applicants, stakeholders and community for the next 20 years.”

However not everyone is celebrating.

Federated Farmers Southland executive member Maarten Van Rossum said the local community is “bitterly disappointed” with the ruling, which imposes tighter restrictions on when the lagoon can be opened to relieve flooding.

“The applicants have been granted pretty much everything they asked for,” Van Rossum said.

“Meanwhile, the arguments of the local community—the people who’ll have to live with more severe flooding and compromised catchment drainage—have been completely ignored.”

He said farmers and residents have long supported the lagoon’s health but sought a balanced approach that also addressed flood protection and land drainage.

“They put a lot of hours and effort into the hearings process, but it seems like we were wasting our time,” he said.

Historically, the community-driven Lake Waituna Control Association has opened the lagoon to the sea during high rainfall events, with recent consents allowing openings at 2.2 metres.

Under the new consent, the lagoon must reach 2.3 metres for three days in winter or 2.4 metres in summer before an opening is permitted—thresholds that will rise to 2.5 metres over time.

“Landowners could reluctantly live with the 2.3m trigger but not the 2.4m mark,” Van Rossum said, warning that flooding at 2.5 metres would be “significant.”

A community meeting is planned for next week to discuss the 113-page decision and consider a potential appeal.

“There’s a lot of anger and disappointment, but we need time to absorb the decision and decide next steps,” Van Rossum said.

Waituna Lagoon, part of the internationally recognised Awarua-Waituna wetland complex, is home to diverse native wildlife and holds deep cultural significance for Ngāi Tahu. It is also a popular site for trout fishing and recreation.

The current application was publicly notified in August 2024 and attracted 51 submissions, of which 19 presented to the deciding panel.