Warnings that Southland's Waituna Lagoon could "flip" - turn irreversibly septic - with the next heavy downpour have so concerned Ngai Tahu it is are bringing iwi elder Sir Tipene O'Regan to address Environment Minister Nick Smith when he visits next week.
Dr Smith is visiting the lagoon - part of the internationally recognised Awarua wetlands southeast of Invercargill - next Wednesday to be briefed on issues caused by intensive dairy farming run-off.
He will also meet concerned parties and local runanga representatives, including Sir Tipene, who is the traditional head (upoko) of Ngai Tahu's Awarua subtribe.
An Environment Southland monitoring report states that "high levels of nitrogen and phosphorous in sediments are threatening to flip the lagoon from being an ecosystem with clear water and populated by aquatic plants and a range of fish species to one with murky, turbid water dominated by algae" - a scenario that would be irreversible.
Research by the regional authority estimates an extra $1.99 million is needed in the next financial year to continue to stop the lagoon from "flipping".
Southland Conservation Board chairman Robin McNeill said it was thought the lagoon could "flip" with the next big rainfall and "turn into a septic tank ... it could take the rest of the wetlands with it."
The board was writing to Dr Smith, tourism minister John Key and agriculture minister David Carter making them aware of the situation and demanding "leadership from government ... we feel high level intervention is needed".
Apart from a few "rotter" farmers, the majority in the Waituna catchment were doing their "best" to comply with consent conditions, Mr McNeill said.
"But possibly the only way forward is to reduce the amount of stock on the peaty soil on the reclaimed swamps."
Dr Smith is visiting the lagoon - part of the internationally recognised Awarua wetlands southeast of Invercargill - next Wednesday to be briefed on issues caused by intensive dairy farming run-off.
He will also meet concerned parties and local runanga representatives, including Sir Tipene, who is the traditional head (upoko) of Ngai Tahu's Awarua subtribe.
An Environment Southland monitoring report states that "high levels of nitrogen and phosphorous in sediments are threatening to flip the lagoon from being an ecosystem with clear water and populated by aquatic plants and a range of fish species to one with murky, turbid water dominated by algae" - a scenario that would be irreversible.
Research by the regional authority estimates an extra $1.99 million is needed in the next financial year to continue to stop the lagoon from "flipping".
Southland Conservation Board chairman Robin McNeill said it was thought the lagoon could "flip" with the next big rainfall and "turn into a septic tank ... it could take the rest of the wetlands with it."
The board was writing to Dr Smith, tourism minister John Key and agriculture minister David Carter making them aware of the situation and demanding "leadership from government ... we feel high level intervention is needed".
Apart from a few "rotter" farmers, the majority in the Waituna catchment were doing their "best" to comply with consent conditions, Mr McNeill said.
"But possibly the only way forward is to reduce the amount of stock on the peaty soil on the reclaimed swamps."
