Once we’ve transformed the inner city, how about the estuary? – صحيفة الصوت

Liz Craig is an Invercargill-based list MP

With Parliament in recess, it was fantastic to be able to attend the grand opening of Invercargill Central – Stage One earlier this month. The much-anticipated event was a testament to all those who’ve worked so hard to get the project to the current point, despite supply chain disruptions, lockdowns and worker absences due to COVID-19.

Once completed, Invercargill Central, the ILT’s new Langlands Hotel and the streetscape work which accompanies them, will have transformed the inner city, making it a premiere shopping, dining and entertainment destination.

Yet the liveability of any city is determined not just by the quality of its built environment but also by its connections with the natural environment, and in the case of Invercargill’s New River Estuary, little progress has been made.

READ MORE:
* Saving our wildlife from plastic waste
* Does Invercargill need a waterfront?
* Southland waterways to benefit from $700 million funding boost

A 2021 report by Salt Ecology titled “Macroalgae and Seagrass Monitoring of New River Estuary” paints a very concerning picture.

It found the amount of nutrients going into the estuary far exceeded its ability to assimilate them, leading to the widespread overgrowth of nuisance macroalgae, extensive patches of oxygen starved sediment and the loss of high-value sea grass.

It found 82% of the estuary’s sea grass had been lost between 2001 and 2021 and in some areas the sediment was so degraded even nuisance macroalgae couldn’t survive, with bacterial mats instead forming on its surface.

The authors concluded: “The scale of eutrophic symptoms in New River Estuary is unprecedented in New Zealand and emphasises the urgent need to manage sediment and nutrient loads to prevent further adverse impacts in the estuary”.

Another report by NIWA in 2019 on “Human health risks associated with contaminants in Southland waters”, explored the health impacts of some of the discharges going into the estuary, including waste water (sewerage), storm water and landfill leachate.

It noted Invercargill’s wastewater network, which discharges into the estuary at Clifton, not only received domestic waste but also trade waste and leachate from the regional AB Lime landfill in Winton.

In addition to potentially toxic metals, it noted wastewater effluent was known to contain a range of other contaminants including pesticides and pharmaceuticals.

It also noted Invercargill’s stormwater network, which also discharges into the estuary, had cross-connection issues, which resulted in raw wastewater (sewerage) entering the stormwater network in places.

Another 2019 report by e3scientific titled “New River Estuary Reclaimed Land Desktop Assessment” described concentrations of heavy metals above detection limits and extremely high concentrations of nutrients in surface and ground water samples taken at the northern end of Pleasure Bay, the site of Invercargill’s former landfill.

A visit to the site found large amounts of orange staining and sheen arising from numerous groundwater seepages and no mud snails or infauna were evident.

It’s therefore unsurprising the Regional Forum’s recent report to Environment Southland and Te Ao Mārama outlined its desire to see all direct-to-water discharges of urban and industrial waste water end by 2045, as well as the need to identify options for filtering urban stormwater prior to its discharge.

The Government’s Essential Freshwater package, which includes measures to protect wetlands and streams, exclude stock from waterways, and manage intensive winter grazing and the excessive application of nitrogen fertilizer may also reduce some of the nutrient and sediment loads entering the estuary in future.

However for Invercargill to be a truly liveable city, decisions will need to be made about our natural environment and the best way to restore the estuary, on whose shores the city was built.

Developing a vision of what this looks like is a job for all of us. It’s also the focus of the Gateway Murihiku Exhibition which opens at He Waka Tuia on Friday July 29. I’d encourage anyone with an interest in the New River Estuary to come along and join the discussion about its future.