environment

Watery limbo for flood-prone bay

Residents living near a popular recreation area face tough choices as sea levels rise, reports Eloise Gibson

The birthday party guests couldn’t see the rising harbour from inside the bowling club at Little Shoal Bay, so it came as a surprise when a passer-by, Kyle Aitken, popped in and told them their cars were flooding.

Men stripped to their underwear to move their vehicles, but a few cars’ electronics had already been ruined by seawater.

The flood was one of a few recent, watery incidents at Northcote Bowling Club, which is nestled in a low-lying crook of the Waitemata Harbour on Auckland’s North Shore.

The gradual rise of sea levels means the starting point is getting higher for floods that are already causing problems in the small bay, the worst of them caused by unlucky combinations of king tides, heavy rains, and storm-surges.

In January 2011 a king tide, high winds and a low pressure system joined forces to inundate swathes of Auckland’s coast, including the road, public areas and sports fields that sit near a stream-mouth at Little Shoal Bay.

In January 2014, Little Shoal Bay flooded again, this time without a storm.

Four years later, in January 2018, the bowling club and its playing greens were flooded during large storm tides, leading to an insurance claim and costs to replace the bowling greens.

Already, the bowling club avoids scheduling tournaments during spring tides, but it's not only the club that's being affected, says John Gillon, the chair of the Kaipātiki Local Board.

The sports fields nearby are also flooding, and in between floods their edges are being slowly eroded by seawater. "We are seeing saltwater crabs taking up residence around the edges because there is so much seawater around now and we are losing the freshwater plants [in the stream]," says Gillon. "It was happening anyway because of rising seas but also the mechanical flaps [that used to prevent saltwater backing up] haven't been working for the past 10 years."

The local board and users of the club and playing fields have to decide whether to fight the tides and keep their recreational facilities where they are, or give up and let the area become an estuary.

A preliminary report by Auckland Council’s Healthy Waters division on the future of the bay’s Dudding Park sports field notes that Auckland’s long-running tide gauge measurements show that 15cm of sea level rise has already happened in the harbour over the last century, and the base sea level is expected to continue sneaking up for centuries more. That will add to problems caused by king tides and other naturally-occurring phenomenon.

According that, early, report, the long-term options are to try to engineer a way out of the flooding, by raising ground levels, building bunds, pumping away water and building flood gates; or to engage in what the report calls “educate through acceptance”. That likely means dismantling infrastructure that is not equipped to weather flooding, such as buildings and bowling greens. It would mean allowing the playing fields and freshwater stream in the bay to revert to a salty, floodable estuary; offering locals a different kind of outdoor experience.

It's not clear how much the various engineering measures would cost nor how much time they would buy from the encroaching tides.

“The question is, how much can we do to hold back nature?” says Danielle Grant, a member of the Kaipatiki Local Board. “Do we accept the impact of climate change … and work with it rather than against it, or do we raise the height of the sports field or put in a bund? To decide, we need quality engineering advice.”

That advice is supposed to be coming from Auckland Council, which has commissioned a detailed report from consultants on the options to deal with flooding at Little Shoal Bay. The board was told the report was close to completion several months ago. "We're frustrated. We were given a presentation over a year ago and ever since we've been waiting for a copy of this report," says Gillon.

Asked about the bay's future, Auckland Council confirmed it had commissioned a report on the flooding and the future of council assets – including the stormwater, sport fields, walking tracks and the car park, but did not supply any more details.

At a meeting in July, the local board resolved to request an update on the report from Auckland Council and to note that "the Local Board has been waiting for one year for solutions”. It was the second time the board had passed a similar resolution.

Until they learn more about the options, locals like Kyle Aitken say they’re in limbo.

Aitken, a member of the local environmental protection society, has been videoing the floods every time there's a big tide and watching his local environment changing from the added salt water. He’s noticed that the wetland near the playing fields is turning from a freshwater stream into a marine environment, filled with mangroves.

He says the bay is one of the only accessible seaside public spaces on that part of the North Shore. It has already been returned to the public once, decades ago, after initially being sold off for a housing development.

Though he doesn't know yet which plan he'd personally support, Aitken is keen to see the council do something – either by raising the field and surrounding walkways or removing them proactively “rather than let them become eroded mud messes”, he says.

And there's a pressing concern – a box of electric wires sits below the flood zone, which Aitken has photographed smoking during bad flooding.

Gillon, the local board chair, says people who've had to wade through floods near the electric box have reported feeling "tingling" in the water, an issue he has reported to the council.

As well as sorting that out, Aitken says it would be handy if the council put up a warning sign, alerting drivers that the road can flood. That way, he might not have to see unfortunate party guests wading in their underwear to rescue cars. 

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