Tahuna's erosion back on agenda

23:00, Jan 17 2014

It's time Nelson City Council took another look at Back Beach's erosion problems, Nelson mayor Rachel Reese says.

"My personal position is that a review of managed retreat is timely," Ms Reese said. "We do need a plan of attack, of perhaps defence."

The sea is steadily eating away at Back Beach's dog walking area and causing problems at the adjacent Tahuna Beach Holiday Park as Blind Channel swings east, eroding about 3m a year.

Council staff are preparing a parks and reserves asset management plan that will recommend commissioning an up-to-date review of the area, including the impact of sea level rise and options for managing erosion. The draft will be presented to a council workshop in March.

In 2001, the council introduced a policy of "managed retreat" at Back Beach, which meant it would let natural coastal processes happen and not intervene except to remove structures in the way.

A "cut-off line", at which the council would step in to stop erosion, does not yet exist, though council staff had been monitoring the area yearly. In a 2010 report to Nelson City Council, consultants Ocel said the erosion would not recover in the short term, and recommended the council conduct more research into the movement of Blind Channel to compare with the most recent survey, in 2004. It also recommended a study into the effects of sea level rise under climate change.


Ms Reese said previous councils cut funding for modelling the scenarios as part of setting rates. "Reinstatement of this funding will need to be considered . . . as a mayor I want good information before I commit ratepayer funds to capital projects.

"[Modelling] is not cheap to do," Ms Reese said. "It's quite a lot of money to have to do it, but what [Ocel] said would happen has happened. There's nothing particularly unusual happening, but we need to make sure we have an understanding of the rate of change, and there are suggestions from people to use a hard structure approach."

However, protecting one asset often meant degradation of another further along the coast.

"Every council needs to be up to date on natural hazard risks - both sea level rise and coastal inundation," Ms Reese said. "We also have to acknowledge that fighting against natural processes and a dynamic environment can be both costly and futile."

Back Beach erosion concerns Tahuna Beach Holiday Park manager Ann Cumpstone, who told The Nelson Mail last week that she wasn't sure if the holiday park, on council land, would exist in the future as the park became "the front beach".

Mrs Cumpstone called for the council to help fund erosion protection works in the area, and said news that the council might review its policy was "brilliant".

A Holiday Parks Association of New Zealand study showed that the camp brought in almost $20m a year to the Nelson and Tahunanui area, she said. "We get less than 15 per cent of that and the rest is campers spending on petrol, food, alcohol.

"Tahuna is not very vocal; we have always been pretty laid back, and have always been forgotten."

Nelson Tasman Tourism chief executive Lynda Keane said the area had been the main hub for the visitor and holiday season for decades.

"[It is] an important asset in the tourism offering and I'm very keen to support the holiday park [in] discussing with the council how we can protect [it]," she said.

Tahunanui Business Association chairman Mike Thomas said the organisation was "very concerned" about erosion.

"Hopefully the city council will do the right thing. We definitely need the park."

Tackling nature, page 13

The Nelson Mail