As New Zealanders head to the sand and surf this summer, Isaac Davison investigates the environmental issues at our most popular North Island beaches. Today it is Mt Maunganui.
In the development heyday of the 1950s, holiday homes shot up on narrow, sandy fingers of land around New Zealand's coastline.
New Zealanders' love for living close to the sea saw dubious subdivisions built on erosion hotspots.
Decades later, the sandy coastline retreated, and homeowners found their homes perilously close to the ocean, or in some cases, swamped by the tide.
Residents at Omaha, north of Auckland, Aotea Harbour, near Raglan, and Mokau, north of New Plymouth, had to abandon their properties or shift their house to the back garden.
As scientists predict rising sea levels over the next century, could the same coastal unsettlement ever occur at one of New Zealand's most popular resorts, Mt Maunganui?
The Mount community has grown rapidly since a deep-water port was established there in the 1950s.
The striking, 230m tall mountain and magnificent arc of white-sand beach which first attracted settlers in the early 1900s has made the Mount into a holiday mecca.
Squeezed into a narrow strip of land between the main beach and Pilot Bay, development has surged upwards on the peninsula, with several 18-storey buildings now lining the town's centre.
Facing sea level rises of 55cm over the next 100 years, local authorities have moved to make sure that further development is strictly limited on the coastal fringes.
However, clusters of houses, mainly in Papamoa East, have already been built on the wild dunes and too close to the high tide mark.
The Tauranga City Council's district plan, which is in the public submission phase, is likely to reinforce a 20m gap between the mean high water spring mark and residential buildings. This will prevent houses being built on top of the dune barrier.
Niwa coastal oceanographer Rob Bell says that while sea level rise is gradual, advance planning is crucial.
Coastlines are dynamic strips of land, which "breathe" over decades, gaining and losing their sand. The Omaha development was unwisely built out of phase with the cycle of accretion and erosion, and found itself isolated when the sand retreated - a predicament known as coastal squeeze. "Coastal squeeze is when you suddenly find yourself between a dynamic ocean and a fixed landmass, and you're in an erosion cycle," Mr Bell says.
Coastal defences, such as a seawall, are only a short-term solution and interrupt the natural cycle of the coast. They also lead to the inter-tidal sand being washed away. That sand can be replaced at a small city beach such as Kohimarama, but not at huge beaches like the Mount.
Mr Bell says: "Development into the future will have to consider not only coastal erosion but also storm tide inundation. Rather than being once every 50 years, [inundation] could be quite regular, every other year."
In response to rapid development from Mauao (the Mount) to Papamoa and the popularity of the beach, the regional council pioneered one of the country's first coastal care projects.
The Coastcare group, a collaboration between council, community and the Department of Conservation, focused most of its attention on preserving the beach's dunes. When the dunes degrade, wind blows up on to the road and into houses and shops.
Reduced dunes also made the million-dollar homes on the beach vulnerable to storm surges or tsunami. The Bay of Plenty is in the line of a tsunami in the event of a large-scale event at the Kermadec Ridge of volcanoes in the Pacific.
Coastal care co-ordinator Pim de Monchy says dunes drastically reduce the energy of large waves. "The Boxing Day tsunami demonstrated this by causing more damage in resorts where dunes had been flattened compared with others where the dunes had been left unmodified."
He has overseen volunteer planting of 180,000 coastal plants, which grip the dunes and strengthen them. The use of dune plants such as spinifex and wiwi has allowed the council to extend its seaward fence 10m closer to the sea.
While Mount residents have built monstrous properties on the beachfront, they have also been quick to buy into the volunteer projects, which include controlling rabbits, fencing and talking to beach users.
Council officials say that while some residences have impinged on the sand buffer, the greatest threat to the dunes' health was from the influx of visitors over the summer period.
A huge fencing programme has restricted access to walkways at most points except the main beach.
Bulldozers flattened the dunes at the main beach in the 1940s, and they have never returned to their previous height.
Mr de Monchy says the main stretch is impossible to protect, because there are too many visitors to channel them into walking paths. "Aesthetically it looks nicer when it's got dune plants there, and it would do a better job of trapping sand. But in terms of public use it might be better the way it is."
If Mt Maunganui's development is kept in check, it will ensure a buffer remains between the land and the sea.
Residents at the Mount will have to make sure that their love for being close to the ocean is tempered ... for a few metres, at least.
