The Future Beach

The Future Beach How will sea level rise effect the Kiwi Beach Experience?

1

2

Logan Pennington Negotiated Studies Research Project (BLA) Unitec, 2014 Supervisor: Matthew Bradbury Email: logan.pennington@hotmail.co.nz Mobile: +64 21 0232 9183 Other publications: http://issuu.com/logan.pennington

Abstract

The issue of coastal erosion and sea level rise has been threatening the community of Orewa since the beginning of development. Environmental factors caused from this issue have resulted in the loss of ‘dry beach’ at Orewa and the effects of this on the socio-economic; recreation and conservation factors aren’t positively balanced.

Part one of this research project investigates a variety of techniques being used around the world and adapts these core concepts to Orewa’s environmental problems. The use of a flexible approach of these interventions will befit the temporality and flexibility of the coastal environment while using coastal forces to its advantage. Part two explores how the effects of a growing population, growing demand for beaches, erosion rates and rising sea levels will change the kiwi beach experience we all grew up with and know to well.

3

The beach is one of the most valuable public space assets New Zealand has and the issues we are currently facing, with coastal erosion and sea level rise, leaves a big question mark for the future of these coastal zones and how they will be used.

4

Contents 3

Contents

5

Introduction

6

New Zealand Beach timeline

8 11

Case studies

12

Orewa Beach

23

The Hauraki Gulf G.I.S analysis Environmental issues

24 25 28

Design interventions

30

Natural storm water exits Off shore reef / kelp forest Land reclemation Ribbed coastal edge Mini headlands Gridded planting Waitemata reef Recreational island

34 40 46 50 54 58 62 66

Future speculations

70

Protect Adapt Retreat

71 73 75

Conclusion

76

References

78

5

Abstract

Introduction

6

New Zealand’s coastline can be perceived as a cultural, commercial and social magnet to us Kiwi’s.

The relationship between these factors in exchange for an experience is what equates to this summer time beach migration we all know too well. The idea of this summer ritual activates our fragmented memories of growing up tenting, surfing, fishing, diving and just relaxing on sandy beaches in the hot sun. Having grown up on beaches, the experience, fulfillment and energy that we get from these sandy shores is unique. The way we all use our coasts, even off the beach and in the water, on a boat, under the water, these amenities that the Pacific Ocean and the Tasman Sea offer us are some of the most valuable public space assets we have. The constant change and uncertainty within the moving sands, estuaries, and oceans is most interesting to some while the endless views and fresh salty air sees frequent visitors converted to residents. Together with the popularity and a high level of demand from these beautiful locations, are we becoming distracted from the reality of the coast as a natural and fragile environment?

Coastal living around the world and in New Zealand is increasingly common due to the natural amenities of beaches, oceans and harbors (see map). With the increased development of coastal regions, the risk of coastal erosion has increased in many New Zealand localities (Blackett, Hume and Dahm, 2010). Addressing this issue has become a popular topic among many coastal communities since the loss of character and amenities that attracts visitors and residents is, in some cases, deteriorating.

7

“How to address coastal erosion is a challenge for many coastal communities because there is debate about alternative remedial measures, resulting in conflict that needs to be resolved� (Blackett, Hume and Dahm, 2010).

Landscape Architects have been strong advocates for the protection of coastal environments, and specifically involved in the mitigation of coastal erosion. It is well recognized within landscape architecture, that the degradation of beaches, cliffs and ecosystems remains a critical issue, especially given the assumed changes in our natural weather systems due to global warming and sea-level rise. These changes pose a threat to nearly all areas of New Zealand’s coastlines, harbors and oceans, with the issues compounded by human intervention and disturbance through urban development.

Coastal Settlements, North Island, NZ

New Zealand Predominant south west winds and swell sweep the western coast of the North and South Islands resulting in consistently dramatic changes in terms of sediment movement and form of coastal zones.

The eastern coast of the North Island receives little swell when compared to the west resulting in various bays and coves. The share of swell and wind usually comes in the form of a tropical cyclone. This high intensity swell and wind comes from the north east and usually results in devastation to several sea side settlements damaging homes and eroding coastlines. Coastlines can be eroded so much from these events that, in areas of densly populted coastal development, the safety of built infrastructure becomes vulnerable.

Marked predominance of winds at all speeds

8

Marked predominance of strong winds

Figure 1. Prevailing wind direction and strength in New Zealand (McKenzie, 1958)

Figure 2. Geomorphic types around the New Zealand open coast (NZ climate change programme, 2001).

Raglan Bold Coast

Tairua Bay / Cove

New Zealand has a range of coastal types that range from bold coasts, headlands and bays, low cliffed coasts, depositional coasts and beaches. Out of these types some are more susceptible to change than others, the ones with sand, depositional coasts and beaches like Muriwai especially because of the long shore drift that moves sediment up our coastline. ‘Spits’ are also one of the most frequently changing areas as they are totally surrounded by water, a common example of this can be seen at Omaha, they have had to use groins to control the change of the harbor entrance (refer to image on timeline).

9

Mount Maunganui Headland Beach

Ohiwa Spit

Muriwai Depositional Coast

>

1948

>

10

Maori & European Settlement Wind

>

Waves

>

Energy

>

Vulnerability

>

?

? >

> >

Long Term Damage

> >

?

?

Maori establishment was the first coastal settlement in New Zealand, most of the land was then taken over by the early European settlers. As the years passed the coast was a popular place to visit and the kiwi beach culture continued to grow. Tenting in remote places led to more permanent stays with the introduction of small bachs and shacks. As the population grew, the demand for this summer time beach culture was of more demand. The idea of getting as close to the water as possible holds the most value but in some areas, these ‘beach front’ properties are vulnerable to the ocean and the protection for this infrastructure can effect the shape and form of the beach space.

Parallel to this is the process in which the ocean takes to get to the stage of catastrophe.

Wind creates swell, this energy then travels large distances until it hits shallow waters and morphs into a waves. When these waves are in line with vulnerable / fragile areas of coastline, the ultimate effect is erosion and inundation. The energy from the ocean changes the landform and this can produce long term negative effects for a lot of coastal areas.

Looking at the empty box’s, with most coastal settlements at full capacity along beach front areas and with the continuation of storms and the increase of sea level rise, what does this mean for the future ‘Kiwi Beach Experience?’

11

Erosion

2014

Beach Timeline

12

Case Studies

Retreat

Abandonment Coastal Realignment

Artificial Reef

Sand Pumping Sand Replenishment

Coastal Realignment

Artificial Reef

Land Reclamation Sand Replenisishment

Dune Re-establishment Artificial Islands

13

Sand Pumping Sand Replenishment Artificial Islands Coastal Realignment

Recreation

Adapt

Conservation

Socio Economic

Protect

Coastal Realignment

Figure 3. Happy Isles (West 8 and Svasek, 2006)

Figure 4. Happy Isles (West 8 and Svasek, 2006)

Happy Isles

The Happy Isles Consortium - West 8 and Svasek– drew up a plan which combines an agenda for safety, and the necessity of new land. The participants offer the metropolis a new perspective by proposing a series of new, sprayed-up sand islands off the coast of Belgium and The Netherlands. These Artificial Islands, measuring up to 150.000 hectares in size, will break the increasing waves. Also, thanks to ingenious engineering of the gullies, the off-shore under tow will cause the sea level to drop during north-western storms.

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

On the biggest island, Hollandsoog, 150.000-200.000 ha. in size, a broad representation of the community will be able to obtain a lease. The economy of this island will be based on leisure and nature experience; a happy island for family, lonelyhearts, poets and festivals (West 8 and Svasek, 2006).

PROTECT

14

2006, The Netherlands, Belgium, Dutch and Flemish Coast

Naviduct Enkhuizen 2003, The Netherlands

15

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

Artificial Island structures contrast with a curved dike. Behind the dike will verlandingsproces produce whimsical shapes. When constructing one million m3 was released. The material is a port formed, which Naviduct Polder protects against waves and ice. The outer edge is a tight arc, finished with a rip-rap and underlined with an edge black poplars. The opening for the shipping is marked with a stone head. The inside is soft and has inlets. From the dike, the viewpoint of the locks looks across the water each time deep in the lagoon-like area. Gradually, nature will arise here with a diversity of transitions between dry and wet areas (Louis Baljon Landscape Architects, 2003).

(Translated from Dutch to English)

ADAPT

Figure 7. Naviduct Enkhuizen (Louis Baljon Landscape Architects, 2003).

Figure 6. Naviduct Enkhuizen (Louis Baljon Landscape Architects, 2003).

PROTECT

Figure 5. Naviduct Enkhuizen (Louis Baljon Landscape Architects, 2003).

Figure 8. Zandmotor over the years 2011 - 2021 2031 (Rijkswaterstaat, 2011).

Figure 9. Zandmotor (Rijkswaterstaat, 2011).

2011

Zandmotor

SOCIO ECONOMIC

2031

RECREATION CONSERVATION

RETREAT

sand replenishment unnecessary in this area for the next 20 years. An additional benefit is the creation of a stable local ecosystem. The Zandmotor has already become a popular destination for surfers and kite surfers. Seals frequently visit the giant dune, and seaweed has covered the bottom of the new lagoon, creating a habitat for fish.

Living below sea level requires a different way of thinking about how to live with the forces of nature. The Zandmotor is an important experiment in dynamic coastal management, and may become a model for similar projects along the Dutch coast as the weather becomes more erratic, and protection of the coastline becomes a matter of survival. This approach proves that the largest projects are best managed by working in harmony with nature, not against it (Rijkswaterstaat, 2011).

ADAPT

2021

In 2011 an innovative alternative method of coastal protection was implemented by Rijkswaterstaat and the Province of South Holland in the area between Rotterdamand The Hague: 21.5 million cubic metres of sand was dumped into the North Sea all at once, creating the Zandmotor (Sand Engine), an artificial peninsula of 128 hectares, or 256 football fields. Within 20 years, if everything works as expected, the wind, waves and sea currents will evenly distribute the sand along the 20-kilometre stretch of coast, reinforcing the coastline and creating wider beaches and new recreational areas.

Construction of the peninsula cost â‚Ź70 million, an investment that should make further

PROTECT

16

2011, The Netherlands

Figure 10. Artificial reef at the Gold Coast, Australia (Vroom, 2013)

Figure 11. Narrowneck artificial reef Gold Coast QLD Australia (Banks, 2008)

Multi Purupose Reef

2000, Narrowneck, Gold Coast, Australia 17

At the Gold coast in Australia an artificial reef is constructed with large filled sandbags (up to 350 ton). The aim of the artificial reef is to provide beach protection and to enhance surf conditions.

At the beach a salient formed in the lee of the structure, resulting in an accretion of approximately 10-20 m in two years (Vroom, 2013)

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

The outcome: “The Narrowneck submerged reef has been hugely successful at retaining sand nourishment material pumped onto Surfer’s Paradise Beach from the Broadwater. Argus coastal imaging has shown that wave energy is dissipated by the reef for up to 90% of the time and that Narrowneck reef is an erosion control point on the coast. The reef is primarily a coastal protection structure, as the Gold Coast experiences ongoing issues with beach erosion and shoreline retreat during storm events. Officially, the secondary objective of the reef is to improve surfing”. (Surfing ramps, 2014).

ADAPT

The Gold Coast is Australia’s primary tourist destination, with its wide sandy beaches being a major attraction. The erosion problem on the Gold Coast was confined to a hotspot at Narrowneck where only the coastal road separates the Broadwater from the sea. This causeway was breached several times in the previous century and coastal protection was proposed as part of the Gold Coast Beach Protection Strategy to address this problem.

The aims: of the project were (a) to widen the beach and dunes along Surfers Paradise Esplanade; and (b) to improve the surfing climate at Narrowneck.

PROTECT

Figure 12. Narrowneck Reef (Edwards, 2014)

18

Figure 13. Medmerry (Breiner, 2014).

Strategic Retreat

2014, Medmerry, Sussex, England

Before the realignment project there were just two short stretches of public foot paths around the small, 50 hectare RSPB reserve.

Now there are 10 kilometers of foot paths and seven kilometers of new bike paths in an area completely dependent on tourism for the local economy. In addition to attracting more people, the project has also actually extended the tourism season in the area. Bunn Leisure in Selsey, the largest vacation home development in the area, once only allowed to be open for eight months because of the risk of flooding, can now extend its season for an additional two months. The vacation home park employs over 300 people (Breiner, 2014).

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

The controversial plan? Cut a 100 meter channel into the shingle bank and let the ocean reclaim 500 hectares of land, transforming three farms and the RSPB nature reserve into a saltwater marsh. Then behind the newly created inter-tidal zone, about two kilometers inland, build a new seven kilometer curved clay embankment — completely “realign” the coast. The price? £28 million ($46.5 million). The coastal realignment not only moves the sea wall further inland, it also creates a powerful buffer zone of marsh that can absorb storm energy. Interestingly, there is archeological evidence that the area was originally dominated by saltwater marsh hundreds of years ago.

PROTECT

Vast stretches of the Somerset Levels, an expanse of coastal plains and wetlands in southwest England, have spent much of the winter underwater. At the peak of the crisis, some 11,500 hectares (28,420 acres) was submerged as violent storms brought “biblical” deluges week after week, for months on end. Along Britain’s scenic coastline, 80 mph gales and tidal surges have left cliffs crumbling into the rough sea, beaches and sand dunes eroded, sea defenses breached, and shorelines and harbors damaged beyond recognition. […]Since the 1990s, the probability of the shingle bank being breached in any given year, however, was one in one, necessitating that the Environment Agency haul a fleet of diggers out to the beach each winter and reconstruct what nature seemed so determined to destroy.

Figure 15. Hurricane Sandy (USGS, 2012).

Hurricane Sandy

2012, Eastern Seaboard, United States Hurricane Sandy, one of the biggest storms ever to hit the United States, struck the Eastern Seaboard on October 29, 2012. It caused dozens of deaths and billions of dollars worth of damage forcing abandonment. […]

“We found that there was widespread dune erosion and overwash,” said St. Petersburg-based USGS coastal geologist Cheryl Hapke. “On average, the dunes eroded back 70 feet—the equivalent of 30 years of change, which had previously been measured. Our data also showed that dunes lost as much as 10 feet of elevation.” (USGS, 2012)

Figure 14. Hurricane Sandy and cliimate change (AOSIS, 2012)

RECREATION CONSERVATION

RETREAT

ADAPT

PROTECT

19

SOCIO ECONOMIC

Tweed River Entrance Sand Bypassing Project

1998, Coolangantta, QLD, Australia

Figure 16. Superbank Gold Coast (Coasalwatch Australia, 2013)

River dredging had been undertaken in the Tweed since the late 1800s in attempst to improve navigability and these works culminated in the extension of the training walls at the river entrance during 1962-65. Although extension of the training walls improved navigation for a period, the sand bar over the entrance began to reform in the 1980s and 1990s. While the rock walls did help to improve the passage of watercraft for a time, their presence ended up altering the erosion and sediment patterns of the southern Gold Coast beaches, resulting in a build up of sand along Letitia Spit and significant erosion along the southern Gold Coast beaches.

The first stage of the project (undertaken between 1995-1998) involved dredging more than three million cubic metres of sand from the Tweed Bar and entrance to create a navigable channel. The sand was pumped out via outlets at Snapper Rocks and Kirra, and it did an excellent job of replenishing the beaches in Coolangatta’s Rainbow Bay. While that pleased the sunbakers, the natural tides and currents quickly worked their own magic and turned the fresh sand into a massive bank stretching between the two pumping outlets.

When the northern and easterly swells began to hit this new bank, a brand new type of wave was formed, and in big swells, under the right conditions, the superbank becomes a combination of the original Rainbow Bay surf spots: Snapper, Greenmount and Kirra. In Autumn 2002, local Surfer Damon Harvey managed to ride a 4-6 foot wave the entire distance from Snapper Rocks to Kirra - earning him a slot in the record books as the person to ride the longest ocean wave at over 1.5km (about four minutes in length).

SOCIO ECONOMIC RECREATION

Figure 17. Snapper Rocks Coolengatta QLD Australia (Snapper Rocks, 2006)

CONSERVATION

RETREAT

ADAPT

PROTECT

20

While that pleased the sunbakers, the natural tides and currents quickly worked their own magic and turned the fresh sand into a massive bank stretching between the two pumping outlets.

When the northern and easterly swells began to hit this new bank, a brand new type of wave was formed, and in big swells, under the right conditions, the superbank becomes a combination of the original Rainbow Bay surf spots: Snapper, Greenmount and Kirra.

In Autumn 2002, local Surfer Damon Harvey managed to ride a 4-6 foot wave the entire distance from Snapper Rocks to Kirra - earning him a slot in the record books as the person to ride the longest ocean wave at over 1.5km (about four minutes in length). (Snapper Rocks, 2006)

Fig 20. Polders and Dikes along the North Sea, the Netherlands (Lunar and Planetary Institute1997)

Figure 19. Land reclamation in Spieka-Neufeild (Monika & Peter, 2006).

Polders and Dikes The Netherlands

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

PROTECT

Once drained, each of these land parcels was sown with plants to remove moisture and bind the soil. Rainfall helped to remove salts from the soil. Subsequently the plant cover was burned and plowed under.

From the time the dikes are in place, it takes approximately 15 years before the land is ready for planting. Since the twelfth century, more than 7800 square kilometers of land has been reclaimed from the sea by the Dutch. (Polders and Dikes along the North Sea, the Netherlands, Human imprints from space, 1997)

21

Figure 18. Dutch lowlands from the air (Stewart, S & Marseille, H 2011)

The extent to which humans manage the natural environment is starkly apparent in this scene over the Netherlands. Most of the tan portions of this scene are land that lies below sea level and was reclaimed from the North Sea (dark blue). Some of the most recently reclaimed land — referred to as polders — is visible in the righthand (southwest) side of this image. At the entrance to the bay is a large dike (thin, straight line) that has effectively turned the estuary behind it into a shallow, salty lake. Large areas behind this dike were then isolated with additional dikes. Extensive pumping of water behind this second system of dikes eventually exposed the sea bottom.

22

Orewa Beach Orewa Beach is one of New Zealand’s many beach towns. Nestled within the islands and peninsulas of the Hauraki Gulf just north of Auckland, the ENE fronting beach is currently facing its own unique problems within its context of beaches. The 3 kilometer long white sandy beach that attracted over “7000” of its inhabitants is being eroded at such a rate that makes it impossible to walk on sand from one end to the other during high tide’s (Statistics New Zealand, 2006). The long flat gradient and lack of dry beach are just some of the key symptoms of a “sick beach” and if the remedy is not discovered in the near future, Orewa’s sand will continue to fall deeper and deeper into the Hauraki Basin (Sea friends, 2000). With the Royal Society, (2010), predicting sea level’s to rise an average of 1.1 meters by the year 2100, is Orewa, “The magic getaway just 20 minutes north of Auckland,” going loose what makes New Zealand beaches the most magic of all? (Destination Orewa Beach, 2014).

23

Oceanic Incursion Sediment Transport - Storm

The Hauraki Gulf

Sediment Transport - Calm Hen & Chicken Is. Mokohinau Is.

Bream Bay

Sediment transport and erosion susceptibility Mangawhai

Little Barrier Island

Great Barrier Island

“Water circulation and currents in the Hauraki Gulf are largely driven by the combined influences of ocean currents, wind, tides, bathymetry and the shape of the coast. The East Auckland Current is a key oceanographic feature of the outer Gulf, which flows southwards along the margin of the continental shelf and effectively defines the boundary between coastal and oceanic waters. The continental shelf bulges out in the northern Gulf, where the 200 m depth contour is situated around 80 km from the mainland. Further south, the continental shelf curves towards the shore and in the southern-eastern section of Coromandel Peninsula the 200 m depth contour is only 23 km out from the coast. Depths increase sharply out from the Alderman Islands to exceed 500 m at the Park boundary�

(Hauraki Gulf Forum, 2011).

Cape Rodney

Colville Channel

24

Hauraki Gulf

Orewa Beach

Waiheke Island

Coromandel Peninsula

Auckland

Manakau Harbor

Firth Of Thames

´

Legend High tide_average StormwaterDrain20110810_Clip

GIS Analysis The flood plain is located in the slack zones of the dune system and connects with the edge of the estuarine margin at the south end of Orewa. Overlapping the building footprints shows just how large the area of effected infrastructure is.

Including the future predictions for coastal erosion, the exchange of land for sea is already happening and the use of GIS data has educated this research project to accurately measure the vulnerability of Orewa Beach.

Flood_Plain Impervious_Surfaces_2008 Building_Outlines_2008

The wave characteristics, when directions are between 50° and 110°, are low height and period indicating sea conditions rather than swell. During large swells the range of wave directions is truncated at 200° and 270° because of sheltering behind Great Barrier Island and the northern tip of the Coromandel Peninsula. If the local sea swells generated by offshore wind is discarded the average wave direction is 236° with a standard deviation of 22°.

0

0.175

0.35

1:10,000 @A3

0.7 Kilometers

The maximum significant wave height at the hindcast site during the 20-years was 7.19 m (13.5 s, 236°; 22 June 1996). (ASR ltd)

25

Wind and swell roses show the frequency of occurrence for wind and wave heights to different directions. It can be seen that the majority of waves come from a 30° directional window. A small amount of swell is directed in the offshore direction (towards eastnorth-east) because of local sea blowing offshore from Orewa.

´

´

Legend Current storm high tide ELEVATION 0.000000 0.000001 - 0.500000 0.500001 - 1.000000 1.000001 - 1.500000 1.500001 - 2.000000

1.75m rise Legend

ELEVATION 0.000000

nznativeforests_Clip

0.000001 - 0.500000

nzexoticforests_Clip

0.500001 - 1.000000

lucasnewzealandlandusemap1991

1.000001 - 1.500000

LUC_NAME

1.500001 - 2.000000

Cropland - Annual

2.000001 - 2.500000

Cropland - Perennial

2.500001 - 3.000000

Grassland - High producing Grassland - Low producing

3.000001 - 3.500000

Grassland - With woody biomass

1.25m rise

Natural Forest

ELEVATION

Other

0.000000

Planted Forest - Pre-1990

0.000001 - 0.500000

Post 1989 Forest

0.500001 - 1.000000

Settlements

1.000001 - 1.500000

Wetland - Open water

1.500001 - 2.000000 2.000001 - 2.500000

Wetland - Vegetated non forest

2.500001 - 3.000000

LUC_NAME Grassland - High producing

0.75m rise ELEVATION 0.000000 0.500000 - 2.000000 2.500000 100yr Erosion_13m_LIKELY

26

100yr Erosion_28m_POSSIBLE

HILLSHADE_2006 Value

High : 254 Low : 0

0

0.5

1

1:30,000 @A3

2 Kilometers

0

0.175

0.35

1:10,000 @A3

0.7 Kilometers

´ Legend Rural_Contours_2006 ELEVATION -1.000000 - 2.500000 2.500001 - 3.000000 3.000001 - 3.500000 3.500001 - 4.000000 4.000001 - 4.500000 4.500001 - 5.000000

´ Legend

5.000001 - 5.500000 5.500001 - 6.000000 6.000001 - 6.500000 6.500001 - 7.000000 7.000001 - 7.500000 7.500001 - 8.000000

Rural_Contours_2006

8.000001 - 8.500000

ELEVATION

8.500001 - 9.000000

-1.000000 - 2.500000 2.500001 - 3.000000 3.000001 - 3.500000 3.500001 - 4.000000

9.000001 - 9.500000 9.500001 - 10.000000 High tide_average

4.000001 - 4.500000

Urban_contours_2006_2008

4.500001 - 5.000000

ELEVATION

5.000001 - 5.500000

0.000000 - 2.500000

5.500001 - 6.000000

2.500001 - 3.000000

6.000001 - 6.500000

3.000001 - 3.500000

6.500001 - 7.000000

3.500001 - 4.000000

7.000001 - 7.500000 7.500001 - 8.000000 8.000001 - 8.500000 8.500001 - 9.000000

4.000001 - 4.500000 4.500001 - 5.000000 5.000001 - 5.500000 5.500001 - 6.000000

9.500001 - 10.000000

6.000001 - 6.500000

High tide_average

6.500001 - 7.000000

Natural_Drainage_Catchments

7.000001 - 7.500000

Flood_Plain

7.500001 - 8.000000

Urban_contours_2006_2008 ELEVATION 0.000000 - 2.500000 2.500001 - 3.000000 3.000001 - 3.500000 3.500001 - 4.000000 4.000001 - 4.500000 4.500001 - 5.000000 5.000001 - 5.500000 5.500001 - 6.000000 6.000001 - 6.500000 6.500001 - 7.000000 7.000001 - 7.500000 7.500001 - 8.000000 8.000001 - 8.500000 8.500001 - 9.000000 9.000001 - 9.500000 9.500001 - 10.000000

8.000001 - 8.500000 8.500001 - 9.000000 9.000001 - 9.500000 9.500001 - 10.000000

27

9.000001 - 9.500000

Orewa Beach

Environmental Issues Fragile Coastline No Dry Beach Low Lands Prone to Inundation Estuary Exit

28

Stormwater Exits

The Waitemata Reef was the pivotal point for the exit of water from the Orewa estuary. Pre development, the exit took a northerly direction hugging the land before diffusing into the Gulf. This produced a natural circulation of sand, from the sediment that was moving south, caused by long shore drift, to be relocated north by the estuarine currents. According to the historic imagery, this was a natural recycling system that produced a closed circuit loop of sediment transport resulting in significantly larger areas of dry sandy beach. The manmade destruction of the reef was a transformation that slowly changed the course of sand movement. “For a finite-size (flow) system to persist in time (to live), its configuration must evolve such that it provides easier access to the imposed currents that flow through it” (Bejan, 1996).

This erosive force acquired a new configuration because an easier exit was revealed that “provided more access for the currents that flow through them” (Bejan, 1996). The outcome of this procedure meant that the natural recycling of sand soon grew obsolete.

During large storm events, eroded sand now accumulates at the southern end groyne and is pushed out to an off shore location creating the tidal delta. When Orewa Beach is running low on dry sand, expensive dredging is used to move the accumulated south end sand back to severely eroded stretches of beach (Thompson, 2010). However, the problem is now so bad that access to the beach’s amenities at high tide is virtually impossible, highlighting the need for ‘dry sand’ as the major problem for the community of Orewa. How could this issue be explored in a way that focuses on the erosive energy, from Orewa’s coastal dynamic forces, to be used in ways that assist the repair of this now damaged beach? How can the idea of enhancing Orewa’s Beach experience be explored through the means of artificial environmental infrastructure? northern exit of estuary water before the reef was destroyed.

Tidal delta

Waitemata Reef

1955

Fig 23. Orewa Beach 1951 (NATLIB, 2014)

1951

Fig 24. Orewa Beach 1950 (NATLIB, 2014)

1950

29

2014

2014

30

Design Interventions

Retreat

Natural Storm Water Exit’s Waitemata Reef

Natural Storm Water Exit’s

Artificial Island Ribbed Coastal Walkway Artificial Reef / Kelp Farm

Artificial Island Mini Headlands Gridded Planting Waitemata Reef

Mini Headlands

Land Reclamation Off Shore Reef / Kelp Farm Ribbed Coastal Edge Mini Headlands Gridded Planting

Natural Storm Water Exit’s

Conservation

Artificial Island

Artificial Reef / Kelp Farm

31

Socio Economic

Adapt

Recreation

Protect

32

Explaining the ‘matrix’ The organization of design interventions into a matrix has allowed for a clear understanding of how different methods and techniques will produce different outcomes. Protect Adapt and Retreat are the three generalized methods used to solve coastal issues while socio economic, recreation and conservation are the three main factors that will be effected either positively or negatively. The development of this research project has resulted in a series of different interventions using different methods and techniques from around the world (case studies) to solve Orewas specific environmental issues whilst benefiting all three socio economic, recreation and conservation factors.

Inspiration 1.

“Treasure our coastline, harbours, islands and marine areas. ‘Protect coastal areas, particularly those with high values – including special natural character, significant marine habitats and recreational importance – from the impacts of use and development, and enhance degraded areas.”

- The Auckland Plan, Priority 3 33

2.

Coastal “landscapes are shifting, living material phenomena that demand an attitude of negotiation.” To befit “the temporality, uncertainty, and complexity of a terrain between land and sea,” proposals should be “conceived as seeds” that evolve in harmony with the transforming coastline - Mathur & Cunha, 2009

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

Issue: storm water exits

PROTECT

34

Natural storm water exits

35

Natural stormwater exits:

Figure 26. Tahoe Pipe Club (Bunker, 2012).

“In the natural environment rainfall run off directly enters the ocean via rivers, creeks, lakes and lagoons that can be intermittently open or closed. It can also indirectly find its way to the ocean as a dispersed groundwater flow through beaches and dunes. When development takes place these natural systems tend to be disrupted. Roads, buildings, lawns, gardens and driveways, to name a few, cut through natural drainage paths and collect, concentrate and re-direct rainfall runoff into what is conventionally referred to as storm water.

Further, rainfall that would have previously found its way into the groundwater system by infiltration is incepted by non-porous hard surfaces and redirected to storm water systems there by increasing the volume of water taking direct routes to the ocean and reducing the time it takes for that water to reach the ocean” (Gordon, 2011). The effects this has on fragile coastal ecosystems results in “pollution of sand,” water and additional human influences to the movements and form of the beachscape (Anthoni, 2000).

´

36

According to G.I.S mapping, Orewa’s vast stretches of flood plains are located in the ‘slack zones’ of the dune system. “The dune slacks are found in between the more mature dunes where the water table reaches the surface causing seasonal or even permanent waterlogging and surface water” (Beagle, 2001). At Orewa, underground piping infrastructure relieves these flooding areas during times of heavy rainfall and discharges it towards the ocean. Ten of these exit points are located on the main beach of Orewa and is one of the many causes to the “silt and clay particles” found in Orewa’s sand resulting in a beach that never seems to dry (Anthoni, 2000).

Legend 1.75m rise ELEVATION 0.000000 0.000001 - 0.500000 0.500001 - 1.000000 1.000001 - 1.500000 1.500001 - 2.000000 2.000001 - 2.500000 2.500001 - 3.000000 3.000001 - 3.500000

1.25m rise ELEVATION 0.000000

After studying the natural formation of storm water exits up the eastern coast of the North Island, the common factors are visible in the meandering form that allows for pooling, filtration and a naturally controlled exit into the ocean. From understanding how these unique paths are built into the landscape, I was able to estimate the major zones in which this could be applied to Orewa.

Being titled as a retreat/adapt technique, the highs and lows revealed through G.I.S mapping aided with historic aerial photography, highlight the locations of original (pre-development) storm water exits.

0.000001 - 0.500000 0.500001 - 1.000000 1.000001 - 1.500000 1.500001 - 2.000000 2.000001 - 2.500000 2.500001 - 3.000000

0.75m rise ELEVATION 0.000000 0.500000 - 2.000000 2.500000 High tide_average 100yr Erosion_13m_LIKELY 100yr Erosion_28m_POSSIBLE StormwaterDrain20110810_Clip Flood_Plain

Fig 27. The beach sand of Orewa Beach looks polluted by fine particles (silt and clay) and it never dries. Erosion from urban development and roading and sewage from the local sewage treatment plants, end up in the sea (Anthoni, 2000)

0

0.25

0.5

1 Kilometers

37

38

The outcomes from this move will provide a solution to one of Orewa’s problems in a way that is approached in a semi permanent way. The retreat of reserves and residential zones will be the sacrifice for the proposal of daylighting natural streams.

In return, this coastal system will regain certain natural functions by using the build up and release of storm water to re-shape the form and build up of sand for larger amounts of dry beach. For locals and visitors, the experience they are familiar with will change. Sensory connections will be heightened through the opening of new view shafts while the transformation of built environment to ponding wetlands will redeem this clay-capped suburbia.

39

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

Issue: fragile coastlines

PROTECT

40

Off shore reef / kelp forest

Whilst researching the effects that this damaging force has on coastal environments, the North Island fell victim to one of several large storms so far in 2014. Lasting around three days and six high tides, the coastal margin of Orewa came up against roughly 24 hours of consistent storm swell energy. The outcome of this resulted in large amounts of sand lost from the beach and a jump landward for the new coastal edge.

41

“Humans have lived in New Zealand for only a relatively short time, but their impacts on the natural environment have been profound. The degradation of the environment began with the arrival of Mäori, and was accelerated once European settlement occurred. Within the last two human lifespans we have seen the extinction of a number of native terrestrial species, native forests and vast wetlands being replaced by pastoral land use, rapid sedimentation of the coastal zone, the destruction of ecologically important marine habitats, large reductions in the populations of fished species, and continuing growth in urbanisation leading to the loss, modification and contamination of the coastâ€? (Hauraki Gulf Forum, 2011).

Built infrastructure on coastal landscapes has rooted itself into ever morphing coastlines and with rising seas and coastal erosion, this built environment becomes increasingly vulnerable. The cause of this problem comes from the oceans energy. Wind from storms in the Pacific Ocean and Tasman Sea generate chop, this then turns into waves and over a long distance, swell is formed. When these storms pass over New Zealand, the energy in the wind and water unleashes on our coastlines. Large storms bring devastation to most vulnerable coastal settlements resulting in loss of sand from dunes, undercutting on cliff sides, inundation for low lying areas and damage to homes and roads.

42

Through out intensive research of coastal environments, the formation of outer reefs, especially with coral atolls, began to influence several design moves. As the water shallows, the oceans forces break down in size and speed leaving calm water on the landward side of the reef. Adapting this theory to Orewa resulted in a series of off shore reefs that will disturb the frequency of short period storm swells before they hit the shore. Because of the under water nature, the intense growth of kelp will be introduced to promote the increase in marine bio diversity.

43

44

The outcomes of “kelp forests provide a wonderful opportunity to observe a diversity of marine creatures in a setting that is accurately described with overused terms such as awesome, magnificent, breathtaking and stunning” (Snyderman, 2014). The amenities, not only for Orewa but also for the surrounding Whangaparoa Peninsula, and communities further to the north, will all increase.

The core idea behind this concept was to minimize storm swell from reaching Orewa’s shoreline. By introducing kelp, the use of organic material, when washed ashore, can be used to aid the reclamation of land in Orewa’s estuary.

45

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

Issue: coastal inundation

PROTECT

46

Land reclamation

47

35

Figure 29. Orewa estuary, Auckland king tides (king tides, 2014) “Climate change will substantially alter the frequency, extent and magnitude of coastal (saltwater) inundation. Interactions between changing sea levels, tidal ranges, changes to the frequency and magnitude of storm surges, and changes in storminess and wave conditions will add to this problem. An increase in mean sea level will allow the gradual advance of seawater at high tides on low-lying coastal and estuarine land. Unless constrained by coastal protection works, these inundated low-lying areas will eventually become a permanent part of the coastal or estuarine system” (Ministry for the environment, 2008).

2100 inundation (likely) 2100 inundation (possible)

0.7 Kilometers

With G.I.S data revealing the low-lying zones of Orewa, “Many of the risks from climate change can be managed if we plan ahead” (Geoscience Australia, 2013).

According to the Royal Society’s (2010) future predictions of sea level rise, the slack zone of Orewa’s original back dune will soon become an extension to the estuaries intertidal zone.

“Estuaries and coastal wetlands, both vegetated (mangroves, salt marshed, and sea grass beds) and unvegetated (mudflats and sand beaches), are critical transition zones (CTZs) between land, freshwater habitats and the sea. These zones provide essential ecosystem services, including shoreline protection, water quality improvement, fisheries resources, and habitat and food or migratory and resident animals. They also have aesthetic appeal and offer recreational opportunities for human populations.” (Levin and others, 2001).

The idea of reclaiming land in this ‘critical transition zone’, to prevent inundation as the Dutch have done in the past (case study), is an efficient way to adapt the landscape with the rise and fall of tides. Investigating this concept further led to the developed idea of using the consistent turbid water movements in Orewa’s estuary to move sediment behind enclosed embankments.

This self-regulating movement will, over time, produce a build up of fine-grained material and organic matter. Once areas of sediment are built up and surface above high tide levels, vegetation growth may then occur aiding the stability of this newly reclaimed land.

48

The outcomes of this seen in the Netherlands show how, over time, the growth of land produces habitat for a range of coastal species. For Orewa, The polder, “a low-lying tract of land enclosed by embankments or barriers,” will grow slowly with the rising sea while taking advantage of organic material found in the coastal transition zone, (Wikipedia, 2014). The effects this has on bird life will be positive and the distance between land and sea will be increased resulting in socio economic benefits, as homes and other infrastructure decrease their vulnerability to the encroaching tide line.

Figure 30. Wadden Sea land reclamation (Wikipedia, 2014)

Figure 31.

Schematic representation of (A) species number and bio mass, (B) pollutant concentrations, and (C) suspended organic and inorganic (sediment) matter concentrations across the marine critical transition zone (Levin, 2001).

The arrangement of ‘polder’ in Orewas south end estuary strategically placed to work with the flow direction of the entry and exit of water from the ocean..

49

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

Issue: fragile coastlines

PROTECT

50

Ribbed coastal edge

After understanding the reasons for the failure of previous beach front walk way proposals, the introduction of rib like structures to fragile areas of the coastal margin could help to prevent periodic storm damage and promote sustainable management of natural and physical resources.

Previous beach front walkway proposal (RMA):

Decision of the Rodney District Council: That, pursuant to Sections 104, 104B and 104D of the Resource Management Act 1991, the notified application for resource consent by Rodney District Council to undertake works above MHWS associated with the upgrade of an esplanade walkway, construction of hard and soft coastal protection measures and associated earthworks and works to trees on Section 1 SO 64795, Section 1 SO 64796, Section 1 SO 64797, Section 1 SO 64798, Part Lot 140 DP 12795 and Lot 32 DP 12795 is refused consent for the following reasons.

Reasons for the decision: Pursuant to Section 113 of the Resource Management Act 1991, the reasons for this decision, based on our findings of fact, are as follows: age 6 (a) We consider that there is an unacceptable risk regarding the likely engineering stability of the wall and its ability to withstand erosion forces in this exposed coastal location due to the untested nature of the wall structure proposed and the lack of any comprehensive testing or evaluation of the structure combined with shortcomings in design details. Although the probability of that risk is relatively low the impact in this situation would be relatively large. (b) We have determined that potentially significant adverse effects on the environment could arise from the exposure of rock rip rap wall for considerable periods of time subsequent to periodic storm damage. (c) We find that Orewa Beach is of key importance to the Orewa community both in terms of its aesthetic and recreational value to the community and in terms of the economic wellbeing of the Orewa business community that depends on the attractiveness of the beach for the visitor traffic that provides a significant part of their business turnover. (d) We consider that removal of existing areas of grassed and planted dune areas along parts of the existing esplanade walkway to accommodate the seawall will result in some loss of amenity and the loss of an existing visual and recreational resource. (e) We consider the potential for either failure or exposure of the rock wall would give rise to potential cumulative effects in terms of aesthetic and recreational amenity, loss of beach access, and adverse economic effects for the Orewa community. (f) When taken together we consider there is potential for significant adverse effects on the environment. No adequate measures were proposed to enable those effects to be appropriately avoided, remedied or mitigated. (g) We do not consider that the applicant satisfactorily established that the proposed seawall was the “best practicable option� and for that reason was not consistent with the directions of the Regional Policy Statement or those of the Regional Plan: Coastal in regard to the provision of coastal defence structures. (h) We have concluded that the objectives and policies of the Partly Operative District Plan 2000, which relate to protection from natural hazards, would not be given appropriate regard if consent were granted. (d) It is our overall broad judgement that the proposal would not promote the purpose of sustainable management of natural and physical resources and while it would enable some members of the Orewa community, and visitors to the area, to provide for their social and cultural wellbeing through the provision of an improved walkway along the beachfront, it would have potential adverse effects on the environment that are significant and for which the applicant did not adequately provide appropriate avoidance, remediation or mitigation. (Auckland Council, 2010).

51

Application reference details: Decision on resource consent application under section 88 of the Resource Management Act 1991 to undertake works above MHWS to upgrade a public walkway and erect a sea wall to protect the walkway together with associated works including earthworks, removal of protected trees and works within the dripline of protected trees.

52

Sand moving into the intertidal zone and entering the sediment train is the cause for the loss of dry beach.

Solid infrastructure proposals such as sea walls increase this problem as it accelerates backwash during periods of large swell. The idea of weaving a material into the landscape will help to eliminate the approach of solid infrastructure and minimize direct foot traffic while providing unique walking paths and new look out points for the public. By letting the water absorb into this weaving structure at high tides, back wash and sand movement will be limited. Being located on fragile margins of Orewa Beach, the outcome will result in a walkway that has minimal impacts on the environment. Knowledge of coastal processes has led tothe idea of uncertainty and it is with this that I have proposed a concept that is flexible with change. The evolving edge will have no effect on the amenity value of the walking path and for the future years, this single installment will provide the public with unique easy access points for the beach to be used at any time, for any reason.

53

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

Issue: fragile coastlines

PROTECT

54

Mini headlands

55

Can existing erosion rates be used to an advantage?

Orewa’s evolving coastal margin

Waitemata Reef - pre development Waitemata Reef - post development 1950 2014 2100 (likely) 2100 (possible)

56

Inspired by a retreat approach to the ‘Ribbed Coastal Edge’, mini headlands take place by reinforcing strong points of Orewa’s coastline while allowing for natural erosion to occur through out surrounding zones. By reinforcing these points along the fragile coastline, the outcomes will promote a new experience that relies on the damaging forces of the ocean to reveal new pocket / cove like formations up the length of Orewa. Slat like pieces aligned parallel to the coast will discontinue the loss of sand to the Hauraki Gulf and maintain it in an area producing larger areas of dry beach.

The result of this produces new intimate spaces on the sand while up above, the revealed mini headland provides new look out points and relaxation areas for the public to enjoy. Locals and visitors walk the length of this beach every day, providing quality walking and resting surfaces will enhance their beach experience in a way that doesn’t desecrate the attraction.

57

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

Issue: no dry beach

PROTECT

58

Gridded planting

59

“Beach nourishment is a practice in which sediment is brought onto a beach to replace sediment which has been lost through erosion. There are advantages and disadvantages to beach nourishment, and in some regions, it is a controversial practice. Because humans like to settle near beaches and enjoy using beaches as recreation areas, this practice is quite common around the world, despite some of the environmental problems associated with it” (Wise Geek, 2014).

At Orewa Beach, nourishment of sand comes from the south end groyne were sediment transport accumulates. Moving sand with machinery cost the council “$30,000 to $70,000 a year, depending upon the amount of sand shifted” (Thompson, 2010). With increasing tides and storm occurrences, the time and money put into Orewa’s constant recovery will only rise.

In the Netherlands, grid-planting techniques are being utilized to strengthen controlled build up of sand (fig 32).

Figure 32. St Maartensvoltburg (Google Maps, 2014).

Dune planting at the south end of Orewa seems to be well established and the outcome of this has maintained a steady level of sand. Typically, dune planting is most effective at catching sand that is wind blown toward its direction; this is how dunes maintain their ever-changing nature. At Orewa, the predominant wind direction is from the southwest meaning that the chance of dunes growing more from catching sand is rather slim. Waiting for sand dunes to build up sand levels doesn’t seem like an efficient procedure.

What if there was a final replenishment of sand along Orewa’s beach?

If ideal beach levels (more dry beach) were gained, gridded planting methods will be of benefit to retain these areas of new dry beach. The lines running parallel and perpendicular to the coast maintain the dry beach levels inside each grid. The benefits that this will have for Orewa means that the extension of current dunes is possible, “the natural beautiful beach” will return and the effect that this combination has on the socio-economic, recreational and conservation factors are all positive.

60

Figure 33. Pingao (Department of Conservation, 2011)

Botanical name: Ficinia spiralis Common name: Pingao (Golden Sand Sedge) Size: 30-90 cm tall Habitat: Coastal foredunes through out New Zealand (native) Pushing out the existing high tide line to create the ideal dry beach

61

Introducing gridded planting techniques to maintain the new dry beach

Containment of sand will ensure the ideal dry beach profile is maintained

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

Issue: estuary exit

PROTECT

62

Waitemata reef

1947

1951

Figures 34. Orewa Beach Historic Images (NATLIB, 2014)

1955

63

1955

natural circulation of sand before the destruction of the reef

The Waitemata Reef was the pivotal point for the exit of water from the Orewa estuary. Pre development, the exit took a northerly direction hugging the land before diffusing into the Gulf.

This produced a natural circulation of sand, from the sediment that was moving south, caused by long shore drift, to be relocated north by the estuarine currents. According to Whites Aviation historic imagery, this was a natural recycling system that produced a closed circuit loop of sediment transport resulting in significantly larger areas of dry sandy beach.

1980

64

The manmade destruction of the reef was a transformation that slowly changed the course of sand movement. “For a finite-size (flow) system to persist in time (to live), its configuration must evolve such that it provides easier access to the imposed currents that flow through it” (Bejan, 1996). This erosive force acquired a new configuration because an easier exit was revealed that “provided more access for the currents that flow through them” (Bejan, 1996). The outcome of this procedure meant that the natural recycling of sand soon grew obsolete. During large storm events, eroded sand now accumulates at the southern end groyne and is pushed out to an off shore location creating the tidal delta.

When Orewa Beach is running low on dry sand, expensive dredging is used to move the accumulated south end sand back to severely eroded stretches of beach (Thompson, 2010).

However, the problem is now so bad that access to the beach’s amenities at high tide is virtually impossible, highlighting the need for ‘dry sand’ as the major problem for the community of Orewa.

proposed sediment transport

proposed esturine current

extension to the Waitemata Reef

65

After discovering that the destroyed reef was “likely the largest factor contributing to a lack of high tide beach at Orewa�, I proposed to mimic the original shape and form of the Waitemata Reef to help enhance the resilience and future health of Orewa Beach (Dr. S. Mead, personal communication, October 18 2014). With a final replenishment of Orewa beach sand, to gain the ideal beach profile, this intervention could then be introduced to protect and adapt the way the beach will work in future years.

SOCIO ECONOMIC RECREATION CONSERVATION

RETREAT

ADAPT

Issue: no dry beach

PROTECT

66

Recreational island

On sandy shores, natural reefs and islands create wider beaches, termed salients and tombolos, due to sediment deposition in their lee.

A salient is a build up of sand in the lee of an offshore structure that does not attach to the structure that formed it and so enables sediment to bypass between the obstacle and the shore and is therefore less likely to cause erosion on the adjacent coastline.

Figure 35. Orewa Beach 4 minutes after high tide (Eyles, 2013)

A tombolo is a build up of sand in the lee of an offshore structure that does attach to the structure that formed it, blocking sediment movement alongshore and thus usually resulting in erosion of the down coast shoreline.

Figures 36. Salient formations on the east coast of the north island, NZ (Google Maps, 2014)

Tombolo formation

67

Salient formation

sediment transport

Island

Splitting the beach into 2 separate systems could also ensure an efficient beach comeback. The idea of a divide is inspired by the natural formations of off shore islands/ reefs. The potential to produce a salient formation on the beach side of its location will ensure a consistent area of ‘dry beach’ both before and after storms. Dividing the beach with a recreational island means that the recycling current from the estuary can be concentrated at the south end while the cove like formation of the north end significantly reduces the amount of sand being eroded from the shore.

recreational

68

Figure 37. The Gold Coast multi purpose reef (McGrath, 2000).

salient build up

Recreational island

69

70

Future speculation of Protect

The issue with typical protection methods being used for low budget remediation projects is the way these methods impact the environment. Common techniques such as sea walls, groins, beach replenishment, just to name a few, all effect the natural functioning of coastal systems.

Sea walls are most commonly seen being used to protect vulnerable areas of coastline while an increased back wash from solid walls gets refracted and localized on another zone of the beach creating new problems further down on the same stretch of coast. While these walls can take the form of steps in areas with no beach creating new access points for the public, the application of these solid interventions on sandy shores can increase erosion rates.

71

“Wherever a hard structure is built along a shoreline undergoing long-term net erosion, the shoreline will eventually migrate landward beyond the structure� (Beachapedia, 2014). The rock walls currently located along the majority of coast at Orewa Beach have begun to fail against the forces of the ocean.

The storm surges infiltrate the rocks and continue to erode areas of land behind this rock line. At Orewa the introduction of large sea walls, to protect the built environment from any further damage, will continue to degrade what is left over from the beach remains. Speculations towards the development of this problem led to the remains of the previous rock wall to be unusable with no real purpose apart from a slight buffer for the new slither of useable beach between the old and new protection devices.

A colossal sea wall will further restrict access to the beach and the remains of the previous rock wall create struggle for beach users. The result this has in terms of social outcomes means that the changing beach has now reached a point of no return. The public space above the beach will be narrowed to new extremes resulting in a lack of reserve walking paths, seated areas, car parking etc. and the relationship between people and place will grow to be built up on the foundation of taking, rather than giving.

72

Future speculation of Adapt

Strict approaches towards the environment and the users are often the result of adaptation techniques.

The idea is to be able to continue certain happenings while tweaking the rules ever so slightly in a way that benefits both the environment and the user. Examples of this can be seen in the form of coastal boardwalks were fragile dune systems, cliffs etc often support a board walk of some sort that provides consistent access for the public while benefitting the health of the dune system below foot. The problem with adapting techniques, such as boardwalks, to areas of beach that have previously been used with the freedom of no boundaries will change the experience for the way that space would be used.

The coastline of Orewa is increasingly fragile. The south end features an established dune system that maintains the structure and form of the dune scape but the relatively flat geographical composition of land at Orewa means that no matter how rigid the planting system may be, when the sea levels rise, inundation will continue to erode these fragile coastal margins. Future speculations of this technique being used at Orewa reveals how this beach experience will change into a controlled experience for most beach users. Positively affecting the environment results in the loss of the recreation factor for this technique. The social outcome from this speculation surfaced the idea of being able to look but not touch, being on a beach but not being able to interact with the elements at certain times of day.

73

Restricting walking in certain areas is commonly applied to already fragile costal zones. The reality is that adaptation can really be a form of any sort of infrastructure that promotes an adaptive approach.

The issue with typical adaptation methods is how certain approaches tend to loose certain amounts of useable beach space.

74

Future speculation of Retreat

Continued storm events and rising sea levels have negative impacts on the urban coastal margin because consistently eroding sand results in an increased vulnerability of beachfront properties.

Previous techniques have resulted in controlled retreats that sacrifice large amounts of land to the sea resulting in a release of pressure against the defending infrastructure. With out a controlled approach to this technique, the socio-economic factors for that specific site could be negative as homes, roads, and parks could all be lost to the sea

The effects that this has on the beach experience for Orewa will mean that the destruction of built infrastructure will become a part of the beachscape.

75

If no action is taken towards the remediation of coastal erosion and sea level rise, slowly but surely, devastation will occur as the advancing tide line displaces sediment under beachfront properties. What used to be a solid building foundation will soon become apart of the coastal margin and the outcome of this will result in a collapse.

Conclusion Through out the development of this research project, it is evident that the investigation has been divided in to two parts.

Part one, how can the destructive forces from the ocean be utilized to aid the repair of an urban coastal system?

Part two; what is the future beach experience?

76

Part One: To answer part one, understanding how coastal environments work was the foundation to this research project. Remediation case studies revealed several different measures and approaches that people around that world took to solve specific issues of coastal erosion and sea level rise. From this analysis, three remediation tropes were developed; Protect, Adapt and Retreat. The repercussions of these three generalized methods was explored in particular the ways in which they would effect the socioeconomic, recreation or conservation factors of the site..

Through a site analysis of Orewa, the discovery of specific environmental problems led to a proposed series of interventions that would work with the temporality and flexibility of the coastal environment.

The implementations of soft green infrastructure was designed to follow Auckland Cities vision that ensures “our natural, marine and built environments are responsibly managed so that our children and their children will be able to enjoy them in the future” (Auckland council, 2014).

The outcome of the 8 different techniques, adapted from previous case study techniques to Orewa’s specific environmental problems has resulted in positive environmental outcomes through a conscious balance between socio-economic, recreation and conservation factors. The implications that these interventions will have on Orewa will positively change the beach experience from what we have all grown familiar to.

The use of sketching through out this stage was used specifically to promote the fact that this research project was not a scientific study of beach remediation but rather an educational project that alerts the viewer to the problems and opportunities of the Orewa case study. The deliberate approach of producing fugitive and allusive concepts represents the fragmented experience, a bit like our memories of the beach, with loose pencil work that mimics the uncertainty and continuous change of the coastal environment.

Part Two: The second part of this research project explores in further detail of the social outcomes from this changing beach experience. The knowledge of the environmental changes gained from the research in part one was used to speculate about the future beach experience. A timeline of Orewa’s history shows the change in the New Zealand beach experience from tenting in isolated places to the beachfront trophy houses of today. With information gathered from part one, the design speculations take into account the fact that the shoreline is receding and the water levels are rising.

“Orewa Beach is of key importance to the Orewa community both in terms of its aesthetic and recreational value to the community and in terms of the economic wellbeing of the Orewa business community that depends on the attractiveness of the beach for the visitor traffic that provides a significant part of their business turnover” (Auckland Council, 2010). Speculation around the social outcomes of the future beach reveals a dramatic change to the ‘kiwi beach experience’. By bring to life a series of soft environmental interventions “to safeguard the integrity, form, functioning and resilience of the coastal environment,” the ‘kiwi beach experience’ will be enhanced in ways that allow for stronger connections with every element of the coast (New Zealand Coastal Policy Statement, 2010). Using adaptation, protection and retreat techniques, that have combined yet balanced outcomes in terms of the cultural, commercial and social factors will continue the summer time beach migration we all know and love. Without this, Orewa could soon become a place that people go to, not for walks on the long white sandy beach, but for an exploration through ruins of beachfront properties littered throughout the eroded foreshore…

77

Images were developed that illustrate the reality of this global issue. If no action is taken, the beachfront will be littered with ruins from destroyed beach front properties. If the beachscape uses adaptive environmental techniques board walk structures will be used to protect planting, creating a restricted beach experience. If the coastal problems aren’t addressed the continuous erosion effects could see a last minute attempt to protect the built infrastructure in the form of a sea wall that will negatively impact the beaches health.

References Creel, L. (2003). Ripple effects: Population and coastal regions. Washington DC, USA: Population reference bureau. Retrieved from http://www.prb.org/Publications/ Reports/2003/RippleEffectsPopulationandCoastalRegions.aspx Blackett, P. Hume, T. and Dahm, J. (2010) ‘Exploring the social context of coastal erosion management in New Zealand: What factors drive particular environmental outcomes?’ The Australasian Journal of Disaster and Trauma Studies Vol. 1. Accessed March 28, 2014. Retrieved from. http://www.massey.ac.nz/~trauma/issues/2010-1/ blackett.htm New Zealand climate change programme. (2001). Planning for climate change effects on coastal margins: New Zealands coastal scene. Wellington, New Zealand: Ministry for the environment. Retrieved from http://mfe.govt.nz/publications/climate/effect-coastal-sep01/effect-coastal-sep01.pdf

Statistics New Zealand. (2006). Quick stats about Orewa. Retrieved from http://www.stats.govt.nz/Census/2006CensusHomePage/QuickStats/AboutAPlace/SnapShot. aspx?id=3505805 Sea friends. (2000). Examples of beaches worth saving. Retrieved from http://www.seafriends.org.nz/oceano/beachsav.htm#do

78

NIWA. (2013). Coastal terms and definitions. Retrieved from http://www.niwa.co.nz/coasts/nzcoast/tools-and- visualisations/coastal-terms-and-definitions Destination Orewa Beach. (2014). Retrieved from http://www.orewabeach.co.nz/joomla3/index.php The Royal Society. (2010). Recent projections of sea-level rise by 2100. Retrieved from http://assets.royalsociety.org.nz/media/SLR-v4.9-for-web.pdf Flemming, B.W., Nyandwi, N. (1994). Netherlands journal of aquatic ecology. Land reclamation as a cause of fine-grained sediment depletion in back barrier tidal flats (southern North Sea). Page 299. Retrieved from http://link.springer.com/ article/10.1007/BF02334198#page-2 Hauraki Gulf Forum. (2011). State of our gulf: executive summary. Page 24. Auckland, New Zealand. Retrieved from http://www.aucklandcouncil.govt.nz/EN/AboutCouncil/ representativesbodies/haurakigulfforum/Documents/hgfstateoftheenvreport2011.pdf Happy Isles. (2006). West 8 and Svasek. Retrieved from http://www.west8.com/projects/all/happy_isles/ Surfing ramps. (2014). Narrowneck reef. Retrieved from http://www.surfingramps.com.au/ Vroom, J. (2013). Building Block - Perched beaches - Practical Applications. Retrieved from https://publicwiki.deltares.nl/display/BWN/Building+Block++Perched+beaches+-+Practical+Applications Anthoni, J. F. (2000). Disappearing beaches: Saving our beaches. Retrieved from http://www.seafriends.org.nz/oceano/beachsav.htm Beagle, D. R. (2001). Coastal sand dunes. Retrieved from http://www.georesources.co.uk/csdintro.htm Gordon, A. D. (2011). Coastal stormwater-challenges and opportunities. Retrieved from http://www.coastalconference.com/2011/papers2011/Angus%20Gordon%20 Full%20Paper.pdf Hauraki Gulf Forum. (2011). State of our gulf: executive summary. Auckland, New Zealand. Retrieved from http://www.aucklandcouncil.govt.nz/EN/AboutCouncil/ representativesbodies/haurakigulfforum/Documents/hgfstateoftheenvreport2011.pdf Snyderman, M. (2014). Forest’s in the sea. Retrieved from http://www.dtmag.com/Stories/Marine%20Life/04-99-feature-1.htm Waikato Regional Council. (2014). Coastal hazards. Retrieved from http://www.waikatoregion.govt.nz/Services/Regional-services/Regional-hazards-and-emergencymanagement/Coastal-hazards/ Ministry for the Environment. (2008). Part Two: Implications for New Zealand’s coastal margins. Retrieved from http://www.mfe.govt.nz/publications/climate/preparingfor-coastal-change-guide-for-local-govt/html/page2.html Geoscience Australia. (2013). Risks to coastal settlements, infrastructure and ecosystems. Retrieved from http://www.ozcoasts.gov.au/climate/risks.jsp

Auckland Council. (2010). Resource consent decision no: L56369. Retrieved from http://www.aucklandcouncil.govt.nz/SiteCollectionDocuments/RDC%20Decision%20 millineum%20walkway-seawall.pdf Wikipedia. (2014). Polder. Retrieved from http://en.wikipedia.org/wiki/Polder Levin, A. and others. (2001). The function of marine critical transition zones and the importance of sediment biodiversity. Retrieved from http://levin.ucsd.edu/publications/ Ecosystems2001%20Levin%20et%20al.pdf Wise geek. (2014). What is beach nourishment? Retrieved from http://www.wisegeek.com/what-is-beach-nourishment.htm Thompson, W. (2010, Nov 12). Warning on Orewa Beach erosion. The New Zealand Herald. Retrieved from http://www.nzherald.co.nz/nz/news/article.cfm?c_ id=1&objectid=10686995 Bejan, A. (1996). The Constructal Law of flow systems. Retrieved from http://wattsupwiththat.com/2010/11/15/the- constructal-law-of-flow-systems/ Bejan,A.(1996).Constructallaw.RetrievedfromDr.Anthoni,J.F.(2000).Disappearingbeaches:savingourbeaches.Retrievedfromhttp://www.seafriends.org.nz/oceano/beachsav.htm http://en.wikipedia.org/wiki/Constructal_law

Figure 1: McKenzie. (1958). Ministry for the Environment. Retrieved from http://www.mfe.govt.nz/publications/ser/ser1997/html/ chapter6.6.html#figure6.2 Figure 2: New Zealand climate change programme. (2001). Planning for climate change effects on coastal margins: New Zealands coastal scene. Wellington, New Zealand: Ministry for the environment. Retrieved from http://mfe.govt.nz/publications/climate/effect-coastal-sep01/effect-coastal-sep01.pdf Figure 3: West 8 and Svasek. (2006). Happy Isles. Retrieved from http://www.west8.com/projects/happy_isles/ Figure 5: Louis Baljon Landscape Architects. (2003). Naviduct Enkhuizen. Retrieved from http://www.baljon.nl/project/naviduct-enkhuizen Figure 6: Louis Baljon Landscape Architects. (2003). Naviduct Enkhuizen. Retrieved from http://www.baljon.nl/project/naviduct-enkhuizen Figure 7: Louis Baljon Landscape Architects. (2003). Naviduct Enkhuizen. Retrieved from http://www.baljon.nl/project/naviduct-enkhuizen Figure 8: Rijkswaterstaat. (2011). Zandmotor. Retrieved from https://worksthatwork.com/1/zandmotor Figure 9: Rijkswaterstaat. (2011). Zandmotor. Retrieved from https://worksthatwork.com/1/zandmotor Figure 10: Vroom, J. (2013). Artificial reef at the Gold Coast, Australia. Retrieved from https://publicwiki.deltares.nl/display/BWN/Building+Block++Perched+beaches+-+Practical+Applications Figure 11: Banks, I. (2008). Narrowneck artificial reef Gold Coast QLD Australia. Retrieved from http://www.divingthegoldcoast.com.au/index.asp?PageID=animal& CritterID=5607 Figure 12: Edwards, M. (2014). Narrowneck. Retrieved from http://surfspotsmap.com/spot/australia-pacific/australia/queensland/narrowneck-surf-forecast Figure 13: Breiner, A. (2014). Medmerry. Retrieved from http://thinkprogress.org/climate/2014/04/09/3422063/england-town-sea-level-rise/ Figure 14: AOSIS. (2012). Hurricane Sandy and climate change. Retrieved from http://aosis.org/hurricane-sandy-and-climate-change/ Figure 15: USGS. (2012). Hurricane Sandy. Retrieved from http://soundwaves.usgs.gov/2012/12/ Figure 16: Coastalwatch Australia (2013). Superbank Gold Coast. Retrieved from https://www.flickr.com/photos/coastalwatch/11210527176/ Figure 17: Snapper Rocks. (2006). Snapper Rocks Coolangatta QLD Australia. Retrieved from. http://www.snapperrocks.com/history.htm Figure 18: Swart, S & Marseille, H. (2011). Dutch lowlands from the air. Retrieved from http://www.rnw.nl/english/article/dutch-lowlands-air Figure 19: Minoka & Peter. (2006). Land reclamation in Spieka-Neufeild. Retrieved from http://www.fischehoch2.de/y2006/norden/1m23/text.htm Figure 20: Lunar and Planetary Institute. (1997). Polders and Dikes along th North Sea, the Netherlands. Retrieved form http://www.lpi.usra.edu/publications/slidesets/ humanimprints/slide_11.html

79

Figure 4: West 8 and Svasek. (2006). Happy Isles. Retrieved from http://www.west8.com/projects/happy_isles/

Figure 21: Local Office Landscape. (2013). Double Dune Forest. Retrieved from http://www.localofficelandscape.com/portfolio-items/double-dune-forest/#lightbox[78]]/2/ Figure 22: Local Office Landscape. (2013). Double Dune Forest. Retrieved from http://www.localofficelandscape.com/portfolio-items/double-dune-forest/#lightbox[78]]/2/ Figure 23: National Library of New Zealand. (2014). Orewa Beach 1951. Retrieved from http://natlib.govt.nz/items?page=5&text=Orewa&utf8=%E2%9C%93 Figure 24: National Library of New Zealand. (2014). Orewa Beach 1950. Retrieved from http://natlib.govt.nz/items?page=5&text=Orewa&utf8=%E2%9C%93 Figure 25: Google Maps. (2014). Natural exits on the east coast of the north island, NZ. Retrieved from https://www.google.co.nz/maps/@-36.8630231,174.8654693,10z?h l=en Figure 26: Bunker, D. (2012). Tahoe Pipe Club. Retrieved from http://www.moonshineink.com/news/tahoe-pipe-club-pointing-out-tahoe%3F%3F%3Fs-polluting-pipes Figure 27: Anthoni, J. F. (2000). Disappearing beaches: saving our beaches. Retrieved from http://www.seafriends.org.nz/oceano/beachsav.htm Figure 28: Jouan, R. (2009). Pateete Lagoon. Retrieved from http://en.wikipedia.org/wiki/The_Structure_and_Distribution_of_Coral_Reefs#mediaviewer/File:Papeete_-_ Lagon.JPG Figure 29: King tides. (2014). Orewa estuary, Auckland king tides. Retrieved from http://auckland.kingtides.org.nz/tag/orewa/ Figure 30: Wikipedia. (2014). Wadden Sea land reclamation. Retrieved from http://commons.wikimedia.org/wiki/File:Wadden_Sea_(land_reclamation)_near_Pieterburen,_ the_Netherlands.jpg Figure 31: Levin and others. (2001). The function of marine critical transition zones and theimportance of sediment biodiversity. Retrieved from http://levin.ucsd.edu/ publications/Ecosystems2001%20Levin%20et%20al.pdf

80

Figure 32: Google Maps. (2014). St Maartensvoltburg, the Netherlands. Retrieved from https://www.google.co.nz/maps/place/The+Netherlands/@52.2129919,5.2793703, 8z/data=!3m1!4b1!4m2!3m1!1s0x47c609c3db87e4bb:0xb3a175ceffbd0a9f?hl=en Figure 33: Department of Conservation. (2011). Pingao. Rerieved from http://tearai.kete.net.nz/site/images/show/5-pingao Figure 34: National Library of New Zealnd. (2014). Orewa Beach Historic Images. Retrieved form http://natlib.govt.nz/items?page=5&text=Orewa&utf8=%E2%9C%93 Figure 35: Eyles, T. (2013). Orewa Beach 4 minutes after high tide. Retrieved from http://www.surf-forecast.com/breaks/Orewa-Beach/photos/6752 Figures 36: Google Maps. (2014). Salient formations on the east coast of the north island, NZ. Retrieved from https://www.google.co.nz/maps/place/New+Zealand/@37.1712485,175.7592601,11z/data=!4m2!3m1!1s0x6d2c200e17779687:0xb1d618e2756a4733?hl=en Figure 37: McGrath, J. (2000). The Gold Coast multi purpose reef. Retrieved from http://pebelrodriguez.wordpress.com/2013/10/17/multi-purpose-reefs/ -

81

Your viewing is much appreciated

82

logan.pennington@hotmail.co.nz