Te Hapū o Ngāti Wheke Inc is the Papatipu Rūnanga legal entity that represents Ngāti Wheke, the hapū with manawhenua status over the Whakaraupō basin and surrounding areas as outlined in the Port Cooper Deed. This entire area is culturally significant to Ngāti Wheke and sustains the hapū. Te Hapū o Ngāti Wheke has a strategic plan, a key part of which is the protection and enhancement of the whenua, moana and awa. Ngāti Wheke hopes to be a part of the leadership in climate action for future generations.

Mō tātou, ā, mō kā uri ā muri ake nei.

For us and our children after us.

Christchurch City Council recognises the rangatiratanga of Ngāti Wheke over its whenua and is working in partnership to plan for impacts on public assets and places of value.

The natural environment in Rāpaki is highly valued for its mahinga kai, ecological and recreational features. The beach is a popular swimming destination and is used a lot by locals and other residents in the Christchurch district. It’s significant as one of the only shelly beaches found in the harbour and it’s an important point of access to the sea for the collection of kai moana. The marine environment in this area supports a wide range of native species.

The Gallipoli Wharf was built in 1916 as a memorial to the young Māori soldiers from Rāpaki who fought in Gallipoli during World War I. It holds historical significance and is an important recreational asset. The wharf is well used year-round for boating and seasonally for swimming. It provides an alternative form of access that can be used in the event of an emergency or when roads leading in and out of Rāpaki might be closed.

Visitors to the wharf and beach often make use of the parking area at the shorefront, which spans public and private land. From the carpark, there’s a short walk along the beach via the local walkway.

There’s some wastewater infrastructure exposed to coastal hazards, including a pumping station and some pipes that provide service to some properties in Rāpaki.

Because the land in Rāpaki is above sea level, coastal flooding and rising groundwater will only have an impact on low-lying land around the shorefront. The images below show that erosion is the main coastal hazard in Rāpaki, one that will increase over time. Some parts of the shorefront are already defended with rock armouring, which provides some protection against the risk of erosion, but, over time, this is likely to be at the expense of the beach. Rising sea levels will eventually cause this armouring to fail, and during storm events it’s likely that large sections of land could be lost over short timeframes. Unprotected areas of the coastline will be eaten away faster than protected areas.

It’s important to note that while we have a good understanding of how coastal hazards will impact us, it is hard to predict the rate at which sea levels are going to rise further in the future. The rate of change will depend on global green house gas emissions and what impact this has on our climate. If different tipping points are reached, it’s possible we will see sea levels rise much quicker. That is why it is important to have a plan in place for the future of our coastal communities

The Gallipoli Wharf, wastewater pumping station and pipes, parking area and walkway will all come under threat from coastal hazards, if not already. Because the land in Rāpaki is well above sea level, the main risk is from coastal erosion, which will impact access to the jetty and eat away at the parking area and walkway, and eventually the pumping station and pipes also. Over time, the wharf could be flooded during storm events and parts of the beach could be lost to rising sea levels if rock armouring is used.

It’s important to note there are other important assets and places of value in Rāpaki that are not public. Close collaboration with Ngāti Wheke will be needed to support the long-term management of the area.

The Coastal Panel has considered the workable options that would address the risks to each of these assets These options are set out in the section titled ‘Adaptation pathways’.

Sometimes the way we decide to address the risks to one asset will have an impact on how other assets could be affected by coastal hazards and the options we have available to manage those risks. In Rāpaki, the decision about whether to protect the shorefront will have a big impact on the other assets.

1. Hold the line

We could keep on defending the existing public assets and spaces over the next century by adding to Ngāti Wheke’s existing rock armouring in front of the parking area and expanding it to protect access to the wharf and the walkway to the beach. The wastewater pumping station sits behind a currently armoured part of the shorefront, so it’d likely benefit from this work. As sea levels rise, small sections of the beach may be lost as water rises to meet the hard edge of any armouring.

The resilience of the wharf itself could be improved through flood-proofing and raising its deck above future flood levels. Over time, it’ll become harder and more expensive to maintain the wharf in its current location.

When the flood-proofing becomes less effective, an option could be to build a new wharf that can cope with raised sea levels better.

2. Work with nature

Instead of building a hard edge along the shorefront, we could create space for the natural environment to move in response to coastal hazards. This would involve moving a number of the at-risk assets away from the coast.

Over time, if the existing rock armouring along the front of the parking area is not maintained it will be worn away and the land will start to erode. For a time, this risk could be managed through planting and fencing, which could help to stabilise the cliff edge and keep people away from the unstable bank. As more and more of the land is eaten away, the parking area may need to be closed to the public. There may be an opportunity to provide parking further inland.

With this approach, the walkway to the beach would need to be moved away from the coast, or closed at a point when there was a clear risk to health and safety. Closure may mean no formal public access to the beach in this location. This would provide the beach with space to move inland as sea levels rise, rather than it being impacted by rock armouring, for example.

The same flood-proofing options are available for the wharf under this approach as well – the only difference being that access to the wharf will be impacted over time as the land around it erodes. Without armouring, it be could difficult to keep access to the wharf for extended periods of time.

Both of these approaches come with their own opportunities, risks and costs, and they may need to be used at different times or could be more appropriate for some assets than others. Importantly, regardless of what we do, it’s going to get harder, more expensive and environmentally disruptive to keep public assets in this area, particularly particularly near the shorefront due to coastal erosion.

Maintaining the wharf and boat ramp is expected to become harder and more expensive over time. The adaptation pathway map below shows that at a certain point – likely around 10 to 20 years from now – changing conditions will mean maintaining the wharf may no longer be worth the increasing costs and disruption. As we near this point, we could look to raise and otect the existing wharf to different levels. Or, to buy more time, we could build a new wharf, slightly further inland.

*We don’t yet have enough information to understand exactly what the cost of this option would be.

In time, coastal erosion will threaten wastewater pipes and the local wastewater pumping station. When this occurs, they will need to be moved to ensure affected properties have access to the wastewater system and to avoid the risk of environmental impacts from damaged pipes. The affected wastewater infrastructure would likely be moved to run underground along an existing road further inland.

*We don’t yet have enough information to understand exactly what the cost of this option would be.

Maintaining the walkway is expected to become harder and more expensive over time. The adaptation pathway map below shows that at a certain point – likely around 10 to 30 years from now – changing conditions mean action will need to be taken to make sure the walkway is safe to use. This could involve protecting the walkway in its current location until this becomes unworkable. Alternatively, we could look to close or relocate the walkway in the first instance, or at a point in time when protecting it becomes less effective.

*We don’t yet have enough information to understand exactly what the cost of this option would be.

The shorefront parking area and the seaward end of the access road are at risk from future coastal hazard impacts. Maintaining these areas is going to become harder and more expensive over time as sea levels rise. The adaptation pathway map below shows that at a certain point – likely in around 20 to 40 years from now if the existing rock wall is maintained – action will need to be taken to make sure the parking area is safe to use. At this point, we could look to improve the existing protection to keep the parking area in the same location, or to relocate some or all of the parking area to another location, or close the area as a public carpark.

*We don’t yet have enough information to understand exactly what the cost of this option would be.