John Creek — Warnings

This page is for residents of John Creek, the small lakeside settlement at the southeast corner of Lake Hāwea, reached via Gladstone Road. The advice on this page is specific to John Creek's geography and is more urgent than the standard earthquake response that applies elsewhere in Hāwea.

The content on this page has been informed by local geological expertise. The current assessment is that the most likely hazards for John Creek in a major earthquake are rock fall from the cliffs immediately above and north of the settlement, road collapse on Timaru Creek Road, and lake disturbance from delta collapse at Timaru Creek and the Craig Burn. The risk of a major tsunami caused by a large landslide into Lake Hāwea is considered lower than sometimes assumed — the hills above the lake have already survived many Alpine Fault earthquakes. A separate hazard worth knowing about is a debris flow coming down John Creek itself after a major rainstorm.

None of this changes the basic advice: if you feel significant shaking, move to higher ground without waiting for an official warning. The cost of moving is low. The cost of not moving, if a wave does come, is total.

The risk

In a major earthquake, landslides into Lake Hāwea can generate large waves — referred to in Civil Defence terminology as lake tsunamis. These waves move quickly across the water and can reach the shoreline within minutes. After the initial wave, the lake may continue oscillating for hours — a phenomenon scientists call a seiche — which means the water can keep moving dangerously even when the immediate threat has passed.

There is no warning system for any of this. By the time you can see a wave, there is no time to move.

John Creek is the most vulnerable settlement on the lake because:

It sits at lake edge, very close to the water
It is at a lower elevation than Lake Hāwea township
Properties are close-packed along the shoreline, with limited high ground immediately behind them

Lake Hāwea is a controlled lake managed at up to 346m above sea level. When the lake is near its maximum level, any landslide-generated wave carries more energy and travels faster. The higher the lake at the time of an earthquake, the greater the immediate risk.

A 2018 NIWA study of Lake Tekapo found evidence of past landslide-generated waves up to five metres high. Scientists believe similar events are possible in Lake Hāwea and other Otago lakes during a major Alpine Fault earthquake.

The specific risks at John Creek

John Creek faces a combination of hazards that makes evacuation more complex than simply moving away from the lake.

The settlement is divided by John Creek, which crosses the road as a ford. In a wave event, water surges up the creek channel quickly, potentially making the ford impassable within minutes of shaking stopping. Residents on the Timaru Creek Road side of the settlement who would normally cross the ford to reach higher ground may find that route blocked.

The steep slopes to the east of Timaru Creek Road show evidence of past landslide activity and will shed material in a major earthquake. Moving toward those slopes is not safe.

These combined hazards — wave from the lake, potential surge up the creek, and landslide risk from the eastern slopes — mean that the safest evacuation route depends on where your property sits within the settlement. The CRG is working with John Creek residents and Emergency Management Otago to develop specific evacuation guidance for this community. Until that guidance is available, John Creek residents should:

Talk to their immediate neighbours about the hazards and routes before an event
Not assume that a single route works for all properties in the settlement
Walk their intended route now, in good conditions

Things to know before an event

Walk your evacuation route. Know how long it takes you, your children, and any older or mobility-affected family members. If your route involves the ford, have an alternative plan in case the ford is impassable.
Know your neighbours, particularly those who live alone or have mobility issues. After the shaking stops there will be no time to organise help — arrangements need to be in place before.
Keep sturdy shoes and a torch beside the bed. If shaking happens at night, you may need to move quickly in the dark over broken ground.
Have a small grab bag near the door — phone charger, water, basic medication, warm layer.
Tell visitors to John Creek about the risk. Renters, holiday-house guests, and visitors won't know unless someone tells them.

When is it safe to return

Do not return to John Creek properties until at least several hours have passed without further significant aftershocks. Even then, treat the situation with caution:

Aftershocks can trigger further landslides and further waves
The lake may continue to oscillate for hours after the initial wave — water can keep moving dangerously even when it looks calmer
Damaged property and the lake edge are both hazardous
Return only briefly to assess and collect essentials
Plan to spend the first night somewhere other than at lake level

Information about whether the area is safe will come through the Otago Gets Ready alert system, the Hāwea Community Resilience Group, and Civil Defence Otago.

Telling others

This advice is critical for everyone who lives in or visits John Creek. The hazard is specific to lake-edge properties and not widely understood.

If you own a property in John Creek and rent it out — even occasionally to friends or family — make sure your guests know:

What to do if there is significant shaking
Where to go for higher ground
That they should not wait for an official warning

Consider a printed sheet on the fridge or noticeboard with the key information.

Related information

Identify Your Risks — the wider context of natural hazards in Hāwea
During An Earthquake — the standard Drop, Cover, Hold On response
Family Whereabouts — what to do about family members elsewhere
Communication — how the CRG will share information after an event

Last reviewed: May 2026.

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