Flooding, storms, and severe weather are the most frequent hazard in Hawke’s Bay. Many major floods have been recorded in Hawke’s Bay. Usually there will be sufficient warning of a storm, however sudden storms and flash flooding can occur without warning in individual catchments.
You can keep up to date with daily weather forecasts online, through the radio, or television. You can sign up to receive MetService Severe Weather Warnings and Watches as they are issued – the MetService has good information on the services it provides. You can also follow the HB Emergency Facebook page and see the recommended radio station page. To find out more about the flooding hazards where you live, work and play, visit out hazard map portal.
Get prepared by having a plan, emergency supplies at home and a grab bag in case you need to evacuate. Find out what the information you need to know, how to best prepare, what to do when severe weather or flooding happens and what to do after by reading the sections below.
Create a household plan and have emergency supplies - Make an emergency plan and make sure everyone in your household knows what you will do during both a storm and flood, your plan needs to cover if access to your house is cut off, or if you need to evacuate due to severe weather or flooding. Visit our Get Ready page to find out what you should have in your emergency household supplies. Ensure you have a grab bag ready to go and a plan for your pets and/or livestock. If you live in an isolated location its particularly important to make sure you’ve got enough supplies for your household for at least three days.
Plan and practicing evacuation routes - The plan should show you the safest routes to higher ground or to your community’s place of safety. If you live in a flash flood area, you should have several alternative routes. All members of the household should know where to meet each other, where to evacuate to, and what route(s) to take if you have to leave. Remember you may be evacuating at night, so have a torch, and also plan multiple routes if the way you evacuate is inaccessible.
To get your home ready - If strong winds are forecast, make sure heavy items (trampolines, garden furniture, gazebos) are taken indoors or well secured. Where possible locate your pets and keep them inside. Farmers and lifestyle block owner need to consider how and where you will relocate stock in a flood situation. If you have livestock ensure they are moved to a safe place away from floodwaters, landslides, powerlines, and isolated trees.
If you live in a flood prone area - consider storing sandbags to protect your home in a flood situation. Know what to do if a flood happens and how you can get out. If you have a disability or any requirements that may put you at greater risk in a flood visit Getready.govt.nz and follow the advice for people with disabilities.
If you or your household feel at risk of flooding and can leave safely, leave immediately and get to higher ground - Do not assume that you are safe close to a river, stream, drain or other type of waterway during a flood. Water may overtop banks, or erosion could make the ground near waterways give way. Debris building up in waterways can create blockage and dams, which can make the potential to release a large amount of water.
When a storm is happening- Stay inside, close all windows, doors and pull curtains and blinds over windows where possible. Unplug small appliances that may be affected by electrical power surges. If you lose power, unplug major appliances. This will reduce the power surge and possible damage when power is restored.
If you are in a flood zone evacuate to high ground - If you are away from home and there is no building in sight, and you are not in a flood zone, take shelter in a vehicle and keep the windows closed. Watch out for fallen power lines or broken gas lines and stay out of damaged areas.
Be wary of storm surges - If you are by the coast or at the beach it can be particularly dangerous around river mouths and low-lying areas. Avoid situations where you could get cut off or swept into the water.
Stay out of flood water - never try to walk, swim, or drive through flood water. There can be hazards like drain holes, debris, silt, and pollution.
After a flooding event - make sure yourself and your family are safe, help others if you can, and check in on your neighbours. Stay alert for extended rainfall, flooding, landslides, and hazardous debris, particularly while driving. If you have evacuated, you should only return home once officials advise it is safe to do so. It may not be safe even when flood waters have receded. In urban areas, flash flooding can overwhelm the stormwater system and cause surface flooding. In flat urban areas – like Napier and Hastings – pumping is needed to get stormwater out of drains, and it can take a while to clear backed up water.
Once home - throw away any food, including canned goods, or drinking water that has come into contact with flood water as it may be contaminated. Avoid drinking or preparing food with flood water until you are certain it is not contaminated. Follow any boil water notice instructions from Te Whatu Ora or Emergency Management.
If your property is damaged, take photos and contact your insurance provider as soon as possible. Renters should contact their landlord if there’s any damage.
Look before you step - the ground may be slippery or covered with debris including broken glass. Stay away from damaged areas.
Storms and floods are the Hawke’s Bays most frequent hazards in terms of impacts and declared civil defence emergencies. Much of the built-up and farmed areas of Hawke’s Bay are on low-lying land and river flood plains, increase the risk of flooding. Major storms affect wide areas and can be accompanied by strong winds, heavy rain or snowfall, thunder, lightning, and rough seas.
There are common factors in most flood events in Hawke’s Bay. Heavy prolonged easterly or southeasterly rains, falling on comparatively shallow soils, which do not have capacity to absorb large amounts of rainfall. Additionally, the region has short, steep catchments in the hill country, resulting in rapid runoff, and a lack of lake/wetland storage with few ponding areas funnelling water into the three major rivers on the Heretaunga Plains - the Ngaruroro, Tukituki and the Tutaekuri.
Heavy Rain - Heavy rain is rain that continues for a long time and can cause streams and rivers to rise rapidly, which can lead to landslides and flooding. MetService will issue a severe weather warning when it is expected there will be widespread rainfall greater than 50mm within 6 hours, or 100mm within 24 hours.
Thunderstorms - Thunderstorms are short-lived weather events, lasting up to a couple of hours. They may cause lightening along with heavy rain, hail, and localized severe winds. MetService will issue a warning if heavy rain from thunderstorms reaches 25mm/h or more, or if there is large hail of 20mm diameter or more, or strong wind gusts from thunderstorms of 110km/hr (60 knots) or more occur.
Severe Wind - Severe gusts of wind can be dangerous to people and cause significant damage to buildings and property. MetService will issue a wind warning for severe gales with a minimum mean speed of 90km/hr or frequent gusts exceeding 110km/hr.
Heavy Swells - MetService will publish a Heavy Swell Warning whenever there is an expectation that sea swells are significantly higher than typical within the next 24-48 hours.
River flooding – During heavy rain rivers can overflow their banks. River flooding happen when there is too much water, and the run-off is too much to be carried by the rivers, and the water goes out onto the land around rivers.
Urban flooding - Urban areas have a lot of hard surfaces, stopping drain water from soaking into soil. When rain falls faster than systems can manage urban flooding occurs.
Flash floods – Occurs when heavy rain falls in a small area with little warning, resulting in intense rainfall which overwhelms natural or urban drainage systems.
Storm surges - Storm surges are produced when high winds push water onshore.
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