These easily overlooked issues could ruin your home when the rainy season arrives. Experienced plumbing professionals explain…

New Zealand has had an especially unsettled summer this year. The entire North Island has been battered by cyclones and torrential rain, causing widespread flooding and substantial losses to residents' property.

 

Flooding is a very common natural disaster in New Zealand, often causing enormous damage and losses. After a flood, prompt emergency action and preventive measures are needed to reduce the harm it causes.

 

So what important information should we be paying attention to? Mico invited three Auckland plumbing professionals to share practical tips on responding to floods and preventing damage.

 

 

• Interviewee: Chen Xiao
• Position: Company head
• Company name: Springleigh Project Ltd

There are things homeowners need to watch for in their day-to-day lives. For example, if there are many trees beside a house, fallen leaves can collect in the gutters and cause blockages. Roof tiles can also have damage or cracks that are difficult to spot, but rainwater may seep through over time. Homeowners should clean them promptly and recoat them every few years. Flooding can also contaminate drinking water. If damaged sections of a water main allow soil to enter, siphoning can draw floodwater into the pipes. If the water looks cloudy, drinking tap water directly is not recommended. You can install an activated carbon filter or buy bottled mineral water.

 

From a professional perspective, pipes need regular inspection and repair to prevent problems. When new homes are built, designers usually consider the capacity of stormwater pipes serving the surrounding area and street. They also provide tanks, installed in the garden or underground, to stop rainwater from rushing into the main all at once during heavy rain, overwhelming the system and causing flooding. There are two types of tanks. Tanks that do not supply water for reuse generally require little maintenance. However, tanks that store water for watering plants or flushing toilets need maintenance. Cleaning them every one to two years is recommended, along with checking that openings are tightly sealed to keep insects out and prevent moss growth.

Image source: Westpac

The overflow relief gully (ORG) outside an older home also needs regular checks to keep out dirt, fallen leaves and other debris. Underground pipes can usually last 50 years, but after living in a home for 20–30 years, you still need to take care to prevent toilet blockages. It is also necessary to regularly remove and rinse the trap beneath the basin.

 

Overall, paying close attention to your home is important, and you can seek a plumber's help if needed. I have worked with Mico for many years. They are a leading New Zealand plumbing supplier, offering the products and services customers need, along with excellent after-sales service. Their prices are competitive and their local brands are good quality. I have always been very satisfied with their products and service.

 

• Interviewee: Fan Chao
• Position: Company head
• Company name: EH PLUMBING

Some issues require particular attention after a flood but are often overlooked. For household maintenance, we recommend regularly cleaning the stormwater sumps in your garden. This is especially important for homes on sloping sites in older neighbourhoods, where heavy rain can wash sediment downhill and block the sumps. A stormwater sump may look small, but it is the entry point for all the rainwater. If it is not cleaned, water may be unable to drain away and could even damage the house. New homes should also be designed with drainage volumes in mind, and rainwater tanks around the house need regular cleaning to prevent bacterial growth. Older houses also need regular inspections to prevent water contamination caused by leaks.

 

From a professional perspective, increasingly dense urban subdivision is one reason heavy rain causes widespread flooding: existing wastewater and stormwater systems cannot cope. Heavy rain is more likely to cause flooding in older areas with intensive subdivision. When choosing where to live, you can consult relevant reports to avoid flood-prone areas. New homes offer greater assurance in these respects. Councils require larger rainwater tanks when new homes are built, helping ease pressure on public infrastructure during heavy rain and keeping residents safer.

 

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To prevent problems, routine checks should include whether the basement has been waterproofed, whether water seepage around the house has been properly addressed, and regular inspections of stormwater channels and driveway channel drains. If flooding damages a home, homeowners can ask us as plumbers to assess the damage for an insurance claim. This process takes around 1–2 hours. We can also help clear blocked stormwater pipes.

 

• Interviewee: Christine Wang
• Position: Company head
• Company name: Xiongying Plumbing

In some older urban areas, pipes were designed to standards based on the smaller populations and fewer homes of the time. Population growth in recent years means public pipes no longer have sufficient capacity for current demand. These designs should be updated to account for urban expansion, population growth and the need to cope with extreme weather such as floods. Some older homes also send stormwater and wastewater through the same pipe rather than keeping them separate, further straining capacity. Newer areas, by contrast, take account of urban development and population growth over the coming decades, with public pipes sized as generously as possible. Flooding problems in these areas are therefore generally rare.

 

Inadequate maintenance of private pipes can also cause flooding. We therefore need to pay particular attention to maintaining private pipes and keeping them clear in everyday life. Even when public pipes lack capacity, some households' pipes will drain naturally after a while. Other households, however, neglect maintenance, allowing pipes to become damaged or blocked by roots, leaves and branches. This obstructs the flow and causes water to back up. Regular inspection and maintenance of private pipes is therefore very important.

 

Drainage at the garage entrance also needs attention. Some houses sit on low ground and have no drainage channel outside the garage, or the channel is blocked. These problems prevent water from draining away promptly, allowing it to enter the garage, basement or even living areas. Roof gutters also need regular maintenance. Leaves and branches can easily block them, stopping roof runoff from draining freely and allowing it into the house. Routine maintenance is essential to reducing flood damage and unnecessary trouble.

 

Underground pipes usually have a service life of 30–50 years. However, some older houses have outdated pipe materials that may be vulnerable to root intrusion or ground subsidence, causing blockages and poor drainage. If you notice water draining poorly, you may need a professional to carry out a CCTV inspection.

 

These interviews revealed many easily overlooked factors behind Auckland's flooding, with considerable room for improvement in everything from council planning to private maintenance. Winter is approaching, and heavy rain may once again sweep across New Zealand. Now is a good time to carry out upgrades and maintenance in preparation for the busy period and potential crises ahead.

 

Mico is a leading New Zealand supplier of plumbing, heating and bathroom products. We are committed to making things simpler for our customers, saving you time and improving productivity. We offer 200,000 products and guarantee that more than 500 core products commonly needed by plumbing and heating tradespeople are always in stock. Our branch managers have an average of 19 years of industry experience. With branches throughout New Zealand, we put customers at the centre of our service. Some branches now also offer express delivery within 1 hour to meet urgent needs and help you get the job done faster.
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