How do you protect a landed home from flash floods?

Flood proof house checklist

Landed homeowners prepare for flash floods by keeping water flowing away from the house, having barriers ready at the doors and knowing what to do if water still gets in. Work through this list in dry weather.

• Compound drains. Clear leaves, silt and rubbish from the drains around the house.
• Gutters and downpipes. Check roof gutters and apron drains monthly, as the National Environment Agency (NEA) checklist suggests, and see that downpipes run freely.
• Inspection chambers. Look for water standing under the covers or draining slowly.
• Flood barriers. Set them up once to check every piece is there and fits.
• Main switch. Know where your main switch is and keep the way to it clear.
• Valuables. Keep documents and electronics off the floor in rooms that could flood.
• Flood alerts. Follow flood alerts from PUB, Singapore's national water agency, on its Telegram channel or the myENV app.

This list matches what PUB asks of a Flood-Wise home owner. Its flood safety tips ask you to make sure the drains and drainage systems within your compound are well maintained and choke-free, and that your flood barriers are in good working condition. Set a monthly reminder for the drain and gutter checks.

Keep drains and gutters clear

Clear drains and gutters are the everyday way to prevent flooding at home. NEA's checklist for preventing Aedes mosquito breeding asks you to check roof gutters and apron drains monthly, clear scupper drains weekly, cover gully traps and remove stagnant water. The same routine keeps rainwater moving off your roof and out of your compound.

A choked gutter cannot carry a heavy downpour to the downpipe. The water spills over the edge and overflows into the walls below, which can leave damp patches inside. A blocked apron drain lets water pool against the house instead of draining away.

When you check, scoop out leaves and debris and pour a bucket of water into each gutter to see that it drains. Use a stable ladder with someone holding it, and leave high or steep roofs to a handyman.

If water backs up into an inspection chamber, or floor traps drain slowly across the house, the problem may be further down the line. Read the guide to an inspection chamber choke before you call someone.

Flood barriers

PUB's flood safety tips ask you to install flood barriers when there is a risk of flood, to protect your property from rising water. PUB also has videos on setting up inflatable flood bags and portable flood barriers, worth watching before you choose a type.

When choosing a flood barrier, landed house owners should first measure every opening water could reach at ground level, such as the main door, back door and any low vents. Ask the supplier how each piece seals against your frame or wall, how long it takes one person to set up and whether parts can be replaced.

Practise setting the barriers up once in dry weather, and put them up as soon as heavy rain is forecast, not when water is already at the door.

Private sewers and inspection chambers

The sanitary drain-lines inside your boundary are yours to look after. PUB's page on private sewers says owners are responsible for maintaining private sewers (sanitary drain-lines) within their premises, and that they can engage a contractor to clear chokes or contact PUB for advice.

Keep an eye on the inspection chambers in your compound, especially before and after heavy rain. Water standing under a cover, a sewage smell or floor traps that drain slowly across the house are signs to call a contractor before the problem grows. A choke that is cleared in dry weather is one less thing to deal with when the yard is under water.

When the job is done, ask the contractor what caused the choke and whether any part of the line needs more work, and keep a note of the visit for next time.

When water comes in

If water gets past the barriers, follow PUB's flood safety tips: move essential items to higher ground, such as an upper floor or high shelves. If you need to evacuate, PUB says to turn off all main switches and disconnect electrical appliances, and not to touch electric switches or appliances if you are wet or standing in water.

Once everyone is safe, wait for the water to go down before going back in. Take photos of the damage before you move or throw anything away, and keep receipts for emergency repairs. See the guide to home insurance for repairs before you agree to a quote.

Read cleaning up after a flood before you start, and have a Licensed Electrical Worker check anything electrical that got wet before it is used again. For the next spell of wet weather, see monsoon season home care.

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