Flooding

Flooding can't always be prevented, but good preparation can reduce the risks. Residents can take practical steps to lower the risk of flooding and limit damage if it happens.

If your home or business is near a river, it's especially important to stay alert to weather warnings and local updates. Areas most at risk are New Cross, Deptford, central Lewisham, and low-lying areas around the A21.

Protecting your home or business

Check your risk

• check your home or business for flood risk by post code 

Prevent

• keep drains, gutters and downpipes clear
• install a water butt (you can use the harvested rainwater for your garden)
• de-pave your garden or parking area if you have one
• update your drive-way to permeable paving (you can still park there)
• add a green roof to your home, garage or bin shed
• plant a tree

Prepare now

• sign up for free Environment Agency flood alerts to get warnings by phone, text, or email
• know how to turn off gas, electricity, and water at mains
• make a flood plan for your home or business – how will you, your family or staff get to safety? Where will you or they go?
• store important items and documents above ground level if you are in a flood zone.

Get flood protection

• if you live in a higher-risk area, consider installing door guards or airbrick covers - see Blue Pages directory for flood-proof products
• sandbags can be bought from builders’ merchants
• check your insurance covers flood damage

De-pave your garden or parking area 

Replacing hard surfaces like concrete or tarmac with soil, plants or permeable materials like gravel, is a simple and effective way to prevent flooding, decrease pollution, and improve how your garden looks and feels.  

How it works

Hard surfaces send rainwater straight to drains, carrying pollutants and other materials with them. These pollute our waterways and can also block the system. Heavy rains often overwhelm sewers, leading to flooding and sewage in our rivers. 

Permeable surfaces help prevent flooding, by letting rainwater soak into the ground instead. This slows water flow, filters out pollutants, and prevents drains from getting blocked or overflowing.

Other benefits

• reduces river pollution
• supports plants, soil health and wildlife
• cools your space in hot weather
• increases greenery and access to nature

Even small changes - like replacing a paved corner or driveway edge with planting - can make a big difference.

Further guidance

• De-pave your garden or parking area
• Update your drive-way to permeable paving (you can still park there) 

Immediate priorities: safety first 

• if in danger, call 999
• move people, pets and valuables upstairs or to higher ground if it is safe
• avoid entering flood water - 6 inches can knock you over, 2 feet will float a car
• turn off utilities if safe - gas, water and electricity at mains if it is safe to do so (NEVER touch electricity while in water)
• follow any instructions issued by Emergency Alerts  

Prepare to evacuate

• check weather reports and emergency services
• gather essentials
• arrange accommodation (family/friends) and pet care

Protect your home

• plug sinks/baths and weigh down the plug with sandbags or soil-filled bags
• prepare a supply of clean water in containers
• listen to local radio (battery/wind-up) or call Floodline: 0845 988 1188

Stay safe

• don't drink tap water unless confirmed safe
• take extra care if you need to drive in bad weather and remember you should never drive or walk through flood water. If you must walk through flood water, please use a stick to make sure your path is clear
• don't let children play in the water
• wash hands if you touch flood water, as there are contamination risks

• check it's safe to return: watch for structural damage
• document damage: take photographs
• contact insurance immediately (or your landlord if renting)
• consider flood protection and preparedness when repairing damages

A gully is a grill-topped chamber at the side of the carriageway that collects rainwater. It usually connects to the Thames Water drainage system where it then drains away. After heavy rain, gullies and the drainage system can be overwhelmed and it can take a few hours for water on the road to clear. 

If flooding hasn't cleared after a few hours, report it. 

We will inspect the gully within ten working days to decide whether work needs to be undertaken. Typically, we assess whether the gully pot is clear and whether water is flowing. More complex, or less obvious issues can take longer to resolve and may require further investigation or liaison with Thames Water.

Report

• roadside gullies/drains - report using our online form or Council: 020 8314 6000
• private drains (within your property) - property owner/landlord - or find a trader via Trustmark to fix the problem
• public sewers (outside property boundary) - Thames Water: 0800 316 9800
• Red Route network gullies - Transport for London (TfL) - report a defect to TfL or call 0343 222 1234
• rivers - Environment Agency: 0870 850 6506

Response times

• emergency roadside flooding: 24 hours
• non-urgent gully issues: inspected within 10 working days

Special notice regarding responsibility for roadside drains and gullies on Sydenham Hill

• Northern arm (Crescent Wood Road to 171 Sydenham Hill); Lewisham Council, contact as above
• Southern arm (Crescent Wood Road to Westwood Hill); Southwark Council, 020 7525 5000
• Red Route (TfL main routes) (173 Sydenham Hill to London Road); Transport for London (TfL) - report a defect to TfL or call 0343 222 1234

More information

• Flood management and further guidance