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You are here:home > Environment > Climate change and flooding > Flood Investigations

Flood Investigations

As a Lead Local Flood Authority (LLFA) Southampton City Council has a duty under the Flood and Water Management Act (2010) to investigate flood events that occur within the city boundary.

Section 19 of the Flood and Water Management Act (2010) states that, on becoming aware of a flood in its area, a lead local flood authority must, to the extent that it considers it necessary or appropriate, investigate –

a) which risk management authorities have relevant flood risk management functions, and
b) whether each of those risk management authorities has exercised, or is proposing to exercise, those functions in response to the flood.

It is not the responsibility of the Investigating Officer to resolve the flooding, however they will investigate the cause and notify the relevant authority who then have the duty to resolve the flooding. In Southampton these authorities could include:

• Southampton City Council
• Highways
• Southern Water
• Environment Agency
• Associated British Ports (ABP)

Private landowners also have responsibilities in relation to land drainage and riparian ownership.

Upon learning of a flood event within Southampton, the Investigating Officer will follow the established Flood Investigations Protocol whereby it will be determined whether an investigation should be carried out using the Flood Investigations Guidance, taking into account the available resources and significance of the event. Both the protocol and guidance documents are available to view from the downloadable documents section of this page.

Where an investigation has been carried out, a flood investigation report will be produced and published. Reports will be available on this webpage shortly after the investigation is completed.

Flooding Advice

1. Why should I worry about flooding?

Flooding can occur anywhere, even if you live inland or away from watercourses, because of the drainage system. During periods of heavy rainfall the drainage system, whether open channel or pipes, can become overwhelmed by the volume of water it is expected to carry causing water to accumulate on the surface. In addition, when the ground is saturated even small extra amounts of rainfall will have difficulty draining away from gardens and enclosed spaces.

It is important to remember that it is the responsibility of the property owner to take appropriate action to protect their property from flooding. Information on how to protect your property from flooding is available on the National Flood Forum and Know Your Flood Risk website. The links to these websites are provided below.

2. Advice on what to do in a flood event

During a flood event, you should focus on the safety of yourself and your family.

Upon hearing of a flood warning:
• Move your possessions to a higher level
• Protect doorways and air vents with sandbags to reduce water entry.
• Monitor TV weather reports and Environment Agency’s flood website or calling their Floodline on 0845 911 1188

Should water enter your property:
• Be prepared to act quickly.
• Move possessions upstairs and stay upstairs (if possible).
• Turn off the gas, electricity and water supplies.
• If trapped in deep flooding stay by a window and call for help.
• Dial 999 if you or someone else is in danger.
• Cooperate with the emergency services and evacuate if told to do so.

On returning to your home:
• Do NOT turn gas or electricity back on until systems have been professionally inspected.
• Throw away food which has been in contact with flood water, along with all fridge and freezer food.

Floodwater is dangerous:
• Just six inches (15cm) of fast flowing water can knock you over and two feet (61cm) of water is enough to float your car.
• Flooding can cause manhole covers to come off, leaving hidden dangers.
• Do not let children play in flood water.
• Do not walk or drive through flood water.
• Do not walk on sea defences or riverbanks.
• Be aware that bridges may be dangerous to walk or drive over when water levels are high.
• Culverts are dangerous when flooded.
• Look out for other hazards such as fallen power lines and trees.
• Avoid contact with floodwater as it may be contaminated but if this is unavoidable remember to wash your hands thoroughly afterwards

For more information you can download a copy of the Environment Agency’s practical advice guide from the downloadable documents section of this page.

3. What if there is flooding to my property?

Make sure you stay safe during the flood. Move your personal belongings upstairs if possible and if it is safe to do so.

Who to contact:
• Dial 999 if you or someone else is in danger.
• Contact Southampton City Council via Actionline on 0800 519 1919 Monday to Friday 8:30am-5:00pm. For services outside these times please call 023 8023 3344
• If you are insured, contact your insurance company to explain what has happened.
• Contact your landlord if applicable.

4. What if there is flooding in my garden?

If possible, move your outside belongings to higher ground and move anything that is not fixed down, such as dustbins and garden furniture, to a safer location. If water is likely to enter your property, then follow the advice listed above. You can download the Environment Agency’s practical advice guide for more information.

5. Flooding to the highway

Do not walk or drive through the floodwater, as there may be dangers hidden below the water.

Who to contact:
• Dial 999 if you or someone else is in danger.
• Contact Southampton City Council via Actionline on 0800 519 1919 Monday to Friday 8:30am-5:00pm. For services outside these times please call 023 8023 3344

6. Foul Sewer flooding

If the flooding appears to be from a public sewer, call Southern Water immediately on 0845 278 0845 (open 24 hours for emergencies, otherwise 8am-7pm Monday-Friday and 9am-1pm Saturday). If it is a problem with a private drain serving your property then you will need to contact a private drainage contractor. If you are unsure then you can contact Southern Water and their specialist advisers will be able to give you advice on what to do. Remember to avoid contact with the floodwater as it may be contaminated, and wash your hands thoroughly if you do.

7. Water leak (Can cause flooding within a property, curtilage and/or highway)

If you suspect a leak from the water mains then contact Southern Water’s free dedicated leakline on 0800 820 999 (open 24 hours). If the water leak is inside your property/garden then it is probably a fault on your own supply pipe for which you are responsible.

Who is responsible for a leak?
Southern Water owns and maintains the water mains which carry water to homes and businesses, with your property linked to this main by a service pipe. Responsibility for this underground pipe is split between the property owner and Southern Water.

The property owner is legally responsible for the section of pipe running from the boundary of the public highway to the property. This is the supply pipe which is sometimes shared with other people such as neighbours and would mean responsibility for leaks is shared by several property owners.

Southern Water has responsibility for the section of pipe called the communication pipe. This is the pipe section between the water main and the boundary of the street beneath which the main runs.

If water is leaking from the outside stop tap, the water meter or the joints around the meter (if fitted), Southern Water have responsibility for putting this right. Any leaks on the internal plumbing remain the responsibility of the property owner and a plumber should be contacted to arrange any necessary repairs.

If you are unsure of the layout at your premises you can contact the Southern Water Customer Service Centre (0845 278 0845).

How do I know there’s a leak?
Apart from the visible signs, such as water bubbling out of the ground or a very damp patch in your garden on a dry day, there are other ways of checking whether there is a leak.

If your water supply is metered you can carry out a simple check. Take a reading from the meter, then either turn off the supply indoors or make sure you have no taps or water-using appliances (e.g. a washing machine or dishwasher) running. After one hour, take another meter reading. If the reading is higher, you probably have a leak.

Depending on where the leak is, you may also notice a slight hissing noise, particularly at night time when it is quiet. However where there are no obvious signs of a leak, Southern Water offer up to one hour’s free leak detection work. Contact the Southern Water Customer Service Centre (0845 278 0845) for further information.

Downloadable documents

Contact information