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Last Modified May 14, 2019

The Environment Agency operates a flood warning system, giving information to the public, media, emergency services and local authorities.

Provision of sandbags to protect against flooding

We make sandbags available to Hertsmere residents, during emergency situations, to enable you to protect your home from flooding. However, if you are aware that your home is at a high risk of flooding we recommend you obtain sandbags from a builders' merchant to enable early preparation. During a major incident, we may not be able to reach all properties before flooding occurs.

Flooding picture








Using the latest available technology, we monitor rainfall, river levels and sea conditions 24 hours a day and use this information to forecast the possibility of a flood. If flooding is forecast, warnings are issued using a set of four easily recognisable codes:

Flood watch

Flooding possible. Be aware! Be prepared! Watch out!

Flood warning

Flooding expected affecting homes, businesses and main roads. Act now!

Severe flood warning

Severe flooding expected. Imminent danger to life and property.

All clear

An all clear will be issued when flood watches or warnings are no longer in force.

For more information on the current flooding situation, visit the Environment Agency website.


When there is a risk of flooding the Environment Agency issues warnings through the media; broadcast on TV and radio weather bulletins and travel reports. Make sure you know your local radio station.

The Environment Agency provides the Floodline Service - 0845 988 1188. You can listen to recorded flood warning information or speak to an operator for general information and advice 24 hours a day.

What this council will do

Our emergency assistance during flooding is as follows:

  • We have no legal responsibility to provide assistance to residents during a flood, however we provide emergency assistance on an ad hoc basis dependent upon local knowledge and experience of the situation.
  • We will provide sandbags or other equipment as appropriate, if they are available, to assist with flood defence within Hertsmere.
  • We will keep a stock of filled sandbags during times of potential flooding to aid the speed of response. We will deliver the sandbags or other equipment where the owner/occupier is unable to collect them from our depot. It is your responsibility to dispose of the sandbags once you are satisfied the risk of flooding has subsided.
  • We will provide engineering advice on how you can alleviate the risk of flooding to your property and issue general guidance to properties in Hertsmere of their roles and responsibilities under the Land Drainage Act 1991. We will provide, if possible, during times of severe flooding, engineering advice on site to assist with the use of resources and control the situation where appropriate.
  • We will assist with the dissemination of Environment Agency flood warnings where appropriate. We will keep the necessary equipment at our depot to carry out the above functions, or have facilities to get access to the appropriate equipment rapidly.
  • Very serious flooding, which results in the evacuation of houses and the provision of temporary accommodation is covered by our Emergency Plan.


Events over the past few winters have demonstrated that exceptional storms can cause flooding even on hill slopes, when the drainage system is simply overwhelmed by the amount of water it is expected to carry. In addition, when the ground is saturated even small additional amounts of rainfall will find it difficult to drain away from gardens and enclosed spaces.

We, at times of emergency, will endeavour to protect the public at large and will not be able to assist a large number of individual homeowners who may find their properties threatened.

In the event of flooding please contact the relevant authority as listed below.

Flooding from public sewers

The water company own and manage the network of public foul and surface water sewers. The majority of public sewers are located in highways and we have a copy of the sewer maps, which can be viewed at our offices. To report an overflowing public sewer, you should contact Thames Water for advice on 0800 316 9800.

Flooding from private sewers or drains

If your private drains or sewers are overflowing, you will need a drainage contractor to deal with any blockage. Engineering Services provide a 24 hour fee paying blockage clearance service. If you are uncertain if a blockage is in the public or private sewers contact Thames Water in the first instance as they should be able to determine this, once on site, then recharge you the cost of any work on the private sewers.

Flooding from the public highway

For flooding from the public highway or reporting blocked road gullies or gratings, contact Hertfordshire County Council for advice on 0300 123 4047.

If you require further information not contained on these pages please contact our main switchboard.

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