A very important feature of road construction is drainage. New roads include designed drainage systems intended to remove water efficiently from the surface of the highway to provide a safe passage for all vehicles and pedestrians.
Older roads may have less sophisticated drainage but all have features designed to take the water away from the road surface. It is necessary to clean and maintain these drainage provisions so that they can work properly.
Problems can occur even when drainage provisions are clean and well maintained. Flooded and waterlogged roads result when the amount of water falling on the road is greater than the capacity of the drainage facilities that take it away. This can occur as a result of:
- Exceptional rainfall
- a road being in a low lying area
- changes in 'run off' from adjoining land
- rivers overflowing
These are some situations that can lead to the road flooding or being waterlogged even when drains are in good working order.
Material carried into the drains by floods can also lead to them becoming blocked. Drainage grills and gratings (e.g. on gullies) can become blocked very quickly when materials like mud are deposited on the road or when there is a heavy fall of leaves.
Where a road is flooded and the cause is a ruptured water main the Dwr Cymru/ Welsh Water will be responsible for repairing the damage.
Water is directed to drains by the road profile. Puddles (ponding) tend to occur if there is a depression in the road. This can be rectified where necessary by local patching of the road surface.
The following notes give guidance on who to contact for various types of flooding:
The water company, Dwr Cymru/ Welsh Water, own and manage the network of public foul and surface water sewers. To report an overflowing public sewer you should contact Dwr Cymru/ Welsh Water Customer Services on, 0800 085 3968
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. See Yellow Pages under "Drain and Pipe Cleaning". If you are uncertain if any blockage is in the public or private sewers, Dwr Cymru/ Welsh Water, once on site, should be able to determine this. You will be recharged for the cost of any work on private sewers. The County Borough Council can also provide a service but once again any costs incurred will be recharged.
Flooding from the Public Highway
For flooding from the public highway or reporting blocked road gullies or gratings, contact the Highways section using the details below.
Flooding from a Burst Water Main
Dwr Cymru/ Welsh Water is responsible for the supply up to and including the water stopcock.
Flooding from a Water Service Pipe or Internal Pipe work
This is the responsibility of the homeowner or landlord and would need the attention of a plumber.
The main rivers are the responsibility of the Environment Agency and they provide a "Flood line", 0800 807060, which is a 24 hour advice and information service for floods and flood warnings.
For further information visit the Environment Agency Flooding site.
For general enquiries you can telephone 08708 506506,
or minicom 08702 422549, 8am-6pm Mon-Fri.
Flooding from Watercourses other than Main Rivers
Watercourses, other than main rivers, are the responsibility of riparian owners. You are a riparian owner if your property or land is on or very near a watercourse. Riparian owners have a duty to keep the watercourse clear of any obstruction to flow and the Council can serve legal notices on riparian owners to deal with obstructions. Certain "strategic" watercourses that are known to pose a high risk of property flooding if they become blocked are checked and maintained by the County Borough Council on a regular basis.
Provision of Sandbags to Protect against Flooding
We make sandbags available to residents of the district, during extreme situations, to enable them to protect their homes from flooding. However, residents who are aware that their homes are at a high risk of flooding, e.g. as a result of the close proximity of a watercourse, are recommended to obtain sandbags from a builders' merchant to enable early preparation as, during times of flooding the County Borough Council may not be able to reach all properties before flooding occurs.
For more information use the below:
Highways Network Group
Merthyr Industrial Park,