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Coldbrook Flood Alleviation Works

The Coldbrook Flood Alleviation Scheme has been created to reduce the risk of flooding to over 200 properties and 3 schools in the Barry area. The Council, Welsh Government and Natural Resources Wales have worked together to create the scheme and various works have been scheduled along the Coldbrook watercourse


Works are  being undertaken throughout 2016 in the Barry area, and here you can find information on the history of flooding in the area and updates on the latest news and developments with the scheme. 


Coldbrook Dyfan Road works




Contact us

Dyer and Butler are the lead contractor on site carrying out the works. Their Community Liaison Advisor, Sian Gadd, can be contacted to discuss any concerns regarding the works being undertaken.


Dyer and Butler
Rampart House





Peter Brett Associates (formerly Martin Wright Associates MWA) are the engineering consultants that have been appointed by the Vale of Glamorgan Council to design, develop and supervise the construction phase of the scheme. If you have any queries or comments about any aspect of the project you are more than welcome to contact Peter Brett Associates by post or telephone.


Peter Brett Associates

Caversham Bridge House

Waterman Place



  • 0118 950 0761


Other useful links

All the following sites contain useful information about the organisations involved in developing this scheme, or information to raise awareness about flood risk and what you can do to reduce it. 


Key Facts

Scheme promoted by:

 - Vale of Glamorgan Council 


Funded by:

- Vale of Glamorgan Council 
- Welsh Government

- Natural Resources Wales

- EU Regional Development



At risk of flooding:

205 Residential properties 
3 Schools


Estimated Cost of scheme:

£2.9 million


Anticipated timescale:

Construction Phase Completion

    December 2017


Construction/Improvement Works



Overall objective:

To significantly reduce the risk of flooding in the Coldbrook catchment of Barry


Lead officer:

Clive Moon


Main Scheme Contractor:

Dyer and Butler


  • Who is promoting and funding the scheme?
    The Coldbrook Catchment Flood Risk Management Scheme is being promoted by Vale of Glamorgan Council, with funding provided by Welsh Government, European Regional Development Funding, Natural Resources Wales and the Vale of Glamorgan Council.
  • What causes the flooding?

    The Coldbrook is a relatively small watercourse that originally would have been open and clearly visible as it flowed from west to east through the catchment. However, over the past few decades, lengths of the watercourse have been piped and buried underground to allow for new development. This ‘closing in’ of the watercourse has gradually created a significant flood risk as a consequence of the following factors:


     - Before the land was built upon, during a flood event, the watercourse would have spilt onto the adjacent fields where it would have eventually drained away without causing any problems. These areas of natural ‘flood plain’ are now built upon. Most of the catchment of the watercourse that was originally green fields has been developed for residential or commercial use. Fields and open spaces can ‘soak up’ much of the rainwater that falls upon them, but once developed, hard roofs and paved areas prevent that from happening and most of the rainwater is channelled directly to the watercourse through a system of pipes, sewers and highway drains.


     - The urbanisation of the area has meant that maintenance of the culverts is very difficult. Some of the critical lengths pass under roads, and through private property.


     - Climate change is increasing the intensity of rainfall events. Nowadays, more water needs to get into and through the system. This is a problem that will get worse as climate change continues to happen.

  • What is the aim of the project? 

    To significantly reduce the risk of flooding in the area.
  • How will the scheme reduce flood risk?

    Various options have been considered to reduce flood risk and the final solution is a combination of each of the following:

    Larger pipes will be constructed that can cope with flows from all but the most extreme rainfall events. This involves increasing the size of existing culverts, or constructing additional culverts on a different route.

    Rainwater will be diverted into specially designed storage areas until the rain has passed over. Once the rain has stopped and the amount of water in the pipes has dropped, this ‘stored’ water can be released and will flow away without causing any problems.

    By using detailed computer modelling, it has been possible to predict where flooding may happen, and where any flood water will go. We then used this information to make alterations to the system, and the local built environment, to ensure that if flooding does occur, it does not seriously affect people and property.

    Ensuring that the public, local businesses, the emergency services and the relevant public bodies in the area are aware of, and understand, the potential flood risks and what they need to do to protect themselves and the community.

    Ensuring that all drainage systems in the area are going to be maintained properly and that any future developments are designed to ensure that flood risk is not increased.

  • Will the proposed scheme prevent flooding from happening ever again?
    The scheme will significantly reduce flood risk, BUT, no flood risk management scheme can ever remove risk completely. There will always be a small chance that a rainfall event may be so extreme that is exceeds the capacity that the new system has been designed for. 
  • What level of protection has the new system been designed to provide?
    It is standard practice in the UK to design new surface water drainage systems to a standard that will prevent flooding during rainfall events that typically are so severe that they should only occur once every 100 years (we also include an additional factor of +20% to account for the detrimental impact of future climate change). 
  • When will work take place and how long will it last?
    Investigation works, assessment of options and detailed design of a preferred option were completed by March 2014. The construction phase of the scheme commenced in January 2016 and is proposed to run until October 2016.  
  • Will there be much disruption when construction work takes place?
    It is very difficult to lay large pipes in the ground without any disruption to the local area. Minimising this disruption is a significant factor taken into account when designing how the scheme will be built. Wherever possible we will ensure that noise is kept to a minimum and the use of traffic lights or short term road closures are only used where essential. 
  • What impact will the scheme have on the environment?
    Protecting and enhancing the environment is an important part of the project. Throughout the development of the scheme, we have worked closely with Natural Resources Wales. The area has been carefully monitored and assessed for the presence of species such as otters, water voles, great crested newts, migratory fish, bats, and nesting birds. Any proposed construction works have been designed to minimise disruption to existing habitats and where possible we will take every opportunity to enhance the environment. 
  • How do I find out more about the scheme?

    Elsewhere on this web site there are details about the history of the scheme and information about the proposed work.


    The Latest News section will also be regularly updated to keep you in touch with progress. 


    Alternatively, the main compound has been set up at the Council Depot in Court Road, Barry, and Sian Gadd, the Community Liaison Officer, is available for drop-in sessions on Mondays between 09:30am and 02:30pm