Burst water main affecting Llanrumney/St Mellons & surrounding areas of Cardiff, CF3

exclamation icon

Updated: 08:00 04 September 2025

Our teams have worked overnight to fix the burst water main and supply bottled water to over 700 vulnerable customers. The burst water main has now been fixed, and water supplies are now restored due to rezoning and tankering operations.

We are in the process of re-filling the network but this needs to be done carefully and slowly to avoid any further bursts. Some customers may still experience intermittent supply, low pressure or discoloured water as things return to normal. The bottled water stations will remain open this morning.

Bottled water stations are available at:

  • Eastern Leisure Centre, Llanrumney Avenue, CF3 4DN
  • Tesco Supermarket, St Mellons, CF3 0EF

We’d like to apologise for the inconvenience this has caused customers.

More information is available here.

Water resources


The water resource position of Welsh Water’s area of supply is relatively strong.

Around 95% of our water resources originate as surface water either from reservoir storage or river abstractions. We have very little dependence on groundwater supplies. This reliance on surface waters can increase vulnerability to short periods of low rainfall as river levels change more quickly than groundwaters.

All Welsh Water’s abstractions are licensed by Natural Resources Wales and the Environment Agency who are responsible for ensuring the sustainable use of water resources in Wales and England. These licences set the maximum volume and rate at which water can be abstracted each day throughout the year. Rivers in Wales have high ecological status and licences are set to ensure that this is maintained. Releases from Welsh Water’s reservoirs during dry spells help to maintain river flows.

Keep an eye on this page to see how levels change.


Our Water Resources Management Plan

To ensure that water is available to our customers when it is needed and in the quantity required, Welsh Water prepares and maintains a Water Resources Management Plan (WRMP), which forecasts over a 25 year period the supply and demand balance across our water supply area.


Our Drought Plan

To ensure we are able to manage water and maintain supplies during extremely hot and dry weather conditions, Welsh Water prepares and maintains a Drought Plan. This document sets out the key indicators of drought and the operational strategy, management structures and communications plan that would be implemented during a drought.