Mermaid Quay


Welsh Water invested over £2 million to upgrade the sewer system in the Mermaid Quay area of Cardiff Bay. This page provides an overview of the work that was done in the area.

Welsh Water invested over £2 million to upgrade the sewer system in the Mermaid Quay area of Cardiff Bay. This work was essential to make sure we continue to provide customers in the area with a first-class wastewater system they can rely on. This page provides an overview of the work that was done in the area.

Work was needed following reports of local internal flooding caused mainly by the illegal discharge of fat, oil and grease (FOG) down the drains and other items such as wet wipes and cotton buds being flushed down the toilet that build up in the sewer and cause blockages. Frequent cleaning to clear the blockages damaged the sewer in Mermaid Quay which needed to be replaced.

Work carried out in the area was done in a phased way to minimise the impact on the local area. The first phase of the scheme involved the removal of the temporary footbridge on Stuart Street, repairing the original Victorian brick sewer, removing FOG blockages along Stuart Street and Bute Street and installing a new sewer pipe on Stuart Street was completed in December 2018.

Due to the number of collapses found in the area, a second phase to the scheme was delivered to fix the collapsed areas and install a new long term sustainable sewer within the existing sewer on Bute Street in Mermaid Quay was started in January 2019. This was completed in July 2019.

Here is a timeline of what we have done in Mermaid Quay since September 2017: