Lake water levels lowered at popular city park

Ted Peskett, local democracy reporter

Cardiff Council said it is carrying out essential work on a popular city park after people noticed a major change to the lake there.

The water level of Roath Park Lake decreased this week to the extent that the bed of the lake in large parts of its northern section was exposed.

Cardiff Council said the water level was deliberately lowered on Monday, January 20, to carry out essential works on the dam valves and that it will remain lowered for a further five days.

A fish rescue was carried out as part of the works.

Dam valves

When asked about the lowered water level a Cardiff Council spokesman said: “The water level was lowered on Monday… to carry out essential works to the dam valves and the work was approved by Natural Resources Wales (NRW).

“The council lowered the lake but at half flow to ensure there were no flood impacts further downstream.

“This was a stipulation by NRW. The council lowers the lake annually to carry out vegetation and rubbish clearance as part of our maintenance programme.”

Park users noted in May last year that the lake appeared to be silting up with some people likening its appearance to a “fetid swamp” and “unsightly mess”.

At the time Cardiff Council said the potential future dredging of the lake would be considered as part of a scheme to redevelop the dam at the southern end of Roath Park.

Months later pictures showed the patches of exposed land transform into what one ecology expert called vegetated islands.

Silt

Speaking at the time Professor Steve Ormerod of Cardiff University said: “Residents have noticed changes in the depth and shape of Roath Park Lake at its northern end where sediment has accumulated to create what are now vegetated ‘islands’ at low flow in summer.

“In some respects this is a natural process as all lakes tend to trap silt and sediments through the passage of time.

“However recent wet winters and high river flows have almost certainly accelerated this process in the lake’s catchment.”

When asked about the potential impact of lowering the water level of Roath Park Lake on fish a Cardiff Council spokesman said: “Contractors from Five Rivers attended the site to carry out the fish rescue within the pool of the spillway.

“There was no impact on wildlife.”

The Roath Park dam project, which is aimed at protecting the park from potential future flooding events, will involve the replacement of the current spillway with a wider and deeper feature.

It will also see the addition of a flood wall along the promenade of Roath Park Lake and a new open seating area next to the Terra Nova cafe.

An online update on the project published in 2022 states that subject to planning permission works on the dam were scheduled to begin in 2024.

The latest planning application relating to Roath Park Lake on the council’s online planning page, relating to structural coring and pitting works to investigate the resevoir’s condition and integrity, was approved in October 2024.