A 24-year-old man from Trecenydd has been named as one of two reservoir swimmers who died in the Brecon Beacons on Sunday.
Police said Daniel Colin Clemo died while swimming in Cantref Reservoir
Emergency services were called to the reservoir, between Brecon and Merthyr Tydfil, at 2.45pm.
In a separate incident a 52-year-old man also died while swimming in the Ponsticill reservoir.
Tributes have been paid to Mr Clemo on social media.
Following the tragedies, authorities have warned about the dangers of swimming in reservoirs.
Peter Parry, Welsh Water’s executive director of operations, said: “Firstly, our thoughts are with the families of those involved in these terrible tragedies that have happened.
“Our reservoirs are great places to enjoy organised activities but all too often people are tempted to risk taking a swim which can lead to tragic consequences.
“While reservoirs might seem like a great place to cool off, they are full of hidden dangers.”