Anita Mary Parry’s body was discovered in a field near the river in Llanfrynach on December 1 last year, a day after she had gone into the river near her home in Llanfaes, Brecon.
The 50-year-old had left her home while preparing the family dinner at around 5.30pm on Monday, November 30.
Her partner Roberto Calloni, who had only recently moved back into the the family home, then called her on her mobile phone.
Coroner Andrew Barkley said: "She told him she was by the river, she had had enough and ’I can’t take it anymore’."
Yvonne Hammond, who had been walking her dogs on the river bank with partner David Barrett, just after 6pm said they heard a scream and then saw a woman in the river.
Ms Hammond told the inquest at Brecon Combined Court she and her partner were carrying powerful torches.
Ms Hammond said: "She was about two, three of four foot away and we shouted at her. At that point she could have come back to the bank, but she almost put herself back into the torrent."
Asked by Mr Barkley if she was able to communicate with Ms Parry, and what she said, Ms Hammond replied: "Yes. She said ’I want to die’. She went under the water and came back up and said ’I want to die’.
"While she was in the slower water we’d thrown a dog lead to her, she could have grabbed it. She didn’t make any effort to grab it.
"She 100% knew what we were saying. I made eye contact, she was calm, relaxed and seemed in control of what she was doing.
"She could have grabbed the branches if she had tried."
After Ms Parry, a former primary school teacher, disappeared from her sight Ms Hammond ran to raise the alarm while her partner continued to search the river bank.
Brecon Mountain Rescue Team, Dyfed-Powys Police and the fire service launched an immediate search of the river which was called off for the night at 11pm.
It resumed the following morning and Ms Parry’s body was found later that day.
A toxicological report showed there was 288 milligrams of alcohol in her blood, which in a normal social drinker would usually cause extreme drunkenness but is below the fatal level.
Mr Barkley said he was satisfied Ms Parry had intended to take her own life and recorded her death as a suicide.