Plaid Cymru has called for an independent public inquiry into the devastating impact of flooding in Rhondda Cynon Taf, which forced hundreds of people to evacuate their homes.
A major incident was declared when Storm Dennis brought the worst flooding to hit Wales for more than 40 years.
The River Taff, a major river that runs through Rhondda Cynon Taf, saw levels higher than 5 metres – breaking the record held since 1979.
It is estimated that more than 530 homes and at least 300 businesses were damaged in the south Wales county borough.
It prompted a visit from Prince Charles to Pontypridd to meet some of the residents and business owners affected.
A review later found a number of flood warnings were issued late or were not issued at all.
All 137 people who took part in a report carried out by Plaid Cymru wanted an investigation, which the party said would identify those responsible.
An independent inquiry into flooding will be debated in the Senedd this week, after nearly 6,000 people signed a petition.
Leanne Wood, MS for Rhondda, will take part in the debate and highlight the "confusion over the cause or causes of the flooding".
She said: "Having a multi-agency approach, each with their own different take on what happened and their own agenda, has created a scenario whereby lines of responsibility are blurred.
"A public inquiry would untangle this confusion and get to the heart of what happened and what needs to happen to stand the best chance of preventing it from happening again.
"This is much needed in the Rhondda as we have seen successive floods this year and they have mainly been in places with no real history of flooding."
February 2020 was the wettest February on record and fifth wettest month since records began in 1862, according to the Met Office.
The UK was also hit by Storms Ciara and Jorge during that month, with average claims data from the insurance industry valuing the flood damage to be around £81 million.
A review by Natural Resources Wales, which issues and manages flood forecasts, found its operations had been stretched and hampered its ability to react to "rapidly escalating and unforeseen events on the ground".
It also found 12 flood warnings were not issued when they should have been, and six were issued late.
The Plaid Cymru report included testimonies from those affected, which councillor Heledd Fychan, who represents Pontypridd, described as "heart-breaking".
She said: “From speaking to many victims, I know that they will not find peace until they receive the answers they deserve, and measures are put in place to safeguard their homes and businesses.
"Nothing done to date achieves this, and given that extreme weather is far more likely in the future due to the climate crisis, this must be urgently addressed.
"A public inquiry – which has been unanimously backed by people surveyed in this report – is the best way to ensure that the voices and experiences of victims are heard, to help inform how lives, homes and businesses can be safeguarded in the future."
A Welsh Government spokesperson said they recognise the devastating impact of the flooding on homes, businesses and people's well-being, adding that they "have taken significant steps to learn the lessons from this year's floods".