The Calderdale Flood Commission said authorities must "act now" to deal with the "immediate issues and future risk".
Almost 2,000 homes and more than 1,000 businesses in the Calder Valley were affected by flooding over Christmas.
The report said incidents were "projected to get worse" due to changing weather patterns, climate change and ageing infrastructure.
The commission - set up to consider the "causes, impact and response" to flooding in Calderdale - also said changes in land management and use were major factors in increasing the likelihood of flooding.
Paul Cobbing, chair of the commission, is due to present the report with recommendations to Calderdale Council later.
The full report can be read here
Mr Cobbing said: "We all know that the Calder Valley is particularly vulnerable to flooding but, due to climate change, the threat of more severe and more frequent flood events is increasing.
"We believe the solutions we implement today must not just tackle risk as it exists now, they must also take into account the increasing year-on-year risk."
The report calls for a significant investment in flood risk management in the Calder Valley and welcomes the creation of a board to "coordinate and monitor" flood risk management and response.
The Department for Environment, Food & Rural Affairs said it was "committed to helping with the recovery" and was investing Â£52m in flood protection in the the Calder Valley.
It was also looking at making affordable insurance more accessible, a spokesperson added.
Paul Kearney, whose home in Mytholmroyd was flooded when the River Calder overflowed, said: "It's always a worry when it rains, and hearing the report that it's likely to happen again it does make you think hat it could happen anytime soon.
"We just have to hope for the best and hope that the things they do to make the river safer are going to work."
Widespread flooding in West Yorkshire will happen again and could become more frequent, a report has warned.