Some of Horizons' protection schemes had been "pushed to within mere millimetres of their capacity" and the council had undertaken numerous flood gate operations, she said.
"Many of our communities, including Manawatū last year, Whanganui in 2015, and the wider Manawatū in 2004, know first-hand just how devastating a significant flood can be.
"Not only do these large flood events affect people, properties and local economies, they cause disruption to Crown assets such as roads, railway, lifelines infrastructure, and other central government-supported projects and assets such as community centres and marae. Government pays no rates contribution to the protection of these."
As part of the Government's Covid-19 recovery initiatives, the council received $26.9 million from the Infrastructure Climate Resilience Fund. Ratepayers contributed a further $9 million towards flood protection projects in Foxton, Rangitīkei, Palmerston North and the Lower Manawatū.
"This co-investment is a great example of how regional councils can accelerate work on flood protection schemes that are already planned or under way," Keedwell said.
"However, for Horizons this investment only supports four of council's 34 river and drainage schemes which include over 500km of stopbanks, 1100km of drains, 22 pumping stations and 53 dams.
"These schemes are funded through general and scheme rates, and have an asset value of $800 million, providing $15 billion worth of benefit value to the region."
Since 2019, regional councils and unitary authorities had committed to increasing annual regional funding for flood protection by a further combined $25 million, Keedwell said. Community support for increased flood protection had been demonstrated through their collective long-term plan processes.
"With the escalation of extreme weather events, we now need central government to step up and meet this challenge alongside our ratepayers, who are currently paying the bill for critical flood protection in response to climate change.
"Flooding is the number one naturally occurring hazard in Aotearoa. Regional and unitary councils will continue to advocate to central government for co-investment solutions which deliver to the needs of communities now and into the future."