"The only safe and cost-effective way is to lift and remove houses over a period of time. The Wanganui District Council must not issue building permits from this point forward. The One Plan has pretty clear guidelines on building in flood-prone areas anyway," he said.
Mr Walker said that like other parts of New Zealand, Wanganui had developed on some river plains and while they were desirable flat land they were also exposed to the risk of flooding.
He said a historic reliance on structural protection works to stop flooding had created a false sense of security and encouraged a higher level of development.
He said reports he had read suggested flood banks actually increased the hazard, because they encouraged building in areas at risk and that in the past 20 years there had a growing realisation that stopbanks were unrealistic and not cost effective.
Mr Walker said that in the United States those building in a flood-prone area had to ensure their property was sitting at least above the level of a 100-year flood.
He said that at the moment, the Anzac Pde stopbanks were between 20 to 30-year flood levels with 50-year flood protection repairs approved for 2014-15.
"A number of towns in the US have been moved from a flood plain but Wanganui has only six houses in the Anzac Pde area that may get wet floorboards in a reasonable flood," he said.
He said during hearings into Horizon's Annual Plan, district council head Kevin Ross was asked if his council had considered moving properties up or away from floodwater and replied that was not being considered.
"But a similar 'managed retreat' was carried out on residents at Whangaehu a number of years ago when their village was flooded.
"The results are permanent and unlike costly stopbanks do not require maintenance nor constant repair and then run the chance of collapsing," he said.
Mr Walker said people needed to come to grips with what flood plains and relocation was all about and his view was the only "safe and effective" choice.