Is there an actual offence for knowingly filling out a planning application form wrong, in this case for saying in the Site History that the site never flooded?
If you answer no then I cant see a problem as this is something the council will have knowledge of in any event so that shouldnt be an issue. However if pp was granted and you were flooded well, depending on the claim, your insurance company may well have something to say about it if they investigated it fully.
The application is direct to ABP (strategic housing), so they won't know anything about the flooding, especially since floodmaps.ie hasn't been updated since 2014.
While there are lots of offences to do with social housing and not adhering to permission that is granted, I cannot see a specific offence for providing wrongful information on the application form itself.