The ex-prince’s Marsh Farm is on a flood plain with residents advised to sign up for alerts in case local measures fail to stop a torrent of water from a nearby bog.
It comes as work continues on the ramshackled former farmhouse in Wolferton, Norfolk — two miles from the King’s Sandringham House — ahead of his move there after he is kicked out of Royal Lodge in Windsor.
Workmen have added a 6ft fence around the perimeter, CCTV and security lighting and installed Sky TV.
Several new doors have also been lined up, but sources say there is still a lot of work to be done.
Andrew could be out of Royal Lodge in weeks but has been offered temporary accommodation before he moves to Marsh Farm.
A flood risk assessment from last year for Wolferton Barns — metres from Marsh Farm — said it would be “prudent” for the owner to be added to the flood warning system in case the pumping station which drains marshland had a mechanical breakdown.
The assessment by Ellingham Consulting states: “The Environment Agency operates a flood warning system to enable householders to protect life or act to manage the effect of flooding on property.
“Failure of Wolferton Pumping Station may occur due to long-term mechanical breakdown or power supply being disrupted.”
“If conditions put properties and land at risk of flooding, emergency action would be taken using temporary pumping equipment.”