The finding of thousands of unreported private swimming pools in France has given French tax authorities with an unforeseen bonanza. More than 20,000 hidden pools were detected by means of an artificial intelligence (AI) experiment.

According to French media, they have made around €10 million in revenue.

Pools, which increase property value and must be declared under French law, can result in higher property taxes.

During a trial in October 2021, the software developed by Google and the French consulting firm Capgemini detected the pools on aerial images of nine French regions.

The trial included the regions of Alpes-Maritimes, Var, Bouches-du-Rhône, Ardèche, Rhône, Haute-Savoie, Vendée, Maine-et-Loire, and Morbihan, but tax officials say it could now be implemented nationwide.

According to data website Statista, there will be more than 3.2 million private swimming pools in France by 2020, with sales already brisk prior to the Covid pandemic.

However, as more employees worked from home, there was an increase in pool installations.

According to Le Parisien, an average pool of 30 square meters (322 square feet) is taxed at €200 per year.

According to the tax authorities, the software could eventually be used to detect undeclared home extensions, patios, or gazebos, all of which contribute to property taxes.

“We are particularly targeting house extensions like verandas,” Antoine Magnant, deputy director general of public finances, told Le Parisien.

“But we have to be sure that the software can find buildings with a large footprint and not the dog kennel or the children’s playhouse,” he added.

The crackdown comes after Julien Bayou of France’s Europe-Ecology Greens party said that a ban on new private pools was not ruled out.

In an interview with BFMTV, he stated that France requires a “different relationship with water” and that the ban would be a “last resort.”

“The challenge is not to ban swimming pools, it is to guarantee our vital water needs,” he said.

His remarks come as France deals with its worst drought on record, which has left more than 100 municipalities without drinking water.

According to the national weather service Meteo-France, France had 9.7mm (0.38in) of rain in July, making it the driest month since March 1961.

Irrigation has been prohibited in much of France’s north-west and south-east to conserve water.

(Adapted from BBC.com)