The drone’s flight, always stealthy, begins at seven in the morning in Calafell (Baix Penedès). The road map of the surveillance device, obtain images of the 2,500 swimming pools scattered throughout the extensive municipal area, with numerous housing estates. Flights are made in duplicate and images are compared to check for changes. Thus, the City Council, with competences in the management and control of the use of drinking water, can detect if there are residents who fill empty swimming pools despite the express prohibition of the Generalitat’s Special Drought Plan.

The drones are raised so early to respect the privacy of the tenants in their homes. At this time, between seven and eight, it is very unlikely that any neighbors are bathing or sunbathing next to the sheet of water, municipal sources explain. If a drone records people in one of the pools, the images are immediately deleted, according to the company that has been awarded the service.

Each drone that is raised can cover a radius of half a kilometer with a single operator on the street and sweep in five minutes. “It is difficult to see from the street if the pools are filled, and we have decided to make an inventory of the pools that are empty with periodic drone flights to monitor whether they are filled or not. If they are filled, we proceed with the corresponding sanction”, explains Aron Marcos, councilor of Urban Ecology in Calafell, in a video published on Instagram.

The councilor himself admits that the control could be carried out by analyzing the water consumption, house by house, to detect if it is fired and then check if the reason is that the pool has been filled. The consumption reading does not allow to detect the violation as quickly as through periodic drone flights. In addition, the bill is bimonthly and the water meters are not yet digital.

“The aim is not to impose fines, it is to save water”, says the City Council. The surveillance method has been publicly disseminated to seek a deterrent, almost preventive effect. If the neighbors know that they are being watched from the air and their still empty pool is registered, they will not fill it now no matter how much of a heat wave they have to endure, seeing their pool without water. The measure, the Consistory insists, is not intended to open disciplinary proceedings and collect fines, but to reduce water consumption in the midst of a drought.

The system has just been launched now, in the second half of July, after the administrative process to award the contract to a company specializing in drone flights has ended. If the process could have been sped up, it would have started earlier, with the municipal government aware that residents have had time to fill the pools despite the ban on doing so.

The precedent is from 2002, when there were still no drones and their use had not been as widespread as it is now. The City Council then had to contract the flight of a small plane with its pilot to fly over the sea of ??private swimming pools in the municipal area. The aim was to check if there were unregistered swimming pools, operating irregularly, as suspected by the Consistory due to the skyrocketing water consumption in many of the houses when summer arrived.

The measure, with small plane flights and a photographer taking images from the air, served to detect about 800 swimming pools that were not listed anywhere, including some in neighboring communities that, due to the size and capacity of bathers, were obliged to hire the services of a lifeguard.

Whether in a small plane, much more expensive and expensive, as at the beginning of this century, or in drones, more effective, fast and cheap, the efficiency of monitoring swimming pools from the air has been proven in Calafell. A method used by other administrations, such as the Central Government, to detect irregular constructions outside the cadastre, in rustic and urban estates, and thus be able to collect the corresponding taxes in each case.