The south of Alentejo where the Herdade dos Lagos is located, has annual rainfalls of 200-600mm (compared to 984mm in the region around Bordeaux). In the summer months temperatures around 40°C occur regularly which results in complete dryness in many regions of the Alentejo. The otherwise unused expiring winter rain water is now collected in five reservoirs that have been built in recent years. It is used for irrigation of olives and wine in the dry season.
The water surfaces form rich habitats in the otherwise completely dried region.