What were the advantages of keeping water storage systems like the “aljubs” underground in Mallorca?

The underground positioning of water storage systems like the “aljubs” in Mallorca offered several significant advantages, especially in the context of the island's Mediterranean climate. Being situated below ground helped to shield the stored water from direct sunlight and extreme heat, which minimized evaporation. This was crucial in an environment where fresh water was a valuable and often scarce resource, particularly during the dry summer months. By maintaining a cooler, more stable temperature underground, these cisterns enabled a more reliable and efficient conservation of rainwater collected during wetter periods.

Moreover, placing aljubs underground also protected the water from contamination and debris. The enclosed nature of these cisterns helped prevent leaves, dust, and other pollutants from entering the storage, ensuring that the water remained cleaner for longer durations. This design was practical not only for sanitation but also for maintaining the durability of the system. Since underground structures were less exposed to the elements, they were less susceptible to physical damage from storms or temperature fluctuations. In addition, the subterranean location reduced water loss through leakage or structural wear, contributing to a sustainable water supply for local populations and agriculture.

The strategic use of underground aljubs reflects the ingenuity of historical water management techniques in Mallorca. They served small communities, farms, and estates by providing an accessible water source without relying solely on unpredictable surface water or distant springs. Their discreet integration into the landscape also helped preserve the aesthetic and natural environment of the island, avoiding the need for large, exposed reservoirs. In essence, the underground placement of aljubs combined practicality with environmental sensitivity, ensuring that water storage was secure, efficient, and in harmony with Mallorca’s climate and topography.