What materials were commonly used in building water storage structures like cisterns in historic Mallorca?

In historic Mallorca, water storage structures such as cisterns were essential for managing the island's limited and variable rainfall. The materials used in building these cisterns were selected for their durability and local availability, reflecting traditional construction methods adapted to Mallorca’s Mediterranean environment. Predominantly, limestone, which is abundant throughout the island, formed the primary building material for the walls of cisterns. This stone provided both structural strength and resilience against the wear of time and water exposure.

In addition to limestone, bricks made from locally sourced clay were also commonly used, particularly in areas where finer masonry was required. These bricks, often rendered with a lime-based mortar, helped seal joints and prevent water seepage. The interiors of cisterns were typically coated with a waterproof plaster called "cocción," a mixture made from lime and other natural additives, which created a smooth, impermeable lining that protected the structure from leakage and contamination.

The roofs or covers of these water storage systems were often constructed using flat stone slabs or tiles, sometimes supported by vaulted arches, a design feature that not only added strength but also helped shield the stored water from evaporation and debris. Wood was used sparingly, mainly for access covers or maintenance hatches, but never for the main structural elements since it was vulnerable to rot in moist conditions.

Overall, the construction of cisterns in historic Mallorca was a thoughtful combination of locally sourced natural materials and traditional techniques, ensuring these water reserves endured for centuries in the island’s dry climate. The result was an efficient, long-lasting solution to water scarcity that remains a testament to Mallorca's resourcefulness and respect for the natural environment.