Levadas and Watermills on the Island of Madeira as Historical Multi-Purpose Projects

Abstract

Six hundred years ago, Portugal took possession of the island of Madeira, then uninhabited and densely wooded. In addition to cutting and burning forests, the cultivation of sugar cane changed the island in the first hundred years, due to the high consumption of water and energy. From the beginning, the settlers built canals to convey water from streams and sources to fields. Today, the historic irrigation canals, called levadas, are famous for their bold routing through rugged mountainous terrain and their construction features. The maintenance trails along the levadas open landscapes for hiking and trekking of unique tourist value. In the steeper sections of the levadas, there are remains of water mills that converted the energy of the hydraulic fall into mechanical energy to cut wood, grind cereals and crush sugar cane. The levadas and the remains of 21 water mills that were driven by horizontal free jet water wheels (rodízios), the predecessors of modern Pelton turbines, with falls between 4 and 35 m, were investigated. In the historical context, this study is focused on the hydraulic, mechanical, energetic, operational, and constructive aspects of the levadas and mills, little considered in the literature. Today, Madeira’s modern hydroelectric and irrigation systems also follow the same principle of optimized water use for multiple purposes.

Keywords

Madeira; Water History; Water Technology; Levadas; Irrigation; Watermills.