Understanding Landscape of the Pico Island Vineyard Culture: the tidal wells

April 22, 2022

Tidal wells are some of the references of the Landscape of the Pico Island Vineyard Culture – World Heritage, currently under the management of the Regional Secretariat for the Environment and Climate Change, and, whiting this landscape, are cultural values.

Their presence is one of the great milestones of what was the gigantic epic of the toil of the Man of Pico to establish himself and survive.

Apart from those already destroyed by coastal erosion, there are more than 30 tidal wells since, in this part of Pico Island, they were the easiest way to access water due to the inexistence of springs, streams or even tanks and cisterns that only appeared at the end of the 19th century. I emphasise that there are no streams or springs from Santa Luzia parish going westwards to São Mateus parish.

The inexistence of watercourses and springs would have been a strong factor in the late human occupation of this western side of Pico island – formerly called "Fronteira" –, today almost entirely integrated in the municipality of Madalena, formed in the 18th century, two centuries after the municipalities of Lajes and São Roque do Pico.

Besides the lack of water, vast lava fields and rocky soil and the lack of arable land suitable for agriculture are the main differences with the oldest part of the island on the east side, after the spreading of the great Pico Mountain.

It is also in the Landscape of the Pico Island Vineyard Culture that the most distant tidal well from the coast on Pico island can be found – the Poço do Aço (Steel Well). It is more than 700 metres from the coastline, on private property in Criação Velha parish, and has a depth of about 16 metres.

The toponymy of some streets of the parishes still preserves the memory and importance of the tidal wells. The following street names are proof of this: “Canada do Poço”, “Canada do Poço Velho”, “Canada do Poço Novo” in the parish of Bandeiras, the “Caminho do Poço” or “Rua do Poço” in the parishes of Madalena, Criação Velha and Candelária and “Pocinho” in Candelária. All these paths gave access or culminated near a tidal well near the coast.

The construction process of these wells was completely manual, using tools and utensils that implied the use of human strength to break and remove the successive layers of rock and stones, opening a deep crater until water was found (basal aquifer*). The next phase of this process consisted of the construction of the walls of the pit, from the bottom to the surface, in stone masonry: the crater excavated in the meantime was gradually filled with stones resulting from the excavation, as the walls of the well were built up towards the surface. Finally, at the surface, the great slabs of carved stone that sealed the "well's mouth", usually square or rectangular, were laid, and, around them, the floor was levelled and slabbed or cobbled with the stones or slabs that suited them best.

At the bottom of the well, the maximum water depth is little more than 1 metre and fluctuates with the tide: following the logic of hydrodynamics in this context, the best quality water would be obtained at low tide. Contrary, at high tide, more water would appear at the bottom of the well, but more likely to be brackish water – of lower quality. In some wells, eels appeared.

To draw water from the well, all that was needed was a bucket and a rope. However, in some wells, wooden structures were added suspended over the well's mouth, with ropes and pulleys, which facilitated the raising and lowering of buckets process, dividing their weight so that it became a less strenuous task.

Besides providing water that was indispensable for human and animal survival, this water was also used for domestic purposes, and fundamental for the operation of the distilleries, given the need for large quantities of water for cooling the coils and washing the distillation boilers. This is why, in the Vineyard Cultural Landscape, there is always a tidal well in the vicinity of a distillery, and there are also cases where rudimentary pipes and gutters have been constructed, which carry the water from the well directly to the interior of the distillery.

On the properties where the manorial houses or manors are located, as well as next to the convent houses near the coastline, there was always a tidal well that, for its importance and symbolism, was framed in the space of the main entrance of the property, in a privileged central position, instilling in that scenario of the main façade a great protagonist: as more expressive examples we have the Solar dos Salgueiros (in Lajido de Santa Luzia) and the Solar dos Arriagas (in Guindaste). These are rare examples that marked the importance that wealthy families gave to their private tidal well.

The streets and access paths to the public tidal wells show evidence of a grand movement of people and oxcarts, notable for the existence of rilheiras (marks carved on the stone by the oxcarts) and large stone washbasins, which demonstrate that large quantities of water were transported to the villages established a few kilometres away from the coast and the tidal wells (Santana, Santa Luzia, Bandeiras, Toledos, Criação Velha, and Candelária). At that time, fetching water was a daily routine.

The portrait of the time would be a permanent teeming of life and people around these tidal wells: water came out of those wells to quench thirst, for cooking, for tending animals, for washing. And it was by the tidal well that most people washed their clothes and stayed there waiting for those white clothes to bleach in the sun, stretched over the black rocks of the coast. 

Nowadays, tidal wells are solitary elements in the landscape, lifeless around them, mysterious: they have lost their importance and are no longer used. However, they preserve what is essential for human survival: water and memory.

(*) Basal aquifer: mass of fresh groundwater in hydrodynamic equilibrium with seawater; due to its lower density, freshwater floats on top of saltwater; common phenomenon near the coastline of small volcanic islands.