Tidal mills in the Bay of Cádiz

What is a tidal mills? Tidal mills were devices devoted to grind

cereals (wheat) and salt. They were built along the European costline (Holland, Great Britain, France, Portugal and Spain) and were mainly located near canals and rivers. Here, the tide potential energy is maximum. This location allowed these tidal mills to work for at least six hours during the whole going out and coming in tide process.

Where are they in Cádiz?

How does it work?During the low tide, and with a significant drop, all the gates are open to release the water towards the sea. The water flow turns a wheel, called “rodezno”, which makes the millstone move and grind the wheat.

Tidal Mills on the Bay of Cádiz

The approximated locations of the ancient tidal mills in the Bay of Cadiz are: 1) Rio Arillo; 2) Santibañez; 3) Sierra; 4) San José; 5) de Soto; 6) Santa Cruz; 7) Montecorto; 8) Ormaza; 9) Bartivas; 10) La Aceña; 11) Ocio; 12) Zaporito; 13) Caño Herrera; 14) Fadricas; 15) El Pilar; 16) Trocadero; 17) Mendoza; 18) Goyena; 19) del Puerto. (After Molina 2001). The small solid squares denote the location of the main secondary channels, from South to North these are:Carboneros, Iro and Zurraque.

How does it work? Tide mills take advantage of high and low tides

to turn a stone wheel that grind the cereal in order to transform it into flour.

How does it work?When the tide goes out, the higher areas in the marshes are flooded in such a way that, when the tide starts coming out, the water is kept in that part of the marshes by using gates.

How does it work?During the low tide, and with a significant drop, all the gates

are open to release the water towards the sea. The water flow turns a wheel, called “rodezno”, which makes

the millstone move and grind the wheat.

How does it work?When the tide starts coming in again, the waterwill gradually

loses potential until it definitely stops. Then, the whole cycle is repeated once again.

Kinds of tidal millsThe oldest, in which the water makes a wheel called “rodezno” turn.

The wood used to make this “rodezno” was obtained from olive trees, whereas the vertical shaft was made from pine tree trunks.

Kinds of tidal millsThe most modern waterwills, where the wheel is called “rodete”.

Comenius Project

• Chiclana de la Frontera• February, 2011