Mills in Altoaragón - harinero, central eléctrica


Aísa is situated in the Jacetania region between Jaca in the South and the French border. It is probably best approached from the main road between Jaca and Canfranc (N 330). Coming from Jaca you'll first drive through Castiello de Jaca. About 2 km further on turn left for Aratorés. Once there continue toward Borau and then Aísa where you can drop your vehicle somewhere in or near the village and then from there walk the GR15 down towards the Río Estarrún where the mill is. It is probably more rewarding to drive a bit further on and then halt at the area recreativa Santa Juliana next to the afore­mentioned river. From there a path is laid out which will bring you back to the village: after less than one km you'll be at the mill (1).


(1) The site of the mill with an explanatory panel
The mill is on a hiking trail and that is probably the reason why the building is thoroughly secured. There is no way to get between the walls and I can therefore only guess at the layout inside.

There is however an explanatory panel (1) from which we learn that the mill produced meal mainly from wheat (for bread) and barley (fodder for pigs) and in lesser amounts also of oats and rye.

The site produced electricity from the beginning of the 20th century — presumably earlier than Jaca, capital of the region. The turbine also powered a saw, which has now disappeared.

The upper floor served as living quarters of the miller. The last miller was a Mariano Ara Lanaspa. The mill was in use till the beginning of the 1960s.

(2) Display of some of the equipment of the former business.
The site counted two other constructions. A stable of which some remains can be seen and a so-called porgadera where the fresh produce was cleaned before the grinding. This cleaning building was swept away by the river.
Some of the equipment was preserved and is now on display (2). There is an old monolithic stone and a pair of composite ones (5). The monolith has a diameter of 125 cm and the other stones measure ∅ 130cm.

(3) The turbine
(4) N°405 of M.M.A. - Utebo dated 1945

(5) Monolith and composite stones
There are also several belt- and cogwheels and a turbine.

The turbine is tagged with: N° 405 MMA/UTEBO 1945 (4). MMA stands for Maquinaria y Metalurgia Aragonesa S.A.. Read more about this company in our page about Salinas de Jaca. We have encountered the same brand in some other mills also and the oldest turbines we have seen are installed in Puyarruego and Aguinalíu (Serial 35 and 39 respectively, both dated 1916).

No equipment related to the production of electricity was found. The only trace we could find were some insulators (8) mounted in a small slit in the back wall. They helped to bridge the wall and connect the wiring inside with the grid outside.

The mill pond (9) is located behind the mill. When the pond was full the water reached above the roof of the mill (6). At the time of our visit the pond was still in a rather good condition (9): largely free of vegetation and with solid walls. Unlike ponds at other mills the walls do not converge into a narrow pressure pit or a saetín. Here the wall against the mill is wide and features three openings (10).

(6) Side view of the site. The mill pond is at right side. Stones are visible bottom left.

(7) Annex to the mill, likely dedicated to the powerstation.

(8) Window through which the lines connected to the grid.

(9) The mill pond with the inlet at the right. The mill is top left.

First we have a huge grid (10) which protects the tube feeding the turbine. The tube sits at the bottom (14). At the bottom right (10) a saetín-like opening can be seen. It may have been the inlet to the grain mill, but I cannot know for sure.
Finally there is a small square opening high in the middle of the wall. It serves as an overflow which drains the pond when the water reaches too high. The overflow channel starts as a duct and at the other end of the wall becomes an open canal which first bridges an open space (11) and then descends (12, 13) towards the level of the river.

(10) Left: grid with inlet to turbine; center: overflow (see 11–13); bottom right: inlet for grain mill.

(11) Overflow channel: first section.
(12) Overflow channel: middle section.

(13) Overflow channel: last section.
(14) Grid with inlet to turbines.

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