The construction of multiple Mills in sequence was a unique project. The mills were built in order to best use and optimize the natural slope of the area, which is the basis of the hydraulic system of the entire valley.
The exact point where to build a Mill was determined by the availability of the necessary space and also had to take into account the possibility of allowing the construction of the next one. This explains why the distance between the mills is not uniform. To better understand the technical needs that the engineers of the time had to face, it must be kept in mind that in the construction of a mill three mandatory parameters had to be respected:
1. Distance from the stream level of not less than one meter (to avoid flooding in case of flood);
2. Total height of the Mill of eight meters;
3. Slope of the arrival channel from the previous Mill and towards the next not exceeding 1%
Therefore the position of each mill was established by the altitude compared to the previous one and taking into account the need to build a subsequent one with the same characteristics, this is why we can talk about a SINGLE PROJECT, if there had not been the need to use the territory to the maximum possible the Mills would have been built in "convenient" places, without paying too much attention to their total number.
But why was there this need to build so many mills and this obsessive optimization of the territory? One reason is certainly the size of the Mills and therefore their REDUCED production capacity (which was a function of the limited availability of water at the source). Since it is the sum that makes the total, it was possible to increase total production by building many mills.
A perfect hydraulic system that is a technological marvel today. It will be a pleasure to illustrate this research to anyone interested.