The irrigation canals of l’Horta of Valencia have all a main canal that starts at the Turia River, in the corresponding diversion weir. Its traditional name is "la séquia mare" (literally “mother canal”) and in order to get water to each of the plots it is necessary for several secondary canals to be diverted from it, which are often divided up again several times. These diversions have different names: “braç” (arm), is the most important of the secondary channels, but there are also the “files” (rows) and the “rolls” to reach the watering can that enters or passes through the side of each of the terraced fields.
The material form of these partitions has also been historically resolved in a different way. The simplest ones are a gate, floodgate or even a hole (also traditionally called "eye") in the side or bottom and side of the main canal. These partitions have usually had a gate or “paleta”, a wooden "post", to open and close the water flow to the secondary irrigation canal, although nowadays they are usually metal “paletas” with a lathe for ease in height and drop.
Yet in terms of the larger diversions from the main irrigation canal between two main arms, the traditional form of dividing the flow of water has been and still is what is a divisor called “llengua”, this is “tongue”, a tongue-shaped stone. The name is not by chance: its physical morphology is based on a starling formed by stone blocks that end in a fine point facing the flow of water that arrives through the irrigation canal. They are usually placed in the centre of the canal and split into two equal parts for each of the two new irrigation canals, but there are also cases of splitting into a third and two thirds or a quarter and three quarters, logically placing the starling at the appropriate distance from the sides.
Although in the last two centuries they usually had gates to make a batch between the two arms, since the Middle Ages these water divisors did not have them, and the water always circulated and split between them. The reason for this design is to make a partition that is always proportional to the flow of water that arrives through the main canal, whatever it is. Whether in times of drought or abundance of water, as there were no gates, the social agreement that these language dividers built was respected as each new irrigation canal corresponded to 50%, or 33% or 25% of the available water.
Archaeological excavations and studies over the last few years have also confirmed its antiquity. While they have undergone some modifications to their structure, in general they have consisted of adding concrete, sometimes piping, and installing gates to open and close the water flow for each of the arms. But what has remained untouched are the dimensions of each part of the partition: two Islamic cubits (called “Rasasi”, one of the measures of length used in the Islamic Valencia before the conquest of  King James I in the 13th century and that are equivalent to 105 cm wide.
This is an example of the durability of these key points in the distribution of water from the Valencian irrigated areas as well as their origin in the Muslim era, between the 8th and 12th centuries.