The Salt Flats of Torrevieja,
The Torrevieja Salt Flats in Alicante are a clear example of the convergence of the good work of the people who make up the salt flats and the environment. They offer an extraordinary opportunity to appreciate the natural beauty and biodiversity of Spain's Mediterranean coast. They are a place that embodies the history of this city, the culture, and the ecology of the region, and are well worth a visit for anyone interested in our industry, its nature, its preservation, and curiosity about this mineral so important to everyone around the world.
History
The earliest origins of salt extraction are not located in the Torrevieja lagoon but rather in the La Mata lagoon. An underwater archaeological survey uncovered remains of what may have been a Roman factory. This important discovery dates the beginnings of salt exploitation to at least the 1st century BC.
However, the oldest document on record mentioning the salt flats is a Privilege of Alfonso X, dated January 11, 1273. It authorized the residents of the historic district of Orihuela to take salt for their own consumption from the Torrevieja Salt Flats. The Torrevieja and La Mata Salt Flats were part of the Crown's inherent royalty, and were finally ceded to the Orihuela Council in 1321 for exploitation by Prince Don Sancho, son of King Alfonso XI. In 1488, the city of Orihuela ceded the La Mata Salt Flats to the Catholic Monarchs, who were seeking resources for the conquest of Granada.
In 1766, the State administration began to take over the operation of the Torrevieja and La Mata salt mines for salt production. Beginning in 1869, with the abolition of the salt monopoly, a lease-based operating system was implemented, with contractual modalities that have since varied and been transferred among various companies. The concession is held by the New Lease Company of the Torrevieja Salt Mines, belonging to the French multinational group "Salins du Midi."
Geography
The total area of the Torrevieja salt flats is 2,100 hectares, of which 700 hectares correspond to the La Mata Lagoon and 1,400 hectares to the Torrevieja Lagoon, occupying 55% of the municipal area, which is equivalent to 2,187 football fields .
The origin of the Salinas is due to a series of geological movements that gave rise to the formation of two depressions that were later occupied by the current lagoons of La Mata and Torrevieja.
Chemistry
The salt mines contain a chemical industry complex, built between 1956 and 1966 to manufacture byproducts derived from concentrated lye. This industrial project failed to achieve the expected results, as its production exceeded the needs of the domestic market and was uncompetitive for export. All the factories were finally closed in 1977. These warehouses are now practically unused, and only a few are used for storage.
Natural park
The Torrevieja Salt Flats are located in the La Mata and Torrevieja Lagoons Natural Park. This 3,743-hectare site has been declared a Special Protection Area for Birds, a Site of Community Interest, a Ramsar Wetland, and a Natura 2000 Network, among others. Together with El Hondo and the Santa Pola Salt Flats, they make up the so-called southern Alicante wetland triangle, which is of great importance for the development of the biological cycles of numerous species, as they use it both for their migrations and for nesting and wintering.
Among the birdlife, the most notable are waders such as the Black-winged Stilt and Kentish Plover, various gulls such as Audouin's and Slender-billed Gulls, and also the group of ducks such as the Great Shelduck. Pink flamingos are also common in La Mata Lagoon, as they find more food there than in the Torrevieja lagoons due to the lower salinity. Among the plant species, plants adapted to live in very saline environments, such as salicornias or barrel plants, particularly Salicornia, Sarcocornia, and Limonium, stand out.
Pink color
Why is the Torrevieja lagoon pink? The pink color of the Torrevieja lagoon is due to the presence of pigments possessed by a series of very peculiar bacteria that inhabit very extreme environments characterized by high salinity. These bacteria are called halobacteria.
Another organism that contributes to this coloration is Dunaliella salina. It is a unicellular alga that produces a pinkish pigment called carotene. Finally, we highlight the role of Artemia salina, a crustacean that also acquires this pinkish color by feeding on halobacteria and Dunaliella.
Flower of salt
The former Chemical Ponds are currently used for the extraction of fleur de sel. It is a product with unique qualities due to the environmental characteristics of the Torrevieja lagoon.
Its production takes place during the warmer months due to the temperature contrast between day and night. During this period, the lagoon water reaches the ideal salinity level, causing a thin layer to form on the surface. This layer is collected manually before the wind causes the salt to precipitate to the bottom of the lagoon. Finally, it is stored to dry, and after a manual process to remove impurities, it is packaged for consumption.
Salt crafts
One of the traditional crafts linked to the salt industry is the creation of the famous salt boats typical of our city. The assembly of a salt boat is done by hand and consists first of forming the boat's structure from pieces of wood and covering it with cotton cloth.
Then, when the lagoon is crystallizing, what is known as "boat setting" begins. This involves lowering the boat into the brine so that the salt crystals adhere to the structure. Finally, they are placed in glass urns.
Production system
How is salt produced? The sea salt production system is based on achieving a sodium chloride content of 30 g/l in seawater, or common salt, by solar evaporation, which reaches 300 g/l, at which point the salt crystallizes. To this end, seawater is introduced into the La Mata lagoon, where, little by little, thanks to the combined action of the sun and wind, it evaporates. When it reaches 120 g/l of sodium chloride, it is transferred to the Torrevieja lagoon.
There, the brine (water highly concentrated in salt) continues to evaporate until it reaches 300 g/l, at which point the salt crystallizes and settles to the bottom of the lagoon. Subsequently, when the salt reaches a minimum thickness of 5 cm, its extraction begins. This is done using a machine called a volvedora or extractor, which, using a GPS system, travels around the entire lagoon, scraping the salt crust from the bottom with a blade, and then loading it onto different boats.
Each barge has a capacity of 7 tons and is pulled in groups of 10 to 13 by tugboats, forming a navigation unit known as a "rache." The extracted salt is then transported to a facility located in the middle of the lagoon, known as "the island." There, after unloading the barges, the initial salt washing takes place, removing much of the accompanying sludge and gypsum. Then, via a conveyor belt, the salt is sent to the "washing place" located on land. Here, the salt is sifted and washed again. This second washing is more intensive than that on the Island, effectively eliminating virtually all impurities. Finally, the salt is stacked using a two-wing stacker known as "the bird." This structure allows for the formation of two longitudinal piles on either side of the conveyor belt.
Manufacturing
The Torrevieja Salt Mines produce various formats of sea salt for sale in both the national and international markets, dedicating almost 50% of its production to export, primarily to Northern European countries and occasionally to the United States. Exports take place through the port and can load salt vessels with a capacity of up to 30,000 tons. The salt production process basically consists of washing, grinding to different granulometries according to customer specifications, drying in a natural gas oven, packaging in 25 kg sacks and Big Bags of up to 1,500 kg, and finally loading and shipping by land or sea. In certain formats, additives can also be added, such as iodized salt, especially in developing countries, as it helps prevent diseases caused by iodine deficiency.
Another commonly used additive is the anti-caking agent used in de-icing salt. Salt is the only edible mineral and, along with water, the only food product that doesn't have an expiration date.
Another interesting fact is that salt has more than 14,000 uses. The main ones are:
- road de-icing,
- in the pharmaceutical industry: saline solutions
- for the production of feed in animal feed
- and the best known, for human consumption as direct consumption or for food preservation using the salting technique.
Garberas
In salt-making jargon, salt mountains are called "garberas." These mountains can reach a height of 20 meters, equivalent to the height of a seven-story building. The triangular shape of the garberas facilitates the drainage of rainwater. When it rains, a crust forms on the surface and the water slides off, preventing it from entering the mountain and dissolving the salt. Each cone contains an average volume of 15,000 tons. The total capacity of the garbera is almost 800,000 tons, equivalent to an excellent harvest year.
Acequión Canal
The so-called "Canal del Acequión" is a 1-km-long canal built in the 15th century to connect the Torrevieja lagoon to the sea, in an attempt to convert it into a fishing lagoon. This project was motivated by the difficulties in leasing the Torrevieja lagoon due to the priority given to salt production from the La Mata lagoon. For this reason, the Orihuela Council decided to use it for fishing in 1389.
The project suffered several delays due to the continuous blockage of the Acequión during storms and was not completed until 1509. This canal allowed fish to enter. However, poor water circulation caused high salinity in the lagoon, negatively affecting fish development and leading to large fish die-offs. All these problems led to the project being definitively abandoned in 1763. This canal is still in use today, allowing seawater to enter the salt flats.
Pinoso diapir
Average annual production is approximately 650,000 tons, but this value varies each year depending on meteorological factors such as solar radiation, wind, and rainfall. This production comes not only from seawater but also from the contribution of brine from the Pinoso diapir. Through a series of wells, brackish water is injected under pressure to dissolve the rock salt. This dissolved salt is sent through a 55-km pipeline to the Torrevieja lagoon, where it crystallizes.
