Period 1 –  from 4000 B.C. to 218 B.C.

It is believed that pre-Roman Iberian peoples already used small-scale irrigation techniques, supposedly enriched by the contribution of knowledge from Eastern Mediterranean peoples, such as Phoenicians and Greeks.

Period 2 –  from 218 B.C. to 476 A.D.

It was the Romans who systematically developed infrastructures for the use of water resources in irrigation, supply and sanitation of cities, and mining operations. To this end, they used the techniques they had learned in the Near East, perfecting them with their ability to design and execute hydraulic engineering works.

The Romans also developed laws to preserve and ensure the supply of water to their users, considering water resources as res communis, not appropriable.

From 476 to 1492

The subsequent Arab contribution was also decisive. They consolidated and expanded the irrigated areas, and created others thanks mainly to the use of groundwater, as they had already done in the Middle East.

They also introduced new crops of great economic and landscape relevance, and left a rich institutional legacy of bodies for the administration of irrigation and water courts.

From 1492-1789

During the 16th and 17th centuries, Italian and Spanish engineers and architects developed a series of large-scale works for the storage and transport of water. To this end, they applied new techniques, such as the design of gravity-arch and vault dams. In this way, irrigation continued to be strengthened to feed a growing population.

During this period, the knowledge accumulated in Spain regarding irrigation and water use in general was also spread throughout the American continent.

In the 18th century, the Enlightenment reformism continued to promote the construction of reservoirs and canals of public and private initiative for the socio-economic development of the country.

Likewise, agrarian settlement was also promoted, and administrative reforms were undertaken in traditional irrigation systems.

Since 1789

The incipient liberal state brought with it private initiatives for the development of large irrigable areas in the 19th century, and at the same time the first Spanish and European code of water legislation was developed (1866), the predecessor of the Water Law of 1879, which established the public domain over surface waters and remained in force until 1985.

At the beginning of the 20th century, Spain was one of the pioneering countries in the creation of basin agencies, the Confederaciones Hidrográficas (1926), which were entrusted with the integrated management of water resources at the level of river basins. This holistic and politically decentralized approach facilitated the development of a Water Works Plan (1933) which, for the first time, embodied in an organized, systematic and coordinated way the will of the public authorities to promote and invest in the use of water, mainly for irrigation.

After the war, the execution of the proposed hydraulic works, together with the technological development in areas such as heavy machinery, materials and energy, allowed the great expansion of irrigation during the second half of the 20th century.

At the beginning of the 21st century, the socio-economic and technological development achieved, and the progressive liberalization of agricultural markets, meant that the age of irrigation infrastructures constituted a threat to the economic, social and environmental sustainability of many irrigated areas.

For this reason, a process of modernization of these infrastructures was initiated, which is making it possible to obtain greater socio-economic productivity from water, while limiting the impact of irrigation on water quality.

The current level of development of Spanish irrigation is linked to the level of R&D in this sector, since Spain is the country with the third highest scientific production in the world in the field of irrigation (by number of scientific articles indexed).