This project developed hydrological models that facilitate a differentiated understanding of actual water balance conditions before and as a result of implementation of water management measures in the western Mediterranean region.
On the Iberian Peninsula, the challenging task of water allocation among stakeholders has given rise to local water communities and legal institutions for local water management. Some of the applied techniques and governance structures can be traced back to the Muslim period or even to Roman times, especially in Andalusia. At present there are about 600 irrigated regions, administrated by so-called irrigation communities (span. Comunidades de Regantes).
These irrigation communities are often of private origin and show a wide variety in their size, water availability and cultivated crops. The relationships between landowners and applied water laws usually testify a Muslim origin. Based on the classification by Butzer (Irrigation Agrosystems in Eastern Spain: Roman or Islamic Origins?,1985) they can be differentiated into the so-called Syrian system, where land property is inseparable from irrigation and water rights or on the other hand, the Yemenite system, which separates the ownership of water and land.
The project focus was on the irrigation community of Vélez Blanco in the dry sub-humid region of southeast Spain, Andalusia. Here, annual rainfall in the lowlands of the drainage basin averages ~450 mm per year. The city is located at the southern edge of the Betic cordillera where the surrounding area is characterized by a mountainous landscape. Especially the high mountain areas receive higher annual amounts of precipitation and thus function as regional water towers, feeding several springs. Downslope of these springs the irrigated terraces of Vélez Blanco are located. Locally, this area is also called vega.
One of the most important institutions for the citizens of Vélez Blanco is the local water law body (span. Alpochron) that traditionally regulates the irrigation waters and maintains the infrastructure for its distribution and storage. One of its specific task is the organization and execution of regular water auctions. It is assumed that this institution has existed since the Muslim period. Especially during the dry summer months, additional irrigation water is needed to gain better harvests or to avoid crop failures.
Further information and results are available on (A-3-5-1) Functionality and Effectiveness of Technical Water-Management Measures