Hydrologic Cycle
Diputación de Alicante
The rough orography determines the marked fragmentation of Alicante’s basins. There are over 100 small and medium basins, among which stands out the Vega Baja of Segura River, its last 36km run across the province territory (6.5% of its total basin area), through a traditional irrigation area, forming an ecosystem and a singular space.
Precipitation in the county causes a total runoff of about 450hm3/year, of which 300hm3/year are the contribution to groundwater and the rest is surface runoff.
Alicante Rivers: Except Segura and Vinalopó rivers (which have an important part of its basin in Castilla-La Mancha) the rest of Alicante’s rivers belong entirely to the Comunidad Valenciana. Except the Serpis and the Bullens rivers, all the other rivers (Guadalest-Algar, Amadorio, Girona, Gorgos, Monnegre, Torres and Racons) place their basins only in the territory of Alicante. Those rivers show high slopes and an irregular regimen highly modified by human activity and have Mediterranean pluviometric features, even the highlands basins in the north, where snowfall is incidental. Alicante’s rivers can be classified in two groups:
– Rivers with a Mediterranean pluvial regime (Serpis and Algar-Guadalest) that have a continuous water input/contribution.
– Ravine rivers of Mediterranean semiarid character (Amadorio, Monnegre, Vinalopó, Girona, Gorgos y Torres). All these rivers have seasonally dry riverbeds because of the low subterranean contributions and, in some cases, also because of the human regulation to which they are subjected and the groundwater seepage in aquifers with a high degree of exploitation.
Endorheic basins: The main endorheic basins in the province are “Laguna de Salinas”, “Hondón de las Nieves”, “Hondón de los Frailes” and the “Hondo de Elche”. The formers are framed by a marked topography, while Hondo de Elche is situated on the coastal plain and has little slope.
Reservoirs: In the province of Alicante there are four main regulation reservoirs:
– Beniarrés (in Serpis basin with a normal capacity of 27hm3, its waters are used for irrigation in the province of Valencia).
– Amadorio and Guadalest (with 16 and 13hm3 of capacity respectively, both are integrated in the scheme of joint use of the Marina Baixa)
– Tibi (with less capacity).
The main aim of La Pedrera and Crevillente reservoirs are to storage flows from the Tajo-Segura. Currently, Relleu and Elche reservoirs are not being used due to the decreasing contributions to their basins, caused mainly by the increased exploitation of the aquifers that feed them and their grounding. Finally, Isbert reservoir, situated on the Girona river, has an extremely permeable base that the volume stored quickly infiltrates. However, it is tapped by groups of wells that fed from the Mediodía aquifer.
