Besaya River

The Besaya (from the Latin Bis-Salia) is a river located in the north of Spain, on the Cantabrian slope of the peninsula. Iberian, which runs through Cantabria. It rises in the Campoo-Los Valles region, near the town of Fresno del Río at an altitude of 870 m and flows into the Saja River in the municipality of Torrelavega, providing an annual flow of 390 hm³.

Its 47.2 km long route is practically straight in a south-north direction. It forms the Iguña and Buelna valleys, in addition to collaborating, together with the Saja, in the formation of the Torrelavega plains. The basin has a total area of 465 km² and has more than one hundred thousand inhabitants, concentrated mainly in the municipalities of Torrelavega and Los Corrales de Buelna.

The name of the river comes from the Latin term Bis-Salia, double or second salia in reference to the current Salia Saja. Salia is an Indo-European hydronym that could mean running water or salt water.

Course

Its route, 47.2 km long, is practically straight in a south-north direction, crossing the municipalities of Campoo de Enmedio (where it is born), Santiurde de Reinosa, Pesquera, Bárcena de Pie de Concha, Molledo, Arenas de Iguña, Cieza, Los Corrales de Buelna, Cartes and finally Torrelavega, where it joins the Saja River, providing an annual flow of around 390 hm³.

It is described in the fourth volume of the Geographical-statistical-historical dictionary of Spain and its overseas possessions by Pascual Madoz as follows:

BESAYA: r. en la prov. de Santander, part. jud. de Reinosa: born from the source of his same name to 1/2 leg. N. de la cab. del part.: runs the entire line of the road that leads to Santander until it flows into the ria of Suances, with another portion of r. and riach. to join him in his transit.

(Madoz, 1846, p. 292)

Hydrography

The river has a length of 47.2 km until its confluence with the Saja River and an average flow at the mouth of 12.1 m³/s.

Flow rate

Monthly Besaya Floods in Las Caldas de Besaya (period 1970-2000)

Average annual Besaya flow through Torrelavega (period 1970-2000)

Cuenca

The Besaya basin has an area of 465.41 km² and forms, together with the Saja River, the largest hydrographic basin in Cantabria, the Saja-Besaya System, with a total area of 1048.24 km², of which the 44.4% are slopes to the Besaya. The Besaya sub-basin is delimited to the east by the peaks of Mediajo Frío and Bastrucos and to the west by the Bárcena Mayor mountain range and the peaks of Ibio. i> and Mozagro; The southern limit is marked by the watershed with the Ebro River.

This area totally or partially encompasses the municipalities of Campoo de Enmedio, Pesquera, Santiurde de Reinosa, San Miguel de Aguayo, Bárcena de Pie de Concha, Molledo, Arenas de Iguña, Anievas, Cieza, San Felices de Buelna, Los Corrales de Buelna, Cartes, Torrelavega and Suances. Compared to other basins in Cantabria, it is a densely populated area, with three municipalities that exceed five thousand inhabitants (data from 2017): Torrelavega (52,034 inhabitants), Los Corrales de Buelna (10,912 inhabitants) and Cartes (5742 inhabitants). This is because it is the main road connection between Cantabria and the plateau.

Main tributaries

The tributaries of the Besaya have a fairly short route due to the orography of the region and are affected by strong low water levels, which dry out some channels during the summer months. Its main tributaries on the right are the Irbienza, Torina, León, Erecia and Casares rivers. On the left are the Bisueña, Llares, Cieza, Rebujas rivers and the Mortera stream, among the most relevant.