Access

Access to the installations is from local road number 3211, where some 500 metres North-west of the centre of La Paca (in the North of the municipality of Lorca) there is a turning to the south on a minor road. Alter about 15 kilometres, this road passes through the village of Zarcilla de Ramos, and leads through a tunnel of approximately 60 m to the left-hand side-wall of the Valdeinfierno dam and its crest. The crest road then continues along the right-hand side and joins a series of country roads through which access can be gained to the Puentes reservoir, which is located downriver, by following the roads through the villages of Fuensanta and La Parroquia (to the west of the city of Lorca). From here a local road can be taken to the city, about 20 km away.

Characteristics

Paramento de aguas abajo de la presa

Purpose

The construction of the Valdeinfierno reservoir is an improvement in the system of control of the River Luchena-Guadalentín, and therefore also in the contribution of the river to the water available for irrigation in the municipalities of Lorca and Totana. It is used mainly in the supply of water for irrigation, but in addition it is useful as a defence against flooding occurring in the basin of the River Luchena.

Vista del interior del túnel de descarga del aliviadero

Territorial and Administrative Context

Physical characteristics of the basin

The Valdeinfierno reservoir is located at the western edge of the water basin of the Segura, in the municipality of Lorca, in the province of Murcia.

The reservoir is currently blocked with sediment up to a level of 30 m, meaning that of the 43 m between the bottom and the peak only 11.4 m is useful space.

The basin of the Valdeinfierno reservoir is located in the province of Almería, except the eastern edge, in which the reservoir is located, and the northern extreme, which belong to the province of Murcia. In total the basin occupies 429 km².

The morphology of the basin is irregular, but it can be explained by considering four flanks, or margins, which are to the south, the east, the north and the west.

Vista desde la margen derecha de los arcos que forman el aliviadero

The reservoir is on the southern flank. This flank extends from the Sierra de María, which boasts a high point of 2,045 m above sea level in Cerro Poyo, where the headwaters of the River Caramel (or Alcaide) are located, to the Collado de los Bollos, 985 m above sea level.

This area is very uneven and is marked by a series of rises, ridges and carbonaceous peaks. Near the reservoir is the Alto del Pericay (1,236 m), which lends its name to the range of mountains of which it forms part.

The eastern flank runs from the Collado de los Bollos to the Alto del Carro (1,264 m above sea level), which marks the northern extreme of the basin. Other relevant topographical features are the Sierra del Almirez and the Sierra de La Pinosa (1,103 m above sea level). The northern flank runs from the Alto del Carro to the Loma de la Cabaña (1,247 m). Here the altitude is constant, between 1,200 and 1,300 metres above sea level.

There are no important variations in altitude on the western flank of the basin, although the topographical features include the Alto del Paso (1,151 m) and the Alto del Gallardo (1,263 m). Topographically, the most interesting part of the centre of the basin is the southern half, where it is worth mentioning the Pico del Gabar, which reaches 1,500 m above sea level.

The highest part of the basin, then, is in the Cerro Poyo in the Sierra de María, which reaches 2,045 m above sea level. Between here and the course of the river in the ravine there is a difference in altitude of some 1,400 m. In the basin of the Valdeinfierno reservoir the main courses are the Rambla Mayor and the River Caramel (or Alcaide). The Rambla Mayor and its tributaries drain the northern part of the basin and present a dendritic distribution. The River Caramel or Alcaide runs along the southern half of the basin.

The drainage network in this area is mixed, with a mixture of some dendritically distributed courses existing alongside others with a radial or centrifugal arrangement. This latter is characterised by a circular network with parallel courses emanating from an isolated raised area (in this case the Cerro Gabar). The River Caramel runs around the case of this raised area, acting as the main collector.

It is also worth mentioning the existence in the River Caramel (or Alcaide) basin of land-locked areas.

Environmental information

Not available

Geology and seismology

Regional geology

The Valdeinfierno reservoir basin is located in the Baetic mountain ranges and, more specifically, the Sub-Baetic domain, belonging to the middle and interior Sub-Baetic. The materials which constitute this domain are calcareous and most were formed during the Mesozoic era.

These materials have suffered three phases of deformation during the Alpine orogeny, which have bought about folds, bedloads, slips, etc. Along with them, although not in such great amounts, there are also sediments which are termed “non-solid”. These are largely composed of detrital and carbonaceous materials generated during the Neogene. The sediments are separated from the underlying solid geology by an unconformity (a break in the sequence of strata).

The different strata can be categorised by their lithology, and four groups can be recognised:

• Clays (with gypsum): These are common in the north of the basin, and consist of colourful clays, interbedded with thin layers of sandstone, dolomitic conglomerates and multi-coloured and carniola gypsum, all formed during the Triassic. These clays are reddish, blue-violet and greenish in colour. The sandstones are fine-grained, and greenish or blueish in colour. The dolomites are frequently subject to slumping. Together with the gypsum (yeso) there is an abundance of volcanic rock commonly known as ophites, which are characteristic of dolomites, and many of which are rich in diabases and dolerites. The predominant materials, the clays, are susceptible to rapid erosion, and therefore a lot of material is transported from them into the reservoir.
• Detrital materials: These are found mainly in the western and northern parts of the basin. They consist of conglomerates, sandstones and clays. The conglomerates, which are all roughly the same size and rounded, are carbonaceous in their composition. These materials are estimated to be Pliocene in age. When eroded they generate silica and limestone sediments of varying granule sizes, which are then carried to the reservoir.
• Calcareous materials: A large surface area within the basin is formed by carbonaceous materials including limestone, dolomites and marls. Most of these rocks belong to the Mesozoic but there are also limestones from the Tertiary. When they are eroded the limestones generate dissolved fragments, clays and carbonates in solution. Due to their predominance and proximity, these calcareous materials are the main source of sediments in the reservoir.
• Quaternary Materials: Under this heading we group together all the alluvial flood deposits which are found in the wadis valleys and river beds. These consist of boulders, pebbles, gravel, sands, silt and clays, all of which can be carried into the reservoir.

Geología regional (428 KB)

Geology and geotechnics of the downstream boundary and the storage area upstream of the dam

The Valdeinfierno reservoir is located in a narrow gorge. The River Luchena, flowing roughly from North-west to South-east, is at an altitude of approximately 654.7 metres above sea level (644.7 metres above sea level). The underling rock at the location of the reservoir is formed largely by an oolitic limestone from the upper Jurassic. A fault in the storage area upstream of the dam brings marly limestone into contact with the oolitic limestone. The fault, which starts on the left bank of the basin, passes under the reservoir itself and continues downstream on the right bank, causing fracturing of the rock in the vicinity of the reservoir.

Seismology

Information not available.

Planos

• Top view draw (225 KB)
• Geographical (7,2 MB)
• Cross-section (169 KB)
• 1st Base of the reservoir (1,7 MB)
• 2nd Base of the reservoir (1,5 MB)

Ortofotos

• Presa del embalse (2,4 MB)
• Vaso del embalse (5,2 MB)

Galería de acceso a la cámara de válvulas del desagüe de fondo y a la galería inferior

Situation

The Valdeinfierno reservoir is located on the River Luchena, a tributary of the River Guadalentín, in the basin of the Segura river. Specifically, it is situated in the municipality of Lorca (region of Murcia), in the Valdeinfierno gorges of the Sierra Culebrina

El punto de intersección del río con el eje de la presa tiene las siguientes coordenadas geográficas (referidas al meridiano de Greenwich):
X: 1º 57' 51'' West
Y: 37º 48' 22'' North

Las coordenadas U.T.M. del punto anterior son:

Reference system ETRS89. Time zone= 30
X=591.211
Y=4.184.741