Logo of the Confederación Hidrográfica del Segura, go to home page

 You are in :: Inicio > Information > Infrastructures > Reservoirs > Camarillas

Reservoirs

Territorial Framework.

Características físicas de la cuenca.

The total catchment area of the Camarillas dam occupies an area of 2,382.9 square kilometres, of which 766.5 km² correspond to the basin of the Talave dam, located upstream. The basin of the Camarillas dam itself, therefore, has an area of 1,616.4 km².

The whole basin lies at an average altitude of 818 m and is spread over the provinces of Albacete, Murcia, Jaén and Granada. The main tributaries of the Mundo river in the basin are the Rambla de Bogarra, before the Talave reservoir, and the Rambla de Minateda and Rambla de Bayco, which flow into the Mundo between the Talave and Camarillas dams.

The Camarillas reservoir has a surface area of 320 ha at its usual maximum contour height, and all of the area lies within the municipal district of Hellín, in the province of Albacete. The capacity of the reservoir at the given contour is 35.84 million cubic metres. The perimeter of the reservoir measures 34.2 km, while the length of the bed inundated by the reservoir is 9.5 km.

The main characteristics of the Camarillas reservoir and its catchment area are detailed below:

Main Characteristics of the Camarillas reservoir
Catchment basin
Surface area of own basin 1.616,4 km²
Surface area of whole basin 2.382,9 km²
Average altitude of own basin 818 m
Average altitude of whole basin 705 m
Maximum altitude of basin 1.520 m
Average annual rainfall 322 mm
Runoff
0,08
Average water collected annually in the basin
39,8 hm³
Maximum recorded flood 755 m³/s (oct. 1.982)
Reservoir
Maximum normal level altitude (NMN) 354,63
Projected flood level (NAP) 355,63
Minimum level of Exploitation 320,95
Total capacity (at NMN) 35,84 hm³
Total capacity (at NAP) 38,63 hm³
Reservoir surface area (at NMN) 320 ha
Reservoir surface area (at NAP) 359 ha
Section of river regulated 9,5 km
Length of shore 34,2 km

go back to top

Environmental information.

The Camarillas dam and reservoir are included in the LIC (Site of Community Importance) of “Sierra de Alcaraz y Segura y los cañones del Segura y del Mundo” (Code ES4210008). These “LICs” are natural areas so chosen on applying the European Directives on Birds (79/409/EEC) and Habitats (92/43/EEC), and they are characterized by their contributing to maintaining and re-establishing a type of natural habitat or species in a state of favourable conservation within the biogeographical area to which they belong. The LICs form part of the Network of Protected Areas of Castilla-La Mancha.

The LIC in question occupies a surface of about 1,750 km² of the province of Albacete and comprises a group of mountain ranges interspersed with narrow river valleys, which together make it a place of extraordinary beauty.

However, given the period in which the projects and the building of the dam were carried out, no study on environmental impact was made. It should be pointed out that numerous reforestations have been performed by the Confederación Hidrográfica del Segura over the years. These were carried out in places like Las Higuericas, Soto de la Montiela, Los Colorines, Soto del Quinto, etc. And were all directed by an engineer of the Confederación Hidrográfica del Segura - Mr. Luis Aycart Benzo.

As regards any environmental conditioning in the exploitation of the dam, it should be mentioned that the Hydrological Plan of the Segura River Basin lays down a minimum flow rate of 1.5 million cubic metres/month (0.58 m³/s) for the stretch of the Mundo river between Camarillas dam and the confluence with the Segura.

go back to top

Geology y sismology.

Regional Geology.

The Camarillas dam is located to the north of the Cordilleras Béticas in an area of a transitional nature between the structural units of the Cordillera Ibérica and the tectosedimentary units of the Prebético Externo. It is an area of highly irregular reliefs with extensive plains surrounded by reliefs of between 350 and 800 m or more. It is crossed by the Segura river and its tributary, the Mundo river, with the dam located on the course of the latter. Around the Camarillas reservoir basin Mesozoic and Cenozoic geological materials exclusively appear.

The overall geological framework presents flake tectonics sloping always towards the Meseta, in which Keuper gypsiferous-clay deposits act as the surface on a regional scale, being injected in favour of fractures or diapiric forms.

The Jurassic lithologic units are well represented by the Lias, Dogger and Malm groups, generally of a secondary dolomitization nature on the left and right embankments of the reservoir basin tail-end, in the mountain ranges known as Los Donceles and El Alto de las Cabras.

From the Lower Cretaceous era one can observe only small outcrops comprising conglomerates, various coloured sands and clays, located on the left embankment of the reservoir basin tail-end. The Upper Cretaceous is likewise sparse, with a few remains in the area of the natural downstream boundary where there is a superficial level of limestones.

Directly over the Upper Cretaceous there are some formations from the marine Miocene. These are folded and fractured and link up with others of a clearly continental influence. The latter formations, in the Pliocene, have a clearly fluvial and alluvial fan character, which correspond to a greater network than the hydrographical one existing today.

The Quaternary deposits are present in several surface deposits of irregular forms and varied extensions. They are frequently encrusted and located at the foot of an area of sharp relief, between the morphological ledge and the areas of gentle slopes or at the foot of a mountain. They are alluvial fans, debris cones, accumulations, alluvial or wadi deposits and flood plains.

The most outstanding structures of the area correspond to the diapiric dome in the narrow gorge of Los Almadenes and the structural arch of the Sierra de los Donceles, together with the system of discontinuities from the tearing of the base, forming a wide band of highly complex structure, which has led to diapiric alignments (among them the dome where the dam is located) in which Keuper units appear locally, which are the structural elements that end up defining the geological framework of the surroundings of the reservoir.

The natural downstream boundary of Camarillas dam is located at the entrance of Los Almadenes gorge, on a rocky massif in the form of a diapiric dome, with centripetal surface draining, basically formed by calcareous materials which appear on both embankments with numerous exokarstic features and signs (hollows, open diaclases with sealing by decalcification) and signs of important endokarstic development (caves, clayey fillings with rock fragments, stalactites and stalagmites, etc).

The massif is made up of a massive calcareous layer which often presents a brechoidal aspect, at times cemented, and which is associated to tectonic and Karstic phenomena. Stratigraphic dating reveals a Cretaceous age for these formations, very probably from the Senonense-Maastrichtian epochs.

Field surveys show up the existence of a large variation of directions and dips in the calcareous formation, from the site of the dam downstream and at the exit of the gorge of the Mundo river, revealing a dome formation with dips in all directions which are often cut short by geological discontinuities delimited by raised or sunken blocks.

The many Karstic processes, ranging from moderate to highly developed, are seen on the surface on both banks of the ravine- on the upper part of the right embankment on the tunnel leading to the dam crest and on the left embankment, downstream from the natural boundary, at the joining systems and the bedding planes as well as in the caves that were opened by the explosions carried out in the works on the main body of the existing dam.

Field surveys have led to the definite identification of a dome structure (of double deformation axis with an ellipse with the lesser axis in the direction of the Mundo river), with tilting and sinking of the central blocks of the structure, forming lax folds on the surface of the dome which are more vertical in the materials at the base of the cliffs, where the ascending effect of the diapir is stronger.

The general fracturing of the rocky massif is intense. The diaclase families identified show preferential distribution directions in the immediate surroundings of the dam, while as they move away from the Mundo river gorge, the directions and dips become widely dispersed.

Subhorizontal families also appear, which are rare but well developed, and these reveal greater brecciations as well as traces of karstification.

The combination of these diaclase families and the bedding planes causes the appearance of rocky wedges which locally have been the cause of instability. On both outcrops of the gorge, there are geometric wedge forms whose stability is at times extreme.

The microfracturation of the rocky massif may be considered to be generalized, with a high level of brecciation or milonitization in places. This phenomenon appears in all the materials of the natural downstream boundary as well as on both embankments and is present through to the rocky formations at the tunnel exits.

Sismology.

The location of the Camarillas dam lies within the area of the intersection of the Baetic and Iberian mountain ranges, an area which is seismogenetically generally active in neotectonic terms and is, therefore, seismic.

Within the seismotectonic compartments of the area around the reservoir, the Camarillas reservoir lies within Zone 4 (Prebético Central). Its eastern and western limits are determined by the geological faults of Caudete-Elda and by that of Hellín. Seismic activity in the area is lower than that of the Prebético Oriental (Zone 2), and the most outstanding activity was the Salinas earthquake (1916) of force VIII. The seismicity of the area is mainly diffuse and of low intensity and is generally associated to halokinetic and diapiric phenomena.

The Seismoresistant Construction Regulations NCSR-02, approved by Royal Decree 997/2002 –in Section 2.1 includes a chart of seismic hazard areas. The latter is expressed according to the basic seismic acceleration “ba” –a characteristic value of the horizontal acceleration of the surface according to gravity g– and of the contribution coefficient K, which takes into account the effect of the different types of earthquakes to be expected regarding seismic hazard at each point.

The range of “ba” values in the areas of our country considered to have seismic hazard runs from 0.04g to 0.24g, while the K figure stands between 1.0 and 1.3.

According to the above-mentioned map and Annex 1 of the Regulations, which includes a list of the “ba” and “k” values for different municipal districts of Spain, the characteristic parameters of the seismic hazard for the area of the Camarillas dam are: ba=0.07g; K=1.0.

go back to top


previous next back