Alfonso XIII reservoir
Background
Events such as heavy rains or floods are not unusual in the Segura basin. Damages caused by water have historically represented a concern for area residents in terms of economic and human losses.
The long series of floods that took place during the 1870's and, above all, the flood of October 15, 1879, which was classified as highly catastrophic, called for the celebration of the Eastern Region Flash Flood Conference in Murcia, in March 1885, and its conclusions led to the development of a broad flood defense plan entitled the Segura Valley Flood Defense Project, signed in 1886. The Quípar river reservoir was included in this plan as a matter to be studied.
Later on, when the Segura Basin General Flood Defense Plan was adopted in 1977, the Alfonso XIII reservoir became part of the general plan of the aforementioned project.
Overview of the dam upstream from the left margin
The Quípar river is one of the right-margin affluents of the middle section of Segura river (together with the Moratalla, Argos and Mula rivers) which contribute steady but scarce volumes of water which, in most cases, is consumed locally without any relevant back flows to the Segura.
The Alfonso XIII dam is located in a Quipar river gorge in the municipality of Calasparra (Murcia). It is a curved cyclopean masonry gravity dam.
This document replaces the previous one, published in 1994, and includes the modifications carried out in the dam and its other installations starting on that year, which obviously are not included in the previous document.
The original project was dated 1893, but it was later modified in compliance with Ministerial Ordinance of February 12, 1901.
The final project for the “Dam for the Alfonso XIII reservoir” was drafted by August 30,1902, and approved by Royal Decree on September 10, 1903. The calculation of the Reservoir was based on the general plan that was attached to the plan drafted by the Studies Committee on May 31, 1893.
On April 25, 1902, the National Plan of Hydraulic Works was approved, and it was in effect until 1926, when the Segura Hydrographic Confederation was created, and which started a series of studies, such as the General River Management, covering the entire Segura basin.
This National Plan, also known as the Gasset Plan, included the project for the construction of the Quipar Reservoir, whose authorization for the execution of the works was issued through a Ministerial Ordinance dated September 5, 1903, immediately leading to the start of the works which were completed in 1915.
Dam crest
Even when reconsidering the works and checking the gorge where the dam was to be located, there were some relevant differences in view of the detailed plan of the project, but it was not considered necessary to check out the entire reservoir plan, even if later it was done while developing a new reservoir plan which was presented in the First Reformed Project.
During the execution of the works, through a Ministerial Ordinance dated March 14, 1908, the aforementioned First Reformed Project for the Alfonso XIII Reservoir Dam was approved; subsequently, through a Ministerial Ordinance dated July 13, 1911, the Second Additional Project for the Alfonso XIII reservoir dam was approved, and later on, the Third Additional Project of the Alfonso XIII Reservoir Dam on February 1, 1916, and finally, the fourth Additional Project in 1918.
The content of all such reforms to the dam construction is shown in paragraph 2.2.
The bottom sluices and the water intake valves were the object of the special tender approved through a Ministerial Ordinance dated September 11, 1913, whose execution was authorized through a Ministerial Ordinance dated April 24, 1914, and awarded to Maquinista Terrestre y Marítima by a Ministerial Ordinance dated January 12, 1915; and it was completed in 1918.
Supplementary Projects:
Supplementary Project Nº 1 involved the completion of the reservoir service paths.
Supplementary Project Nº 2 (1970), drafted by Alfonso Botía Pantoja, concerned the construction of galleries, drains and conditioning of the Alfonso XIII dam crest. Its provisional award took place in 1974, while the final award was approved in 1979.
Subsequent projects:
Many modifications and changes have been developed during the life of the Alfonso XIII dam; however, we must point out the successive surface spillways built.
Already in 1920, Emilio Arévalo drafted a project to modify the surface spillway. Again in 1949, Roberto Goma Pujadas drafted a repair and improvement project of such spillway. Finally, in 1964, Juan Luis Fernández Madrid drafted, and later executed, the project for a new surface spillway, given the low capacity of the original spillway.
Later, when the Argos–Quípar Channel, which sends the excess waters of the Argos dam to the Alfonso XIII dam started operating, it was considered necessary to adapt the different overflow systems in order to face new flows. Thus, in 1993, Antonio Maurandi Guirado drafted the project to adapt the of the overflow elements. When this work was awarded, the contractor introduced a series of changes, so a new project was drafted, this time dealing with the construction and adaptation of the overflow elements. This last project led to a Modification Nº1 in 1999, which was actually carried out.
In March 1997, the classification proposal according to potential risk of breaking or malfunctioning was implemented, obtaining the A rating for the dam. Such a proposal was definitely completed by the Directorate-General of Hydraulic Works and Water Quality on July 29, 1998.
Vista del aliviadero secundario desde aguas arriba
Characteristics
| DAM SITUATION | |
|---|---|
|
Province
|
Murcia |
|
Local term
|
Calasparra |
|
River
|
Quípar |
|
Hydrographic basin
|
Segura |
|
BASIN DATA
|
|
|
Surface of the hydrographic basin
|
571,00 km² |
|
Max. height of the basin
|
2.081,00 m |
|
DAM DATA
|
|
|
Dam surface at the Maximum Normal Level (MNL))
|
216,00 ha |
|
Capacity at MNL
|
23,00 hm3 |
|
MNL spot height
|
301,00 m |
|
DAM BODY
|
|
|---|---|
|
Type
|
Gravity |
|
Top
|
303,00 |
|
Height from the foundations
|
46,00 m |
|
Spot height longitude
|
87,00 m |
|
Foundation spot height
|
256,00 m |
|
Bed spot height in the dam
|
262,00 m |
|
CHUTE
|
|
|
Total number of chutes
|
1 |
|
Capacity
|
180,00 m3/s |
|
Setting
|
Sluices |
Inspection gallery
Purpose
Its main missions include bringing the water volumes for the watering of the main bed of the Segura River (it is particularly near to the Quipar Union and the Segura) and the lamination of the basin floods.
It is possible, through such a dam, to avoid flow tips which would add up to the river ones in case of a flood in the Segura basin.
Downstream water wall with an intake box with a spot height of 30 from the bottom
Territorial and Administrative Context
Physical features of the basin.
The surface of the reservoir basin reaches 833.37 km². The elevation of the riverbed in the dam is 261.68 above sea level. The maximum altitude in the basin is 2.081,00 m.
The reservoir surface at the maximum normal level, hereinafter MNL, is 223.26 ha. Its entire surface is within the Region of Murcia. The reservoir volume at such elevation is 13.70 hm³.
Alfonso XIII Reservoir Catchment Basin
Environmental information
No record of any environmental or dam construction impact studies exist, undoubtedly because of the date of execution of the works.
Afterward, the works carried out have generally been small, so that no study of the kind has been required.
In addition, the Alfonso XIII reservoir as such is considered an ICS (Important Community Site), ES6200043 called Río Quípar.
Furthermore, the reservoir is adjacent to another ICS area called Sierras y Vega Alta del Segura y Ríos Alhárabe y Moratalla (código ES6200004).
The reservoir is located inside the SPA (Special Bird Protection Area) area known as “Sierra del Molino, Embalse del Quípar y Llanos del Cagitán” con el código ES0000265, establecida por Resolución de 8 mayo de 2001. Además, por ser una zona ZEPA, el embalse está incluido a su vez en un Área de Protección de la Fauna Silvestre denominada Embalse de Alfonso XIII, Cagitán y Almadenes.
Geology and seismology
Geology
The general geology of the area is described in:
- Geological map of Spain. E: 1/50.000 (IGME). Page number 890 (Calasparra)
- Geological map of Spain. E: 1/200.000 (IGME). Page number 72 (Elche)
- Geomorphology of Spain. Different authors. Editorial Rueda, 1994.
There are no specific geological or geotechnical studies of the reservoir available, although information from different projects carried out for the dam has been collected.
The Alfonso XIII reservoir is located in the northernmost part of the Baetic System, which makes up the northwestern segment of the Alpine Peri-Mediterranean Orogen (alignment of mountain chains with asymmetric topologies created during the Cretaceous and Tertiary periods, centrifugally arranged relative to the sea; Martín Algarra, 1987).
In the Baetic Mountain System, the area under consideration is framed within the External Areas or the South Iberian Domain. The materials of such a domain cover an extensive area in the mountain system and represent a time period going from the Triassic to the Miocene. Its structure is characterized by a general detachment between the bedrock (Hercynian Paleozoic) and the deformed cover (Mesozoic and Cenozoic folds, faults and buckled strata), where the clayish-evaporitic Triassic layer acts as detachment material, and the buckled strata generally lean towards the W and NW. The Paleozoic layer does not surface, remaining at a depth of 5-8 km, and it is made up of the same materials as the Macizo Ibérico.
According to the nature of the materials and strain rate, it is possible to clearly distinguish two areas:
- Pre-Baetic, with facies located in shallow areas which, during the Mesozoic, represented the area nearest to the continent, formed by the Iberian Massif.
- Sub-Baetic, with pelagic facies from the middle Liassic, representing the most distant marine area from the continent with oceanic basin materials and, possibly, volcanic effusive rocks from the Mesozoic.
Between them, it is possible in some areas to observe the Intermediate Units of the continental slope, with generally turbitidic facies, linked to the deposit in submarine flares and which can locally reach considerable width. They have their own features with important lateral differences from the Pre-Baetic and the Sub-Baetic.
General geological map of the Baetic System 
(4 MB)
Furthermore, it is possible to distinguish the autochthonous materials in our area of study, the relative pre-layer formations (belonging to the Miocenic period), as well as the post-orogenic formations which were deposited after the allochthonous units were placed, representing the Tertiary and Quaternary layers.
The basin rests, almost completely, on materials belonging to the External Sub-Baetic, mostly on Albian marls, marlaceous limestone and sandstone.
Furthermore, the mid basin area is transversely crossed by a strip of limestone, marl and marlaceous limestone of the Turoniensis and Senoniensis, both within the External Sub-Baetic. Due to the nature of such materials, water tightness is practically guaranteed.
The only area of the basin on the Internal Front Sub-Baetic is that nearest to the dam, where it is possible to observe gypsum marls and Keuper gypsum. This terrain is characterized by the presence of rich gypsum pits which, together with the clay it is made of, make the Triassic ground waterproof.
The Alfonso XIII reservoir has been built in an enclosure belonging to the Cretaceous Cenomatensis, practically in contact with the Triassic Keuper, as it starts some meters upstream from the reservoir.
Because of its closeness to the over-thrusting front, the geological structure is particularly complicated. Therefore, although the reservoir is set on the massive Cenomanian dolomites, it is possible to see stratified dolomites from the Turonian (Cretaceous of the Internal Pre-Baetic) and sandy limestone from the Lower Miocene (Authochtonous Tertiary); in addition to the aforementioned Keuper gypsum marl.
Downstream view of the riverbed
Seismology
Seismic hazard is different from one place to another, and it has been common practice to classify areas according to it. Taking into account the recommendation criteria included in the "Dam Safety Technical Guidelines. Geological and Material Prospecting Studies” published by the Spanish National Committee on Large Dams (SNCLD), paragraph 3.3., there are three large groups:
- Low seismicity areas. Coefficient ab < 0,04 g
- Medium seismicity areas. 0,04 g < ab < 0,13g.
- High seismicity areas. 0,13 g < ab
(ab is the standard acceleration of the area.)
According to this classification, the Alfonso XIII reservoir is located in an area of medium seismicity, given that the standard acceleration for the Calasparra municipality is 0.07 g (data taken from the Seismic Resistance Regulation NCSE-02).
According to the the Dam Safety Technical Guidelines. Geological and Material Prospecting Studies and taking into account the land factor (applying Seismic Resistance Regulation NCSE-2002 and by analogy with the previous instruction), the Project's calculated earthquake acceleration is 0.073•g, and it is 0.116•g for extreme earthquake.
Plans
- Geographical environment
(9 MB) - Dam plant (396 KB)
- Gathering of waters above the dam (162 KB)
- Dam sections (102 KB)
Ortofotographs
Photo of the main overflow channel with the control box in the middle
Situation
The reservoir associated with the dam of Alfonso XIII and environment they are inside the basin of Segura, in the Region of Murcia, to the north of the Autonomous Community. Concretly they are located in the leaves 890 (CALASPARRA), from the IGN to scale 1:50.000. The territory corresponds to the province of Murcia, Calasparra´s municipal area.
The dam is located in the river Quípar, in Calasparra´s municipal area (Province of Murcia), to scanty kilometres of the limit between the above mentioned term and that of Cieza, in narrowly named " The mines of the Quípar ", and to a scanty kilometre of the river mouth of the own river Quípar in Segura.
The intersection of the axis of the dam with the riverbed of the river takes place in the point of geographical following coordinates, referred to the meridian of Greenwich in the following coordinates:
X 1º 35' 54" West
Y 38º 13' 28" North
U.T.M. coordinates:
Reference system ETRS89. Time zone= 30
X=622.684
Y=4.231.715
Access to the dam and reservoir
The access to the facilities of the prey is effected, from Murcia, across the highway A-30. After going out of the above mentioned route in Cieza´s link and this population crossing, the Regional Road takes 330, which leads to Mule. To approximately 3 kilometres a road divides towards the right property of the Hydrographic Federation of Segura that, to approximately 17 kilometres, it happens for the coronation of the prey. In the access for this side to the prey, once spent the settlement of the prey, two tunnels exist before coming to the body of prey, existing the suitable signposting of the gauge of the tunnels.
To reach the dam of Alfonso XIII from Calasparra, there takes the road MU-552. To 6 Calasparra´s kilometres there divides towards the left side a road belonging to the Hydrographic Federation of Seguta that it happens for the coronation of the dam. In the access for this side to the dam, also a tunnel exists before coming to the body of dam, existing the suitable signposting of the gauge.
It is necessary to emphasize on the other hand the risk of detachments in several zones of the road of access, having executed measures preventive and put up signs suitably incident is.
The location of the reservoir can be seen in the following map:
