Morrón Reservoir
Background
On July 25 and 26, 1986, heavy rains in the area flooded the town of La Estacada, a rural district in Jumilla with a population of 1500 inhabitants, as well as the entire lower Morrón basin up all the way to its mouth in the Judío riverbed.
As a consequence of this event, the drafting of a local protection plan aimed at reducing the risk of future floods, which had historically affected the area, was ordered. In order to accomplish its end purpose, it was necessary to establish a battery of at least three sequential dams while taking advantage of a suitable area in El Morrón riverbed. In any case, it was decided to immediately carry out the project and build the first dam (El Morrón dam).
Said requirement was urgently completed, so that in September of the same year of the flood (1986), the 09/86 Project, the "Morrón riverbed laminating flood dam" drafted by the Segura Hydrographic Confederation Engineer, Francisco García Ortiz, was finished. The project received final technical approval on September 17, 1986, by means of a resolution issued by the General Directorate of Hydraulic Works of the Ministry for Public Works and Urban Planning.
Morrón dam. Downstream view.
The works were directly awarded to the Sociedad Anónima de Trabajos y Obras (SATO) on December 23, 1986, and the contract executed three days later. The document verifying readiness for construction was issued on December 26, 1986, the date marking the start of the works. Works were finished on March 1, 1987, and they were provisionally received on June 14, 1988 and entered into the record on September 10 of the same year.
The aforementioned provisional liquidation was approved in September 1989. The final reception document was issued on December 12, 1989 at the works site. The final liquidation was drawn up in October 1991.
In March 1997, the El Morrón dam classification proposal based on potential risk was established as category B. Finally, on May 12, 2000, the El Morrón dam was classified according to potential break or malfunction risk as B.
Access
The access to the dam, from Murcia, is realized taking the highway A-30 with direction to Cieza. The past above mentioned population must think direction to Jumilla in her connect with the Sale of the Olive tree, by means of the road C-3314.
In Jumilla, the regional one must think 3213 to Hellín, with kilometric origin in Jumilla. To something more from 7 km from Jumilla it departs towards the left side a dirt track that leads to the dam(cross without signposting).
This way is passable without difficulty in his first meters though before reaching the dam of The Morrón he is very damaged, being difficult the access to the closed one.
The location of the reservoir can be seen in the following map:
Characteristics
| SITUATION OF THE DAM | |
|---|---|
|
Province
|
Murcia |
|
Municipal territory
|
Jumilla |
|
Hydrographic basin
|
Segura |
|
Bed where it is located
|
Morrón watercourse |
|
DATA OF THE BASIN
|
|
|
Surface of the hydrographic basin
|
13.21 km² |
|
Length of the bed of the Morrón watercourse
|
12.00 Km |
|
DATA OF THE RESERVOIR
|
|
|
Surface of the reservoir at a Project Flood Level (NAP)
|
2.22 ha |
|
Capacity at NAP
|
0.073 hm³ |
|
Spot height of NAP
|
594.23 m |
|
DAM BODY
|
||
|---|---|---|
|
Type
|
Gravedad | |
|
Top spot height
|
595.54 m | |
|
Maximum height above foundations
|
15.00 m | |
|
Top length
|
58.00 m | |
|
Spot height of foundations, chute
|
580.54 m | |
|
Top width
|
1.54 m | |
|
CHUTE
|
||
|
Total number of chutes
|
1 | |
|
Draining capacity at Project Flood Level(NAP)
|
59.26 m³/s | |
|
Adjustment
|
Fixed lip | |
Entry of the bottom drainage on the left margin. Details of the surroundings.
Purpose
The purpose of the dam is to laminate the floods of the basin, characterised by a high intensity of rainfalls and a short concentration time.
Through the construction of this dam, it is possible to avoid flows which would add to the ones of the Judío watercourse in case of a flood occurred by this basin (a fan of watercourses and small ones concur to the point where the limited zone is located) and, on the other hand, it would protect the uncontrolled action of the waters both in the Jumilla district of the La Estacada and to its adjustable and production zone.
Dam top. View from the left wall.
Territorial and Administrative Context
Physical characteristics of the basin.
The Morrón watercourse, affluent of the Judío on its right margin, has a length of about 12 km and a basin of 20 km², approximately, up to its mouth. A few kilometers from its origin, it crosses a limestone block shaping a soft 1.5 km canyon, where the Morrón dam is located.
The upper segment of the watercourse, from its origin to the dam itself, has a catchment basin surface of 13.213 km², with many small affluents, quite a rugged terrain and sharp slopes. Several riverbeds draining into the dam already have small dikes which contribute to fix the beds and retain a large volume of dragged solids. Such dikes have been built by what used to be known as the Institute for the Preservation of Nature (ICONA).
Drainage system. View from downstream
The basin is generally covered by short brush of low-medium density. On some slopes, there are still some trees whose percentage does not exceed 10% of the total surface. The flatter intermediate area supports numerous rain-fed crops, basically grapevines, almond trees and some olive trees. The Morron dam crest height has been recorded at different values in different documents reviewed. After the cartographic works carried out for the current Technical Assistance, the crest height has been confirmed at 595.54 a.m.s.l. Based on this reference, the rest of the dam height has been determined.
Environmental information
There is no environmental report or environmental impact assessment associated with the building of this dam or any related works. Regarding exploitation, the environmental integration regulations are part of the Moro watercourse Exploitation Regulations drafted in this Technical Assistance.
In these integration regulations, the current environmental legislation that could affect exploitation is reviewed, but there is no measure worth mentioning, basically because normal exploitation is the empty reservoir. On the other hand, the dam and its reservoir are not located in an area under environmental protection.
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Geology.
The Morrón reservoir is located in the northernmost part of the Baetic System, which at the same time is the north-western segment of the Peri-Mediterranean Alpine Orogen (aligned mountain chains with a structure of runoff cover created during the Cretaceous and Tertiary, centrifugally arranged in reference to the sea.; Martín Algarra, 1987).
Return flows. Unclad spill basin closed by cross dike
Within the Baetic System, the area under consideration is framed within the External Areas or South-Iberian Domain. Materials in this domain occupy an extensive area in the system and represent a time period from the Triassic to the Miocene. Their structure is characterized by a detachment between the base (Hercynian Paleozoic) and the deformed cover (Mesozoic and Cenozoic folds, faults and buckled layers), where the clayey-evaporite Triassic act as detachment material, and the buckled layers have a general vergence towards the W and NW. The Paleozoic base does not surface and remains at a depth of 5-8 km, and it is made up of the same materials as the Iberian Mountains.
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.
The materials of the area of study are post-orogenic formations belonging to the Tertiary and Quaternary. The emerging Tertiary materials are of neogenic formation (Serravaliensis-Tortoniensis).
The dam enclosure rests on Miocene marly-limey materials, covered by granular materials from the Quaternary (red conglomerates). Miocene materials appear close to the dam and are characterized by fractures or faults, filled by Quaternary materials, which are not affected.
Miocene marl has a whitish color with fossils and well-defined stratification layers which sometimes appear micro-folded. Sandy limestone produces small highlights in the sequence. Regarding the waterwheels which are placed in the Miocene marl, they seem well-preserved, although some of them are partially buried.
Criteria to determine the Flood Project and Extreme Flood is based on acceptable risk according to the dam category, as established by the Technical Safety Regulations for Dams and Reservoirs, which in this case is A.
The Morrón watercourse upstream from the dam. View from the crest.
Planos
Plans
- Dam plant
(79.5 KB) - Dam elevation (75.7 KB)
- Transversal section of the dam through the chute (97 KB)
Ortophotographs
Dam top. Cover of the vertical connection pipe of the ventilations with the bottom drainage
Situation
The dam of The Morrón is in the province of Murcia in Jumilla´s Municipal area. It is placed on the Ravine of the Morrón, which takes his name of the High place of the Morrón, at the foot of whose hillsides it thinks up the ravine in question. In ancient planes, it is named also A Ravine of the Rodalizas and in relatively recent cartography (1993) it is the Ravine of the Jinjolero the one that gives name to the riverbed.
The place where there locates the dam and almost all his basin slope 26-34 "Jumilla" is in the high part of the leaf(sheet) n °, of the Map 1:50.000 of the Geographical Service of the Army (SGE) corresponding to her(it) n ° 869 of the Geographical National Institute (IGN). A small part of the basin happens to be in the immediate leaf n ° 26-33 (SGE).
The riverbed ends, as already has been indicated, in the ravine of the Jew, riverbed that does it in turn in the Segura.
U.T.M. coordinates:
Reference system ETRS89. Time zone= 30
X=639.957
Y=4.259.316
