Water supply from La Palma
The water supply of La Palma has only one of the Canary Islands have sufficient own water from natural sources. The water rained down from the trade wind clouds over the mountains of La Palma penetrates deep into the porous lava rock , is filtered and stored in its crevices . A large number of tunnels and tunnels driven into the mountains catch the water, which is present in high purity, and feed it to consumers on the island via an extensive network of canals and pipelines.
The largest consumer of water is agriculture (especially the banana cultivation with its intensive irrigation) with a good 85%, which pollutes the water balance on La Palma. On the other hand, 11% is consumed by the local population, and 3.4% is used by the tourism sector.
geology
Thanks to the altitude of the mountains of La Palma, the trade winds in the northeast of the island hit the wooded mountain slopes of Barlovento at altitudes between 600 and 1700 meters , where the pine trees comb out the clouds with their up to 30 cm long needles ( fog condensation ). Due to the fog condensation, the annual rainfall is 1,000 to 1,500 liters per square meter and exceeds the average amount of rainwater on La Palma of 325 l / m² per year by about three times. The island's large population of Canarian pine thus contributes significantly to the total water balance of La Palma.
The water that penetrates deep into the porous lava rock is filtered naturally and thus gains a special purity. The northern mountain range of La Palma acts as a large natural water reservoir, which is criss-crossed by a multitude of galleries ( las galerías de agua ) for water extraction and is thus tapped.
The entire water balance on La Palma results from an average rainfall on the island of 516 hm³ per year, of which 219 hm³ enter the island's groundwater and of which 62.3 hm³ flow off via the island's wells, galleries and springs.
This type of water extraction is also used intensively on the neighboring islands of Tenerife and Gran Canaria with corresponding altitudes. There are over a thousand galleries on Tenerife, which together have a total length of 1,700 km.
Because of the lower altitudes on Fuerteventura and Lanzarote , there is no natural harvest of water from the trade winds. The islands are therefore dependent on artificial water extraction.
history
Even the pre-Hispanic natives on La Palma settled where there was water. Paths and small canals to the natural springs as well as storage basins were created in order to survive the recurring periods of drought on the island.
The Spanish conquerors also built their first settlements at the mouths of the Barrancos, where abundant water flowed from the mountains to the sea. There were the places Santa Cruz de La Palma on the Barranco del Rio, San Andrés on the Barranco del Agua and Tazacorte and Los Llanos on the Barranco de Las Angustias .
With the increasing cultivation of sugar cane and later that of bananas, the demand for water increased considerably. In order to extract the groundwater from the permeable structure of the mountains, numerous tunnels and tunnels were driven into the mountains over the centuries. The abundant draining water was also used to drive various sugar cane and grain mills on the island.
With the occupation of the Canary Islands by the Spaniards, the royal ordinances of November 15, 1496 and the amended version of August 31, 1505, laid down the distribution of land and water on La Palma - mainly for the benefit of large estates. It took 300 years until the decree of August 6, 1811 abolished the system of rule and the privileges of large estate and the equality of the claims of the individual was established. The Spanish Water Act of 1866 reorganized the rights for the use of water. The general use and distribution of water, which was previously left to private initiative, was re-regulated by a series of ordinances from 1934 onwards and enshrined in a law of December 24, 1962.
In the National Water Law “Ley de Aguas de Canarias” of August 2, 1985, the competences of the autonomous communities of the Canary Islands were determined and concerned the use of water and canals as well as the distribution of water for agricultural, urban and industrial purposes. The various changes in water law were always accompanied by considerable political disputes in the state and in the region.
A large part of the rights to the water from the Caldera de Taburiente are still in the possession of communities of heirs of the former noble family Monteverde, who had become immensely wealthy through the sugar cane cultivation.
In the 1940s and 1950s, the water owners set up joint stock companies to attract new capital for the development of new springs and for the construction and maintenance of the extensive canal and pipeline network by issuing so-called water shares to the members of the cooperatives. The dividend consists in the purchase of water that the owner of the share receives in a certain amount. In order to control the continuously flowing water, the recipient has to create his own water reservoir. Since the 1960s, all municipalities on the island began to build a public water supply.
With the construction of further tunnels in the mountains to develop new water sources, the island's water reserves, which had built up over thousands of years, were severely attacked. The spring water of the Caldera de Taburiente, once regarded as inexhaustible, was already in decline at the end of the 20th century, a third of the springs had dried up. The result is a dramatic lowering of the groundwater in the vicinity of the tunnels, which has led many municipalities to no longer approve new galleries. Another problem is the outdated and leaky pipe network, in which almost 50% of the water is lost in transit.
Water Council and Water Framework Directive
With the Canarian Water Act of July 26, 1990, the Consejo Insular de Aguas was created on La Palma (and on the other Canary Islands) , a water council with its own legal personality and full functional autonomy, which, within the framework of a system of decentralization and participation, is responsible for Organization, planning and uniform management of the water takes over. The statute of this water council of the island was approved by the government of the Canary Islands in 1993 on the proposal of the island government . The municipalities of La Palma are represented in this council, which also sets the water prices and is responsible for water protection and the maintenance of the infrastructure, according to their water consumption.
The Water Framework Directive 2000/60 / EC of the European Parliament and of the Council of October 23, 2000 aims to prevent deterioration, improve the condition of aquatic ecosystems and promote the sustainable use of water. Like the other member states, Spain has to ensure that a management plan is drawn up for each hydrological unit (e.g. La Palma), which is to be published in 2009 at the latest and to be reviewed and updated every six years from 2016 onwards. The management plan for La Palma is the Plan Hidrológico Insular , which includes the revision of the management plan for the six-year period 2016-2021, based on the general study of the delimitation, the program, the timing, the consultation and the Public participation in the planning process was created.
Water supply system
swell
The system for water production and distribution in La Palma consists of different (private and public) organized networks of galleries, wells, open sources, the connecting canals / pipes and various water tanks.
The galleries represent the main resource of the water supply, followed by a total of 84 wells, of which only 23 are still actively used. The wells have an average depth of 35 meters.
The most abundant springs are those of Marcos and Cordero in the Barranco del Agua, in the municipality of San Andrés y Sauces , which provide about 10.1 hm³ of water per year.
Of the 187 galleries, the majority of which are in the north of the island, only 94 are still actively used. A gallery usually consists of a vaulted ceiling, is 2 meters high, 1–2 meters wide and has an average length of 1,100 m. It slopes slightly towards the opening so that the water can flow away via gravity.
The galleries are distributed across the municipalities of La Palma as follows:
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Pipelines
The main distribution of the water from the water-rich north into the rain-poor southern areas of the island takes place via three large pipeline strands, on the east side of the island there are two lines ( Canal General La Palma I and III ) and on the west side there is one line ( Canal General La Palma II ).
A fourth pipeline, the Conducción Aduares-Hermosilla, is located in the middle of the island and represents a connection between the two main lines ( Canal General La Palma I and II ). Its task is to compensate for water deficits between east and west.
At their connection points on the east side in Breña Alta and on the west side in Los Llanos there is a pumping station (Complejo Hidráulico Aduares / Complejo Hidráulico Hermosilla), which covers the height difference of 635 m of the line routing over the mountain range ( Cumbre Nueva and through the Túnel de la cumbre ) must overcome.
| Name of the pipeline | History / map | Length (km) | Altitude (m) |
|---|---|---|---|
| Canal General La Palma I | Barlovento - Fuencaliente / LP1 | 81.57 | |
| Canal General La Palma II | Barlovento - Garafía- Los Llanos - El Remo / LP2 | 64.73 | |
| Canal General La Palma III | Santa Cruz de La Palma - Fuencaliente / LP3 | 37.61 | 860 |
| Conducción Aduares-Hermosilla | Brena Alta - Los Llanos / CAH |
water-tank
In 1975 the largest water reservoir in Spain, the Laguna de Barlovento, with a capacity of 5.5 hm³ was built to absorb the large amounts of water in the north of La Palma . Due to high water losses, the storage wall - previously sealed with a layer of clay - was lined with a waterproof PVC film. On April 16, 2011 the foil of the storage tank tore up to 150 m² due to the soil being washed away, whereupon large masses of water escaped and flowed through the adjacent banana plantations to the sea. The storage capacity is currently 1,094,000 m³.
To supply the large banana plantations in San Andrés y Sauces and Los Llanos de Aridane, the next larger storage facilities Adeyahamen with 350,016 m³ and Dos Pinos with 400,000 m³ were built.
To improve the water supply to the large banana plantations in the arid Aridane valley , the second largest water reservoir on the island, the Balsa de Vicario with a capacity of 1.6 hm³ , has been built in the municipality of Tijarafe since 2010 , and its completion will take years.
Depending on the amount of rain that has occurred, the island's containers are filled differently. Due to the prolonged drought in 2016 and 2017, the storage tanks were only filled to an average of 20% in October 2017. Due to heavy rain in the following autumn / winter, the storage tanks filled up again to 49%.
Sufficient filling of the large reservoirs is also necessary to fight forest fires on the island - especially during long dry periods. The use of the directly available seawater is avoided as far as possible in order not to permanently damage the forest stand through over-salting.
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Water storage: geographical location, capacity and degree of filling (%)
| water-tank | local community | Capacity (m³) | 2015 | 2016 | 2017 |
|---|---|---|---|---|---|
| Laguna de Barlovento | Barlovento | 1,094,000 | 48 | 34 | 38 |
| Adeyahamen | San Andrés y Sauces | 350.016 | 98 | 49 | 28 |
| Bediesta | San Andrés y Sauces | 170,000 | 7th | 49 | 77 |
| Las Lomadas | San Andrés y Sauces | 103,800 | 100 | 86 | 99 |
| Los Galguitos | San Andrés y Sauces | 108.225 | 90 | 69 | 54 |
| Manuel Remon | Puntallana | 133,000 | 100 | 82 | 80 |
| Cuatro Caminos | Los Llanos | 108,000 | 55 | 73 | 98 |
| Dos Pinos | Los Llanos | 400,000 | 46 | 57 | 56 |
| Puntagorda | Puntagorda | 113,603 | 82 | 33 | 63 |
| Montaña de Arco | Puntagorda | 107.102 | 70 | 30th | 28 |
| La Calderetal | Fuencaliente | 110.127 | 0 | 0 | 30th |
| Sum / average | 2,793,710 | 58 | 46 | 49 |
Sewage treatment plants
The large settlement areas of La Palma are connected to sewage treatment plants and sewage pumping stations:
| Sewage treatment plants in the municipalities | With affiliated municipalities | Quantity (m³ / month) |
|---|---|---|
| San Andrés y Sauces | 5,000 | |
| San Andrés y Sauces | 0 | |
| Santa Cruz | 50,000 | |
| Breña Alta | 227 | |
| Breña Baja | 12,000 | |
| Breña Baja | Villa de Mazo | 45,000 |
| Los Llanos | El Paso, Tazacorte | 90,000 |
| Villa y Puerto de Tazacorte | 10,000 | |
| Los Llanos | Puerto Naos | 0 |
Consumer
There are two types of water supply for the end user, so-called city water , which is supplied to the consumer directly by the municipalities or in the municipalities of Santa Cruz, Breña Alta, and Tazacorte by the privately owned company Canaragua (which is also active on other Canary Islands) and is billed via a water meter, and the stock or gallery water , which is all privately organized.
The constantly flowing gallery water is stored in closed or open tanks during distribution, depending on whether it is used as drinking water or exclusively for watering the garden. Currently, a share with a water volume of 1.6 l / min (sufficient for a garden of 2,000 - 5,000 m²) costs around 7,000 euros.
The largest water consumption is for irrigation of the island's intensive banana cultivation, which accounts for almost 80% of total consumption. To harvest one kilo of bananas, 400 liters of water are usually needed today (in extreme cases 800 liters). With around 70% of the island's income from the export of bananas ( Plátanos ), the island is highly dependent on this industry. Tourism only follows with around 18% of income.
Web links
Individual evidence
- ↑ a b Rolf Goetz: La Palma. Active holidays on the greenest of the Canary Islands . 5th edition. Peter Meyer travel guide, Frankfurt am Main 2000.
- ↑ a b Water in abundance ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , La Luna Baila.
- ↑ a b Will the water run out soon? (Graja News)
- ↑ a b Climate & Weather , La Palma Travel.
- ↑ ER - HI1 Evaluación técnico económica de una instalación de microgeneración hidráulica en Santa Cruz de La Palma , Servicio de Consultoría y Asistencia Técnica en materia de Eficiencia Energética, Creara, January 2015 (assessment of the technology and economy of the installation of hydraulic mini power generation systems), accessed on February 6, 2018.
- ↑ José Alberto Hernández: Las Galerias De Agua en Canarias , ( The Galleries in the Canary Islands ), February 11, 2017.
- ↑ Historia - Galerías La Palma , Consejo Insular De Aguas de La Palma, 2016.
- ↑ Susanne Lipps-Breda: La Palma travel guide , DuMont travel paperback, 2017.
- ↑ Francisco Suárez Moreno: Historia y Cultura del Agua en Canarias , ( History of Water in the Canaries ), VII Jornadas de Cultura del Agua, July 11, 2012.
- ↑ Water, our most precious asset , La Palma-Parati.
- ↑ a b water supply
- ^ Institution of the Consejo Insular de Aguas
- ↑ Aguas de La Palma , La Voz de La Palma, May 31, 2010.
- ↑ Mapa de capaciones de La Palma , ( map of the galleries, fountains and sources ) Consejo Insular De Aguas de La Palma, 2016.
- ↑ Nacientes , ( sources on La Palma ), Cabildo Insular de La Palma.
- ↑ Solo la mitad de las galerías de agua de La Palma se mantienen activas , ( Only half of the water tunnels on La Palma are active. ), Diario de Avisos, 13 June 2012.
- ↑ Galarias , Consejo Insular de Aguas, January 19, 2015 ( map shows the positions of the galleries on La Palma ).
- ↑ Galerias , Island Council of Aguas de la Palma, January 19, 2015 ( Galleries and Fountains La Palma ).
- ↑ Mapa de los tres canales de La Palma , ( overview map of the three canals ), Consejo Insular De Aguas de La Palma, 2016.
- ↑ Laying plan of the pipelines on La Palma
- ↑ Conducción Aduares-Hermosilla ArcGIS June 6, 2016th
- ^ Canal General La Palma I , ArcGIS, June 6, 2016.
- ^ Canal General La Palma III , ArcGIS, June 6, 2016.
- ↑ Canal General La Palma II , ArcGIS, June 6, 2016.
- ^ Sealing of the Barlovento basin
- ↑ Dam break after earthquake on La Palma , OÖNcard, April 17th 2011.
- ↑ La balsa de Vicario, otra obra pública que se eterniza en La Palma , ElApuron, June 28, 2016 (The Balsa de Vicario, another public work on La Palma that lasts forever).
- ↑ News from the water , La-palma24, January 5, 2018 ( Volume de Agua en las Balsas de La Palma - 2017 ).
- ↑ Location of the water reservoir , Cabildo Insular de La Palma.
- ↑ Volume de Agua en las Balsas de La Palma - 2016
- ↑ Volume de Agua en las Balsas de La Palma - 2015
- ↑ Map shows the sewage treatment plants
- ↑ Canaragua
- ↑ Banana cultivation remains the export engine of La Palma
