Location
Groningen, The Netherlands
Event Website
http://fishpassage.umass.edu/
Start Date
23-6-2015 2:30 PM
End Date
23-6-2015 2:45 PM
Description
Abstract:
The Robledo de Chavela dam removal can be considered a milestone in river restoration as, due to its 23 meters high, is the highest dam ever demolished in Spain and probably in all Europe. The dam was located in Cofio river (belonging to Tajo river basin), 70 km northwest from Madrid. It was built for supplying purposes during the early sixties, but few years later it became unusable, due to water quality problems caused by livestock discharges from upstream.
On June 8th, 2012, the Tajo River Basin Authority (Confederación Hidrográfica del Tajo, CHT) detected a water leak from the drain line impossible to repair, and, consequently, launched urgent measures to avoid an extreme fish death in the reservoir and also sediment transport downstream. The CHT carried out a massive electric fishing in order to transfer fish population from the empty reservoir to downstream.
For security reasons, sediments were analyzed to confirm that heavy metal concentration, ecotoxicity and irritability were under legal limits. When dry enough, sediments were removed from the reservoir to an old meander upstream. Slopes were reprofiled and reinforced by a breakwater wall. To prevent erosion, revegetation was accomplished by hydroseeding and native trees and bushes plantation.
On September 2014 the final crucial task was achieved: the dam removal. A highly specialized company was hired in order to reach the goal of an efficient detonation, taking into account that more than 9.000 m3 of concrete had to be reduced into small pieces. Next three months were spent in removing the concrete waste from the river. The main part of it was crushed and used to restore paths in the surroundings, and the rest was disposed in the lower parts of the river banks to prevent erosion.
Session A5: A Dam Removal in Robledo de Chavela (Madrid, Spain) and River Restoration
Groningen, The Netherlands
Abstract:
The Robledo de Chavela dam removal can be considered a milestone in river restoration as, due to its 23 meters high, is the highest dam ever demolished in Spain and probably in all Europe. The dam was located in Cofio river (belonging to Tajo river basin), 70 km northwest from Madrid. It was built for supplying purposes during the early sixties, but few years later it became unusable, due to water quality problems caused by livestock discharges from upstream.
On June 8th, 2012, the Tajo River Basin Authority (Confederación Hidrográfica del Tajo, CHT) detected a water leak from the drain line impossible to repair, and, consequently, launched urgent measures to avoid an extreme fish death in the reservoir and also sediment transport downstream. The CHT carried out a massive electric fishing in order to transfer fish population from the empty reservoir to downstream.
For security reasons, sediments were analyzed to confirm that heavy metal concentration, ecotoxicity and irritability were under legal limits. When dry enough, sediments were removed from the reservoir to an old meander upstream. Slopes were reprofiled and reinforced by a breakwater wall. To prevent erosion, revegetation was accomplished by hydroseeding and native trees and bushes plantation.
On September 2014 the final crucial task was achieved: the dam removal. A highly specialized company was hired in order to reach the goal of an efficient detonation, taking into account that more than 9.000 m3 of concrete had to be reduced into small pieces. Next three months were spent in removing the concrete waste from the river. The main part of it was crushed and used to restore paths in the surroundings, and the rest was disposed in the lower parts of the river banks to prevent erosion.
https://scholarworks.umass.edu/fishpassage_conference/2015/June23/5
Comments
Presenting Author Bio: Mr. Miguel Antolín Martínez, Dr. Ingeniero de Caminos, Canales y Puertos (this means, pure Civil Engineer), is the current President of the Tajo River Basin Authority since March 2012. Before being elected for this position, he was in charge of the International Affairs Unit of the Directorate General for Water (Ministry of Agriculture, Food and Environment), and previously Head of Water Director Support Unit, and, therefore, more than 25 years of professional career within the public management of water.