Dam rehabilitation of the Reservoir of Rakaca

Projet terminé

The dam stability of Rakaca reservoir is deficient at certain places. This problem is aggravated by a drainage system which is not well-functioning. The project partly renews the unstable part of the dam and rehabilitates the drainage system. This reduces the risk of a dam failure with related flood waves for the 5’200 inhabitants of down-stream settlements. Furthermore, supply of drinking water is ensured in the long run for 35’000 inhabitants of the region.

Pays/région Thème Période Budget
Hongrie
Accroître la sécurité publique
Prévention des catastrophes naturelles et des situations d‘urgence
01.03.2013 - 30.11.2016
CHF  1’009’238

Note: the texts under all the headings, with the exception of 'Results achieved', describe the situation before the start of the project.

Contexte Rakaca reservoir was created by an earthen dam designed and constructed 1958-1961. It is the first "artificial" reservoir for water supply in Hungary. The reservoir has a maximum storage volume of 5.8 million cubic meters. It stores river-water during times of high-flow and releases it (1.9m3/s) through the bottom outlet during low-flow periods. The reservoir has a secondary, though limited function as flood retention reservoir. The dam is seriously damaged: Originally placed on unsuitable subsoil, its stability (against sliding on the downstream side) is insufficient at certain places. Furthermore, vertical and horizontal drainage facilities on the downstream slope / bottom section are not functioning correctly. The situation got worse due to the impressive 2010 precipitations. The rainfall / flooding probably led to undue soaking of the downstream slope and consequently a momentary increase of the drainage problems.

Objectifs

The overall goal is to increase the flood safety of two settlements below the reservoir of Rakaca. For this purpose, damages at the dam structure are repaired in order to reduce the danger of inundation respectively of a dam failure with a flood wave.

Groupes cibles

5’200 inhabitants in two downstream settlements with 6’000 ha of land; 35’000 inhabitants in the Edelény region who rely on drinking water supply from the reservoir; municipal, provincial and government authorities.

Activités

The damages at the dam of the Rakaca reservoir are repaired with a section-wise reconstruction of the downstream part of the dam embankment and with the rehabilitation of the drainage system as well on the downstream slope of the dam.

Résultats

Résultats obtenus:  

  • Rehabilitation of the earth dam along the artificial Rakaca Reservoir, which was built in the 1960s; the dam was damaged during a severe flood in 2010, endangering the lower-lying settlements
  • 11'000m3 sediments dredged
  • Reconstruction of 575m of the damaged dam
  • Renovation of the drainage system (a total of 660m pipe length replaced
  • Further repair work on 350m length (drainage system)
  • Protection effect achieved for 5,400 inhabitants in two lower-lying settlements
  • Protection effect achieved for 100 ha of land that was in the risk zone
  • Environmental protection study and monitoring carried out during the remediation measures
  • Protective measures for biodiversity taken (e.g. indigenous plant species promoted over invasive plants; bird protection in the restoration of sensitive areas)
  • Nature conservation path established


Direction/office fédéral responsable DDC
Crédit Contribution suisse à l'UE élargie
Partenaire de projet Partenaire contractuel
Institution étatique étrangère
  • National State Institute North


Budget Phase en cours Budget de la Suisse CHF    1’009’238 Budget suisse déjà attribué CHF    971’121
Phases du projet

Phase 1 01.03.2013 - 30.11.2016   (Completed)