Project Summary

Drinking Water-Irrigation

Client: Ministry of Rural Development and Food
Year: 2006

The purpose of the study was the renewal-modification of the Environmental Terms of the project for the construction of a water dam in the region of Kritinia in order to irrigate the agricultural areas in communities Lineros, Karya, Kopria and Ammoua-of a total surface area of 3000 hectares- and to supply water in the island Halki by ship and the community of Mandrikou, Rhodes.

SOLUTION      ΥΔΡΕΥΣΗ                                                                      View of the works
Until recently, the irrigation and water supply demands of these areas were satisfied by wells. The extensive use of wells had a direct impact on the qualitative and quantitative composition of the groundwater aquifer.
The total storage capacity of the Kritinia dam is 2.115.000m3 and its effective capacity is 1.895.000m3.

The implemented works during the preparation of the study included:

• Excavation for the foundation of the core trench at the right embankment, excavation at the left embankment and excavation for the foundation of the dam; excavations at both embankments revealed severe ground surface erosion from stormwater
• Construction of a diversion channel with rectangular and semi-circular cross-section, total length of 215m, width of 2,50m and height of 2,75m
• Construction of a pre-dam and part of the upstream body of the dam up to elevation 47,50m; the upstream part of the dam revealed, in addition to the erosion problems, significant deformation of its geometric characteristics
• Construction of the downstream part of the dam up to elevation 36m; the downstream part of the dam revealed similar erosion problems but in a lesser degree
• Construction of the core of the dam, the upstream and downstream filters and the drainage system up to elevation 37,50 m which had apparent signs of wear due to the erosion from stormwater
• Construction part of the grout curtains underneath the dam and the right embankment
• Opening of access roadways, which due to the lack of proper drainage works caused flooding problems on the roadways and the surrounding areas

The remaining works for the completion of the dam included:

• Construction of the side spillway with a total length of 250m, the inlet impoundment basin with varied width from 4m to 7m and rectangular/trapezoidal cross-section, the stilling basin with a length of 50m and the outlet channel with a length of 100m
• Construction of the earth dam with clay core, core protection zones for erosion (filters and drainage works), support structures from schistolithic rocks and external protection zones of the embankment with a total volume of 570.000m3.
• Construction of the remaining part of the grout curtain and additional grout curtains for waterproofing of the spillway
• Construction of the water intake outlet pipes with a length of 120m and the water intake works
• Construction of the building for valves and instruments
• Opening of the access roadway to the control building with a length of 210m, asphalt-layering of the roadway with a length of 2.090m and construction of the accompanying technical works; it must be noted that the damaged roadway sections which lead to the quarry, were reconstructed or maintained

In the current study, the exact location for the construction of the works was identified and the existing condition of the natural and human environment was examined. Additionally, the feasibility of the works was demonstrated and a technical description of the works was performed.

Then, a reference was made to the suggested works before and after the final design, the works that had been already constructed, those under construction and lastly an analysis of the required works was made.

This study was submitted to the environmental public authority for the renewal and modification of the Environmental Terms. The implementation of the dam will resolve the problem of irrigating the settlements of Lineros, Karia, Kopria and Ammoua and supplying water to the island of Halki.