Dams

* We participated in this study as subcontractors to the main undertakers of the project.

This project was mainly about the study of the Havria dam in Halkidiki. More specifically the project included focusing on, but not being limited to the following demands. In particular, the person in charge of the study had to fulfill the following:

a) A review of the hydrological study;

b) a pre-study of the electromechanical work on the dam and the work on access roads;

c) the project description for the small hydroelectric power station;

d) the preliminary environmental impact assessment;

e) the environmental impact study;

f) the pre-study for the small hydroelectric power station;

g) the definitive study of the dam, the work associated with it, the potential water-proofing work on the reservoir in the Melissopetra area and the work on access roads;

h) project tendering;

i) the land registry and the land registry signage.

The main object of this study was to investigate the irrigation problems in South Viotia and to look at the possibilities of building a reservoir there. Carrying out the study included the following:

a) Evaluating the demand for water and identifying reservoir locations.

b) Ascertaining the geological locality.

g) Investigating the Geo-financial locality and fiscal situation.

d) Hydraulic locality – Hydrology and Hydraulic work.

e) Recommendations for the advancement of the whole study.

The object of the study was to repair the damage to the Floka Dam and the take protection measures to preserve it.

In summary, the following work was carried out:

a) Implementation and diversion studies were drawn up. The required diversion was built and then dismantled once the required work was carried out.

b) Bores were drilled below the dam.

c) The foundation below the bedding dam (which has been destroyed) was reinforced with pavement blocks (dimensions 0.85 x 0.85 x 0.70) for a length of 10.0m and along the entire breadth of the dam.

d) Work was completed below the overfall basin so as to establish it as an upper bedding to the gradated works (excavations, laying down pavement blocks and natural boulders, filling in holes, geo-matting, impletion with concrete with probable cavitations, and so on).

e) A gradated waterfall was constructed out of concrete with a height of 7.20m, immediately below the upper bedding of the dam’s overfall. The waterfall would eventually have seven levels with a total length of approximately 18 m .

f) An energy dissipation basin at the foot of the gradated structure was configured with a length of 24.0 m and depth 0.50 m , and the basin was lined with pavement blocks with the dimensions 0.85 x 0.85 x 0.70.

g) An abutment slope protection wall (height 4.0 to 6.5 m ) was constructed using concrete.

h) The slope was lined with concrete, 0.30 m thick.

i) The pervious berm (dimensions 0.5 x 1.0), which had been built along the breadth of the dam on the edge of the overfall basin, was dismantled.

j) Part of the riverbed below the dam was adjusted for a distance of approximately 300m.

k) The existing guardhouse was dismantled and a new one was built.

Flood-prevention earth dam at Tsakona, Messinia, with a length of 530 m , an overfall length of 170 m and a height of 5.50 m . Due to problems from undercutting of the bedding and erosion of the riverbed which rendered the dam unsafe.

In the context of the Consulting Services of the Ministry for the Environment, Physical Planning and Public Works (D7) the dam’s overfall spillway outlet was redesigned. More specifically, hydraulic investigation of the overfall and the corresponding discharge basin of the small berm at the exit of the basin of the outflow crest, the waterfall berm ( 12.0 m ) and the evacuator.