Water Supply Works

The study’s subject matter was to examine the possibilities of constructing projects for the immediate reinforcement of the Athens water supply system with water from the Area of the Kifisos River in the Prefecture of Viotia , so as to counter the water famine problems in years 1990-1992. The projects that were eventually selected and studied for construction relate to the collection of water from the existing large public bores of the Ministry of Agriculture from the Sfaka area to Mavrovouni and the summer supplies of the Orchomenos and Poligira springs, and to channel those towards Lake Iliki .

The projects’ construction was planned in two stages (A and B) and include:

- the utilisation of water from 22 water bores (supplying between 400 m 3 /h and 1,1160 m 3 /h) and water from the Orchomenos springs;

- the construction of ten reinforced concrete reservoirs;

- the interconnection of the existing bores with these reservirs via steel pipes; – the construction of ten pumping stations in series; – the interconnection of the pumping stations with the construction of a transfer pipe from the Sfaka area to Lake Iliki, consisting of steel pipes with a total length of 75.40 km and a diameter ranging between 400mm and 2 x 1,300mm.

The study was carried out at an advanced preliminary stage. Based on this study and on the Tender Information Documents drafted by the Design Engineer, the Stage A projects were tendered and constructed. These include:

- the utilisation of water from twelve water bores (supplying between 400 m 3 /h and 950 m 3 /h) and water from the Orchomenos springs; – the construction of three reinforced concrete reservoirs;

- the interconnection of the existing bores with these reservoirs via steel pipes; – the construction of five pumping stations in series;

- the interconnection of the pumping stations with the construction of a transfer pipe from the Mavroneri area to the Orchomenos area, using steel pipes with a total length of 38.23 km and a diameter ranging between 400 mm and 2 x 1,300 mm ;

- five supply pumping stations;

7,200 m 3 /h,

1,650 m 3 /h,

14,060 m 3 /h,

15,160 m 3 /h,

23,740 m 3 /h.

The project study budget for Stage A is 6,215,000,000 drachmas, i.e. 18,240,000€ (1990). Notably, during the stage of project planning, and in addition to the main objective of dealing with the water famine, the projects were designed so that they could be integrated to future irrigation projects, after the immediate water famine issues had been resolved, following a proposal made by study coordinator I. Peppas. As is widely known, these projects have been constructed and are currently in operation (primarily the pipes) as means for irrigation, such as the reinforcement of the Kopaida Plain during the summer season with water from Mornos, the irrigation networks of Cheronia, the irrigation networks of Orchomenos, etc.

The study’s subject matter is the reinforcement of the water supply of the greater Volos area with water from the underground water table of the Karla area.

A comprehensive project was planned, consisting of water release projects from the underground water table and the transfer of this water to an existing reservoir of the Municipal Water and Sewage Corporation of Greater Volos (DEYAMB), from where it will be channelled to the distribution network .

The study was carried out in several stages, as follows:

1 st Stage

- Hydrogeological Study

- Precursor Report

- Draft Environmental Impact Study (DEIS)

2 nd Stage

- Topographic and Geotechnical works

- Preparation of Definitive Study

- Final Environmental Impact Study

3 rd Stage

- Drafting of Tender Information Documents and the Health and Safety Plan and Dossier.

More specifically, in relation to the hydraulic part of the study in the Precursor Report:

a. the water quantity that can be released from the underground water bed, as well as the areas from which this quantity can be extracted, were determined, in accordance with the estimates of the hydrogeological study carried out by the team of hydrogeologist K. Mpezes; b. the main network (pipes, pumping stations) for the collection and transfer of water was designed.

The following projects were eventually studied at a definitive stage, together with the Tender information documents:

- Excavation and equipment for 50 water bores with a diameter of 17.5 inches and a depth of 200 m each, in the greater area of settlements Stefanovikio and Rizomilos.

- Two reinforced concrete reservoirs, with a capacity of holding 440.0 m 3 each; – two pumping stations supplying 972.0 m 3 /h for AI and 1,048.0 m 3 /h for AII;

- water collection network from water bores and transfer of said water to the third-generation polyethylene reservoirs with pipes measuring 32.5 km long in total;

- steel tube pipes for the transfer of water from the pumping station to the pump of the Municipal Water and Sewage Corporation of Greater Volos (DEYAMB), with a total length of 9.4 km and a diameter ranging between 500 mm and 800 mm ;

- maximum water supply capacity of the project;

- annual release quantity: 10.6 million m 3 ;

- maximum aqueduct supply: 45,000 m 3 /day.

The Distomo aqueduct was built as part of the urgent plans for the immediate reinforcement of the Athens water supply (1992). It supplies the Mornos Canal, in the Aspra Spitia area, with water from the sharing project of the Kopaida and Distomo aqueducts, located in the Mavroneri area of the North Kifisos River (altitude +120.0).

It consists of :

- three pumping stations in series, supplying Q=2.50 m 3 /sec each;

- a steel discharge pipe with a diameter of 1200 mm and a total length of 18,200 m;

- the Distomo tunnel (at an altitude between +414.0 and +408.0) ;

- a loading manhole,

- a PVC gravity pipe with a diameter of 500mm and a length of 950.0m (inside the tunnel);

- a steel penstock with a diameter of 1000 mm and a length of 1,550.0 m;

- energy dissipation project (altitude +328.0);

- confluence project with the Mornos water pipe.

During the construction phase of the above projects, the Authority decided to complement the project with the construction of projects for the recuperation of energy and the ability for reverse operation, so that:

a) the energy dissipation project would be replaced by a waterfall energy recuperation project (Q=2.5 m 3 /sec, H=408-328=80 m)

b) a new pumping station would be provided at the confluence point of the Distomo aqueduct with the Mornos pipe for the aqueduct’s reverse operation, i.e. the supply of the Sharing Project with water pumped from the water conduit of Mornos and from there, through the Kopaida aqueduct, the rural area from Mavroneri to the area controlled by the Kopaida Organisation.

The following projects were studied at a pre-study stage for that purpose:

a) For the recuperation of energy during the first phase of operation of the Distomo aqueduct ;

- the Hydroelectric Station (HES) equipped with two Francis hydraulic turbines with a capacity of 800KW each, an adaptor (1250 KW), etc;

- an exit manhole for the turbines and a project for the connection to the Mornos water conduit;

b) for the reverse flow during the operation phase of the Distomo aqueduct:

- a new distribution pumping station (ΑΔ4) in parallel with the HES, consisting of 5+1=6 pumps supplying 1,800 m 3 /h each and 6 electric motors with a capacity of 850KW;

- a suction manhole;

- supplements (by-passes) on the existing distribution pumping stations (ΑΔ1, ΑΔ2 and ΑΔ3) of the Distomo aqueduct by fitting a needle valve.

The Pre-study of the projects did not progress to a Definitive Study and these projects were not constructed.

The aqueduct operated over the water famine years, transferring water from Mavroneri to the Mornos aqueduct.

After the water famine period, and due to the shortage of irrigation water that would occur over the summer season in the Kopaida area, in recent years the aqueduct operates in reverse, transferring water from the Mornos aqueduct to the Kopaida pipe, with a temporary pumping station installed by the Athens Water Supply and Sewerage Company (EYDAP).

Also, funds were recently approved by the Ministry of Rural Development and Food for the construction of a permanent project of a Pumping Station (A4) in the location provided for in the Pre-study.

The study relates to the planning of supplementary works on the main pipes of the aqueducts in Kopaida and Distomo. These projects aim to suggest ways for their integration in the irrigation works of the areas through which the pipes of these aqueducts pass as well as design and construct comprehensive irrigation networks. To this end, projects (water intakes) have been studied for the release of water from these pipes in the areas where these pipes will be transferring water, whether through the existing bores or from water (through Distomo) of the Mornos pipe.

The study determined the locations and supplies of temporary irrigation water intakes on the aqueducts of Kopaida and Distomo.

More specifically :

- 6 temporary water intakes were studied on the Kopaida aqueduct, of a supply ranging from 1,000 m 3 /h to 2,000 m 3 /h, to serve the irrigation of the rural areas from Cheronia to Orchomenos.

The water of the nine large bores of the Ministry of Agriculture will be used for this purpose (XP1-2, AK 4-6), supplying between 300 m 3 /h and 1,200 m 3 /h (7,500 m 3 /h in total) and it will be possible to irrigate between 2,600 ha and 3,700 ha through those.

- 6 temporary water intakes were studied on the aqueduct of Distomo, serving the irrigation of the rural areas from Mavroneri to Distomo, of an area size of 2,500 ha . The water of the large bores of the Mavroneri springs (Ministry of Agriculture) will be used, and possibly also the new bores North-West of Mavroneri, supplying 9,000 m 3 /h in total.

- proposals were also submitted for the irrigation of rural areas north of Mavroneri (Vasilika – Parorio – Profitis Ilias) of an area size of 1,400 ha , and Agia Paraskevi and Kato Tithorea, of an area size of 3,300 ha , through which the collector sewer passes, collecting the water of the bores of Sfaka, Vasilika – Agia Paraskevi and other, with a capacity of 4,000 m 3 /h, and which lets out into the sharing project.

Pre-study for the reverse operation of the Aqueduct at Distomo.
Preliminary Study and Tender Information Documents for the reinforcement of Athens from the large bores by the Ministry of Agriculture on the main course of North Kifisos River.
Study of internal water supply networks and connection of said networks to the external network.
Connection of the internal aqueduct of the settlement to the point designated by the Municipal Water and Sewage Corporation of Greater Volos (DEYAMB). Pre-study and Definitive Study.
Network aqueduct study by the general internal Building Society. Pre-study and Definitive Study.

The study subject matter was to examine the internal water supply network of the town of Portaria .

Specifically, it related to the study of the internal aqueduct of the town of Portaria and the external aqueduct and irrigation pipe towards the lower towns (Stagiates, etc).

Carrying out a Preliminary and a Definitive Study for the internal water supply network of the town of Pamfila.