Tvrdosin Water Work

The main task of the Tvrdosin Water Work is the function of a balancing reservoir of the peak Orava water power station, and use of the water energy of the next section of the river Orava.

The construction of the Tvrdosin Water Work started in the year 1972. From March 1978, only a minimum water level was in the reservoir, and all aggregates of the water power station were commissioned between October and December 1979.

Hydrologic Conditions (see attached table) Construction Design of the Work and Description of Objects

The main objects of the Tvrdosin Water Work are: earth dam and valley reservoir, functional block, water power station, and waste channel.

Earth Dam

It is homogenous with slope sealing made of PVC 1.1 mm thick, which is laid in the gradient 1:2. The sealing is prolonged to the sealing heel in the subsoil of the dam, where it is laid on a layer of foundation concrete. The water side of the sealing is protected by a layer of clays 1.5 m thick.

Ingresses are drained by drains consisting of perforated steel tubes covered by filters made of geotextile. The drains may be closed, at the mouth, by outlet valves, if necessary. The static part of the earth dam is built of gravel excavated from the river Orava bed, without additional treatment. The top of the dam is raised 1.2 m above the maximum emergency level.

Valley Reservoir

It was created by damming the river Orava valley in the rkm 57.90. The heaving reaches the Orava dam, situated in the rkm 65.57.

Functional Block

It is projected as a weir 19.8 m wide, and situated on the right side. The quote of the sill is 567.3 m a. B., and thus it may serve also as a bottom outlet, and during construction, it served for carrying flows through the construction site. Two fields 5.8 m wide and 10.5 m high are dammed by double segments with heated upper part. The capacity of both fields of the functional block in the maximum summer operational level is 600 m3.s-1.

Water Power Station

It is of overflowing type, the under-overflow width in the dam axis is 29.2 m. The top overflow with the spill on the quote 572 m a. B. is 22.8 m wide, the dammed height is 5.4 m, and during maximum summer operational level, it carries through 300 m3.s-1 water. It is dammed by a segment, the overflow hole is divided by pillars for provisional damming into three parts of the inner diameter of 5.8 m. In the power station, three direct-flow turbines are installed, the smaller of which shall continuously process the guaranteed outflow of 3.5 to 5.0 m3.s-1.

The power station has remote control from the Orava water power station. The output is taken to the distribution substation of the Orava water power station, the connecting wiring and the signalising cable are 5.75 km long.

Main Parametres of the Dam (see attached tale)

Main Parameters of the Reservoir (see attached table)

Main Parameters of the Power Station (see attached table)

Information & Contact:

Research Institute of Water Management,
Nabr. arm. gen. L. Svobodu 5,
811 02 Bratislava,
tel.: 00421 (2) 59343111,
fax: 00421 (2) 54415743