The reservoir is confined on the right by a 7-km-long, up-to-15-m-high dyke and on the left by higher grounds. Along the dam crest leads a 9.5-m-wide road from Mojs to Zilina. The dyke‘s outer slope gradient is 1:2.5 and the waterside one is 1:2 – 1:6 – 1:3.

Flood levels of the Zilina water project are as follows:
upper max. – 352.00 m above sea level
upper min. – 350.30 m above sea level
Q1r.average – 95.6 m3.s-1
Q100 flow high – 1,490.0 m3.s-1
Q1000 flow high – 1,690.0 m3.s-1
flow high – adjusted to the effects of the Liptovska Mara and Orava reservoirs

The reservoir’s water volume is divided as follows:
total – 17.97 million m3
working – 3.97 million m3
reserve – 4.10 million m3
storage (b + c) – 8.07 million m3
permanent – 9.90 million m3

The hydro-facilities include (from right to left) a hydroelectric power plant with an operating building, a dam and an earth dam in which a lock may be built in the future.

The concrete dam consists of three 12-m-wide fields dammed with segments 11.4 m high with shutters 3.3 m high. The total length of the dam together with the earth dam on the left is 98 m. The electric control of the shutters ensures automatic regulation of water levels and passage through the shutters of river load and ice.

The hydroelectric power plant has two 5-K-37-1524 Kaplan turbines with synchronous generators. The turbine throughput is 2x150 m3.s-1, and their minimum throughput is 2x75 m3.s-1. Energetic head: max. 26.6 m, min. 14.8 m. The power plant‘s rated generation capacity is 68 MW and its guaranteed capacity is 62 MW. The average annual electricity production is 173 GWh. The proposed 300 m3.s-1 discharge from the service volume of 8.63 million m3 is used in two 4-hour peaks (morning and evening ones). Generated electricity is lead to four distribution stations: 110 kV, 22 kV and 0.4 kV.

The deepening of the Vah River ranged from 0 to 9 m over a 6-km-long stretch. The river bed is 45 m wide, and the slope gradient is 1:2 in the upper part and 1:25 in the lower part. A protective system to prevent a drop in groundwater level on both sides of the deepened river channel (dug in Paleogene rocks). The deepening of the river channel will ensure a complete flood protection of Zilina. Contaminated groundwaters from Zilina‘s eastern industrial zone will be intercepted by drains behind cut-off walls and carried off to a purification station.

A substitute biocorridor will be 10 km long and, thanks to its cup-shaped cross-section with a variable bottom width (5 - 7 m) and slope gradient, it will resemble a natural water course. Its average waterflow will be 5.0 m3.s-1, water depth about 1 m and current speed 0.6 m3.s-1. The small biocorridor will partly compensate for the loss of Vah‘s big biocorridor disrupted by the big barrier of the dam and by a new water regime affected by the body of sluggish and stagnant water in the reservoir (waterflow confined more or less to the upper 2-m layer).

The construction of the water project ensured protection of the water sources Teplicka nad Vahom and Gbeľany (underground cut-off walls) and included also construction of a safe controlled landfill of solid communal waste near Strecno. The construction also stabilized landslides on the slopes of Mt. Duben.

Information & Contact:

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