Photo: BMLFUW/Rita Newman
Water cycle and water balance
Austria is a country in Central Europe, in the temperate climate zone. Two thirds of Austria’s territory are covered by the East Alps, which form a barrier to rain clouds and stimulate the raining out of clouds. Austria profits also from the high inflow. So, what does Austria’s water balance look like?
Water balanceThe water balance relates to the entireAustrian federal territory of 83,858 km² and the period of 1961 – 2000. It consists of the main components precipitation, run-off and evaporation.
The annual averages are 1,100 mm for precipitation, 500 mm for evaporation and 600 mm for the run-off. Taking into account that approximately 320 mm of water enter Austria every year from neighbour countries, the total annual run-off from Austria is about 920 mm.
Water balance expressed in figures – Averages of 1961 - 2000 / year:
- Amounts added per year/m²:
- Precipitation: 1,100 mm
- Water entering Austria from abroad: 320 mm
- Amounts removed per year/m²:
- Evaporation: 500 mm
- Total amount leaving Austria: 920 mm (320 mm from the quantity entering Austria from abroad, plus 600
mm. The 600 mm originate from the 1,100 mm of precipitation, minus the 500 mm of evaporation.) Of the
total run-off to abroad 890 mm are surface run-off and 30 mm subterranean outflow.
Water utilisation
With precipitation and the amounts of water entering Austria from neighbour countries, about 120 billion m³ of freshwater/year are available for Austria. If we reduce this amount by the quantity evaporated, theoretically 84 billion m³ remain available to cover the water demand in Austria. Total water consumption is presently about 2.6 billion m³/year, of which two thirds account for agriculture and industry. Of the amount of water theoretically available, Austria’s households use but one percent.
Annual abstractions/m²:
- Abstraction of 8 mm for households, of which 6 mm return as treated urban wastewater.
- Abstraction of 20 mm for the industry, of which 18 mm return as treated industrial wastewater.
- Abstraction of 2 mm for irrigation in agriculture.
Water as a resource
Water is an indispensable resource for man and the environment. Therefore the quantity and the quality of water have to be maintained for a wide variety of utilisations.
Water as a natural resource is closely linked to other fields of nature. Austria’s high share of forests and the sparse population of its high-alpine and alpine regions promote the superior quality of the Austrian spring waters. To keep the water clean, water bodies have to be protected as ecosystems.
10.03.2009, Lebensministerium Öffentlichkeitsarbeit