The total annual water demand is 2.6 billion m3, around 3% of the total water yield. This represents the total water requirement for usage purposes as drinking water, for agricultural irrigation and process water in trade and industry without cooling water. Of this, 0.8 billion m3 is for drinking water, 1.6 billion m3 is used by trade and industry and 0.2 billion m3 for agricultural irrigation.
A Water Exploitation Index (WEI) of around 4% can be calculated for 1997-2005. This WEI corresponds to the annual total water abstraction as a percentage of available long-term freshwater resources. The WEI takes into account cooling water, contrary to the previously used ratio of total water demand versus available water amount.
Austria obtains its drinking water from groundwater (wells and springs) – the proportion of surface water used for drinking purposes is less than 1%.
Future trends in the availability of drinking water should be seen in a regional context, as climate change may cause regional changes in the available amount of water.
Water supply and waste water management
Public water supply is mainly provided for by local authorities and local authority associations. Around 7.44 million people, approximately 90% of the population, have central water supply; the remaining 10%, 900,000 people, are supplied by their own private wells (ÖVGW [Austrian Association for Gas and Water], 2010). Because of the settlement structure, the connection rate to municipal waste water treatment plants is well advanced. 91.7% of the population was connected in 2006; other waste water is collected and treated in accordance with the legal provisions on decentralised plants through, for example, small sewage treatment plants.
Hydrological and morphological pressures on surface water
Most designations for the risk category in the WFD actual status analysis are caused by hydromorphological pressures. The main causes of this lie in extensive flood protection measures for the populated areas, regulation measures in the valley areas to obtain usable agricultural areas and the intensive use of hydroelectric power.
Hydroelectric power production in Austria
Altogether, Austria’s 6,400 hydroelectric, thermal, wind, photovoltaic and geothermal plants have around 67,000 GWh gross production. In 2008, the total installed maximum capacity was around 20,700 MW and the proportion of hydroelectric power plants in gross electricity production was 61%. Of this, more than two thirds were produced through diverted flow power stations and around 31% by storage power stations.
While power stations over 10 MW produce 88% of the electricity from hydroelectric power, the remaining 12% is produced by numerous small plants.
As hydroelectric power, as a renewable energy source, provides a very high proportion of the electricity production in Austria, it can be assumed in the light of the overall situation in Austria and of the aims of the Renewable Energy Directive, that the amount of elctricity produced in this way can neither be replaced by other sources of renewable energy nor be offset by saving electricity. (BMLFUW, 2010)
Pressures from pollutants on surface water
Pollution by point sources
Waste water is treated in 1,570 urban wastewater plants larger than 50 PE60, with a total capacity of around 21 million population equivalents (PE60).
For the four main parameters – BOD5, COD, total nitrogen and total phosphorus – in urban wastewater, the incoming and discharged loads of wastewater treatment plants are shown in Figure 9.