Freshwater - State and impacts (Austria)

Surface water

Austria has a part in three international river basins: 96% of the country drains into the Danube, 3% into the Rhine and 1% into the Elbe.

The Austrian network of 7,335 surface water bodies with a catchment area >10 km² is about 31,000 km in length of running waters (BMLFUW, 2010 Federal Ministry of Agriculture, Forestry, Environment and Water Management).

Natural surface water bodies without modified or artificial waters account for 88% of the network. Sixteen percent of these have a high ecological status, 23% have a good one, 51% have a moderate, 8% a poor and 2% a bad ecological status (Figure 1).

Around 12% of this network has been heavily modified or consists of artificial waters (e.g. such areas where water is retained for energy production). Of these, at present 87% do not have a good potential, since in particular measures for improving hydromorphological conditions are still possible.

Each of the 62 lakes >50 ha has been identified as a separate surface water body. The total surface area is 1,034 km. Altogether, 61% of these have good ecological status or good ecological potential, and 34% even have a high ecological status (Figure  2).

Hydromorphological pressures on running waters 

Due to impairments of river morphology or the hydrological conditions, about two thirds of running waters do not achieve good status. Examples for this include power plants, weirs and river bottom sills, regulation (including channelising and straightening) and disruptions of the hydrology because of too little residual water being discharged at intakes or due to hydropeaking of power plants.

Surface waters are characterised by:

• the predominantly mountainous nature of Austria and the resulting scarcity of land that can be used for agriculture (see also Figure 7);
• the efforts that have been made for centuries to protect the limited natural living space against natural hazards particularly in the innerAlpine valleys where, taking tourism into account,  population densities that otherwise are only seen in urban areas can be found see also Figure 8);
• due to the lack of sufficient resources of coal, oil and gas, efforts that have been made for many years to cover energy needs from hydroelectric power;
• the efforts to ensure selfsufficiency in food which have been made for centuries, also spurred on by the years of scarcity after two world wars   this was not achieved until the 1960s through the reclamation of wetlands by drainage (BMLFUW, 2005).

Pollutants affecting surface water

Pollutants

The quality standards of good chemical status or of the chemical components of good ecological status have been exceeded in only 25 of Austrias surface water bodies of running waters (Table 1).

Environmental quality standards of the EU Directive exceeded; at present there is no threshold in the national Ordinance on Ecological Quality Objectives for Surface Waters.

All Austrian lakes have a good chemical status or a good status regarding the chemical components of the ecological status.

Eutrophication and acidification

Running waters

In the intensively agricultural used areas in the north and east there are some deficits in the saprobiological waterquality  and nutrient loads in the running waters, while in Alpine areas, risk identification in this respect had to be carried out only in extremely rare cases. Failure to meet the target due to general pollutant loads organic load, nutrients occurred in just 19% of water bodies.

Most of the water monitoring stations of running waters  83% for annual mean and 60% for maximum value show nitrate concentrations of < 10 mg NO₃/l for the reporting period 20032007, the last reporting period in accordance with the EU Nitrates Directive 91/676/EEC (BMLFUW, 2008B).  

If one considers the development of nitrate concentrations in running waters over many years, on the whole it can be assumed that the situation is stable.

Lakes

None of the 43 natural and 19 artificial lake water bodies investigated for pollutants or the trophic situation were considered to be at risk of possibly failing the target. In more than 75% of water bodies the current status even  relates to the trophic reference status the causes of eutrophication having been removed by an extensive lake restoration programme in the 1960s and 1970s. By setting up ring collecting systems, the direct discharge of treated wastewater was prevented, and wastewater treatment plants in the catchment areas were upgraded for nutrient removal . In some cases, lake restoration measures, such as deepwater aeration, were used.

Acidification was found occasionally in the 1980s in bodies of water in silicate river basins, caused by the geological limestone. In most of the affected waters, studies in the 1990s showed that their acidification status had been improved.

Wetlands

The main causes for the loss of wetlands are river regulation and largescale drainage operations in agricultural areas.

In a survey on the protection of habitats or species in 2005, it was considered that there was no risk to any water body due to poor water quality or an insufficient quantity of water in terms of failing to meet the environmental standards in these respects.

Bathing waters

In the 2008 season, Austria identified a total of 268 bathing waters in rivers and lakes, with threshold values met for 261 of them but limits were exceeded in the other seven. In the past five years the proportion of bathing waters exceeding limits was always less than 5%; in the past 10 years less than 10%.

The quality of bathing waters is closely linked to meteorological conditions. Following heavy precipitation, discharges of floodwaters bring increased loads of hygeinically relevant germs, but this situation usually lasts for only a few days. Longterm local climate changes could have some effect on the assessment results of the future. In addition, waste water, mainly of local origin, still plays a part in the quality of bathing waters. Advances in waste water technology and an increasing degree of connection have, however, led to a steady reduction in impacts. 

Flooding

Because of Austrias geographical features, highwater events have always been of great interest for water management and related disciplines: 

• in the Alps, permanent areas of habitation are restricted to the valleys. This presents a great challenge particularly for spatial planning in the Alpine areas;
• the orographic conditions lead to locally very distinct meteorological conditions, resulting in the corresponding highwater events;
• due to the partial storage of winter precipitation and the associated delay of the runoff until the spring and summer, runoff from various causes can combine, for example, precipitation occurring at the same time as the snow melt. 

As a result of the floods in 2002 and 2005, the twopart Flood Risk project came ws launched. Its aims were first to document and analyse the events of the floods in 2002, and then to develop strategies for integrated flood management. The linking of the different disciplines was a further important objective.

This project has highlighted the extent of variability of different climate scenarios making it extremely difficult to come to a statement for the whole of Austria about changes in the dimension values for discharge.

The status of the implementation of the Flood Directive in Austria that work is currently being carried out on the provisional assessment of risk. This is being carried out in close collaboration with the federal Lnder; a working group and a number of subworking groups have been used to this end.

Groundwater

Chemical status

The largely national, uniform and standardised monitoring of the quality of the groundwater has been carried out in Austria since 1991 on the basis of the Austrian Water Act. Therefore, this set of available data forms an excellent basis for evaluating the chemical status of groundwater. In order to comply with the requirements of the Water Framework Directive (WFD), a comprehensive evaluation of the monitoring network and strategy was carried out in 2004 and 2005 and thus slightly adapted. One hundred and thirtysix groundwater bodies or groups of groundwater bodies were identified and defined as management and monitoring units. Approximately 2,000 monitoring stations have been set up around the country. The density and distribution of these has been set up according to the pressures and hydrogeological/natural conditions. The extent of investigation is also based on pressures and covers a wide range of pollutants and indicators that is adjusted regularly.

The results of the chemical status assessment reveal that most groundwater is of good chemical status. Three bodies of groundwater that are used intensively for agricultural purposes in the east of Austria are exceptions on account of nitrate. They are failing to meet good chemical status and have been classified as areas in which measures are to be taken (Bodies of groundwater in which at least 50% of the monitoring stations exceed the environmental quality target for a pollutant) (Figure 4). In accordance with the precautionary principle and to guarantee groundwater as drinking water on a longterm, a threshold value for nitrates of 45 mg/l has been established.

At present, 14 observation areas (Body of groundwater in which at least 30% of the monitoring stations exceed the environmental quality target for a pollutant) have been identified (BMLFUW, 2010): this means that while the good status will be reached, first steps for identifying the causes of the pollution have to be taken. Such observation areas are to be seen as prestage before groundwater bodies are classified as areas  of poor status.

During 20062008, of 2,045 monitoring stations evaluated, 240 approximately 12% have been classified as being at risk from nitrates. This means that the groundwater threshold value of 45 mg/l is, on average, exceeded. The areas at risk are concentrated mainly in the arable farming areas in the north, east and southeast, due for the most part to the small quantities of precipitation and the resulting lack of dilution. Nonetheless, 74.1% of the monitoring stations show, on average, concentrations of less than 25 mg/l.

Figure 5 shows the trend in nitrate in groundwater expressed as percentage of monitoring stations exceeding the threshold value based on the annual mean values per site. . After a clear reduction from 1997 to approximately 2000, there was an increase up to 2006. Then the values exceeding the threshold values clearly fell again approximately to the 2000 level. It can be assumed that this development is heavily influenced by the precipitation situation.

For other pollutants such as, for example, pesticides, orthophosphate, ammonium and nitrite, threshold values are exceeded although this does not lead to failing good chemical status.

For Eionet, in accordance with the criteria specified (EEA, 1998), 14 groundwater bodies with a total of 388 monitoring stations were selected. These have been regularly reported to the EEA. For 20062008, 17.5% of the Eionet stations were classified as being at risk from nitrates while 64.8% show a mean concentration of less than 25 mg/l of nitrate.

The results of drinking water monitoring for water supply plants, which abstract more than 1,000 m³ of water per day or which serve more than 5,000 people, are in line with EC 1998 Drinking Water Directive (98/83/EC), reported to the European Commission by the Federal Minster of Health every three years.

The assessments show that the quality, apart from a few exceptions, was excellent. The exceptions related to values being exceeded by the no longer permitted active ingredients of plant protection agents, atrazine and its metabolites desethylatrazine and desisopropylatrazine, as well as of nitrate and nitrite. The exceeded limits reported were predominantly found in the untreated water from springs or wells, or at the chemical analyses of water from intermediate stages of treatment in the context of step control (BMG, 2009B). 

Quantitative status

The network for monitoring the quantitative status of groundwater has grown steadily since 1930 and currently consists of 3,290 stations.

In drawing up the national water management plan, investigations were carried out, among other things, into how the quantity of water contained in groundwater bodies behaves. For 32 individual groundwater bodies in porous media the status was assessed via groundwater tables; for a further 32 individual groundwater bodies in porous media as well as for the groups of groundwater bodies the assessment was carried out by balancing. It showed that all groundwater bodies are of good quantitative status in the long term, abstraction does not exceed the available groundwater resource.

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