Freshwater - State & Impacts

What are the state and impacts?

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.

Figure 1: Ecological status of the natural running waters in Austria, (excluding heavily modified and artificial waters. The percentages refer to the length of the surface water bodies of the natural running waters in Austria with a catchment area greater than> 10 km2 (BMLFUW, 2010 - modified)
Figure 2: Ecological status of Austrian lakes >50 ha, including heavily modified and artificial lakes. The percentages refer to the number of lakes > 50 ha) (BMLFUW, 2010 - modified)

Table 1: Number of water bodies in which the quality standards for pollutants are exceeded (BMLFUW, 2010)

  Number of water bodies
Priority substances  
Hexachlorobutadiene 2
Tributyltin* 3
National pollutants  
Ammonium 13
AOX 1
Copper 1
Zinc 6

Table 2: Nitrate concentrations in running waters in Austria, 2003-2007 (BMLFUW, 2008B - modified)

Nitrate concentration in running waters 03/07 -  Concentration in classes
Concentration in mg NO3/l 0 - 1.99 2 - 9.99 10 - 24.99 25 - 39.99 40 -50 > 50
0-0.45mg NO3-N/l 0.452-2.257mg NO3-N/l 2.259-5.645mg NO3-N/l 5.648-9.034mg NO3-N/l 9.036-11.3mg NO3-N/l >11.3mg NO3-N/l
Number of monitoring stations per concentration class
Annual mean 46 179 42 4 0 0
Mean value (winter period) 39 164 58 4 0 0
Maximum 8 154 74 23 6 6
Percentage of monitoring stations refered  to the total number of monitoring stations
Annual mean 17.0 66.1 15.5 1.5 0.0 0.0
Mean value (winter period) 14.7 61.8 22.0 1.5 0.0 0.0
Maximum 3.0 56.8 27.3 8.5 2.2 2.2
Figure 3: The quality of Austrian bathing waters 1997-2008 (BMG [Federal Ministry of Health], 2009A)
Figure 4: Chemical status of bodies of groundwater bodies and trends (BMLFUW, 2010 - modified)
Figure 5: Nitrate - Development of the exceedances of the threshold value 1997-2008; Number of groundwater monitoring stations which exceed the threshold value by their annual mean values in proportion to the total number of monitoring stations available in bodies of shallow groundwater per year, (ENVIRONMENT AGENCY 2010, OWN EVALUATIONS)