Austria’s Landscape, Climate and Water Flow
Austria is a mountainous country with about 62% comprising of mountainous terrain; the remainder is hilly, with low-lying plains to the East. Alpine geological formations run in a predominantly west-east direction, with water draining both north to the Danube and south to the Drava/Drau. The gradient of the Austrian Danube is circa 0.4‰, much steeper than in Lower Bavaria and the Hungarian Plain. Austria’s continental climate typically displays high precipitation rates in Alpine areas (up to 3,500mm/annum), whereas <500mm/annum is recorded in the dry Northeast. Average precipitation within the Basin is 1,090mm/annum in Austria, with an evapotranspiration rate of c.500 mm/annum and an outflow via the Danube and southern/eastern tributaries of 575mm/annum. Consequently, Austria contributes 46.3 km³/annum (< 25%) to the direct flow of the Danube.
- the Wachau Valley – a UNESCO World Heritage Site and an outstanding example of a fluvial and cultural landscape bordered by mountains;
- the Donau-Auen National Park - a protected floodplain area with a still relatively intact ecosystem linking Vienna and Bratislava;
- the Thayatal National Park - an impressive protected area on the River Thaya/Dyje (Austria - Czech border);
- and Neusiedler See (Fertő-tó in Hungary) – also a UNESCO World Heritage Site - consistsing of a large, shallow lake, more than half of which is dominated by reeds.
Austria’s major rivers and valleys are heavily utilized. While more than 40% of Austria’s Danube Basin is used for agriculture, settlements and infrastructure; most of the remainder is too mountainous for such activities. With all available valley floor space developed, there has been a marked impact on rivers. Due to this development, and combined with steep river gradients, which result in low water storage capacity in the inundation zones, Austria has a long history of dealing with floods and landslides. Major river systems are also utilised for hydroelectric power generation (an important power source for the country); navigation (the Danube is a major international commercial waterway); as well as receiving waters for effluents and drinking water supply (nearly 100% of Austria’s domestic supply stems from alluvial and karstic ground water bodies).
Around 86% of Austrians live in houses with main sewerage. The remaining 14%, located largely in rural areas, are the focus for future wastewater management resources.
Treatment of point source nutrient discharges go beyond the requirements of the EU Urban Waste Water Directive and estimates for such discharges leaving Austria via rivers to the Black Sea are 15.2 kt/a for reactive nitrogen and 1.2 kt/a for phosphorus. The situation for diffuse discharges is less ideal, with past data for reactive nitrogen showing elevated concentrations in groundwater. Although it should be noted that these concentration have been declining. Concentrations are high where agricultural activities take place above groundwater bodies with a limited recharge rate. However, it is the low concentrations from Alpine areas that are more important in terms of their relative dispersion. Due to the large run-off from Austria, background fluxes are also elevated in relative terms when compared with other states. Estimates of the diffuse discharge of reactive nitrogen leaving Austria to the Black Sea is 64.3 kt/a. With regards to phosphorus levels, the share of reactive phosphorus from deposition is small. Estimates of the diffuse discharge of phosphorus leaving Austria to the Black Sea are around 4.7 kt/a.
Priority Substances, a large set of emission ordinances specifies the requirements for industrial wastewater discharges to waters and public sewerage systems. The effective implementation of emission-based requirements for industrial effluents is primarily characterised by internal (“front of pipe”) measures, such as prevention of raw material losses or water reuse added by reasonable “end of pipe” techniques of wastewater treatment.
For detailed information and statistics on the impact of pollution and hydro-morphological alterations to the Danube system, download the fact sheet below.
- Austria Facts & Figures (107.07 KB)
Floods are natural phenomena. They can, however, turn into disasters causing widespread damage, health problems and even deaths. This is especially the case where rivers have been cut off from their natural floodplains, are confined to man-made channels, and where houses and industrial sites have been constructed in areas that are naturally liable to flooding.
The Drava River is the fourth largest, as well as the fourth longest Danube tributary. It connects the Alps with the Danube and the Black Sea. The Drava has been considerably regulated with dams constructed to generate hydroelectricity and channels dredged to direct its flow. Nevertheless, natural habitats along the middle and lower reaches host unique varieties of flora and fauna, and several endemic species.