Water bodies and resources

Water bodies and resources
Hungary’s borders are crossed by 24 incoming rivers, bringing in 114 km³ of water per year. On exiting the country, the three major rivers (the Danube, Tisza and Drava) discharge an annual average of 120 km³ water.


The vast majority of Hungary’s waterworks are reliant on groundwater: more than 90% of the population is supplied in this way.

Water utilities supply 560 million m3 of drinking water/year and a further 240 million m3 water for economic and other public use.

Annual industrial and agricultural abstraction accounts for almost 5000 million m3 and 680 million m3 respectively. 95.48% of industrial use is power generation. 68% of agricultural use is for fishponds; 27% for irrigation.

Major rivers are important for transportation and Hungary contains 1600 km of navigable waterways. The Danube and Tisza are key international routes while the Drava is used for internal transport.

Cargo transport is very small (currently c. 8-10% on the Danube and only 1-2% on the Tisza) and potential is limited by the lack of a connection between the two rivers. The water regime depends highly on the flow regime and has a major impact on the efficiency of shipping transport.

Hungary’s rivers also play a vital role in disposing of effluent, being the major recipients of both municipal and industrial wastewater. There is little potential for hydroelectric power (c. 1% of energy production generated by hydropower).

With 21,712km2 of Hungary below river flood level, flood control is a key consideration. Crucially, this area includes 1.8 million ha arable land, 32% of the rail network, 15% of roads and 2000+ industrial plants. The highest flood discharge in the Danube is 20 times low flow; flooding on the major rivers can last several months.

In smaller rivers e.g. the Körös system, the ratio is several hundred to one and floods can develop in a few hours. Devastating, fast-rising ice-jam floods are especially dangerous. Flood control over past centuries has resulted in the construction of 4181 km of defences (mainly earthen embankments).

Ten emergency lowland flood reservoirs (with a total volume of 360 million m3) provide protection for 97% of the floodplain area.
Water Pollution

Of 876 natural and 150 artificial water bodies identified in Hungary, 579 freshwater surface bodies have been classified as being “at risk” from organic, nutrient or priority hazardous substances (according to EU Water Framework Directive definitions).

Approximately 70% of artificial lakes (mainly fishponds) are “at risk” from organic and nutrient loads.

Organic and nutrient loads from point/diffuse sources are as follows (in 1000 t/year); total nitrogen: 24.8/20.0; total phosphorus: 3.9/3.0; BOD5 (Biochemical Oxygen Demand): 60.0/3.2; COD (Chemical Oxygen Demand): 12.3/20.5. Point source load is mainly from urban discharges (80%-95% depending on pollutant).

None of the 108 groundwater bodies identified are considered to be “at risk” due to human intervention, but 46 sites are listed as “possibly at risk” (mostly from nitrate pollution from diffuse sources).

Pollution has made phreatic groundwater near the surface unfit for drinking water. (NB 349 water bodies have been identified as “at risk” and 234 “possibly at risk” from hydro-morphological alterations. These represent 42% and 25% of the total length of Hungarian water bodies respectively. In the case of lakes, 47 water bodies are “possibly at risk”, including Lake Balaton.)