On April 19, 1995 Governments of the Slovak Republic and the Republic of Hungary signed an Agreement concerning certain temporary technical measures and discharges in the Danube and Mosoni branch of the Danube[1] (Appendix A.1) - hereinafter the Agreement. The Agreement prescribes the monitoring of environmental impacts of realised measures - increased discharges into the Danube and Mosoni branch of the Danube, and water supply into the right side river branch system. Activities of Nominated Monitoring Agents connected with the realisation of environmental monitoring in the influenced area are described in the Statute[2], signed on May 29, 1995 in Gabčíkovo (Appendix A.2).

The Agreement originally had to expire after the judgement of International Court of Justice in the Haag in the case concerning the Gabčíkovo - Nagymaros Project. On October 23, 1997 the Slovak Republic, through the Ministry for Foreign Affairs, informed the Republic of Hungary of its readiness to prolong the validity of the Agreement from April 19, 1995 until an agreement on implementation of the Judgement of International Court of Justice, declared on September 25, 1997, is reached. The Republic of Hungary accepted the proposed prolongation by the Resolution of Hungarian Government from December 17, 1997.

On April 25, 2007 Nominated Monitoring Agents agreed on Statute modification (Appendix A.3). The agreed modification reflects changes in water quality monitoring according to Water Framework Directive (2000/60/EC) and defines changes in time schedule for elaboration of National and Joint Reports. There were also agreed changes in monitoring sites, observed parameters and frequency of measurements.

Slovak Party, according to the intergovernmental Agreement, has undertaken to release an annual average discharge of 400 m³.s^-1 into the Danube downstream of Čunovo dam and 43 m³s^-1 into the Mosoni branch of the Danube and the right side seepage canal, both discharges depending on hydrologic and technical conditions described in Appendices No. 1 and 2 of the Agreement. Hungarian Party, according to the Agreement, constructed a submerged weir in the common section of the Danube at rkm 1843, and put it into operation in June 1995. This weir enables supply of water (up to 250 m³s^-1) into the river branches in the inundation area on Hungarian side. The water discharged into the Mosoni branch of the Danube ensures the water supply of Mosoni Danube and branches in Hungarian flood-protected area.

According to the Article 4 of intergovernmental Agreement the Parties are obliged to mutually exchange and evaluate data obtained by environmental monitoring on both, Slovak and Hungarian sides of the Danube, which are necessary to assess the impacts of increased flow rate in the Danube and the water supply on the Hungarian side. Technical details of environmental monitoring on both sides – the determination of influenced area, sampling and measuring points, frequency of measurements, list of exchanged parameters, frequency of data exchange, etc. – are described in the Statute (Appendices A.2 and A.3) and relevant documents.

Observation results and measured data in tabular and graphical forms, together with their evaluation, create the National Annual Reports prepared by Parties themselves, according to the Article 3 of Agreement. This Joint Annual Report was elaborated jointly and it is based on approved and mutually exchanged National Annual Reports.

The present report is the seventeenth Joint Annual Report on environmental monitoring and gives an evaluation concerning the year 2011. The evaluation of Slovak side is based on data collected by the Slovak Hydro-meteorological Institute (SHMÚ), Faculty of Natural Sciences of the Comenius University (PriF UK), Slovak Academy of Sciences, National Forest Centre (NLC-LVÚ), Soil Science and Conservation Research Institute (VÚPOP), West Slovakia’s Waterworks Company (ZsVS), Bratislava’s Waterworks Company (BVS), Slovak Water Management Authority (SVP-BA), Water Research Institute (VÚVH) and Ground Water Consulting Ltd. (GWC). The data exchange and the evaluation of monitoring under the frame of joint monitoring were co-ordinated by the Plenipotentiary of the Government of the Slovak Republic for Construction and Operation of Gabčíkovo - Nagymaros Project.

The evaluation of Hungarian side is based on data collected by the North-Transdanubian Inspectorate of Environment and Water (ÉDUKTVF), North-Transdanubian Water Authority (ÉDUVIZIG), Regional Waterworks Companies, Forest Research Institute (ERTI), West Hungarian University, Museum of Natural Sciences, Hungarian Academy of Sciences and Eötvös Lóránd Science University. The data exchange and the evaluation of monitoring were co-ordinated by the State secretary for the Environment and Water at the Ministry of Rural Development of Hungary.

Goals of Joint Monitoring 

The main goal of Joint Slovak-Hungarian Monitoring in accordance to the intergovernmental Agreement is to observe, record and jointly evaluate quantitative and qualitative changes of surface and groundwater bodies and water dependent natural environment in connection to the realised measures and water supply. The water supply into the river branches on Hungarian side is assured by the submerged weir, which is increasing the water level in the Danube upstream of weir.

The evaluation includes changes in hydrologic regimes of surface and ground water, changes in surface and ground water quality, changes in soil moisture and changes in forest stands and biota.

The goal of mutual data exchange is to provide information on monitoring results, on progress of parameters included in the data exchange, and on environmental changes in the influenced area of respective Parties. The basic condition of data exchange is usage of equal or similar methods of measurements and analysis and application of agreed interpretation methods.

The final goal of Joint Annual Report is to submit joint evaluation of monitoring results and joint recommendations for monitoring improvement and environment protection activities to the respective governments.

Joint monitoring activities in the year 2011 

Monitoring activities in the year 2011 on both sides mostly continued in accordance with the intergovernmental Agreement and the Statute modified on April 25, 2007. Contrary to the planned joint aerial survey of the health state of forest, which takes place every three years, aerial photography and assessment of the health state of forest in 2011 were carried out only on the Slovak side. Monitoring in 2011 consisted of surface and ground water regime observations, surface- and ground- water quality monitoring, and measurements of soil moisture content, forest monitoring, fauna and flora observations.

On March 17, 2011 approval and signing of the Joint Annual Report on environment monitoring in 2009 took place in Bratislava. In accordance with the Statute on monitoring the Slovak Party handed over the complete set of monitoring data for the year 2010 on March 31, 2011. in Győr. The Hungarian Party handed over the monitoring data for the year 2010 on May 27, 2011 in Bratislava. The mutual exchange of National Annual Reports on environmental monitoring in 2010 was realized on June 30, 2011 in Budapest. The approval and signing of the Joint Annual Report on environment monitoring in 2010 was done on December 16, 2011 in Budapest. Concerning the elaboration of the actual Joint Annual Report the Slovak Party handed the monitoring data for the year 2011 on April 2, 2012 in Győr. The Hungarian Party handed over the data for the year 2011 on July 16, 2012 in Bratislava. The Slovak National Annual Reports on environmental monitoring in 2011 was handed over to the Hungarian Party on May 3, 2012 in Budapest; the Hungarian National Annual Report on environmental monitoring in 2011 was handed over to the Slovak Party on July 19, 2012 in Budapest.

Fulfilment of recommendations in Joint Annual Report 2010 

1. Hungarian experts suggest discussing a slight change of the method for average annual flow rate calculation, which would consider the circumstances that occurred in the hydrologic year 2010.

Slovak and Hungarian experts agreed on a slight modification of the method for average annual flow rate calculation in relation with the higher water amount discharged into the Danube old riverbed in case of maintenance works carried out on the power plant. In this case similar principle will be applied as during flood waves. Higher discharges released through the Čunovo weir during maintenance works will be reduced to amounts corresponding to discharges defined in operation rule in the Appendix 2 of the intergovernmental Agreement. As a basis the average daily flow rates at Bratislava - Devín gauging station will be used and the higher discharges in the Danube old riverbed will be replaced with the lower limit of the appropriate discharge interval.

2. Considering the differences in the evaluation of surface water quality according to national methodologies, experts of the Slovak Party propose to discuss and reconsider the evaluation method of surface water quality, which was agreed by both Parties on the meeting of Monitoring Agents on April 25, 2007.

Discussions still going-on and will also continue in the first half of the year 2013.