APPENDIX D: SCENARIO SUBMITTED BY THE SLOVAK EXPERT

See separate Volume

APPENDIX E: STATEMENT BY ING. I. UHLAR, ING. J. FRANKOVSKY AND ING. J. CABEL: "POSSIBILITY OF EVERYDAY DISCHARGE THROUGH INUNDATION WEIR CUNOVO INTO THE OLD DANUBE"

1. The inundation weir was designed and constructed for temporary use (discharge of floods), until the definitive weir (with the sill in the level of the river-bottom) is constructed in the second phase (by the end of 1996). Under these presumptions, also the fortification of the spillway was designed and partially already realised. It was supposed that after each use (flood) necessary reparation of the fortification wi11 be realised.

2. The first four fields of the weír could be used from May 1994, for everyday discharge at these conditions

	-	the completion by May 1994 of the relevant part of the fortification works (the whole fortification is scheduled to be completed in December 1994);

	-	the discharge of 340 cumecs wil1 not be exceeded (hydraulic stability of the water-jump in the stilling basin is assured only up to this limit);

	-	inspection and reparation of the outlet canal downstream of the spillway and of its fortification must be ensured (there will be damages after certain time of use, presumably each week), even with the discharge mentioned above (the costs of reparation at such periodical use - one week: of use and one week: of reconstruction - are estimated to 3 mi11. Sk/month).

It should be noted, that the everyday use of four fields will complicate the rest of remaining works.

3. For daily use of the weir with higher discharges, an additional heavy fortification of the spillway would be necessary, similarly as downstream of the bypass weir.

The additional costs of such fortification are estimated to 120 mill. Sk. As there is not enough experience with such a construction, the risk of damage remains high. If such a decision is taken by the end of 1993, the fortification for the daily use of the inundation weir could be completed by the end of 1994.

The maximum discharge capacity in this case is 1300 cumecs and a11 openings have to be used, to avoid uneven distribution of flow. The estimated maintenance costs are 15 mi11. Sk/month.

4. A higher water level downstream of the spillway, reduces the risk:. of damages caused by the everyday use of the inundation weir. The relationship between the possible safe discharge and the downstream water level could be established only by means of hydraulic research on a model.

Bratislava, November 30, 1993.
Estimated by Ing. I. Uhlar, Ing. J. Frankovsky, Ing. J. Cabel

 

APPENDIX F: SEPARATE STATEMENT BY THE HUNGARIAN EXPERT

SEPARATE STATEMENT OF HUNGARY

More than a year has been spent with futile negotiations on water distribution due to the unilateral diversion of the Danube at Cunovo. The dispute is rooted in the fact that the water discharge of the frontier river, which formerly was shared egually by the two countries, now exhibit a 80%+1/2*20% = 90% Slovak and 10% Hungarian proportion. Consequently, most of the positive effects are on the Slovak side,-while all the negative ones occur in our country.

During the last 13 months there has been no Slovak indication of willingness to reach a-compromise. Instead, there are some signs which give us reason to deny the credibility of the Slovak or Czechoslovak party (see London Agreed Minutes signed by Czechoslovakia on 28 October, 1992). On the contrary, Hungary was ready to accept the very unfavourable minimum ecological conditions of directing roughly two third of the total discharge into the shared Slovak-Hungarian main riverbed (and the operation of Gabcikovo Hydropower plant) as a temporary water management regime.

Each time in the long series of negotiations Hungary was prepared to accept smaller proportion of discharge, while the Slovak side recommended correspondingly lower and lower values. The last Slovak offer is already a further reduction of the present discharge into the shared main river (cf. Appendix about Slovak Proposal).

During the present Working Group sessions started on 8 September 1993. It has been stated at the onset of our WG that recommendations of Temporary Water regime will be based on the technical realities. One day before the end of the working group meeting new statement was given to us by the Slovak party on the state of the C variant structures. This made almost impossible to formulate realistic recommendation. It was finally declared by the Slovak party that at present they cannot satisfy the request of providing water continuously through the variant C structures more than 600 m³/sec, but they perhaps will be able to give 940 m3/sec (less than 1/2 of the total discharge) after May 1994 under some conditions. The daily operation of the floodweirs which were promised to be finalized by 1 January 1993 (1) (see ref . Working Group Report, November 23, 1992, page 7-8) are now in a distant future. This unexpected announcement upset many time schedules worked out under the scenarios in the present report.

It cannot be excluded therefore, that the signing of another temporary water distribution agreement much worse than before can only be regarded as an accepted humiliation without any improvement of the present environmental situation in Hungary. It has become also clear, that the approach of collecting and evaluating environmental impacts of the unilateral action with the resent method is insufficient. Obviously major negative effects can be differenciated into "insignificant" changes in several single factors, especially considering relatively slow gradual processes. Many such damages are practically very difficult or impossible to measure. It is undisputable from analogous situations, that we cannot avoid the followings (unless rapid return towards the original conditions is provided):

	-	decreasing the biodiversity;
	-	loss of natural habitats and beauty;
	-	loss of the ability of self-maintenance of the flood plain ecosystems;
	-	loss of long-term evolutionary-ecological experience so far stored in genetic informations of the natural communities;
	-	loss of genetic diversity within the diminishing populations.

In addition, the risk of contamination of our unique, large drinking water reservoir cannot be excluded for the following reasons.

After damming the pattern of groundwater recharge (infiltration) and discharge-zones, and this way the total three dimensional flow system has changed basically. Infiltration rate its dynamics and the infiltrated raw water are also different, then they were at pre-dam conditions.

This changed situation is shown in the figure, where the groundwater levels indicate that after the damming, the Danube became a major discharge zone between Rajka and Ásványráró, while Mosoni-Danube and water supply channel on the flood protected area are now major recharge zones. The groundwater movement now directed to the Danube.

This change could have been important inconnection with vulnerability of the drinking water reserve.

The present proposal cannot guarantee even the average 40% discharge into the shared reach of the main Danube. It actually aims to improve variant C structures known to be unacceptable to Hungary.

Bratislava, December 1, 1993
G. Vida