Lessons Learned

Integrated Transboundary River Basin Management of the Sava

Introduction
In December 2002, Slovenia, Croatia, Bosnia and Hercegovina and Serbia and Montenegro signed the Sava Framework Agreement as a first step to achieve Integrated Transboundary Management and Protection of the Sava River. This Framework Agreement is the first international agreement the countries signed after the Federal Republic of Yugoslavia fell apart and a war broke out. The agreement is an important tool for achieving trust and understanding between the four countries that were once part of Yugoslavia.

The Sava
The Sava is the largest tributary of the Danube and is of significance because of its outstanding biological and landscape diversity. It hosts the largest complex of alluvial wetlands in the Danube basin (Sredni Posavina - Central Sava Basin) and large lowland forests complexes. The Sava River is a unique example of a river where the floodplains are still intact, supporting both flood alleviation and biodiversity. The most important landscape characteristics are to be found in the Central Sava Basin in Croatia. Here, a mosaic of typical floodplain-type natural and cultural landscapes is a reminder of what ever occurred along all major Central European rivers.
The lack of co-ordinated management poses a threat to the biological and landscape diversity of the river and the safety of people living along the river. The protection of these valuable ecosystems while at the meantime supporting economic development in the region require coordinated integrated management of the basin resources across country borders and national interests.

Sava Basin Framework Agreement
Based on the Sava Framework Agreement the Sava countries will establish a Sava Basin Commission of which the main tasks will be to restore the navigation and to secure sustainable water management through the elaboration of an Integrated River Basin Management Plan.
The main objectives of the Framework Agreement are:

resuming navigation of Sava and tributaries;

promoting integrated water quality management and preservation of ecosystems;

coordinating protection against hazards (flooding, drought, pollution); and supporting sustainable, environmentally and socially responsible economic development.

Dutch support
Through the Water and Ecosystems Programme, the Dutch government supports the implementation of the Framework Agreement by providing technical assistance to the establishment of a Sava Basin Commission and by supporting the elaboration of an Integrated River Basin Management Plan.
Because of the significance of the Sava Basin for biodiversity, the Dutch support will help the countries to get a clear and accurate overview of the ecological values of the Sava and its floodplains. Data stored at various institutes and organizations will be collected and analyzed and national data bases will be created to store the information and make it accessible for the management of the river and its floodplains.

The database will be linked to a Geographical Information System holding relevant geographical information like land use, protected areas and flood prone areas along the Sava River. An overview of floodplain areas important for the storage of peak discharges of the Sava will be made to support the elaboration of recommendations for harmonizing flood retention and biodiversity protection of the floodplains.

Evaluation of Lonjsko Polje
The Lonsjko Polje Nature Park is one of the most important floodplains areas along the Sava because of its outstanding landscape and biodiversity and because of its capacity to retain floods during peak discharges of the Sava River. The storage capacity of Lonjsko Polje has been increased in the frame of the implementation of a Sava Flood Defense Plan adopted in 1972.
In the frame of the Sava Project the impact of the retention of floods on the vegetation has been assessed. The main objective of the evaluation of the retention capacities of the Lonsko Polje floodplains is to elaborate recommendations for flood management of the area that combine flood protection, ecosystem management and nutrient trapping. The evaluation has been carried out by comparing different flooding scenarios. To work effectively the retention areas need to be able to store significant amounts of water during a longer time; this requires the possibility of managing the flood duration and the flood depth through inlet and outlet structures like sluices.

The evaluation produced :

Maps of flood inundation depths, flood duration and available time for life-stock evacuation for different flood events.

Assessment of the vegetation growth and succession for different flooding scenarios.

Assessment of the nutrient trapping efficiency of Lonjsko Polje, important for assessing the Sava nutrient load and subsequently the Danube load

In case the 1972 plan to improve the flood safety along the Sava would have been executed completely, the duration of the inundations of Lonsjko Polje would have been shorter than in the current situation. Contrary to the assumptions on which the 1972 plan is designed, the evaluation revealed that the shorter the flood duration the less the impact on the vegetation will be. The evaluation of the current situation also revealed that the duration of the inundation of Lonsjko Polje is not depending on the inlet of water but on the limited capacities of the outlet facilities. It is therefore recommended to consider an in- and outlet structure that can take in water during dry summer periods and can discharge water to drain the filled detention area faster.

The evaluation brought also to the light that the storage capacity is 613·106 m3 instead of the calculated storage capacity of 845·106 m3 according to the 1972 plan.

Although the effects of a large flood event on the vegetation are considerable the evaluation shows that the full execution of the 1972 plan for Lonjsko Polje would have been less detrimental than the current situation. However, results show also that nature management has a bigger impact on the succession of the vegetation than flood duration.

For more information: Flood detention, nature development and water quality and Maps of the lowland river Sava

Movie of the flood pulse in Lonjsko Polje

Lessons learned
The two main lessons that can be drawn from the implementation Sava project so far (December 2004) are:

Setting up the organisational structure to implement the Sava Framework Agreement (in which the Sava Basin countries agreed to cooperate on management of the Sava) and which should allow for smooth communication and coordination between the respective countries is a time consuming and complex process because of its legal and financial implications. These implications were not sufficiently tackled during the negotiation process that led to the signing of the Framework Agreement and it takes more time than anticipated to solve these issues now the agreement has been signed.

Communication between the water sector on the one hand and the nature protection and environmental sector on the other hand in each of the countries is not common practice. With an exception for Croatia, where the water sector and the nature protection sector co-operated in the evaluation of Lonsjko Polje, the nature protection sector appeared not to be aware of the activities and objectives of the (Interim) Sava Basin Commission and of the Dutch project focusing on integrating the protection and management of ecosystems into River Basin Management Ongoing efforts in terms of training and institutional strengthening is required to achieve Integrated River Basin Management.

Partners Slovenia, Croatia, Bosnia and Hercegovina, Serbia and Montenegro Center for Ecology and Natural Resources, Bosnia and Hercegovina Institute of Nature Conservation, Croatia Institute of Nature Conservation, Serbia and Montenegro Institute of Nature Conservation, Slovenia The Netherlands International Agricultural Centre (IAC), Wageningen-UR (lead) Alterra, Wageningen-UR Delft University of Technology - RBA Ecorys Nedeco RIZA WL | Delft Hydraulics

For further information, please, contact:
Mr. Henk Zingstra
International Agricultural Centre (IAC)
PO Box 88, 6700 AB Wageningen,
The Netherlands
+31 (0) 317 495495
+31 (0) 317 495395
henk.zingstra@wur.nl
www.iac.wageningen-ur.nl