Delta Life 9

26 and manage the fresh water in a way that improves life for humans and animals in the river basin. Four years later, the International Sava River Basin Commission (ISRBC) – the Sava Commission for short – was established to provide monitoring, and to exchange information and high- water forecasts. The tide of enthusiasmwas unstoppable: the initiative generated intense media attention and, two years later, 1 June was proclaimed Sava Day, which the inhabitants of the catchment celebrate with an international bike ride along the banks of the river. Digital differences Even so, it continues to be challenging to shape and streamline data exchanges and decision-making for the Sava. After exceptional rainfall in 2014 and problems with the timing of the opening of the reservoirs, with the largest floods in history as a result, a plan was drawn up for a robust solution: a Flood Early Warning System, largely financed by the World Bank. That system is being developed by Deltares, Royal HaskoningDHV, Eptisa, the Hydro-Engineering Institute Sarajevo and Mihailo Anđelić . As soon as that system is available, the management authorities can use weather forecasts to predict where there will be problems at an early stage. The effects of reservoir management, the opening and closing of dams, are also shown in real time so that different stra- tegies can be compared in good time. Klaas-Jan van Heeringen, a water management specialist with Deltares, is flying back and forth between Zagreb, Ljubljana, Sarajevo, Podgorica and Belgrade to ensure that the automatic warning system works as well as pos­ sible in all countries. The differences between them, he says, now relate more to the digital side than to the actual information. 'Internet speeds in the five countries vary considerably and there are regular malfunctions. The Internet needs to be improved but we also need to think about making alterations to requirements without compromising the robustness of the whole.' Management in own hands A special feature is the organisation underlying the system: however much the countries have been reconciled, they prefer to manage the system for flood risk management themselves. 'Fortunately, that is actually possible nowadays. That's the beauty of the thing,' says Klaas-Jan. The main system is housed in Slovenia, which is well developed technologically, but each country has its own backup system. That allows the countries to share information while retaining ownership. 'Sharing information always makes you stronger. There is only one risk: an increase in your own knowledge level. And who can be against that?' he laughs. A number of technical releases have now been made and the system can be tested for a year to eliminate teething problems. Klaas-Jan notes with satis­ faction: 'The momentum is there now and the foundations are in place.' Recovery All that may apply to the system but a lot of work still needs to be done on the river. Croatia, where the Sava is a lowland river, wants to create more room for the river and allow it to flow outside its banks. Other, more mountainous, regions have to cope with severe floods and they benefit from the improved management of the reservoirs. 'Obviously, these measures generate different expectations and decisions, and they will all have to be built into the system in time,' explains Klaas-Jan. After being involved in the process for half his life, Mihailo Anđelić is very happy that the countries are now working together again thanks to the Sava. 'I have seen many signs of recovery since my return. We are pooling our forces to make this beautiful region flourish again. I hope that our work will push our differences into the background as we work together towards a shared goal: protection from the water.'   More information? klaasjan.vanheeringen@deltares.nl DELTARES, APRIL 2018