The key goal of preparing the study documentation was the completion and adaptation of the existing flood control system with the actual hydrological inputs and design standards. Drafting the study documentation took two years. The multi-disciplinary approach was very important for the successful completion of this contract.
This project for the respective field enabled systemizing the collection of survey maps (topographical, geomechanical and project documentation). Based on more precise topographical survey maps created using LIDAR technology (the LIDAR Sava Project) and actualized hydrological-hydraulic inputs, mathematical formulas were prepared for the purpose of analysing the existing state and conceptual variant solutions. A preliminary categorisation of the embankments was performed which serves as the basis for a probabilistic approach to estimating flood risks for the complex flood protection system, and which consists of 1,705 hm3 of retention areas, 760 km of the embankment, and regulation structures (spillway and barrages) as well as channels.
This project enables us to resolve the prioritised flood risks through measures of natural retention of water and measures for preventive flood risk management (infrastructural measures). The selected optimal conceptual design required drafting the preliminary design, environmental protection report and feasibility study for gaining co-financing from EU funds. The total investment costs of the project are estimated at HRK 6.2 billion (incl. VAT). The benefit of this project is that it is for 836,000 inhabitants who live in potential flood areas covering an area of approx. 800 square kilometres. What is special about this project is the positive environmental impact on biodiversity, through measures for natural retention of water, which increases the utilization of the retention areas. Furthermore, a uniform level of security will be achieved for the entire floodplain and more effective implementation of flood protection measures as well as maintenance of system facilities. This improved system is adequately secure even for larger flows which can be expected because of climate change.