Reconstruction and Improvement of Surface Drainage Systems as a Preventive Flood Protection Measure

In recent years, rising water levels, floods, and landslides following heavy precipitation have occurred with increasing frequency in many European countries. During the last decade, climate changes have led to an increase in average annual temperatures and significant changes in the distribution of precipitation in Bosnia and Herzegovina. Devastating floods have become more frequent, causing damage to people, property, and infrastructure, especially in sectors such as agriculture and water management. Flood protection in Bosnia and Herzegovina was mainly carried out by passive measures and drainage systems are unevenly built - somewhere the basic drainage is completely completed, somewhere only partially, and in some places, the work has not even started. Most of these systems were not effective, either because of insufficient maintenance or because of inadequate design criteria. The pumping stations and other accompanying structures of the drainage system were of insufficient capacity, which, along with an insufficiently dense network of drainage channels, reduced the efficiency of the evacuation of excess water and prolonged the period of flooding and retention of excess water in the system. The increased risk of flooding due to climate change on the one hand and outdated drainage systems on the other hand indicate the need for reconstruction of drainage systems by checking and revising design criteria. The paper presents a theoretical overview and practical example of the reconstruction of the surface drainage system in Lijevče polje, as one of the largest melioration systems in Bosnia and Herzegovina.