Extreme hydrological events such as floods have been and still are one of the most important natural hazards causing loss of human life and economic losses. Flooding is a phenomenon that has had a strong impact over the centuries around the world. Society is more and more vulnerable to extreme events like floods and droughts due to climate change. Detailed research in recent years show variation in flood frequency and types in Bulgaria. The reasons are based on long term climate change effects along with short term weather shifts. According to scientific investigations of many institutions and universities (NOAA, NCAR) as well as reports and resolutions of international organizations (IPCC, WMO, FAO, ЕЕА) it is clearly stated that flood risk will probably increase in the future also as a result of socio-economic changes as are population growth, landuse and landcover changes and deforestation. Floods are an integral part of the hydrological regime of river basins. In this paper the typical flood types in Bulgaria are presented. Important floods from both the recent and distant past are shown. A historical flood was compared with the simulated one with the same probability. For mitigating flood risk it is essential to have suitable water resource management measures outlined including registered extreme events (flooding) archive. Studying past floods is useful for understanding the factors that trigger or enhance these events. It is also helpful for effective water resource management, flood risk mitigation and climate change adaptation.