LITANI RIVER FLOOD MANAGEMENT REPORT (EXTRACT)

The Litani River Basin drains the Central and South Bekaa Valley, which is sandwiched between Mount Lebanon to the west and the Anti-Lebanon mountain range to the east. Winter precipitations fall heavily on both ranges, engendering heavy flows that spread across the valley, resulting in common occurrences of floods. Floods have both positive and negative effects on human well-being. High flows and flood waters are needed to cleanse channels of accumulated debris, build stream banks, deposit nutrients in the floodplains, recharge aquifers, and sustain riparian habitat. However, storms and floods also cause direct and indirect damages, including disruption of human and economic activities. With population growth and economic development, more and more infrastructures and human activities settle or take place in floodplains, increasing the impacts of floods. The Litani River Basin suffers from three types of flooding: flooding from the Litani River and major tributaries, seasonal flooding from minor channels, and local flooding in urban areas. The flood of February 2003 was found to be historically significant due to its large scale, significant damages, and availability of discharge and level data. This flood was used as a design flood to calibrate the flood model, assess floodable areas, recommend flood mitigation measures, and design flood protection works. The main findings of the field survey indicate that the Litani River Basin suffers from a lack of riverbed maintenance, existence of obstructions in the riverbed, dumping of solid and hazardous waste, and poor maintenance of agricultural drainage. These factors contribute to the three types of flooding experienced in the region. The report emphasizes the need for more emphasis on natural solutions and nonstructural approaches, such as flood expansion areas and smart urban planning, rather than relying solely on structural solutions like embankments and dams. The report highlights the importance of flood prevention and mitigation measures, including the need for everyone to take precautions and adapt human uses of floodplains to existing hazards. The seven basic principles and approaches for sustainable flood prevention guidelines include recognizing that flood events are a part of nature, human interference has increased the threat of flooding, and flood prevention should cover the entire catchment area. These principles aim to reduce the possible adverse effects on aquatic and terrestrial ecosystems in flood-prone areas.