The Mondego (Rio Mondego) is the longest river flowing entirely within Portugal, stretching approximately 258 km from the Serra da Estrela mountains to its mouth at Figueira da Foz on the Atlantic coast. It passes through Coimbra, one of Portugal's most important historical cities.

The Mondego basin is significant for agriculture, hydroelectric power, and water supply. However, the lower Mondego floodplain is highly vulnerable to flooding, and major flood events have caused extensive damage to Coimbra and surrounding communities. Flood management along the Mondego — including dam operations, levee maintenance, and urban planning — is a recurring policy issue.

The river's management involves coordination between APA (the Portuguese Environment Agency), local municipalities, and the national government, particularly during heavy rainfall events when dam discharge decisions become critical.