Jaguari Reservoir - Cantareira System
                    General data
- Name: Jaguari Reservoir - Cantareira System
 - Water system: Paraiba do Sul River
 - Water type: Artificial lake
 - Progression: Jaguari River (Paraiba do Sul) -> Paraiba do Sul River -> Atlantic Ocean -> Planet Earth
 - Climates: Tropical
 - Continents: South America
 - Countries: Brazil
 
The Jaguari Reservoir is an artificial lake in Brazil's state of São Paulo, a key component of the Cantareira System that provides water to the metropolitan area. Constructed in the 1970s, it faced severe drought and dwindling water levels in the 2010s, highlighting environmental challenges like reduced rainfall, increased demand, deforestation, and water quality issues. The reservoir is also known for the ecological impact of an invasive fish species, the Silver croaker, which has significantly altered the local aquatic ecosystem.