It protects an area of caatinga vegetation adapted to arid conditions to the south of the Castanhão Dam.

The Castanhão Ecological Station is divided between the municipalities of Alto Santo (0.75%), Iracema (15.2%) and Jaguaribara (84.04%) in the state of Ceará.

Objectives are to protect and preserve samples of the caatinga ecosystem, and to enable development of scientific research and environmental education programs.

IBAMA would install an office in Nova Jaguaribara for research into the caatinga, and the flora and fauna of the area.

[7] Native vegetation is mostly woody, grassy savanna in the caatinga biome, with scattered shrub sized hyperxerophilic plants.