The orography and pluviosity of Gardunha promote the development of the presence of a vast hydrographic network, integrated into the hydrographic basin of the Tejo River.

 

Despite the existing network, the water lines are characterized by the non-continuity of the regime, as the majority of them have no volume of flow during the summer months.

 

Due to the reduced permeability of the soils in the muncipality, normally regimes of a torrential nature are generated when the precipitation is abundat and sudden.

 

Given the greater permeabiity of granite, especially when altered, it is submitted that the hydrographic network is more reduced and regular, while in the slate zone, a complex network is formed from the small mountain streams to the principal water ways, being the most sinuous respective precursor. (Ribeiro, 1999). 

 

The main parallel line in the Serra da Gardunha is responsible for the division betwen the hydrographic basins of Zêzere, of the Ocreza Rive and of the affluents of the Ponsul River.

 

The largest part of the Gardunha area drains into the Zêzere River with a hydrographic basin of 4995.7 Km2, through the Alcambar stream (affluent of the Meimoa creek), the Gardunha stream and the Tormentoso stream (affluents of the Ximassas stream).  The meridional slope drains into the Tejooo basin through the Rio Ocreza that has its origin in the Gardunha mountains and through the Alperade stream, affluent of the Ponsul River.