Its tributaries are Quebrada Limon and Quebrada del Agua brooks and the river runs for 19 kilometers before feeding into Río Matilde at a height of 15 feet in Barrio Canas Urbano.

Río Pastillo[note 1] has its origin in the northern mountains of Ponce's Barrio Marueño,[7] in an area called Yagrumo.

[11] Quebrada del Agua was diverted via canalization to drain directly to the Caribbean Sea.

[12] In times of heavy rainfall, Quebrada del Agua was prone to overflow, as it happened on 7 October 1985, when 16 people died due to its flooding.

Roads are listed as the river flows from its origin in the mountains of Quebrada Limon, east of the city of Ponce, to its merging with Rio Canas to form Rio Matilde in Barrio Canas (N/A = Data not available):