Pantà de Vallfornès, Reservoir in Cànoves i Samalús, Spain

Pantà de Vallfornès is a reservoir on the Vallfornès stream in Cànoves i Samalús, Vallès Oriental. Its 160-metre-long dam, 61.5 metres high with a 10-metre crest, has an impermeable clay core and is covered by an artificial hill planted with trees and shrubs. The reservoir holds 2,156,600 cubic metres and stretches 1,100 metres upstream.

Construction of the dam began in March 1985 and finished in 1989, making it the first dam in Catalonia built primarily from compacted earth and stone. It was designed to regulate water flow from the Vallfornès stream and provide water supply to nearby towns and farms in the Besòs basin.

The masia of Vallfornès, halfway between fortress and forest house, stands on the path to Pla de la Calma; it was built by the lord of Tagamanent and restored in 1610 by his son Dalmau de Rocabertí, of the counts of Peralada family. The municipalities of Cànoves i Samalús and Cardedeu are members of the irrigation community that shares the reservoir's water. Near the water stands the Can Cuc chestnut, a monumental tree 14 m in diameter and 15 m tall, said to have sheltered a charcoal burner inside its trunk.

Access is via a new 1,670 m long, 5 m wide track built during the works, since the old path is now flooded; a second 160 m long, 10 m wide track leads up to the crest of the dam. The dam crest is 10 m wide and walkable, with the reservoir stretching 1,100 m upstream to its tail. The wettest months are September and October, with about 109 and 112 l/m², while July receives only around 43 l/m².

The dam is a laghetto collinare, an Italian-inspired design: a compacted earth-and-stone core was covered to form an artificial hill planted with trees and shrubs so the barrier reads as part of the slope. It was the first reservoir of this type built in Catalonia, and the model later spread to other dams.