The Isbert reservoir was designed at the end of the 19th century as a solution to the irrigation needs of the plain of La Rectoria and Dénia, after the raisin crisis caused by the phylloxera period. The plan, which was originally a popular initiative, was well received by private financiers, and the Isbert Reservoir Irrigators Community was established to irrigate 10,000 hectares. This plan, paralysed until 1928, was resumed that same year with the start of the first phase of the works on the reservoir, which in 1931 were concluded with a dam 27 metres high.

After the Spanish Civil War, and thanks to the plan of aid and subsidies, a new project raised the dam, in a second phase, to 60 metres, which allowed the receptacle to deposit 8 hm³ of water. After the project was completed, in 1944, the reservoir was filled up to 27 metres from the pre-existing dam, but twenty days later it was completely emptied, as a result of the leaks in the walls and bed.

Although there were new waterproofing projects, they were never carried out; however, the role played by the dam is not negligible, since the water retention makes it possible to recharge the Migdia aquifer.

When the river flows from the reservoir, it creates a lagoon, El Toll Blau, which holds water all year round and is surrounded by lush vegetation. Later, it enters the plain of Tormos, Orba and La Rectoria, where the bed widens and receives the waters of the ravines of La Bolata and La Cava, which are used for irrigation.