Work began in 2002 on a project to dam the river north of its confluence with the Monchique River. The dam was built as to provide public water supplies for the surrounding municipalities. The dam was built in an important area of Algarve ecological and environmental importance and was opposed by the European Economic Community. The overwhelming need for water in the summer by the local population necessitates its construction despite the opposition. As part of agreements to allow construction, Conservation and environmental programmes were implemented to try to lessen the environmental impact of the Dam. The dam was inaugurated and commissioned for service in June 2012. The dam is high and is constructed of earth and forms a lake behind which, when full, is long and at its widest point. The lake holds of water.
Following the loss of habitats and environments following the filling of the dam measures have been taken to compensate for the losses. Restoration has been carried out along a stretch of the left bank of the river with the aim of encouraging the population of the endangered Iberian lynx and the Bonelli's eagle. This work also includes the National Centre for the Captive Breeding of the Iberian lynx.