In April, the whole of the Régua quay and neighbouring buildings were flooded. One day before new management was due to start operation one of the affected premises it proved necessary once more on Tuesday to remove equipment from the bar.

A local civil defence official, Manuel Saraiva, told Lusa that the river water lapped onto the quay on Tuesday night, but did not reach the buildings. Overnight the situation stabilisation and the river waters fell away.

“But we continue in a very unstable situation," he said. "We're paying attention to the discharges by Spanish dams and to the flows from the tributaries of the River Douro, because of the rain that has fallen in the region."

Saraiva said the situation was “completely atypical” for May and that, since he became head of civil defence for Régua 11 years ago “there has never been a situation such as this at this time of year."

It was necessary to clear "at least six times" the riverside area of Régua, including the quay, cycle path and children's playground and public toilets - a situation that is causing great inconvenience.

Tourist traffic is also being affected. During April's flooding, navigation was suspended and only opened gradually as the entity that runs the ports of Douro, Leixões and Viana do Castelo (APDL) monitored the river's water levels and cleared it of floating rubbish.

Now navigation has once more been suspended, with boats unable to move through the river's locks and being limited to sailing on the stretches in between them.

The APDL has warned of “the extreme necessity of care in practising navigation on the open stretches, given the existence of floating objects in suspension and their lesser visibility, as well as the variable flows."

António Pinto, of the tourist company Douro à Vela, told Lusa of “a very atypical month and a half” and said that the river contained “lots of water and has many currents”. While May is usually very good for business this year's has brought "big losses," he said.

Pinto said he hoped that from Thursday onwards the situation in the Douro region improved.