The waters of the river Agly were higher than during the historic flooding of 1999, officials announced this week.
Batho on Thursday afternoon visited a factory whose offices and workshops had been under 60cm of water and promised to start the procedure for the declaration of a state of natural catastrophe, which would entitle flood victims to claim compensation for damage suffered.
A woman motorist was found dead in her car on Wednesday morning after she ignored warnings not to try and cross a ford on a small river near Perpignan.
Her car was swept away by the waters and was found half-submerged some distance away.
About 750 residents were moved out of their homes near the town of Rivesaltes in a valley below the Pyrénées mountains, an African wildlife park near Perpignan was flooded and a 15-kilometre dyke was breached in several places.
Weather forecasters lifted a red alert on Thursday morning after the rains subsided.
There was also flooding in the Rhone Valley in the south-east.
Six people died in two avalanches and two died when a private airplane crashed in the Alps this week.
While the rain has eased off in the south, more showers and even light snow are forecast for the Paris region next week.