We tried to find the source according to the description above, but it's not correct. When you take the path downhill in south-west direction, you arrive at a bigger road, where there's a sign 'source' pointing in a rather unclear direction. When you follow the road to the left (not to the right), you'll find a source. When we were there (beginning of september 2021), it was only giving 3 drops per minute. With some effort and a water filter, we prepared some drinking water from what was in the container below the source.
Retour sur la fiche de refuge du Brézouard sans action.