The Loup's flow was observed over a 34-year period between 1980 and 2013 at Villeneuve-Loubet, at its mouth. It exhibits fairly marked seasonal fluctuations with high waters ranging from 5.0 to 8.23 m3/s from autumn to spring. The maxima of November and April correspond to the autumn and spring rains. The flow of the river collapses in June until the low summer waters which reach 0.585m3/s in August.