The Trapan dam lake is fed by the Pellegrin, a small coastal river on the course of which it was built in 1969, and its watershed. It has also received a water supply from the Verdon thanks to the Canal de Provence since 1979. The Trapan thus constitutes a drinking water reserve with a nominal volume of 2.1 million cubic meters, intended to supply the towns of the Var coast located east of Toulon.