A large reservoir, the Edersee, on the Eder, the main tributary of the Fulda, is used to allow enough water depth for shipping year-round. The dam, built in 1914, was bombed and severely damaged by British aircraft in May 1943, causing great destruction and about 70 deaths downstream. It was rebuilt within four months. The reservoir is a major summer resort area. Turbines driven by its sluices provide electricity.