the lake is fed by numerous small mountain streams in summer, but only one stream flows out of it into the salzach. in winter the lake completely freezes and is used for winter sports. in summer the lake is used for pleasure boating (boats powered by combustion engines are not allowed except for the ferries that cross the width of the lake from zell to thumersbach, so electrically powered boats can be rented instead). the water is very clear and suitable for swimming or diving, but can be chilly.