The lyrics were penned by none less than Jean-Pierre Claris de Florian (1755-1794). They open with the very philosophical observation that the joys of love last for only a moment but their sorrows last for a lifetime. The singers loved-one, Silvie swears that she will love him as long as water flows. Water is still flowing but Silvie has changed her mind, found another and left him.
All very poetic indeed and matched with a most beautiful melody. The version that I sing and play can be found in Lieder, Songs und Gospels 3