This is the story of Nimrodel, an elven-maid of Lothlórien, and Amroth, the elven-king of Lothlórien.
Long ago, Amroth fell in love with Nimrodel, and she with him. Despite their love Nimrodel refused to accept his hand. Amroth was of the Sindar, and she believed that when the Sindar came to Lórien they had brought destruction and war to Middle-earth. Nimrodel lived in Lórien long before the Sindar came from the West. She considered Amroth's love the only thing left for her in Lórien. When Orcs attacked Moria, she became frightened of the danger and fled Lórien. Upon learning of her disappearance, Amroth set out to search for her. He found her at the eaves of Fangorn Forest, and after much discussion Nimrodel agreed to marry him on one condition: that he would bring her to a land where their love would grow unhindered, and where they could love each other without ever having to be fearful of death.
They decided to flee together to the Undying Land of Valinor, but after setting out they were separated in the White Mountains. Not knowing where Nimrodel was, Amroth continued on alone. He hoped to find her waiting for him in Edhellond, the ancient port city and sea harbor. But when he arrived, she was not there. In Edhellond, Amroth boarded the last ship to sail to the Undying Lands, but refused to set sail without Nimrodel. It was there that he waited for her; passed the summer months and first of fall.
At autumn's end a great storm blew in from the Northern Wastes, and a mighty wind tore the light elven ship from its moorings. When dawn came, the storm had passed and Amroth awoke to find that the ship had been swept out to sea with no chance of returning to Middle-earth. Amroth screamed Nimrodel's name in a cry of desperation and grief, leapt into the sea, and drowned as the greedy current pulled him under.
Neither Elves nor Men ever saw the two lovers again, but there are many legends concerning the elf-maiden's fate. There is a river that was named after Nimrodel, who once dwelt beside it. Nimrodel's river indirectly flows into the Bay where Amroth was lost at sea. According to Elven legend, Amroth's voice is sometimes heard among the foaming waves of the sea, and some claim they can still hear Nimrodel's voice singing in the falls of her river. I believe that they are using the water to speak to each other. Their love will eternally flow by the same water which drowned it.