The myth of her transformation begins in Arcadia when she came across a clear stream and began bathing, not knowing it was the river god Alpheus, who flowed down from Arcadia through Elis to the sea. He fell in love during their encounter, but she fled after discovering his presence and intentions, as she wished to remain a chaste attendant of Artemis. After a long chase, she prayed to her goddess to ask for protection. Artemis hid her in a cloud, but Alpheus was persistent. She began to perspire profusely from fear, and soon transformed into a stream. Artemis then broke the ground allowing Arethusa another attempt to flee. Her stream traveled under the sea to the island of Ortygia, but Alpheus flowed through the sea to reach her and mingle with her waters.

A maiden steps into  a stream
And finds it tingle and living
A transformation from which sweet sweat
Slides down from her thighs and her sides as she runs,
Pursued by a river god, giving life,
As she melts into water.