The San Fernando River originates at the Pampanga River, passes through Mexico where it is called Sapa Matulid ("straight stream") before proceeding to San Fernando then Bacolor then Betis and finally Guagua where it joins the Pasak-Guagua River flowing through Sasmuan before emptying into Manila Bay. The river once teemed with fish and was beautiful enough to inspire two local legends that anthropologist H. Otley Beyer collected from his Kapampangan students at UP in 1917.

The first legend told of a river goddess and a river demon living in harmony in a tiny creek. Their relationship turned sour when the demon started courting the goddess' young daughter. The goddess thumbed down the courtship and in retaliation, the demon whipped up a storm that created turbulence in the creek, causing it to widen into the river that it is today. The local folk believe that the enmity between the goddess and the demon continues to manifest itself today every time the river overflows its banks.

The second legend told of the mountain god Suku (Sinukuan) ordering his slaves to search the land far and wide for a girl pretty enough to be his wife. When the slaves returned empty-handed, Suku ordered a second search, until one slave reported he had found the fairest of them all--the queen of the swamps no less, in a town called Sasmuan. So Suku mounted his golden chariot laden with gifts and rode all the way to Sesmuan, to meet the girl. She, however, played hard-to-get, so Suku had to extend the courtship period, and his constant traveling created a dusty path which annoyed him and the local folk living along the way. Suku ordered his slaves to turn the road into a canal where Suku could take a boat instead. So the slaves dug a straight canal from Suku's abode in Arayat all the way to the swamps of Sasmuan. They connected it to Pampanga River so that it never ran dry. As a result, Suku had a faster and dust-free transport system and even got the queen of the swamps to agree to marry him. The couple took a boat ride through the San Fernando River, where revelers accompanied them all the way to Mount Arayat.

Happy fiesta to all Fernandinos!