Suijin.
Suijin is the Shinto god of water in Japanese mythology. The Water Kami is the guardian of the fishing folk, and a patron saint of fertility, motherhood, and easy childbirth.
One reason people worship and praise the Water Kami and give offerings to it is to hope for pure and unpolluted water for human consumption, as well as for other uses like agriculture and sanitation. Other reasons of worship include praying for success in fishing trips, praying for successful and good fertility and motherhood, as well as for easy childbirth.
In Japan, most Suijin are enshrined near rice paddy fields, irrigation canals, mountain streams, rivers, agricultural waterways, household wells, and even inside sewage water and septic tanks. However, the many small shrines and stone markers dedicated to Suijin rarely show the deity anthromorphically.