Once in Moriyama Shi, there was abundant water network originated from clear spring of groundwater from Yasu River and it was beneficial to residents.  Still now, there are many rivers and creeks, and they flow into Akanoi Bay in Lake Biwa through major 8 rivers.

　Since the geographical condition is one of the major cause of eutrophication in Anaknoi Bay where polluted water flows and concentrates into, it is very important to keep clean these rivers and creeks in our town.