The Zala River is the largest source of water supply to Lake Balaton. The river is the eponym of Zala County and many settlements. The cleansing of the water of the 126 km long river is supported by the Kis-Balaton water preservation system. It joins the Kis-Balaton at the Zalavári water body and flows through the extensive wetland until it reaches the Balaton in the Keszthelyi Bay. The 10 km long dam that accompanies the river between Szentgyörgyvár and Zalavár is part of the blue B cycling route.