Maximum discharge along the river is currently at the reporting a streamflow rate of cfs. This is also the highest stage along the South Mayo River, with a gauge stage of ft at this location. This river is monitored from 1 different streamgauging stations along the South Mayo River, the highest being situated at an altitude of ft, the .

The South Mayo River is located in County Mayo, Ireland, and is approximately 38 kilometers long. The river flows into Lough Mask and is an important source of water for many communities in the area. The hydrology of the river is influenced by a number of factors, including rainfall, snowmelt, and the presence of several reservoirs and dams. One of the most significant of these is the Cong Dam, which was built in the early 20th century and provides hydroelectric power to the region. The river has also been used for recreational purposes, including fishing and kayaking, and is an important source of water for farmers in the area. Despite its importance, the South Mayo River has faced challenges in recent years, including pollution and habitat loss.