River Moyola

Moyola River
Castledawson Bridge over the Moyola
Country	Northern Ireland
Basin features
Main source	Sperrin Mountains
River mouth	Lough Neagh
Physical characteristics
Length	27 mi (43 km)

Coordinates: 54°48′00″N 7°04′59″W / 54.800°N 7.083°W / 54.800; -7.083

The River Moyola or Moyola River stretches for approximately 27 miles from the Sperrin Mountains to Lough Neagh. The Moyola starts a small river (3-5m) for the first few miles of its length and proceeds to expand to a medium sized river (5-20m) and then to a large river (20m+) for its last couple of miles before Lough Neagh. In ancient times, the River Moyola was known as the 'Bior', and served as the border between the Airgiallan kingdoms of Fir Li and Ui Tuirtri.

According to Deirdre and Laurence Flanagan in their book, Irish Place Names, the River Moyola dervies its name from Magh nÉola, meaning Éolas Plain.

The flow or discharge of the river is measured near to its mouth in Lough Neagh. The catchment area to the gauging station is 304 square kilometres (117 sq mi), which yields an average flow of 8.4 cubic metres per second (300 cu ft/s). The maximum recorded flow between 1971 and 2012 was 156 cubic metres per second (5,500 cu ft/s) on 19 January 1988.

The catchment has a varied geology including limestone, schist, shale and basalt with outcrops of chalk. Overlying this solid geology are superficial deposits of glacial till, plus sand and aggregates. Land use is primarily grassland, with areas of bog and heathland, but includes the towns of Magherafelt and Maghera. The average annual rainfall in the catchment is 1,224 millimetres (48.2 in), which is somewhat higher than the average for United Kingdom at 1,101 millimetres (43.3 in).