Runcorn Gap

River Mersey
River
The River Mersey at Liverpool, looking towards the Royal Liver Building
Country	England
Counties	Greater Manchester, Cheshire, Merseyside
City	Liverpool
Primary source	(source of the River Tame)
- location	west of Buckstones Moss, West Yorkshire
- elevation	473 m (1,552 ft)
- coordinates	53°37′07″N 2°00′13″W / 53.6187°N 2.0035°W / 53.6187; -2.0035
Secondary source	(confluence of Tame and Goyt)
- location	, Greater Manchester
- elevation	40 m (131 ft)
- coordinates	53°24′51″N 2°09′23″W / 53.4143°N 2.1565°W / 53.4143; -2.1565
Mouth
- location	Liverpool Bay
Length	112 km (70 mi)
Basin	4,680 km2 (1,807 sq mi)
Designation
Ramsar Wetland
Official name	Mersey Estuary
Designated	20 December 1995
The River Mersey is highlighted in red Click to enlarge map Coordinates: 53°27′00″N 3°01′59″W / 53.45°N 3.033°W / 53.45; -3.033

The River Mersey /ˈmɜːrzi/ is a river in the north west of England. Its name is derived from the Anglo-Saxon language and translates as "boundary river". The river may have been the border between the ancient kingdoms of Mercia and Northumbria and for centuries it formed part of the boundary between the historic counties of Lancashire and Cheshire.

The start of the Mersey is at the confluence of the River Tame and River Goyt in . It flows westwards through the suburban areas of south Manchester, then into the Manchester Ship Canal at Irlam, becoming a part of the canal and maintaining the canal's water levels. After 4 miles (6.4 km) the river exits the canal flowing towards Warrington where the river widens before it then narrows as it passes between the towns of Runcorn and Widnes. From Runcorn the river widens into a large estuary, which is 3 miles (4.8 km) wide at its widest point near Ellesmere Port. The course of the river then heads north as the estuary narrows between Liverpool and Birkenhead on the Wirral Peninsula to the west and empties into Liverpool Bay. In total the river flows 70.33 miles (113 km).