Mersey

The River Mersey () is a major river in North West England. Its name derives from Old English and means "boundary river", possibly referring to its having been a border between the ancient kingdoms of Mercia and Northumbria. For centuries it has formed part of the boundary between the historic counties of Lancashire and Cheshire.

The Mersey starts at the confluence of the River Tame and River Goyt in Stockport. It flows westwards through south Manchester, then into the Manchester Ship Canal near Irlam Locks, becoming a part of the canal and maintaining its water levels. After it exits the canal, flowing towards Warrington where it widens. It then narrows as it passes between Runcorn and Widnes. The river widens into a large estuary, which is across at its widest point near Ellesmere Port. The course of the river then turns northwards 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 .

Part of the Mersey Railway, a rail tunnel between Birkenhead and Liverpool opened in 1886. Two road tunnels pass under the estuary from Liverpool: the Queensway Tunnel opened in 1934 connecting the city to Birkenhead, and the Kingsway Tunnel, opened in 1971, to Wallasey. A road bridge, completed in 1961 and later named the Silver Jubilee Bridge, crosses between Runcorn and Widnes, adjacent to the Runcorn Railway Bridge which opened in 1868. A second road bridge, the Mersey Gateway, opened in October 2017, carrying a six-lane road connecting Runcorn's Central Expressway with Speke Road and Queensway in Widnes. The Mersey Ferry operates between the Pier Head in Liverpool and Woodside in Birkenhead and Seacombe, and has become a tourist attraction offering cruises that provide an overview of the river and surrounding areas.

Water quality in the Mersey was severely affected by industrialisation, and in 1985, the Mersey Basin Campaign was established to improve water quality and encourage waterside regeneration. In 2009 it was announced that the river is "cleaner than at any time since the industrial revolution" and is "now considered one of the cleanest in the UK". The Mersey Valley Countryside Warden Service manages local nature reserves such as Chorlton Ees and Sale Water Park.

The river gave its name to Merseybeat, developed by bands from Liverpool, notably the Beatles. In 1965 it was the subject of the top-ten hit single "Ferry Cross the Mersey" by Gerry and the Pacemakers.

Etymology

The name "Mersey" is derived from the Anglo-Saxon , 'of a boundary' and , 'a river'. The Mersey was possibly the 'border river' between Mercia and Northumbria. Its Welsh name is . Prior to Anglo-Saxon conquest of the region, the river was almost certainly known by a Celtic name - recorded by Ptolemy as "Seteia" (as the Southern border of the Brittonic "Setantii" tribe). "Seteia" and "Setantii" both lack clear Celtic roots, leading some to suggest that this was likely a corruption of the actual name. Some, including David Parsons, have suggested the original forms "Segeia" and "Segantii" - based on the root "sego" meaning "strong". Andrew Breeze instead suggests the original forms "Meteia" and "Metantii" - from "met" meaning "cut" or "harvest" - with the likely meaning being that the Metantii were "reapers (of men), cutters-down (of enemies)", with the river Meteia meaning "reaping one" or "she that cuts down" (Breeze notes the possibility of a local deity associated with the river, but highlights that this is only a supposition based on known deities like Sulis and Aerfen).

Course

The Mersey is formed from three tributaries: the River Etherow, the River Goyt and the River Tame. The modern accepted start of the Mersey is at the confluence of the Tame and Goyt, in central Stockport, Greater Manchester. However, older definitions, and many older maps, place its start a few miles up the Goyt at Compstall; for example the 1911 Encyclopædia Britannica states "It is formed by the junction of the Goyt and the Etherow a short distance below Marple in Cheshire on the first-named stream." The 1784 John Stockdale map shows the River Mersey extending to Mottram, and forming the boundary between Cheshire and Derbyshire. In the west of Stockport it flows at the base of a cliff below the road called Brinksway before reaching flat country. An early Ordnance Survey map indicates the spring at Red Hole on the border of Cheshire and Yorkshire at the head of one of the Etherow's longest headwaters, as being the ''Source of the River Mersey''.

Stockport to Warrington

From Central Stockport the river flows through or past Heaton Mersey, Didsbury, Northenden, Chorlton-cum-Hardy, Stretford, Sale, Ashton on Mersey, Urmston and Flixton, where it flows into the Manchester Ship Canal just south of Irlam Locks. At this point the Ship Canal is the canalised section of the River Irwell. The old course of the Mersey has been obliterated by the canal past Hollins Green to Rixton although the old river bed can be seen outside Irlam and at Warburton. At Rixton the River Bollin enters the canal from the south and the Mersey leaves the canal to the north, meandering through Woolston, where the ship canal company's dredgings have formed the Woolston Eyes nature reserve, and on to Warrington.

During the construction of the Manchester Ship Canal, the original course of the river through Wilderspool (which is north of Stockton Heath and Lower Walton) was diverted westward into a canalised section. Wilderspool Causeway remains the only remnant of the original eastern bank of the Mersey at this point in Warrington. Part of the original river channel became Warrington Dock (Walton Lock) in the ship canal.
In the 1960s, the former river channel was filled. The area is now Wilderspool Causeway Park. At the western end of the canalised section in Warrington is the old entrance to the former Runcorn to Latchford Canal. This waterway was abandoned with the construction of the ship canal. It was constructed because the Mersey is tidal from Howley Weir in Warrington. The canal let river traffic reach Warrington during low tides.

During high spring tides, water levels often top the Howley Weir. Before construction of the ship canal, work to improve navigation on the Mersey included Woolston New Cut, bypassing a meander, and Howley Lock for craft to avoid the weir; the new cut and lock are still evident. The island formed between the weir and the lock is known locally as "Monkey Island".

Runcorn Gap

West of Warrington the river widens, and then narrows as it passes through the Runcorn Gap between the towns of Runcorn and Widnes, in Halton. The Manchester Ship Canal passes through the gap to the south of the river. The gap is bridged by the Silver Jubilee Bridge and Runcorn Railway Bridge. Another crossing, the Mersey Gateway road bridge opened in October 2017, and is situated about 1 mile upstream from the Runcorn Gap where the river is considerably wider.

Estuary

From the Runcorn Gap, the river widens into a large estuary, which is wide at its widest point near Ellesmere Port. The course of the river then heads north, with Liverpool to the east and the Wirral Peninsula to the west. The Manchester Ship Canal enters the river at Eastham Locks. The eastern part of the estuary is much affected by silting, and part of it is marked on modern maps as dry land rather than tidal. The wetlands are of importance to wildlife, and are listed as a Ramsar site