The River Alt rises at Hag Plantation in Huyton, at 125 feet above sea level, and travels roughly 17 miles in a northwesterly direction before emptying into the River Mersey estuary at Hightown, between Crosby and Formby. From there, the waters reach the Irish Sea at the edge of the Mersey’s own outflow. The river drains a catchment area of 40 square miles, with its boundary stretching as far north as Banks and Crossens and as far east as Burscough and Kirkby.
Route and Geology
From its source, the Alt passes through Croxteth Park, runs roughly parallel to the M57 motorway south of Kirkby, then flows north of Aintree and south of Maghull before continuing south of Formby toward the estuary. The geology beneath the river changes considerably along its length – Sherwood Sandstone underlies the Huyton area, Coal Measures run through the West Derby area, and Mercia Mudstone lies beneath the Maghull and North Sefton reaches. The source at Hag Plantation is also designated as the Huyton Wetlands Site of Biological Interest. At its mouth, the estuary forms part of the Ribble and Alt Estuaries Special Protection Area for wildlife.
History and Flood Control
Before tidal floodgates were installed at Hightown in the 18th century, the Alt was described as a “troublesome little river”, with a shifting course that cut through field boundaries and threatened roads and bridges. It was rumoured to have wiped out the hamlet of Altmouth sometime between 1577 and 1713, though studies of period maps found no consistent village symbol at that location. Flooding remained a recurring problem until the 1960s, when the river was straightened and canalised. Pumping stations opened at Crossens in 1959 and at Altmouth in 1972, ending the regular inundation of surrounding fields. The river has since benefited from clean-up schemes and a de-culverting process to improve water quality, after suffering heavy pollution from industry, sewage and agricultural run-off.
Name Origins
The name Alt has several possible origins. It may come from Latin, meaning muddy river, though the surrounding villages largely carry Old Norse place names. Alternatively, the name may derive from the Brittonic word alt, meaning either cliff or, more probably, burn or mountain stream – related to the Welsh allt and Irish ált. A third possibility points to the obscure Celtic element *al-, combined with the Brittonic nominal suffix -ed.