Sefton - Crossens Pumping Station

  • Crossens Pumping Station.

  • Crossens Pumping Station.

  • External pumps.

  • Internal pumps.

  • Criffel granite boulder transported during the last ice age discovered during the excavation in 1959.


Alt Crossens is the name given to a large area of land between the Mersey and the Ribble estuaries, with a good proportion of the low-lying land sitting below sea level.

There is evidence that some land drainage at Alt Crossens goes back to the Doomsday book, however it was not until the 1800s that land began to be properly drained for farming creating the landscape that we know today.

Up until the 1900s, gravity was all that was needed to drain the land to sea. However, as the marshy areas dried, they shrank down below sea level. Since the 1920s, pumping has been used to take water off the land and out to the sea. Today's network consists of smaller drainage ditches and watercourses. Managing water in the area is complex because a proportion of the catchment is not much higher than sea level.

Built in 1959, Crossens Pumping Station is one of the main stations used to pump water from the Alt and Crossens catchments into the sea. Supported by another pumping station at Altmouth (built in 1972), there are an additional nine smaller stations and hundreds of miles of drainage channels and watercourses.

The system of pumping stations, drains and watercourses that maintain Alt Crossens in its mainly dry state is used to prevent flooding. The Environment Agency who operate Altmouth and Crossens pumping stations, use storm pumps to drive flood water from the catchment out to sea and place emphasis on managing and maintaining the parts of the drainage system that play a role in preventing flooding to homes and commercial property.


This system has been very successful in protecting the large urban populations of North East Liverpool, Maghull, Knowsley, Southport, Formby and Ormskirk from flooding events.

The catchment area is 39,600 hectares in size and is home to some of the most fertile agricultural land in the country, supporting 2,500 jobs in farming and many more in the local food and horticulture sectors. This brings an estimated £230 million of income per annum to the local economy.

Without this drainage and pumping system, the lowest lying parts of Alt Crossens would return to their original marshy state. This in turn would reduce the amount of land available to farming as well as increase flood risk for large urban areas.

Further Information

A combination of more extreme weather patterns and a reduction in national funding by Government for draining land where flood risk to people is low is placing increased pressure on the Alt Crossens catchment. A new and long term solution is needed for managing water in the catchment into the future, but it is essential that this solution works effectively and has the support and confidence of the community.

In response to this the Environment Agency is spending £4.9 million on refurbishing the pumping station in autumn 2014. The involves replacing the old diesel pumps with more efficient electric pumps.

During the excavations for the building of the Crossens pumping station a large Criffel granite boulder was discovered five metres below the surface. Geologists stated that the only place this type of rock is native to is Dumfries in the South West of Scotland. Around 18,000 years ago most of North Western England was covered in large ice sheets. Ice forming in Scotland picked up the boulder and carried it to the site via the Irish Sea, which would have been dry land as much of the water had become ice.

Pieces of rock like this, that have been transported by glaciers and found where they would not normally be, are called erratics.