The area was inundated by floodwaters in 1909 and on one occasion gravel was washed all the way to the base of the shaft. A meander loop of the River Ehen was removed and an embankment built to separate the river from the mine area. This did not prevent water ingress during times of spate so the river was boxed in.
The concreted section of the river is referred to locally as The Dub. After abandonment in 1924 the low lying ground flooded and is now Longlands Lake country park nature reserve. Longlands was acquired by Cumbria County Council in 1980.
Longlands Lake is signed as a tourist attraction from the A5086. Free car parking is provided and the footpath to the lake crosses the River Ehen on a footbridge from which the concrete engineering works can be seen in the banks and bed of the river.
Longlands Lake nestles between Egremont and Cleator Moor on the West Coast of Cumbria and supports an abundance of wildlife within a variety of habitats, which include: broadleaf woodland, unimproved grassland and aquatic vegetation. The lake is important for its bird population and breeding species include mute swan, coot, moorhen, goosander, tufted duck and mallard. The circular walk provides safe and enjoyable access all year round for walkers, wheelchair users and those with pushchairs and young children.