The earliest mention of the lake is in 1284, as "La Mare", and in the post-medieval period it was an area of wet grazing shared by local farmers.

A sluice was constructed so that there would be permanent shallow flooding of the site; 1 to 6 hectares (2.5 to 14.8 acres) may lie under water.

[1][2][3][4] Species seen on the site include golden plover, wigeon, jack snipe, lapwing, dunlin, redwing, water rail, marsh harrier and black-tailed godwit.

About 1 hectare (2.5 acres) is covered with yellow flag iris and marsh marigold; there is also bog bean and pink water-speedwell.

[2] Access is restricted, to give security to resident and visiting birds: viewing is permitted only from the lane above the reserve.