Lower Test Valley is a 142-hectare (350-acre) biological Site of Special Scientific Interest near Totton in Hampshire.

[5] It is a nature reserve managed by the Hampshire and Isle of Wight Wildlife Trust.

[6] The valley has extensive reed beds, tidally flooded creeks, unimproved grassland and scattered willow trees.

More than 450 flowering plants have been recorded, including the nationally rare green-flowered helleborine.

The reed beds have large populations of wetland breed birds.