The land comprises some mainly of hydrologically sensitive fen, fen meadow and wet woodland dissected by a series of south and west flowing streams and drains totalling some in length. Some of the drains originate from one-time watercress beds fed by clear chalk water springs and feed into either the Western Stream arising off the 'Sand Boils' or the Eastern Stream arising off Alexanders Moors. Both streams flow into Waltham Mill Pond and from where the water passes to The Moors Stream, a headwater of the River Hamble. The 'Sand Boils' is an area at the head of the West Stream in which upwelling spring water creates swirling sandy patches in the gravelly streambed.