This large, ex-gravel pit is made up of a main lake with gently sloping banks, shallow areas of water and ponds, low lying islands, a large scrape and a fringe of reeds surrounded by grassland and wet woodland. This is ideal habitat for wintering birds: goosander, wigeon and gadwall reach nationally important numbers, joined by large numbers of roosting lapwing and golden plover. Wading birds use the scrape and the shallow lake margins.

Oystercatcher, ringed plover, little ringed plover and redshank stay to breed, while whimbrel, turnstone and common sandpiper often pass through during migration. Numerous pairs of common tern nest in a colony on the islands, so the team cut back vegetation each autumn to keep them safe. Otters are rare but regular visitors to the reserve, while the taller reeds and rushes around the lake may reveal the ball-shaped woven nests of harvest mice.