It consists of three isolated broads in the River Waveney area:
There are extensive reed beds, woodlands and heathlands, also pits created by gravel extraction. Reed is farmed commercially for the thatching industry, whilst enabling the bearded reedling to find a habitat.
There are over 100 species of breeding birds, including marsh harrier, bearded reedling, water rail, and occasionally bittern. The flora includes sea kale, sea holly, and yellow-horned poppy.
Some of the ongoing work at the reserve is stopping the encroaching sea by digging new lagoons and establishing moe sea defences, and replacing the woodland lost to the sea.
Whilst the broads in Norfolk came about through peat digging in the Middle Ages, the Benacre broads are lakes formed in shallow valleys when glacial drift blocked off the outflow to the sea.