Its most important channel is the Piep, which is up to 20 metres deep and divides in Meldorf Bay into three branches: the Wöhrdener Loch (north), the Kronenloch and the Sommerkoog-Steertloch (south).
As a result of several major storm floods in the late Middle Ages and early modern times, the bay expanded further and further into the low marshes and almost reached the town of Meldorf, sited on a geest ridge.
The newly created Speicherkoog on Meldorf Bay is designed primarily to store water from the interior during inland flooding and to discharge it into the sea through two dyke sluices and scoop wheels.
Both the Speicherkoog as well as the other undyked areas of Meldorf Bay belong to protection zone 1 of the Schleswig-Holstein Wadden Sea National Park and are therefore subject to special conservation laws.
In Meldorf Bay lies the uninhabited island of Helmsand, which is like one of the Halligen and many years ago was linked to the mainland by a causeway.