The delta extends for about 35 km into the sea from the adjoining coasts. Geometrically the delta shore is not lobate but like three sides of a hexagon (the Mahanadi delta is also partly like this) due probably to the trimming effect of the strong monsoon-generated currents and long shore drifts which are parallel to the general trend of the coast. This is most probably the cause of the straight seaward face of the delta. The longer side of the delta is some 90 km, the other two sides being about 35 km long.
Neglecting indentations, the deltaic coast is some 150 km long. The geological base of the Godavari delta is similar to that of the Mahanadi. The alluvial cover is relatively thin and the basement is that of crystallines, e.g., khondalites. The limits of the delta are far beyond what is believed to have been in Permo-Carboniferous trough coinciding with the Godavari valley.
The marine Tertiaries occur near the delta head. Pleistocene emergence of the marine floor has made this as well as most other parts of the Indian coastal zones, what is known as ‘coastal plain’—a recently elevated plain from below the sea characterized by seaward dipping marine sediments at an angle slightly greater than the declination of the present plain surface.” The present deltaic load of the sediment appears to be post-Pleistocene. On the basis of the size of the delta we can infer that the subsidence is much less than in the case of the Ganga or the Mahanadi deltas.
The delta of the Godavari is much smaller than that of the Mahanadi although the basin of the former is much larger. This is partly due to the higher precipitation and intenser erosion. Partly it is due to the triple delta character of the Mahanadi where the Brahmani and Baitarani combine with the Mahanadi to form the delta.
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The “estuary-in-delta”, aspect that characterizes most deltas occurs here also. The larger distributaries are associated with ‘jetty-like’ protuberances, e.g., Vasishta Godavari. The older streams are marked by clean-banked estuary.