East-the-Water sits on folded and eroded Carboniferous rocks, in which some layers proved suitable for building stone. In a belt running east to west across the middle of the community these rocks also contain seams of carbonised plant material in the form of anthracite or, less commonly, the carbonaceous pigment known as ‘Bideford Black.’ Most of the plant material is beyond recognition, but one may occasionally find fossil plants that are recognizable as such. A variety of ferns and horsetails have been identified from outcrops including an exposure near the railway station, old workings at Moor Town, and an old adit at Broadstone quarry, near Chapel Park.

To the south of Torrington, the Oligocene period saw the formation of vast ball-clay deposits near Pettrockstowe, that would later find commercial significance for the port, helping drive changes to its East-the-Water shore.

Signs of Ice Age glaciation are found nearby in the form of till deposits (ancient moraine) and glacial erratics (exotic pebbles and boulders transported by the ice). Extensive glaciation caused lower sea-levels than today, allowing forests to grow in what is now Bideford Bay. In warmer interglacial periods, when the ice retreated, sea levels were higher than at present, leaving a prominent wave-cut platform in the cliffs at Westward Ho! (for which related features should be traceable on the hills beside the Torridge). Throughout the recent past, as a rebound effect from the last glaciation, North Devon has been slowly sinking by about 1mm a year. The result is the creation of sea-flooded river valleys, known as rias, of which the Torridge at Bideford is an example.

Whilst there is little evidence for early human occupation in East-the-Water, there was a hilltop enclosure at Eastridge. Implements, including a fine Neolithic greenstone axe-head, were found during the construction of the Torridge Bridge. Flint artefacts have also been recovered from Ayres Close, together with scattered implements along the Industrial Link Road. The presence of a Neolithic midden at nearby Westward Ho! is well documented. There is also evidence, in the form of earthworks, of Iron-age settlement in the area (notably Kenwith Castle).