The cave was formed under phreatic conditions i.e. below the local water table, but lowering base levels to which the subterranean drainage was flowing resulted in some passages being abandoned by the river, and there is evidence of a number of abandoned resurgences. In particular, the passages in the 20th chamber are interpreted as a former Vauclusian spring, the waters of which once surfaced in the Ebbor Gorge. It is uncertain whether that was the original rising or whether it formed when the main rising at Wookey was blocked.