These springs occur where the permeable Jurassic limestone, meets the impermeable Upper Lias mudstone and clays that underlie most of the Isbourne catchment.

[3] The river flows from Cleeve Hill in a steep valley in a northerly direction through the hamlet of Postlip, before reaching the town of Winchcombe which it passes along its eastern side.

The river then crosses into Worcestershire and is joined by the Laverton brook, before it reaches the village of Sedgeberrow.

[5] In terms of geology, apart from the headwaters which are underlain by the Cotswold limestone, the majority of catchment is Lias clay.

This impermeable clay means that Isbourne can become responsive in terms of runoff to heavy rainfall events.