The Scotch Brook Valley, and its tributary The ModdeshallValley proper, convey brisk and reliable watercourses thatfor centuries supported twelve traditional watermills.In the nineteenth and twentieth centuries most of these millswere used to grind animal bones and flint to supply theLongton fine bone china industry. Latterly, the uppermost mill generated electricity to lightthe hamlet of Moddeshall. James R Warren investigates the hydraulics and hydrologicalscience of this small English catchment to consider its revivalfor the generation of small-scale hydro-electricity supply.Traditional watermill scholarship and craft is re-evaluated interms of the physics of flowing water.Contains text, photographs, tabulations, engineering equations and geometrical diagrams.