River Purwell

Its source is springs which rise out of the chalk bedrock at St Ippolyts, forming Ippollitts Brook.

[1] It is known as the Purwell by the time it reaches Ninesprings on the border of the parishes of Great Wymondley and Hitchin.

[2] The river and associated wetlands are protected by nature reserves at Ninesprings and Purwell Meadows.

The existing building is a couple of hundred years old,[3] but a mill at this site is mentioned in the Domesday Book.

This document from 1086 recorded a mill worth 20s in the part of Great Wymondley belonging to King William.