The River Purwell is a

chalk stream Chalk streams are rivers that rise from springs in landscapes with chalk bedrock. Since chalk is permeable, water easily percolates through the ground to the water table and chalk streams therefore receive little surface runoff. As a result, th ...

Hertfordshire Hertfordshire ( or ; often abbreviated Herts) is a ceremonial county in the East of England and one of the home counties. It borders Bedfordshire to the north-west, Cambridgeshire to the north-east, Essex to the east, Greater London to the ...

, England. The entire course of the stream is near

Hitchin Hitchin () is a market town in the North Hertfordshire Districts of England, district of Hertfordshire, England. The town dates from at least the 7th century. It lies in the valley of the River Hiz at the north-eastern end of the Chiltern Hills ...

. Its source is springs which rise out of the chalk bedrock at

St Ippolyts St Ippolyts (historically St Ippollitts) is a village and civil parish on the southern edge of Hitchin in Hertfordshire, England. As well as the village itself, the parish includes the hamlet of Gosmore and southern parts of the Hitchin built up ...

, forming Ippollitts Brook. It is known as the Purwell by the time it reaches

Ninesprings Ninesprings is a country park situated in the South East of Yeovil, Somerset, the United Kingdom. It is the largest country park in South Somerset, spanning over . The site lies on Yeovil Sands (a yellow micaceous sand) of the Upper Lias, in ...

on the border of the parishes of

Great Wymondley Great Wymondley is a village in the civil parish of Wymondley, in the North Hertfordshire district of Hertfordshire, England. It lies east of Hitchin. Despite the names, Great Wymondley is now smaller than its neighbour, Little Wymondley. His ...

and Hitchin. It flows on to join the

River Hiz The River Hiz is a small () tributary river in Hertfordshire that feeds the River Ivel that, in turn, feeds the River Great Ouse. Starting at its source of a chalk fed spring just south of the village of Charlton, the river winds its way thr ...

. The river and associated

wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

s are protected by

nature reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, funga, or features of geologic ...

s at Ninesprings and Purwell Meadows.

Purwell Mill

At Purwell Meadows the river powered a

watermill A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as mill (grinding), milling (grinding), rolling, or hammering. Such processes are needed in ...

until the 1920s. The existing building is a couple of hundred years old, but a mill at this site is mentioned in the

Domesday Book Domesday Book ( ; the Middle English spelling of "Doomsday Book") is a manuscript record of the Great Survey of much of England and parts of Wales completed in 1086 at the behest of William the Conqueror. The manuscript was originally known by ...

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

King William King William may refer to: People Bimbia * William I of Bimbia * William II of Bimbia () Britain and Ireland * William of England (disambiguation), multiple kings * William I, King of Scots (–1214), also known as William the Lion German Empir ...

. Because part of the mill extended over the river to the opposite bank, in Hitchin manor, the Manor of Great Wymondley had to pay an annual fee of 6 d.

References

{{authority control Purwell Purwell