The River Brain is a tributary of the River Blackwater in Essex, England. It is claimed to have given its name to the town of Braintree, although it seems that the name ‘Braintree’ is older, and that the river name is a back formation from the town name; Braintree lies on a low ridge between the Brain and the River Blackwater. To the north of Braintree it is known as Pods Brook. The brook rises near the village of Bardfield Saling. Below Braintree the Brain joins the Blackwater in Whet Mead in Witham.^[1] In 2001, a "flood park" was planned to reduce the risk of overflow from the river.^[2]

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