Oxford Archaeology (OA) was asked by Atkins Ltd, acting on behalf of The Environment Agency, to carry out a programme of heritage asset recording on five paddle and rymer weirs on the River Thames (and Kennet), which are to be replaced. The weirs recorded are those at Radcot, Northmoor, Mapledurham, Blakes and Molesey. OA previously undertook a similar piece of recording on Shepperton 'B' Weir on the River Thames in Surrey. The structure of each of the weirs is substantially, and in some cases entirely, modern but the general mode of operation of the weirs forms part of long tradition which stretches back to the medieval period and they therefore contribute to the historic environment. The aim of the project was to investigate and record the structures prior to their replacement or alteration. The work concentrated on the structures’ construction, history, use, phasing and how they fitted into the overall operations of the River Thames. Each of the structures forms an element in the historic character of the surrounding area and they help to demonstrate the technology and evolution of the navigation improvements on the River Thames. Also SU 6685 7680, SU 7255 7347