The Freshwater Habitats Trust (FHT) and the River Thame Conservation Trust (RTCT) were appointed as the joint catchment hosts for the Thame in 2013 and are leading the development of the catchment partnership with the support of the Environment Agency.
The River Thame catchment straddles two counties (Buckinghamshire and Oxfordshire), encompasses two significant towns (Aylesbury and Thame) and is bisected by the M40 and A40 in its lower reaches. The proposed HS2 rail link will also run across the catchment. Land use is, however, predominantly agricultural with few protected areas, except on the catchment periphery, notably SSSIs along the Chilterns escarpment to the east and the Bernwood/Shabbington forest complex in the west. Numerous tributaries feed into the River Thame: these include the Stoke and Bear brooks near Aylesbury; Scotsgrove, Chinnor, Upper Cuttle, Cuttle and Kingsey Cuttle brooks near Thame; Chalgrove and Lewknor brooks near Watlington; and four brooks (Denton, Baldon and Gainsbridge brooks and the Milton Ditch) in the Lower Thame that form the core of the ongoing FHT/RTCT Catchment Restoration Project.
The 2013 water quality data from the Environment Agency suggests that water quality across the different streams and brooks in the catchment are either “Moderate” or “Poor”. No areas of the catchment achieve “Good” status. Factors influencing the water environment in the Thame catchment are likely to be urban and rural diffuse pollution, waste water discharges, road run-off, habitat/land.