51°41′39″N2°01′47″W / 51.694262°N 2.029724°W /51.694262; -2.029724
Thames Head is a group of seasonalsprings[1][2][3][4][5] that arise in theCotswolds, in the county ofGloucestershire, England. Their location is in fields near the villages of Coates andKemble,[6] on either side of the A433 road, about three miles south-west of the town ofCirencester. The spring water comes from thelimestoneaquifers of the Cotswolds. One or more of these springs are traditionally identified as thesource of theRiver Thames.[7][8]
In actuality, the source of the River Thames does not have a fixed location – rather, it changes according to the level of thegroundwater in the limestone. In dry periods, the groundwater level falls, causing the Thames Head springs to dry up and the river to begin lower down in its course. In wet conditions, the groundwaters rise and the river can begin at one of the Thames Head springs.[9] The spring known as Lyd Well, located south of the A433 (grid reference ST989984), is often where the river starts. In 2011, the lowest recorded start of the Thames was just upstream ofAshton Keynes, which is over six miles (ten kilometres) downstream from Thames Head.[9] During the2022 United Kingdom heat wave, the source dried up completely, shifting five miles (eight kilometres) downstream toSomerford Keynes.[10]
The highest springs of Thames Head are located north of theA433 road (Fosse Way section), in ameadow called Trewsbury Mead. One of these springs is marked with an inscribed stone marker, located 360 feet (110 m) above sea level at grid reference ST980994.[8] Below it, the springhead itself is in a hollow that has been lined with stones.[8] The springs continue immediately south of the A433.
TheOrdnance Survey identifies Thames Head as the source of the Thames on its maps and the UK'sEnvironment Agency follows their precedent. However, there is also a long-standing alternative view that the real source of the Thames is on a different headstream entirely: atSeven Springs, Gloucestershire, the source of theRiver Churn, which is officially a tributary of the Thames that joins the Thames atCricklade and which is longer than the course of the Thames from Thames Head to Cricklade.[11][12]
The marker stone in Trewsbury Mead bears the inscription:
THE CONSERVATORS OF THE RIVER THAMES
1857–1974
THIS STONE WAS PLACED HERE TO MARK THE
SOURCE OF THE RIVER THAMES[8]
The source of the River Thames is disputed. TheEnvironment Agency, theOrdnance Survey and other authorities have the source of the Thames as Thames Head. Others hold that the true source of the Thames is atSeven Springs, Gloucestershire, some 11 miles (18 km) farther north, and east ofGloucester. Seven Springs is officially the source of theRiver Churn, which is a tributary of the Thames that joins atCricklade. As it is further from the mouth of the Thames than Thames Head, the adoption of Seven Springs as its source would make the Thames the longest river in the UK.[12][11]
{{cite web}}: CS1 maint: postscript (link){{cite web}}: CS1 maint: postscript (link){{cite web}}: CS1 maint: postscript (link){{cite web}}: CS1 maint: postscript (link)The source of the Thames is actually in a group of springs just north of the village of Kemble in Gloucestershire. There is a stone marking the official sources at Trewsbury Mead. The catch is the spring is mostly dry. However, the Thames Head group of springs is a few hundred metres away and this is where the water flows from.