Thames Head is a group of seasonal springs that arise in the

Cotswolds The Cotswolds ( ) is a region of central South West England, along a range of rolling hills that rise from the meadows of the upper River Thames to an escarpment above the Severn Valley and the Vale of Evesham. The area is defined by the bedroc ...

, in the county of

Gloucestershire Gloucestershire ( , ; abbreviated Glos.) is a Ceremonial counties of England, ceremonial county in South West England. It is bordered by Herefordshire to the north-west, Worcestershire to the north, Warwickshire to the north-east, Oxfordshire ...

, England. Their location is in fields near the villages of Coates and Kemble,Thames Pathway Ch1
Accessed 15 August 2015 on either side of the A433 road, about three miles south-west of the town of

Cirencester Cirencester ( , ; see #Pronunciation, below for more variations) is a market town and civil parish in the Cotswold District of Gloucestershire, England. Cirencester lies on the River Churn, a tributary of the River Thames. It is the List of ...

. The spring water comes from the

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

aquifer An aquifer is an underground layer of water-bearing material, consisting of permeability (Earth sciences), permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The s ...

s of the Cotswolds. One or more of these springs are traditionally identified as the source of the

River Thames The River Thames ( ), known alternatively in parts as the The Isis, River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the Longest rivers of the United Kingdom, s ...

. In actuality, the source of the River Thames does not have a fixed location – rather, it changes according to the level of the

groundwater Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...

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. 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 of

Ashton Keynes Ashton Keynes is a village and civil parish in north Wiltshire, England which borders with Gloucestershire. The village is about south of Cirencester and west of Cricklade. At the 2011 United Kingdom census, 2011 census the population of the ...

, which is over downstream from Thames Head. During the

2022 United Kingdom heat wave file:UK from ISS on 12 Aug 22.jpg, The UK's largest island, Great Britain, seen from the International Space Station on 12 August 2022 showing clear skies and dry ground The 2022 United Kingdom heatwaves were part of 2022 European heatwaves, sev ...

, the source dried up completely, shifting downstream to Somerford Keynes. The highest springs of Thames Head are located north of the A433 road (

Fosse Way The Fosse Way was a Roman road built in Britain during the first and second centuries AD that linked Isca Dumnoniorum (Exeter) in the southwest and Lindum Colonia ( Lincoln) to the northeast, via Lindinis ( Ilchester), Aquae Sulis ( Bat ...

section), in a

meadow A meadow ( ) is an open habitat or field, vegetated by grasses, herbs, and other non- woody plants. Trees or shrubs may sparsely populate meadows, as long as they maintain an open character. Meadows can occur naturally under favourable con ...

called Trewsbury Mead. One of these springs is marked with an inscribed stone marker, located above sea level at grid reference ST980994. Below it, the springhead itself is in a hollow that has been lined with stones. The springs continue immediately south of the A433. The

Ordnance Survey The Ordnance Survey (OS) is the national mapping agency for Great Britain. The agency's name indicates its original military purpose (see Artillery, ordnance and surveying), which was to map Scotland in the wake of the Jacobite rising of ...

identifies Thames Head as the source of the Thames on its maps and the UK's

Environment Agency The Environment Agency (EA) is a non-departmental public body, established in 1996 and sponsored by the United Kingdom government's Department for Environment, Food and Rural Affairs, with responsibilities relating to the protection and enha ...

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: at Seven Springs, Gloucestershire, the source of the

River Churn The River Churn is a tributary of the River Thames in central England. It rises at Seven Springs, Gloucestershire, Seven Springs in Gloucestershire and flows south for approximately to meet the Thames at Cricklade in Wiltshire. Its length from ...

, which is officially a tributary of the Thames that joins the Thames at Cricklade and which is longer than the course of the Thames from Thames Head to Cricklade. Thames Head Flowing

Marker stone

The marker stone in Trewsbury Mead bears the inscription:

Thames source dispute

The source of the River Thames is disputed. The

, the

and other authorities have the source of the Thames as Thames Head. Others hold that the true source of the Thames is at Seven Springs, Gloucestershire, some farther north, and east of

Gloucester Gloucester ( ) is a cathedral city, non-metropolitan district and the county town of Gloucestershire in the South West England, South West of England. Gloucester lies on the River Severn, between the Cotswolds to the east and the Forest of Dean ...

. Seven Springs is officially the source of the

, which is a tributary of the Thames that joins at Cricklade. 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.BBC News, Gloucestershire. 15 May 2012 Could the River Thames be longer than the River Severn? by David Bailey
/ref>

References

{{River Thames Springs of England SThamesHead River sources

Marker stone

Thames source dispute

See also

References