Sonning Backwater Bridges are two road bridges across two branches of the River Thames

River Thames

The River Thames flows through southern England. It is the longest river entirely in England and the second longest in the United Kingdom. While it is best known because its lower reaches flow through central London, the river flows alongside several other towns and cities, including Oxford,...

 at Sonning Eye

Sonning Eye

Sonning Eye is a hamlet on the River Thames in Oxfordshire, England, in the civil parish of Eye & Dunsden, at the very southernmost tip of Oxfordshire.- Overview :...

, Oxfordshire

Oxfordshire

Oxfordshire is a county in the South East region of England, bordering on Warwickshire and Northamptonshire , Buckinghamshire , Berkshire , Wiltshire and Gloucestershire ....

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. Built in 1986 to replace an older wooden structure, the bridges span Sonning Backwater and the millrace to link historic brick arch Sonning Bridge

Sonning Bridge

Sonning Bridge is a road bridge across the River Thames at Sonning, Berkshire. It links Sonning with Sonning Eye and crosses the Thames on the reach above Shiplake Lock, just short of Sonning Lock. It is a brick arch bridge completed in 1775, to replace an earlier wooden bridge...

 of 1775, which spans the boundary with Berkshire

Berkshire

Berkshire is a historic county in the South of England. It is also often referred to as the Royal County of Berkshire because of the presence of the royal residence of Windsor Castle in the county; this usage, which dates to the 19th century at least, was recognised by the Queen in 1957, and...

 to connect the village of Sonning

Sonning

Sonning, occasionally called Sonning-on-Thames is a village and civil parish in the Borough of Wokingham in the English county of Berkshire, a few miles east of Reading. The village is situated on the River Thames and was described by Jerome K...

, with the smaller hamlet of Sonning Eye. Just upstream along the backwater is a weir

Weir

A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...

 next to Sonning Lock

Sonning Lock

Sonning Lock is a lock and associated weir situated on the River Thames at the village of Sonning near Reading, Berkshire, England. The first lock was built by the Thames Navigation Commission in 1773 and it has been rebuilt three times since then....

 on the main navigable branch of the river.

Close to the bridge are the Mill at Sonning, now a theatre, on an island between two branches of the river, and the French Horn

French Horn, Sonning Eye

The French Horn at Sonning is a luxury hotel and restaurant on the banks of the River Thames next to the Sonning Backwater Bridges , at Sonning Eye, Oxfordshire, England....

, a hotel and restaurant on the northern Oxfordshire bank.

The modern backwater bridges replaced a wooden and somewhat rickety structure. At the beginning of the 20th century, there were complaints about the traction engine

Traction engine

A traction engine is a self-propelled steam engine used to move heavy loads on roads, plough ground or to provide power at a chosen location. The name derives from the Latin tractus, meaning 'drawn', since the prime function of any traction engine is to draw a load behind it...

s causing structural problems with the old wooden bridge and disturbing the peace, much as there is with traffic today . The road (the B478) is the busiest B road in Oxfordshire, being the only way for road vehicles to cross the Thames between Henley-on-Thames

Henley-on-Thames

Henley-on-Thames is a town and civil parish on the River Thames in South Oxfordshire, England, about 10 miles downstream and north-east from Reading, 10 miles upstream and west from Maidenhead...

 and Reading

Reading, Berkshire

Reading is a large town and unitary authority area in England. It is located in the Thames Valley at the confluence of the River Thames and River Kennet, and on both the Great Western Main Line railway and the M4 motorway, some west of London....

.

The bridges are occasionally inundated or closed to traffic when the Thames is in extreme flood; the waters regularly rise to the steps of the famous French Horn

French Horn, Sonning Eye

The French Horn at Sonning is a luxury hotel and restaurant on the banks of the River Thames next to the Sonning Backwater Bridges , at Sonning Eye, Oxfordshire, England....

restaurant and submerge the car park of the nearby Flowing Spring pub.