The River Lambourn is a chalk stream in the English county of Berkshire. It rises in the Berkshire Downs near its namesake village of Lambourn and is a tributary of the River Kennet, which is itself a tributary of the River Thames. The river is a biological Site of Special Scientific Interest and Special Protection Area under the European Union Directive on the Conservation of Wild Birds. Perennial River The upper reaches of the river are seasonal, with a perennial source derived from a number of springs located upstream of the village of Great Shefford. At times when the water table in the chalk aquifer feeding the river is high (usually between November and March) the source of the river migrates upstream. Along the bourn section of the river are located the villages of Eastbury and East Garston, while along the perennial section of the river are the villages of Great Shefford, Welford, Boxford, Bagnor, Donnington and Shaw. Below Shaw is the confluence of the River Lambourn with the River Kennet, located between Newbury and Thatcham. The River Lambourn itself has a single perennial tributary, the Winterbourne Stream, which joins it at the village of Bagnor. Lambourn Valley Way The Lambourn Valley Way from the Uffington White Horse to Newbury generally follows the River Lambourn from Lambourn to Donnington Castle, in many places using the embankments of the old Lambourn Valley Railway. Upper Lambourn and Lynch Wood The highest source of the Lambourn is on the Maddle Road in the village of Upper Lambourn, near the Wiltshire and Oxfordshire borders. It emerges from a rainwater drain and occasionally flows down a channel between the road and pavement. In the village it runs underground in a pipe until re-emerging alongside the road opposite The Malt Shovel and along Malt Shovel Lane. At this point it is usually little more than a damp, muddy ditch, and remains so until halfway through Lynch Wood. Here it is fed by several springs, two of which are close to the Goose Green road, forming a short stream that runs ten feet downhill into the river. These springs quickly fill the channel and the river swells ten to twenty feet wide and over three feet deep, submerging several fallen trees. Although bourne until Great Shefford the river was not dry below Lynch Wood in 2007–08. However, it dried up in June–July 2009 and the riverbed remained