The River Tillingbourne (11 miles in length) is a tributary of the River Wey and runs along the southern edge of the North Downs, from its source near Tilling Springs north-east of the summit of Leith Hill (which at 294 metres above sea level is the highest point in south-east England), to Shalford, where it converges with the Wey near Guildford (dropping to only 30 metres). The Tillingbourne runs through several villages, subsequently powering their mills along the way, including Friday Street, Wotton, Abinger Hammer, Gomshall, Shere, Albury, Chilworth and Shalford. There are also four main tributaries: the stream which has its source at the mill pond at Friday Street flows north and joins the river at Wotton House; that at Holmbury St Mary also flows north to join at Abinger Hammer; the Sherbourne Brook flows south from Silent Pool and joins at Albury; and the Law Brook flows north and joins near Postford.
Despite the tranquil beauty of the waterway, the last round of investigations by the Environment Agency in 2015 showed the Tillingbourne to be in a poor ecological status. This was related to:
- Fish – low fish populations linked to instream barriers such as weirs stopping fish moving up the stream from the main river
- Macrophytes (aquatic plants) – likely linked to phosphate enrichment of the stream, which allows more competitive plant species to dominate at the expense of other species
- Phosphate – linked to waste-water treatment from sewage treatment works, as well as diffuse pollution from agriculture
By generating greater interest in the river, river wardens will also be trained through the project to survey and monitor the Tillingbourne. The Surrey Wildlife Trust’s RiverSearch project will teach volunteers about the identification and management of invasive non-native species and enable wardens to coordinate conservation action days. The volunteers will also support existing River Catchment Management Plans to survey, monitor and report, improving the ecological situation of the river and improve habitat connectivity over time.