Isleworth Ait

Isleworth Ait is a small, teardrop-shaped island in the River Thames, lying between the London boroughs of Hounslow and Richmond upon Thames. It sits on the Tideway opposite Old Isleworth, facing the towpath beside the Royal Mid-Surrey Golf Club. The island is densely covered with trees and floods regularly, yet remains a haven for wildlife. It is owned by Thames Water and managed as a nature reserve by the London Wildlife Trust. Access is restricted to organised events and volunteering days for local supporters. The island supports over fifty-seven species of birds, including tree-creepers, kingfishers and herons. Two rare land snails, the two-lipped door snail and the German hairy snail, also live here along with several uncommon beetles. Its ecological value led to its designation as a local nature reserve and a Site of Metropolitan Importance for Nature Conservation. In the past, Isleworth Ait was used to harvest osier willow for basket-making, linking it to the fruit and vegetable trade of Middlesex. Over time, five smaller islands merged to form the present landmass, shaped further by river erosion. Nearby, the River Crane flows into the Thames southwest of the island, while the Duke of Northumberland’s River and its distributaries feed Syon Park’s lake to the northwest. The island also houses the outfall from Mogden Sewage Treatment Works, which serves over two million people across West London. Recent upgrades aim to reduce untreated discharges into the river. Volunteers from the London Wildlife Trust help manage the reserve, contributing to its conservation and occasional public access.