The Brent Reservoir (popularly called the Welsh Harp) is a reservoir which straddles the boundary between the London boroughs of Brent and Barnet and is owned by the Canal & River Trust. The reservoir takes its informal name from a public house called The Welsh Harp, which stood nearby until the early 1970s. It is the only Site of Special Scientific Interest in Barnet and Brent.
The reservoir is fed by the Silk Stream and the River Brent, and its outflow is The River Brent. It is said to contain enough water to fill 3 million baths, and in 1994 when the reservoir was drained, more than 6,700 lb (3,000 kg) of fish were captured, 95% of which were Roach. However, fishing is prohibited. The reservoir has a sailing centre, home to BTYC Sailsports, Wembley Sailing club, Seahorse Sailing Club, the Sea Cadets, and the University of London Sailing club. In 1960, it also hosted the Women's European Rowing Championships.