Where is the River Brent?

Originating from Totteridge in Barnet and Stanmore in Harrow, the River Brent Catchment includes all the land and waterways that drain into the River Thames at Brentford in Hounslow. The Brent Catchment also includes canal water bodies: the Regents Canal, the Grand Union Canal and Brent Feeder. 

How big is it?

Approximately 175 square kilometres of land drain into the Thames via this catchment. Altogether, the whole river River Brent system classed as 'main river' is 82 km long: the main River Brent is16 km, while its tributaries total another 66 km, with extensive additional 'non-main' river channels and ditches and drains work together to transport surface waters during wet weather.

Natural features

Historically, the river would have meandered particularly in the upper parts around Totteridge and Stanmore, while the lower part was once extensive marshland. Some upper reaches of the Dollis Brook and parts of the River Brent in Ealing between Perivale and Hanwell still keep some of their original natural features and shape.

In the upper catchment, Brent waters rise where glacial gravel deposits sit on top of London clay, forming on the Harrow Weald a geological site of special scientific interest (SSSI). The parks and open spaces of the higher reaches provide accessible green open spaces, woodland, conservation areas, including Bentley Priory Nature Reserve, and green belt to London's north west metropolis.


Like many urban river catchments in and around London, the River Brent valleys and watercourses have undergone significant changes. One of the earliest major changes was the creation of the Welsh Harp reservoir in 1837, now an important SSSI with an amazing variety of visiting birds and other aquatic wildlife. 

Other land use and channel changes have resulted in the health of the River Brent decreasing, either through the deterioration of natural physical processes and habitat quality, or the cocktail of pollutants entering its waters from various sources including surface runoff from surrounding areas. Major changes in many parts of the Brent include straightening and reinforcing the river with concrete to form artificial channels, or diverting it into underground pipes or culverts, seriously impacting on wildlife and water quality.

Navigable Waterways

The Regents Canal and Grand Union Canal (GUC) both cross the River Brent catchment from East to West.  While the Regents Canal passes high over the River Brent in an aquaduct without a connection, the GUC merges with the River Brent near Green Lane in Ealing where it becomes a navigable waterway to its confluence with the River Thames. The Brent Canal Feeder and the Welsh Harp Reservoir are regulating water levels to keep the Regents Canal navigable.

Other Forms Of Transport

There are major transport links including railways routes from Paddington, Euston, the Metropolitan, the Jubilee, the M1 and the M4. Industrial estates, housing developments and visitors to this part of London benefit from good access to this part of London.

Why not start discovering the variety of Brent watercourses by paying a visit to its Sites of Special Scientific Interest (SSSIs), the Welsh Harp Reservoir and Bentley Priory at the start of the Edgware Brook.  Check out our Visit the River Brent page for more information.


Design by LTD Design Consultants and build by Garganey Consulting.