The River Brent flows through suburban northwest London, passing through areas including Tokyngton Park, Stonebridge Park, and Brent Cross before joining the Thames. The river is heavily modified in character, with significant stretches running through culverted sections underground, particularly at Neasden junction and Stonebridge junction. While a 500-metre stretch at Tokyngton Park was restored from a concrete channel to a more natural meandering course in 2002–2003, much of the river remains in an engineered state.

Paddling the River Brent is not recommended. At least one paddler who has descended it has strongly advised others against attempting it. The river presents multiple serious hazards, including numerous weirs that obstruct fish passage and pose risks to paddlers, as well as sections that disappear entirely into culverts. The Monks Park Labyrinth Screen near Stonebridge Park is a structure designed to catch debris and act as a weir during flood conditions; it is considered extremely dangerous to paddlers when the river is running high.

The Brent (Welsh Harp) Reservoir, which feeds the river, is accessible for paddling only to members of the Phoenix Canoe Club and is not open to the general public. The spillway area below the dam can be reached on foot via a footpath behind Harp Island Close, but this does not constitute a paddling access point for non-members.

The river does pass through a notably unusual microenvironment in the vicinity of the dam, described as semi-tropical in character. There have been calls for the river to be regenerated and rewilded along the lines of the River Wandle, but no such transformation has taken place. Anyone considering the River Brent should be aware that its current condition makes it a poor and potentially hazardous choice for paddling.