Four Priority Themes

The Brent Catchment Partnership focuses on 4 priority themes for improving the water environment :

Theme 1: Reducing Pollution


  • By 2021, water quality in the Brent catchment has improved and has a ‘moderate’ ability to support wildlife

A ‘moderate’ ability to support wildlife and means that:

Phosphate concentrations are 0.25 mg/l or less

Dissolved oxygen levels are 54% saturation or higher

Levels of total ammonia are no higher than 1.1mg/l

  • By 2027, it will have a ‘good’ ability to support wildlife

A ‘Good’ ability to support wildlife means that:

Phosphate concentration are 0.12 mg/l or less

Dissolved oxygen levels are 60% saturation or higher

Levels of total ammonia are no higher than 0.6mg/l

Theme 2: Making Rivers More Natural


  • Transforming up to 10 kilometres of heavily modified river to a more natural condition by 2021

Theme 3: Tackling Invasive Non-native Species


  • Decreasing density and distribution of invasive non-native species in chosen locations by at least 20% by 2021
  • Having Giant Hogweed under a management programme in all parks, reserves and pathways by 2017

Theme 4: Creating Better Opportunities for Access and Recreation


  • Completing a 24-mile riverside trail from Barnet to Brentford on the Thames
  • Creating or improving 12 miles of riverside access for walking, cycling and the disabled throughout the catchment
  • Creating at least two new green spaces along the waterways in the Brent Catchment by 2021


Long Term Goal

Under the European Water Framework Directive (WFD), rivers and lakes, reservoirs and canal (artificial) water bodies need to be restored to good ecological health by 2021 or 2027. The Environment Agency monitors the health of rivers, lakes and canals and reports on their ecological health as part of its duties under the WFD.

A Healthy River

A healthy water body has thriving populations of fish, invertebrates, plants and diatoms (microscopic algae). They depend upon a healthy flow of water and a variety of natural habitats. All of these are affected by the levels of pollution and nutrients in the water, and the shape and structure of the water body.

How Healthy Is This Catchment?

Right now, all of the rivers, lakes and canals in the Brent Catchment are considered to be in either ‘poor’ or ‘moderate’ ecological health. This is because they are being affected by pollution from various sources and modifications that have been made to their
shape and structure.The latest information on the health of the eight water bodies in the Brent Catchment can be found on The Catchment Data Explorer website:


> Dollis Brook and Upper Brent

> Wealdstone Brook

> Silk Stream and Edgware Brook

> Lower Brent


> Bentley Priory

> Welsh Harp Reservoir


> Grand Union Canal, Uxbridge to Hanwell Locks, Slough Arm, Paddington Arm

> Brent Feeder Canal


More About The Water Framework Directive

The European Commission page gives a wider introduction and updates about the Water Framework Directive

Design by LTD Design Consultants and build by Garganey Consulting.