The River Colne is a waterway in Hertfordshire, England, that begins at an underground source in North Mymms Park. From there, it flows southwest, weaving through both urban areas and the more rural landscapes typical of southern Hertfordshire before reaching Watford. Its importance lies in providing a vital habitat for local wildlife, supporting the surrounding ecosystems, and offering recreational spaces for nearby communities.

Watford Borough Council and Groundwork are working together to deliver a pioneering ten-year initiative, ‘Rediscovering the River Colne’, aimed at restoring the Colne to its central role in Watford Town and reconnecting it with the local community. Through enhanced access, richer biodiversity, and increased recreational value, this ambitious project will transform the river into a key asset—one that benefits residents, supports wildlife, and brings renewed vitality to the borough.

The River Colne has long influenced local livelihoods and acts as a vital lifeline for diverse wildlife, providing food, water, and shelter. Although sections of the Colne in Watford feature good-quality habitats, the river does not currently meet ‘good’ status. Consequently, improvements to the river corridor are necessary to enhance its overall condition and help the Colne meet Water Framework Directive standards. After the works at Waterfield Recreation Grounds in January 2025, the project will have restored over 52% of the River Colne.

Our partners throughout this project are: Groundwork (East & South) Hertsmere Borough Council Environmental Agency Affinity Water Thames Water ColneCAN Colne Valley Fisheries Consultative Community Connections Project Hertfordshire and Middlesex Wildlife Trust Veolia UK Watford Green Gym Salix River & Wetlands Ltd Among other local stakeholders and community groups.

If you would like to get involved with helping us survey the river for pollution incidents, or help the project monitor water quality, please check the ‘Get Involved’ page for upcoming events, or express interest in volunteering via the ‘Contact’ page.

The European Water Framework Directive came into force in December 2003. It provides an opportunity to plan and deliver a better water environment. The Water Framework Directive requires that all European Member states’ water bodies reach Good Ecological Status or Potential by 2027. This has been taken into UK law upon our departure from the EU.

By implementing sustainable measures to tackle the issues facing the River Colne and revitalising the public spaces it passes through, this project will create a healthier river corridor—featuring clean water, diverse wildlife, and a reduced flood risk. Fully accessible to everyone and offering high amenity value, the renewed waterway will become a significant asset for Watford, improving the quality of life for residents and enhancing the experience for visitors, while safeguarding a vibrant natural environment for generations to come.

Stay informed about the River Colne’s progress by visiting the website, following us on social media (Facebook, Instagram, Twitter), or subscribing to our resident newsletter. That way, you can receive all the latest updates and volunteering oppotunities straight to your inbox and never miss a moment of the project’s journey.

Yes, walking routes and thoroughfares in parks will remain open, with diversion signs in place. Please note that the public will not be permitted to enter contractor working areas, this is to ensure everyone’s safety.

Some trees will be removed as part of the river improvement plans to provide a balance of tree cover along the River Corridor, to provide maximum positive outcomes for the river corridor and species within it. We will be planting new trees, shrubs and native species within the wider project area.

The council declared a climate and ecological emergency in 2019 and is committed to protecting the environment. These works are just one of the many actions we are taking to become net carbon neutral by 2030. Other include: planting 20,000 trees over the next 4 years, creating wild flower meadows and transforming the way people travel around Watford. For more information, visit our 'Sustainable Watford' page.

The works being carried out will not disrupt the local wildlife and if any protected species are found, all works will cease and the proper process will be followed. An ecologist will be onsite during the works to undertake surveys and study of native plants and wildlife to ensure there is minimal impact during these works.

A ‘misconnected’ pipe is when toilets, washing machines, dishwashers and other goods are incorrectly plumbed into a surface water drain. This can allow wastewater and chemicals to drain away into rivers and streams, damaging the environment and harming wildlife. This is illegal (under Section 109 Water Industry Act 1991) and it is the householder’s responsibility to ensure all household goods are plumbed into the wastewater sewer so it can be taken away and treated. For more information on identifying misconnected pipes and the sewage network, please click here.

If you see pollution in the River Colne (e.g. sewage solids, toilet paper, condoms, sanitary products, noticeable sewage smells) please call Thames Water on 0800 316 9800. They will ask: what you saw, when you saw it, where (including postcode, road name or local landmarks and features) and whether the sewage is entering the river or any other watercourse. For more information on reporting pollution, please click here.