Gadebridge Park river restoration information page

Closes 31 Dec 2022

Opened 10 Sep 2021

Overview

We are working with Dacorum Borough Council and Affinity Water to help restore the River Gade at Gadebridge Park, a globally rare and valuable chalk stream. The project will provide multiple benefits, including improved habitats for wildlife, the protection of water resources for both people and the environment, and allowing local residents and visitors to get closer to the river and enjoy nature.

This project is part of Revitalising Chalk Rivers, a wider programme of projects we're working on with Affinity Water that aims to protect and restore rare chalk streams like the River Gade. As part of this programme, Affinity Water has completed a project in the upper section of Gadebridge Park, north of Gadebridge Lane, to provide new river habitats for wildlife and to improve the river’s water quality – you can find out more about this project at www.affinitywater.co.uk/corporate/environment/restoration/river-gade.

Our latest proposals will improve the river in the lower section of Gadebridge Park, between the grade II listed White Bridge and Queensway.

Together with Affinity Water, we are funding the river restoration project and Dacorum Borough Council will be contributing to its recreational and amenity aspects. Subject to gaining planning approval and securing all the necessary funding, we expect the restoration works to begin on site in Spring 2022.

This information page will be updated to share our progress and to let you know how you can get involved. Detailed information about the River Gade and our proposals can be found further below.

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September 2021 – view our latest plans!

We’ll be in the park on 21 September 2021 to share our latest plans, answer people’s questions and hear your views. Come and see us between 11-4pm near the splash park kiosk.  


Don't worry if you can't attend - our updated 'Indicative Landscape Plan' showing our latest proposals on a map of the park is below (a copy is also available to download by clicking 'Appendix 1 - Indicative Landscape Plan Sept 2021' under 'Related' at the very bottom of this page).

Your browser does not support inline PDF viewing. Please download the PDF.


A 'Detailed Designs' report explaining the proposals in further detail will also be available shortly. Check back here soon or join our mailing list for updates via email (details below). In the meantime, a summary of our plans can be found under 'Our proposals' further below. 

We want to hear from you

Subject to gaining planning approval and securing all the necessary funding, we expect the restoration works to begin on site in Spring 2022. There’s still time to decide on a number of finer details and we’re keen to hear your comments and ideas, especially from local people and regular visitors to the park. We are particularly interested to hear people’s thoughts about how we can ensure our plans are accessible to all, including people with disabilities, and how we can provide added benefits for the park’s wildlife and encourage everybody to value and protect our rare chalk streams. Examples of things that we’d like to hear people’s views on include:

  • Landscaping – the location of landscaped areas and plant types/species;
  • The location of wildflower meadows and plant types/species;
  • Accessibility considerations – for example, for footpaths and bridges and audio or braille options for information boards;
  • The best location for the benches, picnic tables, information boards, beach areas and dipping platforms;
  • Community aspects – for example, name plaque ideas for benches and landscaped areas;
  • How we can encourage local people to support our chalk streams – for example, educational riverside talks, resources for children etc.

Please share any comments and ideas with us on 21 September 2021. Alternatively, to get in touch at any time, please email us at gadebridgepark@environment-agency.gov.uk. Please be aware that some elements of our designs will need to be finalised sooner than others ready for construction to hopefully begin on site in Spring 2022. Please contact us with any comments as soon as you can and latest by December 2021.

Join our mailing list

If you would like to join our mailing list to receive future updates for the duration of the project, please contact gadebridgepark@environment-agency.gov.uk with your name and email address. We will not use your contact details for any other purposes. 

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Why does the River Gade need improving?

The River Gade is a chalk stream; a globally rare and valuable habitat. 85% of the world’s chalk streams are in England and 30% (68) of these are in the south east. Chalk streams are unique because they get most of their water from rain-fed groundwater held in underground chalk ‘aquifers’. This mineral-rich water is able to support a wide range of plants and wildlife.

At the moment, only 17% of chalk streams are in their natural state. Like many chalk streams, the River Gade faces pressure from low flows and historic modifications to its channel that limit the river’s habitats and the wildlife it can support. The watercourse is currently classified as having a 'poor' ecological status under the European Water Framework Directive (WFD).

Historic modifications

In Gadebridge Park the River Gade flows down an artificial channel created to supply water to the now demolished Bury Mill. The artificial channel is ‘perched’, meaning that it sits at a higher level than the valley bottom - the natural course of the river through the park. This means that the river is disconnected from its floodplain. When flooding occurs in the valley bottom, the water remains in the park for long periods of time because it is unable to flow back into the channel.

Image 1: Prolonged flooding in Gadebridge Park. The water is not able to flow back into the ‘perched’ channel.
Image 1: Prolonged flooding in Gadebridge Park. The water is not able to flow back into the ‘perched’ channel.


Image 2: A diagram showing a perched channel.Image 2: A diagram showing a perched channel.



The artificial channel is much wider and straighter than a natural chalk stream would usually be. This often leads to a build-up of sediment and excessive vegetation growth. The river has little resilience to drought conditions, as the water is spread thinly across a wide expanse of channel.

Image 3: Excessive vegetation growth blocking the channel in Gadebridge Park.Image 3: Excessive vegetation growth blocking the channel in Gadebridge Park.


The weir at our Bury Mill Gauging Station and other remains of historic in-channel structures act as barriers to fish. These structures can also cause sediment and vegetation to build up, impacting on river habitats and wildlife.

Image 4: The Environment Agency’s Gauging Station. The channel consists of a concrete bed and banks for about 40 metres.

Image 4: The Environment Agency’s Gauging Station. The channel consists of a concrete bed and banks for about 40 metres.

Image 5: Remains of old weirs affect fish movement and cause the build-up of sediment and vegetation.

Image 5: Remains of old weirs affect fish movement and cause the build-up of sediment and vegetation.

Low flows

The River Gade often suffers from low flows due to:

  • Spring flows (groundwater emerging at the surface) being diverted into an underground tunnel (culvert) rather than feeding the river Gade;
     
  • Being disconnected from the groundwater table (see Image 3). For a chalk stream, where over 70% of its flow is from groundwater, this can have a significant impact on its resilience during periods of low flows and to wildlife in the channel;
     
  • Water being taken (abstracted) for public water supply.

Most water we drink in the South East comes from rainwater stored deep beneath our feet in natural chalk ‘aquifers’. These also feed our chalk streams. In 2018 Affinity Water reduced net abstraction in the Gade catchment by 2,342,400 m3/year (that’s an average of 6.4 million litres a day). However, demand for water in the South East remains high. We all need to reduce the amount of water we use - every drop wasted is water that could be sustaining our rivers, streams and lakes.

Visit www.waterwise.org.uk/watersworthsaving/ for ideas on reducing your water use to help our chalk streams. 

Our objectives

Together with Dacorum Borough Council and Affinity Water we want to:

  • Improve the River Gade and the adjacent parkland for wildlife;
  • Provide more opportunities, accessible to everyone, for people to get closer to the river and enjoy nature;
  • Provide more opportunities to learn about the River Gade, both its historical importance to the landscape and its value as a rare chalk stream;
  • Improve the river’s resilience – its ability to cope with and adapt to the pressures of low flows and climate change;
  • Improve floodplain connectivity, but reduce the impact of flooding – i.e. flood water can be stored on the floodplain when needed, but doesn’t sit on the parkland for long periods of time;
  • Improve biodiversity in the River Gade, so that it supports Good Ecological Status under the European Water Framework Directive;
  • Reduce the barriers to fish movement and impoundment caused by river structures, including the Environment Agency’s gauging station;
  • Improve flows in the river, to lessen the build-up of sediment and vegetation and to reduce the need for maintenance;
  • Improve the ability to monitor river flows in the River Gade.


Our proposals

JBA Consulting carried out an initial feasibility study for Gadebridge Park from 2016 to 2018 in consultation with all project partners and key stakeholders. Based on its results a number of proposals were developed that we consulted the public on from 20 July to 30 September 2018.

Thank you to everyone who took part and provided their comments. You can view the submitted responses and our consultation summary report at https://consult.environment-agency.gov.uk/hnl/gadebridge-park-river-restoration/

Our latest proposals include:

  • Realigning the part of the River Gade located downstream of the grade II listed White Bridge back to the valley bottom (through the centre of the park at its lowest point). This will reconnect the river to its floodplain and to the groundwater table below;
     
  • Re-routing spring flows - which are currently diverted through a culvert (underground tunnel) and discharged into a fishing lake at Kings Langley 5km downstream - into the new realigned channel. This will provide additional flow to the river, increasing its resilience to low flows, improve the river’s water quality and help to restore natural characteristics of a chalk stream such as a more alkaline PH and a stable temperature all year round;
     
  • Replacing the existing Bury Mill gauging station with a gauging station on the new realigned channel that is passable to fish and has a reduced impact on the river;
     
  • Creating wetland areas alongside the river channel to provide new habitats for wildlife;
     
  • Providing new footpaths alongside the river, a fully accessible bridge crossing the new realigned channel from the Queensway carpark to the Bowls Club and an informal crossing point in the centre of the park - all for people’s enjoyment of the river;
     
  • Providing dipping platforms and gravel beach areas for people to get closer to nature;
     
  • Installing information boards within the park to share the River Gade’s historical importance to the landscape and help people to understand and value our rare chalk streams.


Contact us

For further information about the project please see the documents and links below and check back for updates on this information page.


If you have any questions we will be happy to help:

*Please only contact Kelly with questions specifically about Gadebridge Park’s river restoration project. Questions about all other aspects of Gadebridge Park should be sent to Robert Cassidy at Robert.cassidy@dacorum.gov.uk

A reminder...

We’ll be in the park on 21 September 2021 to share our latest plans, answer people’s questions and hear your views. Come and see us between 11-4pm near the splash park kiosk.

Or, to get in touch and share your comments and ideas or ask us a question at any time, please email us at gadebridgepark@environment-agency.gov.uk.

If you would like to join our mailing list to receive future updates for the duration of the project, please contact
gadebridgepark@environment-agency.gov.uk with your name and email address. We will not use your contact details for any other purposes. 


We look forward to hearing from you. 

Audiences

  • Recreational and commercial river users
  • Members of the public with an interest in the river, the species and conservation
  • Statutory organisations
  • NGOs
  • Members of the public
  • Elected representatives, including MPs
  • Local councils
  • Academics
  • Environment Agency customers
  • Local authorities
  • District and parish councils
  • Environmental bodies
  • Water companies
  • Community groups
  • Flood action groups
  • Environment Agency colleagues
  • Lead Local Flood Authorities
  • Town and parish councils

Interests

  • Flood management
  • Water resources
  • Water quality
  • Drought
  • Habitats and wildlife