Come and celebrate Chamber Mead with us

Come and celebrate Chamber Mead with us

The South East Rivers Trust (SERT) is inviting local residents to come and celebrate the newly-created Chamber Mead wetlands with a day of family fun, activities and guided tours.

The celebration day on Saturday 20th April will give nature lovers the chance to add plants to this critical pollution buster for the River Hogsmill, a precious chalk stream.

Families will also have the chance to learn about the health of the river by taking part in riverfly demonstrations, a scavenger hunt and nature craft activities. Guided tours of the wetlands will also be part of the day, which runs from 11am to 3pm.

The open day begins a fortnight of planting opportunities for schools and community groups. All the plants have been specially selected to absorb pollutants and attract pollinators and an increased range of wildlife across the Hogsmill Local Nature Reserve.

An aerial view of Chamber Mead wetlands
An aerial view of Chamber Mead wetlands

The wetlands in Ewell now divert urban pollutants from the Green Lanes Stream away from the Hogsmill, one of only 200 chalk streams in the world. Once filtered water is fed back into the river just downstream of the famous Stepping Stones, another 5km of waterway is protected as it flows into south London all the way to the Thames.

Dr Bella Davies, Co-CEO of SERT, said: “We’re thrilled to be giving the community the chance to learn all about Chamber Mead wetlands and crucially give people the chance to complete the project. The public have been very supportive of the wetlands from the start and adding plants is a wonderful opportunity to attract new wildlife not only to the water but the wider nature reserve. This will fulfill the potential of the wetlands to become another jewel in the crown of the reserve and make it an even bigger asset for the community. We’re excited to see the results in years to come on the Hogsmill, which should be a haven for brown trout, water voles and native crayfish, among other species which need our help in recovering their numbers.”

Councillor John Beckett, Chair of the Environment Committee at Epsom & Ewell Borough Council, said: “We are overjoyed to be able to join SERT on the Chamber Mead Wetlands Open Day, to celebrate the fantastic work that has been done here to boost biodiversity and reduce pollution in the Hogsmill River.  I hope that residents will join us to help complete the project, which will ensure the Hogsmill River Local Nature Reserve is a place where wildlife and nature can thrive, and one that we can enjoy for many years to come.”

An example of wetlands planting

Supported by the Hogsmill Catchment Partnership, the project has received funding from The Coca-Cola Foundation, Natural England (through the Species Recovery Programme), the Environment Agency, Surrey County Council, the Rivers Trust, the Zoological Society of London, Garfield Weston Foundation and Thames Water, with in-kind support from the landowner Epsom & Ewell Borough Council. The new wetlands are part of the wider Replenish programme in partnership with the Coca-Cola Foundation and the Rivers Trust. The aim of Replenish is to restore millions of litres of water in this and other local catchments, in turn improving biodiversity.

The public can meet the South East Rivers Trust and other partners for the activities at Green Lanes, Ewell, Surrey KT19 9SZ.

  • Speeches to officially open the wetlands will take place from 11.30am to noon. These will be by Jackie King, Chief Executive of Epsom & Ewell Borough Council, Dr Bella Davies, Co-CEO of the South East Rivers Trust, and The Worshipful Mayor of Epsom & Ewell, Councillor Rob Geleit, who will also cut the ribbon to officially open the wetlands.
  • Events in which the public can join in will run from 12.30pm to 3pm. There is no need to sign up but details can be found on our dedicated events page.
  • A few places are left on a planting day open to volunteers – on 24th April. Booking required.

Chamber Mead wetlands recognised at sustainability awards

Chamber Mead wetlands and their importance to the River Hogsmill were recognised at the 2024 Edie Sustainability Awards in London last night (6th March).

The shortlisting in the Nature and Biodiversity Project of the Year category was a huge honour for everyone involved at the South East Rivers Trust as well as the partners who have helped make the 2,000m2  wetland a reality.

The wetlands were recently completed in Surrey on a stretch of the Hogsmill just south of London. They will filter pollutants and become a haven for wildlife protecting 5km of the river, which is a rare chalk stream.

Part of the Chamber Mead wetlands
Part of the Chamber Mead wetlands with the public bridge in the background

This is a fantastic example of a nature-based solution improving the condition of our rivers. The project has diverted a contaminated tributary into the wetlands, which act as a filter before reconnecting cleaner water into the Hogsmill downstream of the famous Stepping Stones.

One of only about 210 chalk streams in the world, the Hogsmill suffers from urban road runoff, raw sewage discharges and misconnected plumbing that sends drain water directly into the river. A healthy chalk stream’s pure water, stable temperature and flows provide longer growing seasons than other rivers and support important habitat for species such as brown trout and native crayfish.

Creation of the wetlands has been carried out in partnership with Epsom & Ewell Borough Council, which owns and manages the Hogsmill Local Nature Reserve, a popular greenspace which will now benefit from this new community asset.

Bella Davies, Co-CEO of the South East Rivers Trust, said: “We couldn’t be more delighted that the Chamber Mead project has been recognised by the Edie Awards. The project has been more than 10 years in development. It has brought together a wide range of partners and funders to step up and share responsibility for improving water quality in the Hogsmill river, one of the country’s rare and precious urban chalk streams.

Dr Bella Davies at the Edie Awards
Dr Bella Davies at the Edie Awards

“Wetlands such as these are a great way to improve water quality, especially in urban areas, in this case by filtering water from one of the Hogsmill’s headwater tributaries. This water has been contaminated by toxic urban road runoff and sewage from storm tank overflows and misconnected pipes. The water will now enter the Hogsmill after it has been cleaned by the wetlands and help bring back endangered river wildlife such as brown trout and eels.

“We’re also thrilled that the public will see the wetlands develop into a space where wildlife such as dragonflies, birds and butterflies can thrive providing more opportunities to experience nature on their doorstep.”

SERT is now preparing a series of planting days for schools, community groups and the public to take place in the Spring, as well as an open day to introduce the project to the community.

Supported by the Hogsmill Catchment Partnership, the Chamber Mead Wetland project has received funding from The Coca-Cola Foundation, Natural England (through the Species Recovery Programme), the Environment Agency, Surrey County Council, the Rivers Trust, the Zoological Society of London, Garfield Weston Foundation and Thames Water, with in-kind support from the landowner Epsom & Ewell Borough Council.

The new wetlands are part of the wider Replenish programme in partnership with the Coca-Cola Foundation and the Rivers Trust. The aim of Replenish is to restore millions of litres of water in this and other local catchments, in turn improving biodiversity.

New Chamber Mead wetlands brings fresh hope for Hogsmill  

The South East Rivers Trust (SERT) has completed the construction of a 2,000m2 pollution filter which will bring major benefits to the Hogsmill chalk stream.

When planting takes place in the spring, the newly constructed Chamber Mead wetland will protect and improve 5km of river downstream, filtering pollutants and becoming a haven for wildlife. 

Chamber Mead wetlands during construction
The wetlands took shape during several months of construction

The project has been carried out in partnership with Epsom & Ewell Borough Council, which owns and manages the Hogsmill Local Nature Reserve, a popular greenspace which will now benefit from this new community asset. 

The wetland is a crucial project for the Hogsmill, which suffers adversely from pollution such as urban road runoff, raw sewage discharges and misconnected plumbing that sends drain water directly into the river.  

Water from the Green Lanes Stream has been diverted through a sediment trap and two wetlands. Filtered, cleaner water is then reconnected to the Hogsmill downstream of the famous Stepping Stones. 

News about the wetland’s completion comes in the week of World Wetlands Day, on Friday 2nd February. 

Dr Bella Davies, Co-CEO of SERT, said: “We are delighted that the construction phase of this important wetlands project has now been completed. It is destined to become a jewel in the crown of the Hogsmill Local Nature Reserve. The public has shown great enthusiasm for this project, and we will soon be calling on volunteers and community groups to add the plants that will really make the wetlands flourish as a magnet for wildlife. The water quality improvements that will result from the wetlands are designed to help the river become a healthier place for all, especially wildlife that thrive in a chalk stream, such as brown trout.” 

Councillor John Beckett, Chair of the Environment Committee at Epsom & Ewell Borough Council, said: “The council is committed to protecting and enhancing biodiversity in our borough, as per our Biodiversity Action Plan 2020-30.  This partnership project with the South East Rivers Trust will help to ensure that the Hogsmill Local Nature Reserve is a place where nature can thrive; from woodpeckers, hedgehogs and bats – to species whose numbers have dwindled such as water voles, fish and eels. We know our residents cherish this Local Nature Reserve and I hope that many can join the community planting days, which are a unique opportunity to be part of this fantastic project.” 

Michele Cooper, Environment Agency Catchment Coordinator, added: “In partnership with local communities, the Environment Agency is investing millions in chalk stream restoration projects across the country to foster more sustainable abstraction, tackle pollution from agriculture and the sewage system, and restore more natural processes.

“Chalk streams are precious habitats, havens for wildlife and highly valued by local communities and visitors alike. Together with our partners, we also continue to work hard to protect and enhance wetland habitats to benefit people and nature. Their future depends on collective action and this partnership project is therefore a much needed and welcome step towards addressing the many pressures these rare watercourses face.”

Part of the 2000m2 wetlands at Chamber Mead
The construction of the 2000m2 wetlands at Chamber Mead has been completed

SERT is now preparing a series of community planting days, to take place in the Spring. These will give residents the chance to plant the vegetation to help the wetlands counter pollutants.  

Schools, community groups and residents will be given opportunities to install plants that have been specifically selected to filter pollution, trap sediments and attract a variety of wildlife. Plants selected include yellow flag iris, ragged robin, purple loosestrife and brooklime.  

In time, SERT will also offer guided walks and outdoor education sessions for school children. A nature trail is planned for families to interact with the wetlands as they develop, alongside information boards which will detail the reasons why the wetlands were needed and the types of wildlife that should be attracted. 

The construction was carried out with Five Rivers environmental specialists.

Supported by the Hogsmill Catchment Partnership, the project has received funding from The Coca-Cola Foundation, Natural England (through the Species Recovery Programme), the Environment Agency, Surrey County Council, the Rivers Trust, the Zoological Society of London, Garfield Weston Foundation and Thames Water, with in-kind support from the landowner Epsom & Ewell Borough Council. The new wetlands are part of the wider Replenish programme in partnership with the Coca-Cola Foundation and the Rivers Trust. The aim of Replenish is to restore millions of litres of water in this and other local catchments, in turn improving biodiversity. 

 

The Chamber Mead wetland
The Chamber Mead wetland will become a ‘jewel in the crown’ of the Hogsmill Local Nature Reserve

Three actions to take after watching Swimming in Sewage

At the start of October, the South East Rivers Trust appeared on Channel 5’s documentary about sewage in our rivers. The programme demonstrated the extent of the problem nationwide, quoting swimmers and environmental campaigners. Below is a snippet of our involvement in highlighting the issues – and three actions you can take.

A combined sewer overflow
Dr Chris Gardner shows Michaela Strachan a combined sewer overflow © TurquoiseTV

“The soft sediment underneath – I think you can imagine what it’s made up of,” remarked Dr Chris Gardner to TV presenter Michaela Strachan during Swimming in Sewage: Britain’s Water Scandal.

Our Head of Science and Partnerships was describing what lies at the bottom of the River Hogsmill right next to a Combined Sewer Overflow (CSO), an  mechanism that sends raw sewage into rivers during heavy rainfall.

Aired on October 4, the documentary highlighted the effects of sewage being regularly pumped into our rivers, up and down the country. Rivers that were once clean to swim in are now full of what we flush down the loo, causing health issues for those unaware that raw sewage is being sent into them regularly, from these CSOs.

These pipes were designed to stop sewage backing up into homes during heavy rainfall, when sewage treatment works could not cope with the amount of waste and excess rainfall coming from urbanised environments. These single pipes combine waste water from our homes and businesses and surface water. They are supposed to be in operation sparingly. Last year, 15,000 CSOs across the country spilled water into our rivers for 2.5 million hours, the programme reported.

Chris Gardner and Michaela Strachan on the Hogsmill, for the Channel 5 Documentary Swimming in Sewage. Turquoise TV
Chris Gardner and Michaela Strachan on the Hogsmill, for the Channel 5 Documentary Swimming in Sewage. © Turquoise TV

Chris had given Michaela a tour of a clean looking section of the Hogsmill. One of only 210 chalk streams in the world, its clear water – filtered through springs – provides a superb environment for aquatic life.

But as Chris took the presenter to the confluence of where the river meets the Green Lane stream on the River Hogsmill, the colour of the water suddenly became much more murky. The cameras showed dirt and sediment on the riverbed.

Dressed in waders, the pair moved to the site of a CSO, where Chris pointed to clear signs of it sending sewage into the river very recently – most likely the night before when it had rained.

Investment needed

Michaela, recoiling at the thought of raw sewage in this rare chalk stream which should be rich in minerals, asked what could be done?

Chris replied: “We need to invest in the sewage works infrastructure. For the past few decades we haven’t had the investment to keep up with the population growth. We also have climate change and more intense rainfalls.”

Many of the sewers have been around since Victorian times, so Michaela also wanted to know if it was possible to upgrade them?

“There certainly is a technical challenge,” replied Chris, “but we put people on the moon with [what is now] the computer power of a pocket calculator 50 years ago so, surely, we can upgrade our sewage works to the standards required.”

Our Chamber Mead wetlands project, which began in late August, is very close to where the filming took place. The wetlands will help to divert water from road run-off and urbanised pollution away from the Hogsmill. It will divert the Green Lanes stream – as seen in the documentary – into a series of new wetlands and project 200 metres of this chalk stream.

But what can you do to help protect rivers from sewage and pollution?

First, you can demand action from your Water Company. The programme’s airing could not have been more timely, coming just after water companies submitted their business plans for 2025-30 to Ofwat. Our recent blog looks at these plans and urges you to sign up to your water company’s online session, where you can question them about the details. These take place before the end of November. Are their timetables for addressing this urgent problem of sewage fast enough? How will they upgrade infrastructure? What nature-based solutions in urban areas are they planning to combat water, combined with sewage, rushing into our rivers all at once during heavy rainfall?

Second, you can sign the Rivers Trust’s Nature2030 campaign, asking all political parties to make five nature pledges in their manifestos ahead of a General Election, which many expect to take place next year. This asks that the “polluter pays” and for a Natural Nature Service, to protect our environment.

Third, you can back the Rivers Trust’s call to end the #ChemicalCocktail polluting all our rivers. This letter to the Government asks for several protections to be included for rivers in the Chemical Strategy.

Hogsmill Community Newsletter

The Hogsmill Community Newsletter summarises the results of River Monitoring Initiative (RMI) sampling on the Hogsmill, together with other pollution monitoring and river-related activities and events.

The RMI is a national scheme for monitoring the health of rivers. Volunteers undertake regular surveys using a standard net sampling technique to count the number of certain “water quality sensitive” invertebrates.

An overall “score” is then calculated. A sharp fall or a drop below a “trigger” level could indicate pollution. This can then be reported to the Environment Agency (EA) to enable further investigation.