"Leaky dams" at Pott Shrigley in Cheshire have been working well during Storm Barra over the past couple of days, helping to slow down the flow of flood water in Harrop Brook and the River Dean. 


Leaky by name, leaky by nature, even during high flows, "leaky dams" are built in small streams from natural materials - they will only let a certain amount of water through, slowly draining the trapped water to reduce the flood peak.  They are part of Natural Flood Management measures being implemented by a range of public sector and third sector organisations across the Mersey catchment to help reduce flood risk.

Funded by the Environment Agency, Mersey Rivers Trust installed the leaky dams at Pott Shrigley in March 2021, working in partnership with local farmers and landowners. Monitoring by Mersey Rivers Trust staff today (9 December) has shown that these new leaky dams have been able to hold back water in the headwaters of Harrop Brook and slowing down the flow of water into the downstream River Dean. 

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Over the coming months, Mersey Rivers Trust will also be planting new trees at Pott Shrigley to complement the leaky dams.  Once established, the new trees will help take up water and allow more water to soak into the ground during flood conditions, further slowing the flow of water into the downstream river system.

Liverpool City Region Mayor Steve Rotheram joined volunteers in a litter clean-up operation around part of the River Alt on 19 November to support our environmental initiative called ‘Plastic Free Mersey’.

The Plastic Free Mersey project is led by environmental charities Mersey Rivers Trust and Thames21. It builds on Thames21’s award-winning litter survey work, which has identified the most common plastic litter items on the Tidal Thames.

The Plastic Free Mersey project was publicly launched on 22 July in Liverpool and initially runs for two years. This project is training and supporting volunteers to collect valuable data about the plastic items they find along the River Mersey and its 23 tributaries that flow from the Pennines to Liverpool Bay. The litter found will be safely removed and correctly disposed of.

Steve Rotheram, Mayor of the Liverpool City Region, said: “The River Mersey has been central to our region’s fortunes throughout our history. We’ve come a long way towards cleaning it up since Lord Heseltine described the Mersey as an ‘affront to the standards a civilised society should demand of its environment.’

“The Plastic Free Mersey campaign has my full support – and I am hoping to make further announcements on my ambitions to clean up the Mersey in the near future.

“We are very proud to join all the volunteers, Thames21, Mersey Rivers Trust, and Plastic Free Mersey project partners in supporting this brilliant campaign today. It’s great that local residents get to take part in helping to do their bit for the environment and we hope that it will encourage them to reduce, reuse and recycle plastic.”

John Sanders, Director at Mersey Rivers Trust, said: “We are very pleased that the Metro Mayor is supporting our mission to bring awareness to the consequences that littering can have on the River Mersey waterways. We welcome his endorsement of our project aims to identify how plastic litter gets into our rivers and the actions required to achieve a plastic free Mersey. We would also like to thank Knowsley Council for all their help with the litter clean-up today, as well as Merseyside Recycling and Waste Authority for the provision of litter clean-up equipment".

Debbie Leach, CEO of Thames21, said: “We are delighted that the Metro Mayor has endorsed our Plastic Free Mersey project and shares our belief that plastic litter has no place in our rivers or the natural environment. So much plastic is being littered – not only is it trashing our rivers, creating an eyesore and harming wildlife, it is also a waste of a valuable resource that could be recycled into useful products.”

Plastic pollution damages ecosystems, discourages people from visiting their rivers and seas, and is a source of increasing concern for riverside communities. The Plastic Free Mersey project focuses on identifying and quantifying plastic litter and other litter on riverbanks and estuaries to spur changes in people’s behaviour, such as reduced littering and increased recycling, and to provide essential information to the plastics and waste management industries to support circular economy solutions.

By collecting information on plastic and other litter along with information on people’s waste disposal (including littering) habits, the project will tackle how society uses and disposes of plastic. Through industry collaboration, the initiative will help shape behaviour change to keep litter out of waterways. It will also explore ways to increase the effectiveness of plastics recycling and management.

Thames21 and Mersey Rivers Trust is  working in collaboration with LyondellBasell, one of the world’s largest producers of plastics and chemicals, INOVYN, Europe’s leading producer of vinyls and SUEZ, a global expert in the water and waste sectors. These three business partners have company sites in the River Mersey catchment. The project also has the support of the British Plastics Federation, PlasticsEurope, RECOUP, and the endorsement of the Liverpool City Region, Chester West and Chester Council, Warrington Borough Council, and Merseyside Recycling and Waste Authority (MRWA). Both Suez and MRWA have supplied litter pickers for the Plastic Free Mersey volunteers to use.

The project aims to create and test an effective model of co-operation between NGOs, researchers and the plastics industry to tackle plastic pollution in waterways. This model can then be applied to other river catchments in the UK and abroad. The project team is engaging with academic experts and other businesses in the plastics sector to gather advice and contributions to ultimately generate solutions (based on robust evidence and methods) to the excessive levels of plastic and other litter in and around our rivers. Such solutions comprise behavioural and management changes across at the individual, community, business, and government levels.


Background information

  • Collecting robust evidence is fundamental to addressing environmental issues. Thames21’s Thames River Watch project trains volunteers to count and quantify the types and amounts of plastic litter on the Tidal Thames. Its 2015-19 surveyresults can be found on the Thames21 website.
  • Sustainability challenges are being tackled through EU and UK legislation with bans of unnecessary single-use plastics, Deposit Return Schemes and Extended Producer Responsibility and the European plastics producers are now calling for mandatory 30% content of recycling contentin plastic packaging by 2030.
  • LyondellBasell and INOVYN are active participants in the Operation Clean Sweep®(OCS) initiative, run in the UK by the British Plastics Federation, the nation’s leading plastic trade association, and Plastics Europe in their businesses on the continent.
  • The OCS international initiative is designed to prevent the release of plastic granules (pellets, flakes and powders) into the environment during handling by the various parties in the plastics value chain. Companies signing up to OCS commit to improving worksites to prevent and address spills and to create and to publish internal procedures to achieve no industrial plastic material loss, among other points.
  • Keep up to date with our project via our website and #plasticfreemersey on Twitter.

About the Mersey Rivers Trust and Thames 21

The Mersey Rivers Trust and Thames 21 (www.thames21.org.uk) are environmental charities working in partnership with all those interested in improving local rivers and waterways for people and wildlife. Both charities are part of the national Rivers Trust movement. 


Part of INEOS, INOVYN is Europe’s leading producer of vinyls and in the top three worldwide. With an annual turnover of €3.1 billion, INOVYN has circa 4,200 employees and manufacturing, sales and marketing operations in 8 countries across Europe. INOVYN’s portfolio consists of an extensive range of class-leading products arranged across General Purpose Vinyls; Specialty Vinyls; Organic Chlorine Derivatives; Chlor Alkali; Sulphur Chemicals; Salt; and Electrochemical and Vinyls Technologies. INOVYN’s annual commercial production volume is circa 10 million tonnes. More information at www.inovyn.com.

INOVYN has 3 sites in the UK: Runcorn, Cheshire; Northwich, Cheshire; and Newton Aycliffe, County Durham.

About LyondellBasell

LyondellBasell (NYSE: LYB) is one of the largest plastics, chemicals and refining companies in the world. Driven by its employees around the globe, LyondellBasell produces materials and products that are key to advancing solutions to modern challenges like enhancing food safety through lightweight and flexible packaging, protecting the purity of water supplies through stronger and more versatile pipes, improving the safety, comfort and fuel efficiency of many of the cars and trucks on the road, and ensuring the safe and effective functionality in electronics and appliances. LyondellBasell sells products into more than 100 countries and is the world’s largest producer of polypropylene compounds and the largest licensor of polyolefin technologies. In 2021, LyondellBasell was named to FORTUNE Magazine’s list of the “World’s Most Admired Companies” for the fourth consecutive year.

More information about LyondellBasell can be found at www.lyondellbasell.com.

SUEZ Recycling and Recovery UK

SUEZ Recycling and Recovery UK was established in the UK in 1988 as part of the global SUEZ group. We manage the waste sites on behalf of the Greater Manchester Combined Authority (GMCA), managing 1.1 million tonnes of waste arising from nearly 2.3 million residents. We help to reduce the environmental impact of our customers’ waste by recycling and extracting the value from it, putting Greater Manchester’s waste to good use. Our company’s diverse activities are guided by a vision to engineer a society where there is no more waste and our goal is to help create a circular economy in which nearly all waste materials are given a second life and reused, recycled or recovered for their energy content. Passion for the environment is a core value for us and we are proud to support efforts to keep our communities clean and tidy. More information at www.suez.com. Several waste sites which SUEZ manage are located near the River Mersey.

About the British Plastics Federation

Established in 1933, the British Plastics Federation is the UK’s leading trade association for the plastics industry, representing the entire supply chain, including raw material suppliers, manufacturers and recyclers. www.bpf.co.uk

About PlasticsEurope

PlasticsEurope is the pan-European association of plastics manufacturers with offices across Europe.  For over 100 years, science and innovation has been the DNA that cuts across our industry. With close to 100 members producing over 90% of all polymers across Europe, we are the catalyst for the industry with a responsibility to openly engage with stakeholders and deliver solutions which are safe, circular and sustainable. We are committed to implementing long-lasting positive change. www.plasticseurope.org/en

Treasure Your River - Litter Art Weekend

Ahoy there! Join our crew on 18th & 19th September to help us build a giant pirate ship out of litter! There will be lots of other activities too to keep the whole family entertained.

👧 Fun for all the family
🎨 Paint, make a pirate hat and much more!
🌳 Learn about your local river, the animals that live there and the negative impacts of litter

This event is free and does not require booking, just turn up


We are proud to announce that our first wave of volunteers have successfully completed their training to be citizen scientists on the Plastic Free Mersey Project ! 

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The data our volunteers will collect using the litter survey methods they have learnt will help to encourage a positive change in people’s behaviour around plastic waste disposal, with less littering and more recycling. 

During our online training sessions, volunteers learnt about the problems associated with plastics in rivers, including how animals may mistakenly perceive plastic to be food due to the smell and the way that macroplastics can fragment into smaller pieces that looks similar to food.  Eventually plastic will break down to become microplastics which can easily be ingested by river and sea animals.  We emphasised the importance of this project and how citizen science projects can empower many people to become change makers. 

Volunteers then attended our practical training sessions in Salford and Liverpool to practice the survey methods and discuss important risk assessment procedures. Several volunteers have now been carrying out their first surveys and we are starting to get data on the different types and amounts of plastic in our rivers. 

Read more herehttps://www.thames21.org.uk/2021/10/citizen-science-volunteers-ready-to-contribute-to-our-plastic-free-mersey-project/

Want to get involved and help? 

We are running another round of online and practical training sessions as follows:

The next online training session is on:

Monday 18th October:  7pm to 8.30pm

The next practical outdoor training sessions are on:

Friday 19th November: 1pm to 3pm  (Liverpool City Region - venue to be confirmed)

Sunday 21st November:  10am to 12 noon (Kersal Wetlands, Salford)

Please email This email address is being protected from spambots. You need JavaScript enabled to view it. if you would like to get involved.

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