Could you help us this Giving Tuesday?

Could you help us this Giving Tuesday?

Think of us on #GivingTuesday – 28th November

Giving Tuesday was created in 2012 and has now grown into an international movement that is embedded on the social calendar annually, with the simple idea of doing good.

What better way is there to do that than make a donation on Giving Tuesday (28th November 2023) or instead of a physical present this festive season, to help protect rivers – our very lifeblood?

While there are many great causes, one that underpins our very existence – water – is hard to ignore.

Much of our drinking water is abstracted from rivers, supplementing what is stored in reservoirs to supply the needs of our homes and businesses.

However, in the South East we live in an area that is classed as water-stressed. This means that we are already facing a water shortage because of a growing population and climate change, which brings with it erratic weather patterns, from sudden storms from which we can’t capture all the water to drought.

All this puts huge pressure on the wildlife that thrives in rivers. Your rivers. Rivers that have been straightened, boxed in by concrete or boarding along the edges thwarting animal movement between water and land, or restricted by weirs and other barriers – all in the name of convenience for people at various times in our history.

But this has left our rivers unable to function as they should, to allow fish to migrate (some as far as the sea) to better habitats, to allow flowers to flourish to attract pollinators, or to give creatures that move between water and land the chance to do so.

The very habitats that support the wildlife that supports our existence needs help – and we’re on a mission to make that happen.

However, we can’t install fish passes or ‘rewiggle’ rivers to make them places where aquatic life can truly thrive without funding.

By the end of November, many people are already making decisions about gifts for the festive season. Many of you might be tempted by offers on Black Friday weekend (23rd to 27th November). But many of you might be thinking that a gift to nature might be better for your recipients for Christmas-time festivities this year – a year in which we have made inroads in many areas.

Some highlights from this year include:

  • encouraging people in the Medway to take a first step to caring for their local river by addressing their reliance on single-use plastic – 70 people signed up to become official Medway River Guardians with many of them becoming River Champions.
  • working with landowners in the Beult to install nature-based solutions to retain back water in the landscape for the benefit of wildlife and people. We’re now building up similar work on the Darent
  • creating new fish passes, from a baffle weir to improving the wish stream so fish can access better habitats
  • training citizen scientists to map out invasive non-native species on the Wandle and continued our volunteering events at Morden Hall Park
  • starting to create a new wetland at Chamber Mead on the Hogsmill
  • introducing rivers to dozens of schools and hundreds of children through our education programmes
  • Hosting Loddon Rivers Week and contributing sessions to London Rivers Week
  • Setting up a project to reintroduce water voles, eels and trout to the Hogsmill
  • Advising the UK’s largest greenhouse salad crop grower on water resilience

We couldn’t do it without funding.

Please consider making a one off donation to the South East Rivers Trust this Giving Tuesday, or signing up to make a regular donation. Visit our donate page for details.

A backwater to boost the Teise

Anglers have already reported seeing small fish using a new backwater on the River Teise in Kent just days after it was created by the South East Rivers Trust.

Taking just over a week to construct in September, the backwater has created a refuge for aquatic life taking cover from high flows or pollution incidents emanating from the main river.

A natural depression had formed in the land
A natural depression had formed in the landscape

A natural depression in the landscape, which might actually have been the original course of the river, proved the perfect place to construct this new backwater, near Goudhurst.

The depression was dug out to a size of 20×8 metres by our contractors FGS Pilcher. They used two diggers and four dumpers to create the full depth of the wetland.

The deepest section was created where it would be fed by the river and then a slope was built to the far end. This will prevent fish becoming trapped and ensure that the backwater will always hold water, even during low flow conditions.

It is always a bonus when materials can be reused. We placed root plates and large pieces of timber within the backwater to provide additional habitat. The complex root plates provide great cover for juvenile fish, while the large pieces of timber may be used by amphibians accessing or exiting the backwater, or as a perch for birds.

We also have plans for other large pieces of timber generated during the construction works. We will be returning to the site to introduce some of these big bits of wood into the river, to help increase habitat diversity within the Teise itself.

We have begun to plant the backwater's edge with ferns
We have begun to plant the backwater’s edge with ferns

We have recently planted some of the backwater edges with ferns and other flora sourced from the riverbank nearby. These have been supplemented with a natural pond/wetland seed mix to attract insects and birds when they grow next spring. These will help the backwater become a haven for dragonflies and damselflies.

The work, supported by the Environment Agency, is part of our mission in the Teise Habitat Improvement project to improve this sub-catchment of the River Medway.

In recent years we have removed four concrete weirs to allow fish to reach different habitats and added woody materials such as deflectors to improve river habitat.

We have also worked closely with the Teise Angling and Conversation Society to improve the course of a heavily modified and dredged river and improve the habitats for brown trout, rainbow trout and grayling which frequent the watercourse.

The completed backwater on the Teise
The completed backwater on the Teise

New online tool highlights nature-based solutions to tackle road runoff

A new online tool has been launched this week to help tackle road runoff pollution in London’s rivers by highlighting the best places to install nature-based solutions such as wetlands.

The development of the first-of-its-kind tool by Thames21 builds on years of research by the environmental charity and its partners Middlesex University and the South East Rivers Trust, which contributed with mapping, scoping and reporting.

Pollution from our roads adds to a number of problems for our rivers coming from sewer overflows, litter and misconnected drains. However it is often the Cinderella of pollution topics, because it receives far less public attention than sewage or agricultural causes.

Research from the Rivers Trust shows that the UK’s 1,600 rivers are affected by a cocktail of chemicals that are speeding up aquatic nature-loss, affecting insects, birds and mammals.

Road runoff goes straight to rivers
Road runoff goes straight to rivers

Road runoff can contain residue from oil spills, as well as tyre and brake wear from vehicles. These build up during dry weather and are then washed into rivers and streams when it rains.

The new tool will help decision makers prioritise the right water quality improvements:

  • in greenspaces that lie between the road and the river
  • at road locations in Outer London where surface water drains to the rivers; and
  • on London’s main strategic road network (includes Transport for London’s roads and some sections of National Highways’ and local authority roads)

Thames21 started its initial road runoff project identifying key polluting roads in 2019, with funding from the Mayor of London, Transport for London, and the Environment Agency. The British Geological Survey built the online decision support tool ‘Road Pollution Solutions’ and provided some additional support through the UKRI NERC-funded CAMELLIA project.

The South East Rivers Trust contributed research on sites in South London, including Surbiton, using its GIS mapping technology and catchment-based approach, identifying places where solutions such as wetlands could be built to counter the pollutants. By providing a natural barrier and filter using nature-based solutions, some of this road runoff pollution can be captured and prevented from entering rivers in the first place.

Users of the tool can search different boroughs, pinpoint particular areas and see just how polluting they are. This will help to prioritise where solutions could be put in place as mitigation. The tool shows the location of rivers, sewage outfalls and areas that drain into waterways.

Online road runoff tool example
An example of how the road runoff solutions user guide works

Modelling has shown that 2,415 road sections covering a total of 451.43km of London’s roads assessed pose a high risk of causing road runoff and are therefore a priority. Roads where heavy goods vehicles regularly apply their brakes are often the worst affected.

Community groups can also easily see pollution hotspots and help to suggest solutions by working for example with the authorities or through catchment partnerships.

The tool – which extends to all outer London boroughs – allows uses to access data by boroughs or river catchment and includes the Wandle, Beverley Brook, Hogsmill, Upper Darent, Lower Cray and Upper Cray.

Working in partnership, authorities responsible for these roads could intervene by providing nature-based solutions in these areas to help make runoff cleaner, and improve water quality in local rivers and watercourses.

Find out how the tool works by reading the user guide.

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.

Loddon Rivers Week puts focus on the long term

Volunteers came out in large numbers during this year’s Loddon Rivers Week, held in September, to enhance river habitats in various ways, such as by adding gravels and installing deflectors.

Some of the 80+ volunteers across half a dozen sites, who clocked up more than 300 volunteer hours, were part of established groups which regularly look after sections of this river network.

However, this year’s focus week on the Loddon, co-ordinated by the South East Rivers Trust, was also a launchpad for future action to enhance this river network, which stretches across Hampshire, Surrey and Berkshire.

Many people became involved in caring the river for the first time, including families keen to get involved in volunteer work parties or learning to assess river health through carrying out Riverfly monitoring for invertebrates, which they can do regularly in the coming months.

Our Loddon Catchment Officer Lou Sykes reports.

The Fish: improving habitats

Volunteers prepare to install gravel into the River Whitewater
Volunteers prepare to install gravel into the River Whitewater

Volunteers installed 21 tonnes of gravel into the River Whitewater at Bassetts Mead, Hook, to establish deep pools and shallow riffles, creating a rollercoaster of newly improved habitat for fish and invertebrates. Fresh gravels allow fish to spawn.

Over the past three years, in partnership with Hampshire & Isle of Wight Wildlife Trust, 81 tonnes of gravel have been added to the river, improving a 200 metre section of the river.

During this year’s Loddon Rivers Week activities, volunteers also built a willow dead hedge, protecting the new riffles from dogs and children passing by on the footpath.

The new dead hedge at Bassetts Mead protecting the river
The new dead hedge at Bassetts Mead, protecting the river

The sun: bringing light to the Petty’s Brook

Petty's Brook cutting back trees to bring light to the river
Vegetation at the Petty’s Brook was cut back to bring light to the river

In Chineham, near Basingstoke, volunteers ‘daylighted’ a section of the Petty’s Brook. The stream in this section is largely overshaded, has a concrete lined bed and banks, and acts more like a small canal than river environment.

Overshading of a river can be one of the reasons that prevents the river from reaching good ecological status under the Water Framework Directive.

Trees are a vital element of the ecology of a river environment: they help to reduce water temperatures in summer months and to maintain oxygen levels in the water. Aquatic plants and algae are also an important component of a healthy stream, and excessive shading and reduced light prevents these from growing. We must create the right balance when restoring rivers, creating dappled shade to get the best of both worlds.

With the Chineham Volunteer Group, a relatively new group, we removed vegetation that was causing the river to be enclosed in a tunnel of trees and shrub, giving the stream encouragement to grow some aquatic plants.

Sticklebacks – a torpedo shaped small fish – moved in quickly post-clearance, giving young children at the event the opportunity to catch and inspect them in a net before setting them free back into their revamped environment.

The bugs: training communities to identify invertebrates

A riverfly sample from the upper Loddon
Families learnt to identify invertebrates in a Riverfly sample taken from the upper Loddon

Water quality is the hot topic in the Loddon catchment this year, with projects starting to accurately monitor the state of the water on our patch.

Riverfly monitoring, in part measuring which invertebrates are in rivers, is a nationally important citizen science initiative used to monitor the health of rivers and to detect pollution events.

This year, we included a riverfly ‘show and tell’ for a keen group of residents in and around Basingstoke who will soon be donning wellies or waders to start monitoring the upper stretches in our catchment.

We introduced the basics and set them up to get them identifying the invertebrates in the samples. The four bullhead fish that made it into the invertebrates sample were a happy addition to the , freshwater shrimps, mayflies, snails and leeches also found.

Revisiting the past to see the difference

In addition to all the new activities this year, we also revisited on old project at Arborfield near Reading – a novel nature-like bypass channel facilitating fish migration around four permanent weirs, which impound and restrict rivers: 11 years on, a quick fish survey showed brown trout, chub, barbel, perch and pike all living in the established channel.

As part of this event, the Wild Trout Trust demonstrated some habitat improvement techniques, installing a woody deflector and willow ledge, to improve habitat in the new channel.

Our video shows the water flowing over the new deflector.

Thank you to partners and funders

Loddon Rivers Week, which has been running since 2017, does not happen without an enormous amount of collective effort from partners, and a special thank you must go to the Environment Agency and Network Rail for funding the coordination of the week.

We would also like to thank the partners involved in the week, including Hampshire & Isle of Wight Wildlife Trust, Loddon Fisheries and Conservation Consultative, Wokingham Borough Council, Basingstoke & Deane Borough Council, Chineham Volunteer Group, Blackwater Valley Countryside Partnership, SOLVE (Save Our Loddon Valley Environment), Hook Parish Council and Rushmoor Borough Council.

We’ll be back next year to repeat the progress made this year! Meanwhile, read our River Loddon storymap to find out the issues faced by this network, learn about what the catchment partnership, comprised of dozens of organisations, has achieved already and how you can become involved. Or keep an eye on our events page for volunteering opportunities.

 

Water and sewage plans – are companies listening?

On 2nd October water company business plans for 2025-2030 were submitted to Ofwat, who will scrutinise them to determine whether they represent value for money for water bill payers.

Earlier in the year, we asked you to have your say about water companies’ draft Water Resources Management plans. Six months on, these have been updated to final plans, alongside ‘Drainage and Wastewater Management’ plans – which focus on the dirty side of the water equation. These two plans form the basis for how water companies will manage water and sewage for the next five years and underpin the just-released business plans.

Below, we assesses the updated plans from Affinity Water, South East Water, Southern Water, SES Water and Thames Water – the companies operating across the South East Rivers Trust’s (SERT) area.

You can still have your say

We’re urging you to take further action to ensure these plans leave our rivers and the environment in a better state.

Now that plans have been submitted, Ofwat is encouraging you to continue to have your say and question the companies about the details.

This autumn, the companies will host Your Water, Your Say sessions (listed at the bottom of this blog). You will be able to speak to water company representatives, in groups and online, about their plans.

Alternatively, you can write to the Secretary of State for the Environment with your comments at water.resources@defra.gov.uk or fill in a survey about the plans, by 1st December.

What are these plans and why do we care?

Over abstraction affects rivers
Over abstraction from rivers for our water supplies affects wildlife

Water Resources Management Plans (WRMPs) set out how water of sufficient quantity and quality will be supplied to the population for the next 50 years.

This is a massive challenge in the south east, where we face a shortfall of 2.6 billion litres if nothing is done.

The WRMPs include plans to build new ‘supply schemes’ such as reservoirs, water recycling plants and water transfers from other regions, as well as ‘demand measures’ – for example by fixing leaks and encouraging wise water use – to reduce water use per person.

 

At SERT, we care about these plans because ultimately water for use in our homes and businesses is pumped from rivers and groundwater aquifers, which also feed many waterways and their habitats. As climate change bites and the population grows, demand for water is increasing; if water resources are not managed appropriately, rivers and wetland environments will suffer.

Meanwhile, Drainage and Wastewater Management Plans (DWMPs) set out how sewer and drainage systems will be upgraded to cope with population growth and peaks in surface water as rainstorms become more frequent and intense with climate change.

Clearly, the current sewage treatment system isn’t fit for purpose, with raw sewage spilling into rivers and coastal areas on a near daily basis. SERT wants the DWMPs to ensure sewage systems are upgraded at pace and measures are implemented to slow the flow of stormwater into sewers and prevent sewer overflows. This is the first time that water companies have been obliged to develop DWMPs and we welcome their existence.

Do the updated plans respond to our calls for change?

Earlier in the year, we responded to consultations on the WRMPs, and a year ago to consultations on the DWMPs.

Leakage – some improved promises made

SERT, along with many customers and stakeholders, have urged the water companies to do more to tackle leakage.

Water companies in the region are aiming for the government’s target of 50% leakage reduction by 2050, but now with additional interim targets: 20% by 2027 and 30% by 2032.

Thames Water loses around a quarter of the water it puts into supply through leakage; it is particularly encouraging to see an increase in ambition since their draft plan, which only aimed for a 16% reduction by 2030.

We challenged SES Water to roll out ‘smart’ water meters to all customers, household and non-household, by 2030.

We are delighted the company has committed to doing so. Smart meters will help to quickly identify leaks in homes, schools and other buildings.

Leaks from plumbing in homes and buildings, including ‘leaky loos’, currently account for about a third of leakage. Meters will also help customers use water more wisely.

Per person targets for water standardised

Many respondents to the WRMP consultations, including SERT, urged water companies to have stronger targets for personal consumption of water use. We said that Thames Water’s aim that people should use only 123 litres per person per day lacked ambition, particularly when other water companies in the region were going further.

Therefore we are pleased that all water company plans now meet the Government target of 110 litres per person per day – and with new interim targets.

Water use per person targets have been standardised
All water companies have adjusted ‘per person’ water use targets to align with Government aims

For non-household water users – such as businesses, schools, hospitals – water companies are now aligning with the government’s new Environment Improvement Plan target of a 15% reduction in water use by 2050. South East Water, for example, is aiming to achieve this through smart metering for business customers, alongside water efficiency audits and measures to support reductions in water use.

This is welcome given the significant number of ‘thirsty’ businesses in their area, including fruit farms and golf courses.

While it is positive that water companies have stepped up their demand management strategies in response to customer and stakeholder pressure, companies are admitting that the new targets are challenging. Meeting them will require ‘fresh thinking’ and innovative approaches and will rely heavily on the pace of government-led interventions, such as introducing water efficiency labelling on showers and toilets.

Improved positions on reducing unsustainable abstraction

Water company management plans have set targets to reduce extractions
Drought scenes like these will become common without proper plans to supply sufficient water

SERT, alongside many others, supported the most ambitious reductions in water abstraction, particularly from sensitive rivers and aquifers that feed rare chalk streams. We also challenged water companies to increase the pace of abstraction reductions and ensure a robust approach to prioritising them.

So, we are pleased to see that the regional water resources plan looks to deliver reductions more quickly and that further work on prioritisation will be carried out with stakeholders such as ourselves.

In Thames Water’s plan, while we are supportive of abstraction reductions in the Darent valley, we would like to see abstraction reductions in the upper Darent advanced more quickly – this river has been over-abstracted for decades. In the Hogsmill, an over-abstracted chalk stream in south east London, SES Water and Thames Water have been undertaking investigations to establish the effect of abstraction reductions on stream flow.

It is clear there would be a flow benefit of reducing abstraction from the Hogsmill, and we welcome Thames Water’s proposal to reduce abstraction by 10.2 megalitres per day. We urge that this is implemented as soon as possible. We recognise that the shortfall in supply needs to be met but hope that the companies will consider the extra water that would be delivered to London via the Hogsmill itself if flows were increased.

Water supply schemes – big projects going ahead, but…

Improving the size or reservoirs or building more is one solution to water management
Improving the size or reservoirs or building more is one solution to water management

While curbing leakage and encouraging wise use of water will be crucial for addressing our water scarcity challenge, the deficit cannot be met entirely with these ‘demand measures’ – water supply solutions will also be needed.

For this reason, we are supportive of reservoir schemes being progressed in the next water company business plans. These include South East Water’s Broad Oak reservoir in Kent and extending Arlington reservoir in Sussex – provided that they are built on the basis of beneficial or negligible impacts to local freshwater habitats.

The long-proposed reservoir near Abingdon in Oxfordshire (Thames Water) is also being progressed, at the larger size of 150 million cubic meters. Despite local opposition, many customers and stakeholders recognise its importance in securing the south east’s water supplies for future generations. From SERT’s perspective, it will also facilitate reducing unsustainable abstraction from sensitive freshwater habitats such as chalk stream headwaters.

We do have concerns about some of the other water resources schemes being proposed, including the Teddington Direct River Abstraction on the Thames, where there are still questions about the impact on the river ecology.

Thames Water insists that the scheme meets the ‘required level of protection set out by the Environment Agency’ and say that the company is conducting more detailed studies and working with the community to understand and address concerns.

Value of nature-based solutions has been recognised 

Nature based solutions in the landscape
Nature-based solutions help retain water in the landscape for longer and increase biodiversity

Catchment and nature-based solutions are approaches that work with the landscape to retain more water in soils and wetlands.

They allow rainwater to infiltrate into soils and aquifers, replenishing water sources rather than rainwater rushing off the land to cause pollution and flooding.

These approaches offer additional benefits, including increasing habitat for wildlife and carbon sequestration, as well as better value compared to ‘grey’, engineered solutions such as storage tanks and drains.

Encouragingly, after the draft WRMPs only contained one such catchment scheme between them – which was hugely disappointing – last-minute changes to guidance enabled 73 schemes across 24 catchments to be entered into the revised plans.

Sewer overflows action still too slow

A sewage outfall
A sewage outfall © South East Rivers Trust

We welcome the existence of Drainage and Wastewater Management Plans (DWMPs) for the first time.

The targets in the individual DWMPs from each company reflect what has been set out in the Government’s Storm (sewage) Overflow Reduction Plan and in the Defra Plan for Water, published in April this year.

The Government’s plans – if met – mean that 52% of such sewage overflows would be improved by 2040 and all by 2050.

We feel these timelines are too slow. We want cleaner rivers to enjoy now, not in 25 years.

These timelines are also off track to achieve the Water Framework Directive, which requires all rivers to reach Good Ecological Status by 2027 – sewage overflows currently account for 12% of rivers not achieving Good Ecological Status.

We welcome the accelerated rate of tackling sewage overflows in the Thames Water DWMP – with 51% of overflows being improved by 2035. The plan also includes upgrades to 30 sewage treatment works across the Thames Valley by 2030, and the investigation of options for a new sewage treatment plant in the London area.

Southern Water’s DWMP will reduce the use of all their 979 sewer overflows to less than 10 times per year, but only by 2050. However, by 2030 they have committed to reducing the number of spills from sewer overflows by 80%. They say they will start by tackling the overflows that release close to high priority sites, such as shellfish waters, between 2025 and 2030, and bathing sites by 2035.

We welcome the drive in the DWMPs towards nature-based solutions. Southern Water is prioritising the use of these solutions over ‘grey’, engineered solutions to address sewer overflows. There are wildlife, amenity and carbon benefits to these approaches, as well as cost savings: Thames Water says that its plan, which also prioritises nature-based solutions, is two-thirds the cost of a ‘grey-only’ plan.

Verdict

Overall, while we still think some elements of the plans could be fast-tracked, we welcome the increase in ambition since the draft plans.

The business plans amount to £96 billion of investment across England, which is desperately needed to keep our rivers clean and flowing and to ensure plentiful water supplies.

It’s important that customer money is used transparently, responsibly and cost effectively. This is why we urge water companies and government to prioritise nature-based solutions, which offer good value for money, as well as improved resilience to floods and droughts – and benefits for nature.

These should be delivered in partnership with local environmental NGOs that have the expertise and local connection to rivers.

What YOU can still do

Water companies have to demonstrate customer support for their business plans. To enhance and maintain the environmental ambition of these plans in the face of government push back, it’s important that you, as water customers, make your voice heard.

The five-year Business Plans were sent to Ofwat on 2nd October.
Here are the links to the 2025-2030 plan for the five companies in SERT’s area.

Affinity Water

SES Water

South East Water

Southern Water

Thames Water

Each company is now offering an online Your Water, Your Say session to allow customers and stakeholders to challenge the plans.

We urge you to join these sessions to voice your support for:

  • ambitious abstraction reduction targets
  • increasing the pace of tackling sewer overflows
  • prioritising the use of nature-based solutions.

The dates are as follows (known links provided):

Affinity Water Wednesday 18th October 6pm
SES Water Thursday 16th November 6pm
South East Water Tuesday 31st October 6pm
Southern Water Monday 27th November 6pm
Thames Water, Thursday 30th November 5pm

See our attached document for questions you can ask your water company, along with general ones for each supplier.

 

 

 

 

 

Ploughing a joint course for the Medway’s rivers

Sharing a stand with the Kent Wildlife Trust at the Weald of Kent Ploughing Match in September gave us a fantastic platform to tell the public all about rivers – and in particular our work nearby, writes Cleo Alper, our River Medway Catchment Officer.

SERT and Kent Wildlife Trust at the Ploughing Match. Picture by Anne Tipples
SERT and Kent Wildlife Trust at the Weald of Kent Ploughing Match. Picture by Anne Tipples

The popular annual ploughing match, run since 1947, was held near Tonbridge alongside the River Beult, where we have carried out a great deal of work, including nature-based solutions to improve water sources on land.

Demonstrating what's in rivers with a riverfly spot check
Demonstrating what’s in the River Beult with a Riverfly spot check

Through a Riverfly sample we sourced on the day, we demonstrated some of the life below the surface in the River Medway – of which the Beult is a tributary.

We were able to discuss with the public the importance of monitoring our waters for riverflies – mayflies, caddisflies and stoneflies – which are at the heart of freshwater ecosystems and a vital link in the aquatic food chain. Visitors to our stall were delighted to learn about these species and also see we had found shrimp and pea mussel, among other creatures.

It was inspiring to talk to more than 100 people who had a wide range of interests, knowledge and experiences of the river and local wildlife.

We had encouraging conversations around observations of what is happening with our rivers and about what the community would like to see in the future.

Listing what we found in our river sample taken from the Medway
Listing what we found in our river sample taken from the Medway

The event demonstrated both how much local people are aware of the importance of their local river and the range of concerns they have. These include diminishing wildlife and nature, water quality issues, and low water flow.

Collaborating with Kent Wildlife Trust on the stall was a real pleasure. A shared stand allowed us to talk about the work we are doing in partnership to restore rivers and our landscape and to showcase the wide range of partnership work and restoration occurring in the River Beult, one of four catchments on the Medway, and beyond.

Among the work we spoke about were the benefits of natural flood management and how these manage flood risk, increase water storage and create habitat. We also spoke about the benefits of nature-based solutions and our work on the River Teise. Here we are working on restoring wetlands to create more habitat and increase resilience to low water flows, plus putting in leaky woody structures to improve the river flow and the range of habitat. We are currently working on installing a backwater to increase biodiversity and prevent flooding.

We also told the public about our PROWATER work, managing landscapes to retain water for longer, the results of which include restoring key habitats and healthy soils and grasslands.

Co-Ceo Hester Liakos with staff at the Weald of Kent Ploughing Match
Our Co-CEO Hester Liakos with staff at the Weald of Kent Ploughing Match

 

Working wonders in Wandle Fortnight

Dozens of volunteers made a huge difference to the River Wandle during Wandle Fortnight (11th-24th September), carrying out restoration or learning to record invasive species across the catchment.

Firstly, about 40 volunteers in total worked across five days at Morden Hall Park, continuing our on-going work along this section of the Wandle at the National Trust site.

In a separate event, we also trained more than 20 people how to spot invasive non-native species (INNS) so they could go out during the Fortnight and record their presence using an App, to inform our catchment work.

These two events were intrinsically linked: when we take volunteers to continue our Morden Hall Park work twice a year in autumn and spring, the first task is to remove floating pennywort. This invasive plant is regularly seen across other parts of the Wandle and was one of the top types of INNS our volunteers were trained to record.

We also took the opportunity of Wandle Fortnight to schedule an event to talk to residents about a weir lowering project.

The problems with pennywort

Removing floating pennywort at Morden Hall Park in September 2023
Removing floating pennywort at Morden Hall Park in September 2023 as part of Wandle Fortnight

Like many invasive species, the pennywort might look colourful, but this fast-growing plant crowds out native plants, takes oxygen from fish and insects and cuts out light, inhibiting aquatic wildlife. At Morden Hall, the removed pennywort is composted by the National Trust. It can form a big mat, meaning volunteers drag this a short distance to a boat or suitable exit place for it to be lifted out of the water.

If pennywort is left to decay in the river, the bottom of slow moving sections as useful river channel for wildlife, depleting oxygen levels as it breaks down. This further serves to prevent many invertebrates and other species from completing their life cycles, reducing biodiversity.

Once we removed the pennywort, volunteers then turned their efforts to installing four more deflectors – large pieces of wood – and creating three more berms along the banks at Morden Hall, completing the current round of work, funded by the Environment Agency, we have been doing there since 2020.

Watch volunteers work on a berm

Manoeuvring the deflectors and putting stakes in to keep them in place is tough physical work, but the benefits are huge as we change a once-straight river into a meandering channel where the flow is much more varied. These large tree chunks, cut down as part of woodlands management by the National Trust, help to clean gravels and create pools behind them, providing areas where fish can spawn and thrive.

Planting a berm at Morden Hall Park on the River Wandle
Volunteers planting a berm at Morden Hall Park on the River Wandle

The berms, which are built as an extension of the sides of the river, are made of brash. Volunteers planted them with sedge species that work best in shady areas. These plants were mostly relocated from the wetlands and help to filter out pollutants and excess nutrients while providing habitats for invertebrates.  Golden flag iris was one plant inserted into these berms. Volunteers, many of whom have returned after previous sessions, could see the vegetation from previous efforts providing nourishment for nature.

Project officer Harry Clarke said: “The twice-yearly efforts by volunteers at Morden Hall Park are really starting to bear fruit and be visible. Now we can see moor hens, herons and ducks regularly making the most of the benefits of a narrower river channel and much more vegetation along the banks.”

The flow of the river now has a much more meandering course as a result of our work over the past few years – and our video shows the results.

Training volunteers to help us map invasive plants

Our INNS training session at Sutton Ecology Centre was attended by 22 people, who learned about various plant species that do harm to our rivers. Newly educated, they were empowered to carry out surveys on walks alongside rivers, starting in Wandle Fortnight. They have until the end of October to record them on an .  The data these citizen scientists collect will help us – as catchment partnership hosts for the Wandle – form plans to tackle INNS on the entire river network in the future.

While floating pennywort, Giant Hogsweed and Himalayan Balsam might be best known and the most common invasive fauna on our rivers, volunteers were also trained to look out for Japanese knotweed, parrots feather, New Zealand pygmy weed and giant rhubarb.

Japanese knotweed, introduced to the UK in the mid-1800s, is known to be along the river at Poulter’s Park. Emerging in March, it can grow at 5-10cm a day and easily displace native vegetation. Dying back in winter, it leaves bare soil which, if washed out, can spread downstream. Where large stands of the plant persist on river banks there is an increased sediment input into the river. In slow moving waters this silt will accumulate and smother the riverbed, rendering the habitat unsuitable for fish spawning.

We asked volunteers to survey for giant rhubarb (gunnera tinctoria) for the first time, because it has been found in other parts of the UK. Giant rhubarb is an ornamental plant originally found in Chile and Argentina which thrives in streams or roadsides, liking damp conditions.

This plant’s wide leaf span and large dense stands can have a dramatic impact on the local biodiversity by excluding light. On rivers it causes erosion to banks, exposing them to fast running water after die-back in winter. Identified as a non-native invasive species, it is illegal to knowingly allow it to spread outside a property.

Parrots feather’s rapid growth means it quickly outcompetes native vegetation, forming mats and blocking sunlight and depleting oxygen levels for river wildlife. Left to spread in the wild we’re likely to see an increasing area of land lost to grazing as well as significant impacts on our biodiversity and road-side drains.

Similarly, New Zealand pigmy weed likes garden ponds. It also harms the growth of native vegetation in rivers forming a dense mat and reducing food, shelter and refuge for aquatic species.

Rachael Edwards, Volunteer Officer for SERT, said: “The efforts of volunteers as they walk along riverbanks looking for these species will really have a big impact on the action plan we, as hosts of the Wandle catchment partnership, can put together to tackle INNS for many years to come. We will then be able to focus our efforts on problem areas and know where, for example, to focus our efforts for our popular ‘balsam bashes’.”

Explaining the Goat Bridge weir project

One of our last events in Wandle Fortnight was to talk to residents about a project to lower the weir at Goat Bridge and make changes to the river channel, improving a section at Mitcham for wildlife.

Explaining the Goat Bridge weir and restoration project to residents
Explaining the Goat Bridge weir project to residents

Nearly 30 people attended our community event where partners from Thames Water, the London Borough of Sutton, the Environment Agency and engineering consultancy Mott MacDonald explained the project at a nearby community centre and by conducting tours of the area.

The key reason for lowering the weir and installing rock ramps and bed check weirs is to make this part of the Wandle passable for fish. At present it is totally impassible.

Currently, the weir leaves about a 500m section of the River Wande with conditions akin to a lake, as opposed to a flowing river.

Work on the project is scheduled to begin later this autumn.

Full details about the project and its benefits to the river  can be found on our dedicated web page.

Our video shows how the weir at Goat Bridge creates a barrier to fish passage.

Natural England funds will bring back water voles, eels and trout to the Hogsmill

The South East Rivers Trust (SERT) has been awarded £393,000 as part of Natural England’s Species Recovery Programme, which aims to support targeted action to recover the UK’s most endangered species.

On 14th September, 2023, Natural England chose SERT to host the scheme’s launch at the Hogsmill Stepping Stones in Ewell, Surrey, where the fortunes of water voles, eels and trout will be boosted by the project.

A total of 63 projects across the country have been awarded a share of £14.5 million by Natural England to help recover 150 species nationwide. Following a competitive application round, the money will be used by environmental charities, wildlife organisations, local authorities and charities to deliver the Nature Recovery Network.

Launch of the WET Hogs project
Citizen Zoo demonstrate a water vole realise box at the launch of the Natural Species Recovery Programme

The funding supports propagation, captive rearing, translocations, research and solution-trialling to find the best approaches to enable endangered wildlife to survive and flourish.

Some of the UK’s most iconic river wildlife has been in severe decline for decades, but now thanks to a generous grant awarded to SERT by Natural England, outcomes for rare and endangered wildlife and their habitat are about to improve on the Hogsmill river in South West London.

The WET Hogsmill project led by the South East Rivers Trust, will improve the habitat of the Hogsmill river, a chalk stream in South West London. There are only around 220 chalk streams worldwide meaning that this is an exceedingly rare and special habitat. The project will reintroduce Water Voles onto the river and create new habitats for both European Eel and Brown/Sea Trout. The project will run until Spring 2025.

Water quality testing on the Hogsmill
Water quality testing on the Hogsmill at the Natural Species recovery programme launch

Co-CEO of SERT, Dr Bella Davies said “We are thrilled to have been successful in our application to Natural England’s Species Recovery Grant to support the recovery of water voles, eels and native wild trout which have become near extinct on the Hogsmill river in South West London. The Hogsmill is a rare urban chalk stream meaning that it’s important for nature and an important resource for people too.

“Our project will restore river habitat and create backwaters where fish can take refuge from pollution by creating wetlands to improve water quality which will help reintroduce Water Voles which were once prevalent on the river. We are excited to see this much needed work begin on the ground to bring Water Vole, European Eel and Brown/Sea Trout back to the Hogsmill.”

The Hogsmill river is the first tributary of the non-tidal river Thames and a chalk stream making it a UK Biodiversity Action Plan Priority habitat. Despite its rarity and importance, the Hogsmill has suffered a wide range of pressures leading to decline and loss of habitats and species over the last century and beyond.

Water Vole numbers have declined sharply since the end of the 20th Century making them currently the UK’s fastest declining mammal with a 97% decrease in population. Once ubiquitous and found in their millions, they are now considered to be on the brink of extinction. Water Voles were once prolific on the Hogsmill but became locally extinct in 2017.

Partnering with Citizen Zoo, a conservation charity, SERT will release 150 Water Voles across two sites on the Hogsmill, supplementing 101 Water Voles previously released by Citizen Zoo in 2022. This will help to increase the genetic diversity of the population.

Water vole
Water voles will be restored to the river Hogsmill as part of our WET Hogs project

European Eel are also critically endangered with levels declining by 90-98% from historic figures. Eels migrate up rivers during their life span and recent surveys on the upper Hogsmill recorded just one eel in 2016 and three in 2022. The WET Hogsmill project will support the creation of a large wetland and backwater while also creating a more complex instream habitat which is favoured by European Eel.

Trout have been extinct on the Hogsmill since the 1900s, owing to 19 predominantly obsolete weirs barring their passage, and preventing them from reaching critical spawning grounds in the river’s headwaters. Over the past decade SERT has made 18 of these weirs passable for fish and other species by either removing them or installing technical fish passes or easements. In 2024 the final remaining weir will be made passable for multiple fish species including Brown/Sea Trout and European Eel. By spring 2025 these fish will once again be able to access and migrate throughout the whole river for the first time in over 200 years.

SERT will provide a wide range of complementary community education and engagement activities for members of the public, schools and local businesses. Planned activities include installation of an interactive nature trail, indoor and outdoor education sessions, and community talks to help local people and businesses understand how they can help protect rivers and wildlife.

There will also be several opportunities to volunteer. Those interested to learn more about the project and volunteering activities can sign up to our newsletter or bookmark our events calendar for more information.

Watch our Co-CEO Dr Bella Davies explain how the project will help species in the Hogsmill.

 

 

Helping the UK’s largest glasshouse food grower with water resilience

The Water and Land Stewardship Team at the South East Rivers Trust (SERT) is working directly with Thanet Earth, the largest food grower using a glasshouse in the UK, to support them on a pathway to greater water resilience.

This is part of our Holistic Water For Horticulture work, an initiative that supports growers across Kent with sustainable water management.

Thanet Earth estimates that it produces about 400 million tomatoes, 30 million cucumbers and 24 million peppers every year. To meet its water needs, the company pumps in groundwater and collects rainwater and condensation from the glasshouses (imagine a greenhouse on an industrial size). However, this is becoming increasingly unsustainable as the company grows and climate change bites.

The drought of summer 2022 was a wake-up call for many commercial food growers, who already faced unprecedented challenges in a time of environmental uncertainty and burgeoning economic constraints.

Thanet Earth from above
Thanet Earth glasshouse has its own reservoir

Extreme changes in seasonal weather patterns, water availability and rising prices for materials, fuel and other goods are just some of the factors affecting the sector as never before. At the same time, measures for food security and environmental sustainability must work hand in hand for the benefit of all.

Kent-based growers already work in an area that is classed as water-stressed, a designation that applies to all of the south east of England. In times of prolonged extreme heat and little to no rainfall such as 2022, restrictions can be applied to protect the environment and ensure that there is enough water for all.

Water is the foundation upon which horticulture businesses are built. The issue of water is particularly relevant for crops that grow under glass or plastic (protected crops), since sufficient quantities of good quality water must be used during the growing season.

Over the next year, SERT’s Water and Land Stewardship team will be investigating options to increase the water supply resilience of the Thanet Earth site. This includes measures to collect, store, abstract and share water, within the context of sustainable water management in the region.

The SERT team will help identify funding options to support the implementation of measures and facilitate contact with key stakeholders and practitioners. These include the local water company, other water abstractors and government agencies. We’ll also help navigate the changes to legislation for water abstraction resulting from the 25 Year Environment Plan and the implementation of the Environment Act 2021.

Water supply of crops at is carefully managed at Thanet Earth

Pleun van Malkenhorst, Managing Director of Rainbow UK (Thanet Earth), said: “As one of the largest local business water users, we are very aware of our responsibility to do so sustainably.  By working directly with The Water and Land Stewardship Team at the South East Rivers Trust this will help us to continually improve the way we utilise water on site.”

Dr Samantha Jane Hughes, Senior Water and Land Stewardship Officer at SERT leading on the project, said: “We are really looking forward to working with Thanet Earth over the coming year on how to improve water resilience for a business that is already highly innovative when it comes to alternative sources of water such as rainwater and even condensation harvesting.

Inside Thanet Earth Glasshouse
Thanet Earth is the largest glasshouse food producer in the UK

“The challenges for this sector are real and we will have to think out of the box and consult with different specialists in order to build a resilient pathway that supports the business, helps to ensure food security and does not impact the environment.”

The HWH project supports food and drink businesses through the Courtauld Commitment 2030 Water Roadmap, a voluntary commitment that supermarkets, food brands and the  businesses that supply them sign up to protect critical water resources for food production, nature and local communities.

The key target of the C2030 roadmap is that 50% of the UK’s fresh food is sourced from areas with sustainable water management.

The HWH project works across the sector to identify site-specific measures to improve water self-sufficiency of growers and to reduce impacts caused by excess water runoff through nature-based solutions.

Would you like us to visit your farm and develop a free plan on using water? Contact us by clicking on this link.

Making a Wish come true for fish

Luke Beckett, one of our assistant project officers, reports on our latest river restoration work on the Blackwater Restoration Project. This has improved the ability of fish to move along the river, opening up a 4.5km stretch known as the Wish Stream tributary, where it meets the River Blackwater, in the north Hampshire stretch of the River Loddon.

Helping fish move between river sections

Concrete shelf in the way
A concrete shelf, just visible below the water, made it difficult for fish to pass when the water flow is low

This was my first fish passage improvement since joining the South East Rivers Trust, so it was particularly fulfilling to deliver this work, which will help fish pass between the two watercourses and access good spawning habitat.

The River Blackwater, a tributary of the River Loddon which stretches across parts of Hampshire, Berkshire and Surrey, has long suffered from ‘poor’ fish classification status and only recently gained ‘good’ status. We aim to maintain or even exceed this status in the future and one way to contribute towards this is by improving the ability for fish to move easily between different sections.

The Wish Stream is an important semi-rural tributary of the River Blackwater, which supports a population of brown trout (Salmo trutta) and offers good spawning habitat in its lower reaches. Subsequently, improving connectivity between the Wish Stream and the River Blackwater is important for ensuring resilient fish populations in the catchment.

At the confluence of the two watercourses, we identified a concrete shelf which poses an obstruction to fish and eel movement, particularly during low-flow conditions.

Sloping notch and coping stones

Coping stones added to the river
The coping stones were added to the river, above the concrete shelf

The concrete shelf reduced the water depth, making it too shallow for fish to pass over. It also created a small weir between the Wish Stream and the River Blackwater during low-flow conditions, preventing fish moving up into the tributary. The smooth concrete also made it difficult for European eels to move along the river. This critically endangered species requires rougher substrates and slower flowing water to migrate along rivers.

Wish Stream brush and notch
An eel brush (right) and notch improve fish passage on the Wish Stream

To make this confluence more fish friendly, we created a sloping notch/ramp down the front of the concrete, allowing water to flow more naturally. The concrete was particularly hard – too hard for our machines and so we had to return with a hydraulic breaker to finish the notch.

In addition to this, we installed coping stones along the edge of the concrete to increase water depth over the shelf, enabling fish species to swim through. Finally, we improved the climbing substrate for European eels by adding an eel brush over the crest of the coping stones and safely down onto the concrete bed and vegetation upstream.

This passage improvement work was a relatively simple and straightforward delivery project. Most of it was completed in just over a day, although we had to wait until conditions were right to complete the final notch, and we were able to use coping stones which were left over from a previous project.

Great for brown trout and eels

Completing the work on the Wish Stream
Completing the work on the Wish Stream

The work enables fish, such as brown trout and European eels, to access important habitat for spawning and juvenile recruitment along the Wish Stream, which is roughly a 4.5km stretch of waterway.

It also allows mature individuals to disperse down into the River Blackwater and mix with other populations. With improved access to these habitats, fish numbers will hopefully increase and provide a greater prey source for other species such as kingfishers and herons.

Such improvement works show that sometimes it doesn’t take much to connect habitat and improve conditions for a range of species. I am looking forward to returning over the coming months to see these benefits. We hope this enhanced connectivity will strengthen fish populations in the catchment long into the future and I hope this is my first of many fish passage improvement deliveries.

 

Liven up the Loddon in Rivers Week

Volunteers sought for gravel seeding and planting the ‘Loddon Lily’

Organisers of the annual Loddon Rivers Week are appealing for dozens of volunteers to don wellies and waders and help meet ambitious targets to put 75 tonnes of gravel into riverbeds.

‘Gravel seeding’ events, which will improve spawning habitats for fish and invertebrates, are among seven public volunteering activities during the annual focus week on the Loddon, co-ordinated by the South East Rivers Trust since 2017.

Another key activity of the week, running from 18th-24th September, will be a chance to plant one hundred Loddon Lily bulbs, re-establishing a rare species.

The Loddon Lily
Replanting the Loddon Lily we be a big focus of the week – Summer Snowdrop, by Elizaveta Mitenkova/Pexels

Adopted by many as the Emblem of the Loddon, where it was first found and categorised, this plant is also known as the Summer Snowflake. It looks similar to a snowdrop, but has more open flowers of drooping, white six-petalled bells. Growing next to rivers in April and May, the Loddon Lily produces seeds in July, which disperse along water courses.

The River Loddon, which rises in Basingstoke and stretches across Hampshire, Surrey and Berkshire before reaching the Thames at Wargrave, has plenty of special characteristics. Its upper reaches – where many of the Loddon Rivers Week events will take place – are globally rare chalk stream habitats, hugely valuable for biodiversity and home to brown trout, water voles and otters.

Twelve organisations, from conservation groups to local authorities, are ready to welcome volunteers, or simply people who are interested in learning more from experts in their fields.

Lou Sykes, Catchment Officer at the South East Rivers Trust, said: “Like most rivers in England, the Loddon faces many challenges such as pollution, invasive species and poor habitat and water quality. Loddon Rivers Week gives local people a real chance to do something about this by getting involved in conservation.

Bassetts Mead gravel seeding
Gravel was added to the river at Bassetts Mead in Loddon Rivers Week 2022

“This work is vital to improving rivers and helping a wide range of wildlife thrive around it. Last year, volunteers were thrilled to see instant results of fish investigating the 30 tonnes of newly laid gravels on one riverbed and this year we have several opportunities to do this vital work in different places.

“Improving rivers and their surroundings makes them wonderful places not only for nature but also to visit. So, we’re particularly excited about boosting numbers of the beautiful Loddon Lily at our planting event, which will be huge fun for all the family.”

Loddon Rivers Week is supported by the Environment Agency and, for the first time, Network Rail.

The public will need to sign up in advance for activities:

Monday 18th September and Tuesday 19th September: Get stuck in to gravel seeding to create spawning ground for fish at Greywell Flyfishers Club, Hook, on the River Whitewater, 9am to 5pm.

Wednesday 20th September: Don waders for restoration work at Ivy Park Rec on the River Blackwater, Aldershot with the South East Rivers Trust and the Blackwater Valley Countryside Partnership, 10am to 3pm.

Wednesday 20th September: Come and install woody deflectors in the River Whitewater, creating some fantastic flow diversity in the watercourse at Greywell Flyfishers Club, 9am to 5pm.

Wednesday 20th September: Plant the Loddon Lily, re-establishing this rare species at Wokingham’s riverside parks.

Thursday 21st September: Join in gravel seeding at Bassetts Mead on the River Whitewater with the Hampshire & Isle of Wight Wildlife Trust, Network Rail and Hook Parish Council, 9am to 3pm.

Saturday 23rd September: The Chineham Conservation Group wants your help clearing vegetation to provide some much-needed light to the Pettys Brook. Tasks also involve a litter pick.

To book a place on any of the activities, visit our events page.

 

Promise sticks and sit spots – an education outlook

Jonathan Dean, our Education Development Officer, writes about how the South East Rivers Trust education programme is evolving to address our climate and ecological emergency.

When environmental education really got going more than half a century ago, there was a belief that it would increase environmental awareness and lead to more pro-environmental behaviour.

Research is now proving that our colleagues only got it half right. Environmental education does raise awareness of the climate and ecological emergency, but it doesn’t automatically lead to pro-environmental behaviour. For that, we need promise sticks and sit spots.

A recent RSPB report highlighted that four out of five children in the UK are not connected to nature, specifically their sense of their relationship with the natural world. There are five pathways to nature connectedness: noticing, feeling, beauty, celebration, and care for the natural world.

We’ve taken inspiration from the nature connectedness research group at Derby University to play our part in improving this relationship for the wellbeing of humans and nature.

We’re pleased to be officially including nature-connection activities in all our Project Kingfisher sessions from this September onwards, following successful trials in the previous year. We still deliver learning linked to the National Curriculum, but more than 80% of feedback from teachers and pupils has highlighted that our new nature connection activities are the most popular and memorable parts of the session.

“In the interactive walk they honestly just loved being in nature. So many kids don’t get a chance to be in and explore nature and they loved it!! Pooh sticks was great fun!!” Hillbrook Primary School wrote on our feedback form.

What are promise sticks and sit spots and how do they work?

Pupils contemplate the river during a session
Pupils contemplate the river during a session

Promise sticks and sit spots are activities designed with the five pathways in mind, to improve young people’s connection to nature.

Promise sticks are a nature-connected version of the classic “Pooh sticks”. At the end of a busy session, having learned all about river features, wildlife and the challenges faced by our streams and rivers, ‘promise sticks’ is a chance to reflect on learning, make meaning of what’s been seen and make a promise to take care of nature.

Children search out their favourite stick and come back together as a group. Each child, holding their stick firmly in both hands, quietly makes a promise of action they will take to care for their river.

They might promise to pick up litter, reduce their water consumption, or bring friends along to share their newfound knowledge.

The key is, we (the grown-ups) don’t get to know what the promise is: it’s between them, the promise stick, and the river! From a bridge over the river, children take their turn to give their promise to the river and watch their promise stick flow downstream – and out to sea. They have made a promise to all of it, to do their bit for now and the future.

Taking a quiet moment

SERT staff take a few moments to try sit spots
SERT staff take a few moments to try sit spots during a staff day

Sit spots are a formalised way of taking a quiet moment for yourself. We were hesitant when we first trialled this activity. We wondered if 30 primary school children would manage to sit or stand quietly at the water’s edge for five whole minutes and take the opportunity to connect with the sights and sounds of the environment.

We couldn’t have been more wrong! Sometimes it takes a few moments for the pupils to settle in, but this chance to connect with the beauty of nature and feel alive through the emotions and feelings that nature brings, has yielded some of the most powerful learning experiences for the children we work with.

Here are a couple of comments from pupils who we took to the River Wandle at Ravensbury Park – proof of the simplicity involved in nature:

“School is always go, go, go, so it was great to have time to just chill out, have some peace and quiet and enjoy nature.”

“I noticed the female duck had a blue patch on its side which I never saw before.”

We don’t always call them back after five minutes either, we tell them to come back when they think five minutes has passed. It’s not uncommon for us to witness children paying close attention to the ripples, the fluttering leaves and the floating birds for up to ten minutes. We’re proud to be able to provide these opportunities to young people and give them a bit of respite from hustle and bustle of daily life at school.

Our Project Kingfisher sessions are available across the Beverley Brook, Wandle and Hogsmill river catchments in south London.

Elsewhere, Our River, Our Water continues to run as a partnership programme with other rivers trusts across part of Berkshire, Hampshire, south London, Surrey, Sussex and Kent.

These latter sessions are free and some schools are eligible to apply for support with the costs of transport to get to our river education sites. Check out our website for more information.

Visit our education webpage for details of all sessions and how to book.

Also read: Seven reasons to put the local river on the school curriculum.

 

 

 

Construction to start on Chamber Mead Wetlands

Work to create a major new series of wetlands at Chamber Mead is scheduled to begin on 29th August – pushed back from 21st August – and is planned to take approximately 10 weeks.

The project, developed over several years by the South East Rivers Trust (SERT), is designed to help improve water quality along a stretch of the Hogsmill River near Ewell. The project will also help a wider range of wildlife flourish in this part of the Hogsmill Local Nature Reserve and improve the area as a place for people to enjoy.

Water quality in this section of the Hogsmill River is adversely affected by pollution from road runoff, foul sewage pipes incorrectly connected into surface water drains and discharges from the Epsom Storm Tanks.

Wetlands are a nature-based solution to improving water quality. Water that drains through them is gradually filtered by plants and captured in the soil, intercepting and treating pollution.

Chamber Mead wetlands design
The shaded area shows where the Green Lanes Stream will be blocked and diverted through the wetlands

Increased plants, pollinators and other wildlife connected to the wetlands will provide an attractive addition to this popular open space, as well as providing opportunities for outdoor education.

The new wetlands will intercept water from the Green Lanes Stream, before connecting the river channel back into the Hogsmill River, downstream of the famous Stepping Stones. This will safeguard 200 metres of chalk stream from pollution, reducing the risk to health and improving the area as a community amenity.

Further downstream, the wetlands will continue to provide benefits to the Hogsmill River, which is one of about only 200 chalk streams in the world.

Planning permission was granted last year by Epsom & Ewell Borough Council.

Supported by the Hogsmill Catchment Partnership, the project has received funding and support from The Coca-Cola Foundation, the Environment Agency, Surrey County Council, the Rivers Trust, the Zoological Society of London and Thames Water.

It is part of the wider Replenish programme in partnership with the Coca-Cola Foundation and Rivers Trust which aims to “replenish” or restore millions of litres of water in this and other local catchments, in turn improving biodiversity.

Ed Byers, Senior Project Manager at SERT, said: “We are excited to be bringing the Chamber Mead wetlands to the Hogsmill Local Nature Reserve.

“The wetlands are much needed to improve the water quality of a precious chalk stream for wildlife and for the enjoyment of the public, who have shown great support for this project.

Chamber Mead parking suspension details August 2023
Chamber Mead parking suspension details during construction of the wetlands

“As well as reducing pollution, the plants chosen, such as brooklime, marsh marigold and purple loosestrife, will also act as a magnet for an abundance of wildlife and further improve this much-loved local space.”

Parking restrictions will be in place at two locations along the Green Lanes during the works, to allow site access for vehicles involved in the construction phase and to ensure public safety.

The work will also require a large number of lorry movements to remove excavated material from the site.

Full details of the Chamber Mead wetlands project can be found on our dedicated webpage.

 

 

 

 

 

 

Busting myths about weirs

The South East Rivers Trust regularly works towards removing weirs or installing fish passes. In the second of a series of blogs about the problems weirs cause to rivers, Dr Chris Gardner, Head of Science and Partnerships, writes about two big issues. These are the movements of fish (which he tracked for his PhD) and drought resilience. Here, he addresses some myths about both aspects.

‘Migratory’ fish? All fish migrate

It is often thought that weirs and other barriers that restrict the movement of fish only affects ‘migratory’ species such as salmon, sea/brown trout and eels, as their migrations are relatively easy to observe and are well known.

A proportion of brown trout will migrate to sea and return as sea trout
A proportion of brown trout will migrate to sea and return as sea trout if their migratory pathway is unimpeded. Returning sea trout are very important in maintaining brown trout populations.

However, all fish migrate to some extent, and all fish have life stage specific habitat requirements affected by habitat degradation. Coarse (or freshwater) species such as barbel, chub and dace are affected by habitat fragmentation and degradation caused by weirs.

Higher water velocities on riffles encourages plants such as water crowfoot to grow. Plant growth on riffles makes it difficult for predatory fish to hunt. This also provides an abundant food supply of invertebrates and overhead cover that hides fish from predatory birds and animals.

Riffles are great places for baby trout and young salmon to live, they are also the preferred habitat for juvenile barbel. However, riffles hidden under lake-like habitats upstream of a weir lack the characteristics that make them great juvenile barbel habitats. And if there are low numbers of small barbel then there will be fewer numbers of big barbel and eventually no barbel at all.

Here, the trout and salmon fraternity are ahead of the game. The economic value of salmon (commercial and recreational) and the large declines in salmon populations since the 1980s have caused scientists and anglers alike to research and understand what the habitat requirements are for all life stages of these fish.

They have used this information to minimise potential population bottlenecks or limiting factors because of available habitat. There are many things impacting our fish populations, but in-river habitat is the one thing that is relatively easy to address and benefits all wildlife. Organisations such as the Wild Trout Trust have been encouraging progressive thinking and educating game anglers in fisheries management and river restoration.

Research shows why fish need to access the whole river

Coarse fish migrate and need to move around a river system to locate specialised habitats required at certain times and during certain conditions. Fish are streamlined, live in a near weightless and frictionless environment and need to constantly swim just to maintain a static position in the river. Hence, fish have great potential to be highly mobile.

Modern tracking studies using implanted radio or acoustic tags have revealed these migrations. For example, in 2010 Dr Karen Twine, of the Environment Agency, radio tracked 20 adult barbel (6-15lb) in an 8.2km reach (between two impassable weirs) of the Great Ouse for 18 months. She demonstrated that the barbel utilised most of the river length available to them and made seasonal movements to spawning and over wintering habitats.

Barbel migrate and use different habitats at different times of year
Barbel migrate and use different habitats at different times of year and at different stages in their lives

Similarly, in 1993 Dr Martyn Lucas, of Durham University, radio tracked 31 adult barbel (2-6lb) over 15 months in a 7.2km reach of the River Nidd, a tributary of the Yorkshire Ouse, with open access to the Ouse.

Again, these fish were highly mobile, ranging over sections of river from 2-20km in length. Their movements were associated with seasonal shifts in habitat, upstream spawning migrations and their downstream migrations to ‘over wintering’ habitats in the lower reaches and main River Ouse.

Basically, fish will move as far as they are able to fully exploit the best available habitat/resources: the more limited the resources, the further they will travel.

Other studies on less fragmented rivers with more limited essential habitats have shown that fish have the potential to move over very long distances.

Study shows the benefits of free passage

During my PhD in 2006, I tracked the movements of 80+ adult common bream (4-7lb) over four years in a long 40km reach of the Lower River Witham, a very uniform fenland river in Lincolnshire.

Returning a tagged bream to the main river during my PhD
Returning a tagged common bream to the River Witham during my PhD, to demonstrate how mobile fish can be in open, barrier free habitats

My bream were tightly shoaled and relatively immobile in a deep tributary off the main river at the upstream extent of the reach during the winter, moving short distances of, on average, less than 5km a month up and downstream.

In the spring, they became highly mobile moving on average 30-40km a month, utilising the entire length of the river available, with one individual moving more than 120km in a single month!

At this time, they were visiting shallow tributaries off the main river, before using these for spawning in late May/early June. Once they had spawned, they spread out and spent the rest of the summer in the main river foraging, again moving on average 20-30km a month up and downstream. In the autumn, they moved back upstream to the deep tributary for the winter. This same yearly pattern was observed throughout the study.

These studies demonstrate that adult fish use different habitats at different times of the year and require free passage between them.

Habitat requirements are different for adult and juvenile fish. So, during a fish’s life it will have many different habitat requirements. These requirements will be more crucial for juvenile fishes because of their vulnerability to predators and therefore their need to find safe cover.

If any single habitat type is lacking, limiting or inaccessible, there will be consequences for individual survival and therefore the population as a whole. Weirs often restrict populations to those reaches that have sufficient habitats to enable life-cycle completion.

The “weirs” thing about drought resilience …

A common misconception is that weirs delay river discharge and therefore make the river more resilient to drought. Weirs do hold back a quantity of water in the upstream section, which is “impounded” – leaving the river more like a still canal or pond. However, a weir just stores water in the upstream area – and once the river is full, river flows over the weir at the same rate it enters the impoundment.

Imagine an impounded section of river as being like a kettle being filled from a tap. Once full, the kettle overflows at exactly the same rate as the tap runs and the water bill ticks up exactly the same.

A river in Kent that dried up in the summer of 2022
A river in Kent that dried up in the summer of 2022

In the event of drought, rivers tend to dry from their upstream end first. Impoundments upstream of weirs can and do provide refuge areas for fish in such an event. However, these areas are likely to be heavily silted because of the lack of flow, and will quickly deoxygenate because of biological processes in the silt, leading to fish deaths.

Fish will move downstream naturally in response to a drying river using the river’s flow to navigate.

However, if the fish encounter an impoundment upstream of a weir, and there is no flow going over the weir (because of the drought), there will be no flow cues to navigate by and the fish will simply be unable to move any further and become trapped where they will die as the water in the impoundment deoxygenates.

If no weirs exist fish will move downstream, seeking out deeper, fresher water in the river’s lower reaches. Once the drought has broken, they will then move back upstream.

So, perhaps counterintuitively, weirs actually reduce a river’s resilience to drought.

In conclusion, the impacts caused by weirs are problems for freshwater fish as well as salmon and trout: the principles might not be as well understood or as popular, but they are real. If our rivers are to fulfil their ecological potential, we need to address this and other factors that are limiting fish populations.

 

Sign open letter to political parties to support nature

River lovers are being urged to sign an open letter calling on all political parties to adopt a five-point plan for wildlife in their manifestos for the next General Election, likely to take place in 2024.

The Rivers Trust movement has joined an 80-strong coalition of partners to support the Nature 2030 Campaign. It is led by the Wildlife and Countryside Link and supported by celebrities including television personalities Steve Backshall and Chris Packham.

Research shows that the UK has become one of the most nature-depleted countries in the world, with more than one in seven native wildlife species facing extinction.

The campaign outlines that in 2022 sewage was discharged for more than 2.4 million hours across England, Scotland and Wales, accounting for more than 389,000 sewage spills. Commitments were set in 2021 to protect 30% of land and sea for nature by 2030, but there’s a long way to go to meet these targets. With only seven years to go, just 3% of land and 4% of sea have this protection. We need stronger environmental leadership and the Nature 2030 campaign demands it.

Wetland restoration scene
A wetland restoration scene from our nature based solutions safari © South East Rivers Trust

Thousands of people have already signed the letter, which was launched at Westminster in July.

As one of the largest regional rivers trusts, the South East Rivers Trust (SERT) is urging supporters to back the campaign, which has five key asks for political parties:

  • Double the wildlife-friendly farming budget to £6bn for ambitious farm improvements and large-scale nature restoration
  • Make polluters pay for nature restoration by requiring big businesses to deliver environmental improvement plans and funding to counter damage
  • Create green jobs on a large scale, including setting up a National Nature Service delivering wide-scale habitat restoration
  • Increase protection and funding for wildlife sites by creating a Public Nature Estate to fulfil the promise to protect 30% of the land and sea for nature by 2030
  • Set up a new law guaranteeing a right to a healthy environment, establishing a human right to clean air and water plus access to nature, plus building nature into decision making

Hester Liakos, co-CEO of SERT, said: “Rivers are at the heart of the battle to restore nature. Our work with local communities, farmers and landowners demonstrates the positive difference that nature based solutions and natural flood management can make in improving the health and biodiversity of rivers. But to make this difference on the scale that nature truly needs requires more funding and greater commitment and leadership from Government – so we’re asking our supporters to sign this open letter to demand action from all political leaders.”

Our work backed by either EU or the UK Government includes PROWATER and Environmental Land Management Schemes.

Tessa Wardley, Director of Communications and Advocacy at the Rivers Trust, said: “The public are rightfully outraged by the state of our rivers and we need political parties to make firm commitments towards their recovery, which are then backed up by action. Delivering the Nature 2030 policies would significantly improve the health of our rivers, which are absolutely core to tackling the biodiversity, climate and wellbeing crises we face as a nation and planet.”

Click here to sign the Nature 2030 letter today

 

Helping nature bloom at Morden Hall Park

Working in river restoration, there’s nothing more satisfying than being able to see the difference made when you return to a site – and then embark on further improvements.

That feeling is heightened all the more when you return with volunteers and witness their delight, as they too see improvements, especially when their previous activities included put odd-looking obstacles in the river which, to the untrained eye, could look out of place.

So it was on the River Wandle earlier this year. We led two days of work as part of our ongoing Morden Hall Park restoration project, on a section of the river that is fairly hidden from view when the public visit this National Trust property.

Removing pennywort

Removing pennywort
Removing pennywort – just one of the boatloads taken away at Morden Hall Park in spring 2023

Since 2015, we have been taking volunteers out to this patch every spring and autumn, to carry our river improvement work. Activities have ranged from removing invasive vegetation and taking out toe boarding (which stops animals and fauna making their way from river to land and prevents natural river processes from occurring) and adding more natural looking riverbank materials such as berms – a ridge, made in this case of branches, sticking out from the bank into the river.

Back in the spring, working with the Morden Hall Nature Group, we started two days of work with a litter pick and general tidying. However, the main focus of the first day was to remove a significant amount of pennywort, an invasive species that regularly occurs at the site in large quantities.

We loaded up our small boat several times in our attempts to rid the river of this fast-growing plant, which smothers other important habitats and reduces biodiversity by crowding out native plants – taking oxygen from fish and insects.

Our hardy group of 20 volunteers then set about installing some sizeable deflectors – large tree trunks that protrude into the river – into the river channel.

These will help to improve the river. In this area, the Wandle has been widened and straightened, reducing the energy in the river. This means that silt and sediment settles to the riverbed and smothers natural gravels. Clean, loose gravels are a vital part of rivers, providing spawning habitat for fish as well as habitat for invertebrates and aquatic plants.

Deflector work was tough going

A deflector at Morden Hall Park
Volunteers take a deflector up the River Wandle at Morden Hall Park

Deflectors help to remove sediment and silt from the riverbed by reshaping the water flow and increasing the diversity of the river’s flow. Instead of being straight, the water now meanders around these impediments as it would have done when the watercourse was formed naturally. This work varies the flow in the river, scouring gravels and creating pools behind the deflectors, giving respite to fish and allowing them to hide, spawn and thrive.

Through this work, funded by the Environment Agency, we were able to put in four sizeable deflectors made from ash trees which the National Trust had stockpiled for us when undertaking Ash Dieback work.

Knocking in these large tree trunks into place (a pair at a time) after dragging them up the river and moving them into position, was hard work! The posts to attach them were driven into the riverbed, to make the deflectors look as natural as possible.

A deflector secured in place at Morden Hall Park. Picked for its ability to host birds
A deflector secured in place at Morden Hall Park. The wood was picked for its ability to offer a perching place for birds

Blooming the berms

Adding plants to a berm
Volunteers added plants to a previously installed berm at Morden Hall

Not as heavy work, but equally as important, was planting golden flag iris into one of the berms that we had installed on a previous visit. These berms are made of tree brash that has been pushed together and secured, to give fish and invertebrates another refuge in a varying flow river. The golden flag iris has beautiful yellow flowers in summer, which might still be in bloom by the time we return later in the year, as part of our continued work.

Having worked at this site repeatedly over time, it is amazing to see what a difference our work has made to the riverbed. In this once straight channel we have varied the flow by creating a meandering pathway. Instead of silt covering the whole riverbed, the deflectors and berms have helped to create clean areas of loose gravel; perfect for fish to spawn in and prosper – and now water crowfoot, is also thriving.

Typical of a globally rare chalk stream such as this, this aquatic plant thrives in fast flowing water, providing habitat to invertebrates and is a good source of food. It can also act a bit like the deflectors by redirecting water and increasing local speeds to create clean places in the gravel.

Biodiversity is certainly booming – and we couldn’t do it without our volunteers.

This summer, we made a short video of how our work since 2020 is having an impact on this section of river, changing it from a straight river into a habitat-rich one where a variety of wildlife can thrive in a river that has varied flow speeds.

Statement on Thames Water fine for pollution near Gatwick

The South East Rivers Trust notes today’s judgement at Lewes Crown Court that Thames Water has been fined £3.3million for polluting a section of the River Mole near Gatwick Airport on October 11, 2017.

About 1,400 fish were killed in the incident on the River Mole between Crawley in Sussex and Horley in Surrey.

In a statement, SERT said:

“There is no excuse for polluting rivers which are the lifeblood of our landscapes. This incident decimated fish populations on the Gatwick Stream and impacted the ecology of the river far beyond into the catchment of the River Mole.

“Six years after this pollution incident the river and local angling club are still suffering.

“We welcome Thames Water’s fine, while hoping it would have been higher.

“We are furious to hear the Judge’s conclusion that Thames Water attempted to mislead the regulator.

“They have asked to work with us to help repair the damage by providing £1m in the form of a voluntary reparation to help improve the river’s habitat and water quality that is so important to the local community.”

SERT is already using the voluntary reparation to improve the health and resilience of the Gatwick Stream and other waterways impacted by this pollution event.

The money is being used to fund projects, such as the Caring for Crawley’s Rivers project, that improve the quality of the river habitat, identify and remedy systematic water quality issues in the catchment, and engage local communities in the health of their rivers, including carrying out education sessions.

SERT will also be working to gather data and evidence to support the development and deployment of these remediation projects and to monitor their success.

How weirs affect rivers

In the first of two blogs, Dr Chris Gardner, head of our Science and Partnerships team, outlines some of the problems caused by weirs on habitats and fish. This has a particular focus on the River Darent in Kent, where we have recently carried out several pieces of work as we try to help fish species move along the whole river catchment.

Restoring rivers to help wildlife

The term “river restoration” describes a set of activities that help improve the environmental health of a river or stream. These activities aim to restore the natural state and functionality of the river system to promote improved fish populations, biodiversity, recreation, flood management and development.

Restoration tends to focus on increasing habitat quality and diversity. A popular first step to achieving this is to overcome barriers such as weirs, increasing the access animals have to the existing range of habitats available in the catchment.

Over the centuries, we have adapted rivers for our own use, modifying them to facilitate land use for agriculture and development, navigation, water supply, power generation and other priorities.

Fish and other aquatic organisms evolved in rivers long before humans had this influence, and so they have not adapted to the modifications we have made, such as concrete banks, deep dredged sections, straight uniform channels and weirs, all of which block their passage.

Weirs impact rivers in three main ways

Impassable weir at Sundridge
Tanners Weir at Sundridge on the River Darent, which is totally impassable by fish, fragmenting the habitat available for them to utilise

Habitat fragmentation

This is frequently caused by human activities which disrupt the continuity of habitats used by wildlife and is a land conservation issue as well as an aquatic one. Habitats which were once continuous become divided into separate fragments, restricting the movements of organisms (for example fish) and separating them from habitats, natural resources and other fish required for their survival or the completion of their life-cycle.

Fragmented habitats are also less resilient, preventing re-colonisation after pollution incidents and lowering genetic variability because of the restricted, effective population size, potentially placing populations at an evolutionary disadvantage.

River habitat

This is degraded in quality because an enclosed – or “impounded” – area is created upstream. In other words, river-like habitats become lake-like – stiller, with less water flow than a natural river should be. This drowns out natural features such as riffles (a shallow place in a river where water flows quickly past rocks) causing the loss of important spawning and nursery habitats for river fishes, thus lowering the numbers of fish and breeding success.

Rivers are naturally dynamic with erosion and deposition occurring in balance, creating a highly varied mosaic of temporal micro-habitats for all life-stages of fishes.

An impounded, or enclosed, section of river
An impounded area of river above a large sluice/weir on the River Medway. The river becomes still, affecting vegetation and animals

Weirs stop this natural tendency for change, creating a uniform, static environment. Upstream, an over deep river channel, similar to a lowland river, is formed in the impounded area, which might be inappropriate for the fish community (for instance, barbel habitat may become bream habitat). Impoundments also alter the temperature regime, oxygen content and cause sediment build up (siltation)  in the upstream impounded area.

Sediment transport

Natural processes, such as moving sediment along a river, are prevented by weirs and instead the sediment stays in one place, covering the riverbed. This inhibits the riverbed’s function as a feeding and breeding ground. In a natural river, sediment (for example gravel) is shaped and sorted by water flow patterns. This creates a large diversity of ever-changing habitat types that support a rich diversity of wildlife.

Weirs stop natural processes and impact river channels in two main ways:

    1. Upstream – Sediment transport is interrupted by the weir. Instead, it accumulates upstream. The lack of energy in the impounded area causes the sediment to not be shaped and sorted by the water flow and therefore creates a uniform habitat that supports less diversity of wildlife.
    2. Downstream – Sediment transport is interrupted by the weir, reducing the supply of sediment (for example gravel) to the downstream reach, which is vital for creating habitat features for wildlife. This lack of sediment from upstream leads to increased erosion of riverbanks and riverbed, leading to “channel incision”. This is when the river begins at one height and cuts downward (incises) through its bed while leaving its floodplain behind [higher up] throughout its course.

Incised channels have knock-on impacts for:

Free flowing with riffles
A section of free-flowing River Darent at Shoreham. Shallow gravel riffles supporting abundant growth of Water Crowfoot, ideal spawning and nursey habitat for native brown trout.

Ecology:

The incised channel only connects to its floodplain in extreme flood events, when higher than normal water velocity is maintained in-channel during small to medium flood events. Aquatic wildlife, such as juvenile fishes, may become swept downstream during high flow events. The steep banks also cause a lack of marginal transitional habitats  which provide a refuge for wildlife in flood conditions.

Flooding downstream:

Flood risk may increase downstream, again caused because the incised channel cannot connect to its floodplain other than during extreme flood events. The problem is simply shifted downstream.

Addressing the impacts of weirs

Brasted Lower Weir being removed
The Brasted Lower Weir being removed by drill

Removal of the weir should always be the considered as the preferred option, which solves all the issues described above. However, total removal is often not possible because of the way the landscape has developed since the weir was built.

Other factors that need to be considered include the wishes of landowners and river users, such as anglers, who might value the weir and its effect on the river.

The next best option might be a partial removal (lowering of the weir) and/or the implementation of a fish passage, which solves part of one problem (reducing the impounded reach) and all of another (connecting the upstream and downstream habitats). Fish passage solutions include natural bypass channels (which are preferred as they create additional habitat) rock ramps and baffles, as installed in 2023 by SERT at the Quester weir.

Essentially, any “solution” needs to provide fish with free movement and suit a range of fish sizes and flow speeds and depths that might be experienced at various times of the year.

Natural bypass around a weir
A natural bypass channel around an impassable weir on the River Darent, at Sundridge, Kent.

It also need to be delivered with usually tight budgets available.

Modelling, using an existing locally specific Environment Agency flood model  is used to satisfy these needs and ensures no increase in flood risk for any nearby residential properties.

This approach is best practice and gives all interested parties the confidence to implement solutions with the simplest, and most cost effective design.

In the past few years, we have carried out several projects to improve passage for fish along the River Darent. This started with the removal of a large weir as part of the Acacia Hall River Restoration, completed in 2021. We have more recently  installed an eel pass at the Questor weir in March 2022 and, in spring 2023, we constructed a fish pass using staggered baffles on the same estate.

Mapping out a vision for the River Mole

The health of the UK’s rivers is increasingly at the forefront of the public consciousness. It is therefore vital that organisations working to protect and restore our rivers communicate openly and effectively with the public through innovative channels. It is also vital that all organisations working on a river network combine their efforts in a collective approach. What happens upstream affects the downstream.

We are delighted to launch the latest in our series of catchment ArcGIS Storymaps, on behalf of the wider River Mole catchment partnership. This partnership brings together about 45 organisations and individuals who are committed to protecting and enhancing the health of the watercourses across the entire river network. The South East Rivers Trust (SERT) co-hosts the partnership with the Surrey Wildlife Trust.

Through the River Mole Storymap anyone interested in the multiple threats to the river’s health, and the activities of the Catchment Partnership which aim to mitigate those threats, will be able to access detailed information, beautifully mapped for context and understanding.

Below, Dr Lewis Campbell, the Catchment Manager, provides a brief introduction to the Mole catchment, and highlights the work some of the organisations involved in its care and restoration.

Clay and chalk bring different issues

The River Mole at Leatherhead
The River Mole at Leatherhead

The catchment of the River Mole covers an area of just over 500km², spread across Surrey and West Sussex. The catchment is largely rural pasture and farmland, but is home to some significant urban areas including Crawley, Reigate, Dorking, and Leatherhead.

The catchment’s main watercourse, the River Mole, rises to the west of the town of Crawley, before flowing for 80km until it joins the River Thames opposite Hampton Court Palace.

Differences in the natural characteristics of the catchment in its upper and lower reaches provide a division into two sub-catchments. The area from the town of Leatherhead down to the confluence with the Thames forms the Lower Mole and Rythe sub-catchment, whereas the area above Leatherhead forms the Upper Mole sub-catchment.

Across its watercourse, the River Mole is joined by numerous tributaries, including the Gatwick Stream, Tilgate Brook, and Baldhorns Brook, to name a few. Although the river largely flows over clay, it carves out spectacular cliffs in the chalk bedrock in the area between Leatherhead and Dorking, also known as the Mole gap.

Challenges include pollution, weirs, flood and drought

Tilgate Weir prevents fish passage
A weir at Tilgate is one of many barriers to fish passing along the river

The water bodies that make up the Mole catchment vary in their Water Framework Directive (WFD) classification status from Moderate to Poor, and this reflects the numerous and varied challenges facing the catchment.

The major issue impacting the catchment at large is pollution from waste water sources. The catchment is home to several relatively large towns, so there are a number of sewage treatment facilities present which discharge treated effluent directly into the river, and occasionally also untreated sewage in times of higher than usual rainfall.

The Storymap allows residents to see Thames Water’s live sewage release data. These discharges carry with them excessive nutrients, such as phosphates and nitrates and micro-organisms, which can have a negative impact on the quality of the habitat available for aquatic life such as fish and plants.

The catchment runs primarily over clay. Couple this with the relatively large urban areas and the presence of the UK’s second largest airport (Gatwick) and rain that falls on the catchment very quickly makes its way into the water course, directly from hard surfaces such as roads and runways, or from fields.

This run-off carries with it numerous chemicals and other pollutants which can also degrade the quality of the river habitats available for wildlife. In rural areas, run-off will also carry significant amounts of soil and sediments from fields which can clog up the valuable gravel areas in which aquatic invertebrates like to reside, reducing the food availability for larger organisms such as fish.

Another issue is that fish are also negatively affected by the numerous barriers within the catchment. These barriers are often types of weir – solid structures placed into rivers to alter their level and flow. These physically stop fish from navigating the full extent of the water course. This prevents them from accessing the variety of habitat types that they require to thrive, something particularly harmful to those species such as salmonids and the critically endangered European eel which have complex life cycles that involve migration to and from the ocean.

Parts of the River Mole are prone to low flows
Parts of the River Mole are prone to low flows

Interestingly, the catchment is prone to both flooding and problematic low flows. Many of the catchment’s waterways have been historically altered to make them more navigable, or to make way for development. This often involves straightening and re-enforcing the river channels, which disconnects the river from their adjacent flood plain.

Disconnection from the flood plain means that during periods of heavy rainfall the water which quickly runs over the catchments clay and concrete into the rivers has no way of escaping the channels, resulting in excessively high water levels and flooding. Conversely, in times of low rainfall, connected flood plains can retain water which slowly makes its way into the watercourses, maintaining flow. A lack of connected floodplains in the catchment means that the Mole and its tributaries often experience low flows during the height of summer, again negatively impacting aquatic life.

Water quality work under way

As the climate becomes more unpredictable it is likely that these issues will occur more frequently or with increased severity. Fortunately, there are steps that we can take to try to avoid this situation, or help the catchment cope.

Partnership members work either individually or together on projects to improve the catchment, but meet on a regular basis to share expertise and experience. The idea is that by working together, groups can pull their knowledge and resources together and agree actions that are right for the whole river (a holistic approach) rather than act in isolation on small sections.

One of the partners, the River Mole River Watch, which is spearheading catchment wide water quality monitoring efforts through their network of volunteers. This initiative will allow the partnership to identify locations which are being particularly impacted by pollution and poor water quality. Armed with this knowledge, catchment partners will then be able to design and implement measures to prevent pollution, or reduce its impact.

Learn more about our eels project and Crawley focus

European eel
European eel image Photo by Darryl Clifton-Day

SERT also works with communities and landowners to identify ways to reduce run-off pollution in urban and rural environments, such as changes in land management practices.

Where reduction of pollution is not possible, SERT is involved in projects to improve river habitat, create backwater refuges and remove barriers so that fish and other aquatic organisms can move into less polluted areas. SERT is also leading on projects to reconnect the waterways of the Mole catchment with their flood plains, providing natural flood management and low flow resilience.

Our work at SERT on the Mole already, among many listed on the Storymap, has included a project to promote and help the critically endangered European eel. During the Thames Catchment Community Eels project – part of wider work on several rivers across the south east – we found twice the number of barriers to eel migration, such as weirs, as had been recorded previously.  We also ran workshops and assemblies for 1,136 children and put on other public education sessions, to highlight how this species of fish needs to be able to reach the ocean to complete its life cycle.

We are currently working up our Caring for Crawley’s Rivers project, which will combine river restoration with community engagement such as education in schools and with other groups.

With our newly launched catchment Storymap, you can take a deeper dive into River Mole catchment and the actions that our catchment partners are taking to protect it. You can also find information on opportunities for you to get involved.

Visit our River Mole Storymap, find out about the work to protect and enhance the river and how to get involved!