Category Archives: Wandle Catchment Plan

Fish Passage Restored!

Last year we were working on a fish passage project on the Wandle at Trewint Street, Earlsfield.

Although there are many weirs on the Wandle which impede the migration of fish Trewint Street is one of the largest, with two weirs either side of a large concrete channel. With funding from the Environment Agency, Thames Water and Defra’s Catchment Partnership Action Fund (CPAF), we have restored passage for fish and eels, allowing movement to upstream habitats.

So how did we achieve this?

A bespoke fish pass was designed by Fishtek and installed on the weir by local contractors Amenity Water Management (AWM).

At the top of the right hand weir, a series of recycled plastic baffles were fixed onto the weir. These deepen and slow the flow of water and as you can see from the picture below, the baffles are arranged with a diagonal gap up to the top. This is the path the fish use to swim up the weir.

Baffles

The baffles had to be fixed to the weir in dry conditions, and so sandbags were used to divert the water down the left hand weir, leaving the right hand side high and dry while our contractors worked. Watch the timelapse footage of AWM installing the baffles.

 

The second part of the fish pass were three large wooden pre-barrages at the bottom end of the island which were designed to slow the water down and reduce the drop in water level between the channel and the baffles.

Barrages going in

Each barrage was notched to create a path for migrating fish.

To makes sure the pass works in low flows a huge piece of wood (7m long!) was placed at the top of the left hand weir to divert water at low flow down the right hand side and the fish pass.  This ensures the pass works over a large range of flows.

Deflector and Eel Bristles

Bristles were fixed to each of the barrages to allow eel passage. Eel tiles were then fixed alongside the baffles on the concrete wall making the weir passable to both fish and European Eels.

A big thanks to our contractors AWM, landowner Mr Lammas and Thames Water, Defra and the Environment Agency for their funding.

Contractors

Dam, where’s all the water gone?

We’ve started work on the Trewint Street Fish Passage!

Fish passage on the River Wandle is impeded by over 30 in stream structures, the majority of which are weirs left from the milling era. These weirs and structures are a barrier to the movement of fish both up and downstream and also fragments and isolates habitats.

The Weir

Trewint Street is one of the significant barriers to fish passage, with two weirs either side of a large concrete island. With funding from the Environment Agency, Thames Water and Defra’s Catchment Partnership Action Fund (CPAF), we have started our project to install baffles and a fish pass to the right hand side weir, allowing the movement of fish once more!

The pass will also benefit European Eel populations which have declined by over 98% in the last 15 years, with barriers to movement being a contributory factor.

So what are we doing?

Low cost bafflesOn the right side channel, a series of baffles will be installed to the upper section of the concrete weir. These baffles are made from recycled plastic and fixed to the weirs in rows.  They slow the flow down on the weir, deepening the water and allow fish to swim up the weir through notches cut into the baffles (Image, Fishtek).

Barrages

In the lower part of the right hand channel, three notched barrages will be created to reduce the drop in water level between the channel and baffles. This will allow fish to easily swim up through the notches and through the baffles to new habitats beyond (Image, EA).

What will you see?

You will see a lot of building work on site over the next month as our contractors (Amenity Water Management (AWM) get started. You’ll also notice that the right hand channel is a lot drier than normal…

Dam!

Amenity Water Management have created a sandbag dam to keep the channel dry allowing them to work on installing the structures. All will return to normal once work is complete.

We’ll keep you posted with updates as always, but for now Tim is just happy to have wet feet again!

Tim happy once more

Your River Needs You!

River Rangers

Will you join our River Rangers Team and help hunt down invasive non-native species on the Wandle?

We are looking for enthusiastic volunteers to join our River Rangers team and help us monitor invasive species on the River Wandle from its source to the Thames.

Our team of trained recorders will survey the entire length of the Wandle three times a year, building up a picture of where the invasive species are and how well our management efforts are working in controlling them.

Training for the team will take place this August on the 19th or 20th – date and venue to be confirmed soon.

What will be covered?

  • What makes a biological record?
  • Invasive plant identification in all seasons
  • Invasive plant ecology and biology
  • Biosecurity
  • Uploading your data

What will be involved?

Following training, our River Rangers will be unleashed on the Wande three times a year to map invasive species through the different growing seasons. Data will be uploaded online to LISI – London Invasive Species Initiative.

The first River Ranger day will be Sunday 27th September 2015.

This project will form a valuable baseline monitoring system for our efforts in the eradication of these invasive species. Next year, a Hit Squad will be trained up in the management of INNS and will work alongside our River Rangers to manage and control the species they record.

Pennywort Banner

This project is supported by the National Lottery’s Heritage Lottery Fund as part of the Living Wandle Landscape Partnership.

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Welcome to our new Education Officer!

The Wandle Trust is proud to introduce David Gill as our new Education Officer.

David Gill - Education OfficerDavid is going to be responsible for following on from the very successful ‘Trout in the Classroom’ programme that we ended last year.

We’ll aim to draw on David’s extensive experiences of working in the classroom to create a very innovative teaching and learning package that will engage children and young people throughout the catchment of the Wandle. A project that is possible through the Living Wandle Landscape Partnership, funded by the National Lottery’s Heritage Lottery Fund.

David has been teaching for over twenty years and has taught everyone from pre-school to adults! He has travelled around the world for both business and for pleasure. David also works as an Education Officer for a local wildlife trust where he initiates and develops Programmes of Study in line with the revised National Curriculum. He is particularly interested in the incorporation of information technology in to environmental learning.

David completed his degree in Environmental Sciences at UEA in Norwich before embarking on his Post Graduate Certificate of Education in secondary school geography and sciences. His classroom experiences include teaching in a remote jungle school in Papua New Guinea, working with street children in Southern India and tutoring via the radio in the Australian outback.

David says ‘I am looking forward to the challenges of this exciting job – I hope that in working with schools we can increase the awareness of the Wandle in to the lives of local children and their families in a fun and practical way’.

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Beddington Park: Add Your Voice!

This year there is a Heritage Lottery Fund project to restore Beddington Park, including the lakes and the River Wandle. The Wandle Trust have been involved in developing the bid with Sutton Council, providing expertise and guidance.

If you’re a user of Beddington Park or live close by, please take the time to complete this short survey to add your voice to how you use the Park and how you’d like to see it improved!

Click here to take the survey

Welcome to our new Invasive Species Officer!

We’d like to give a warm welcome to our latest recruit Alan, our new Invasive Non-Native Species Officer!

Polly and Alan

We’ve stolen Alan from Scotland where he was working on Argyll’s three National Nature Reserves for Scottish Natural Heritage. Before this Alan was in Cape Town, South Africa, controlling invasive species in the metropolitan area so he has a wealth of experience.

Alan is running an invasive species project on the River Wandle as part of the Living Wandle Landscape Partnership. The project aims to map invasive species along the Wandle corridor and set up management plans and volunteer teams to work towards eradication.

Alan will be tackling a wide variety of invasive non-native species including some well-known faces such as Himalayan balsam, Japanese knotweed and giant hogweed.

Himalayan balsam

To get started, Alan has been taking a refresher in Pesticide Application along with Polly our Volunteer Officer. Here is our invasive species ghost busting team…

INS

So who you gonna call?

Alan and Polly!

Photo Credit: Himalayan balsam, GBNNSS

Ravensbury Back Channel: The final touches

Two weeks ago, we spent three days back at our Ravensbury Park Back Channel project to finish off the works.

Day 1

Day 1 was spent preparing a site for 2000 plants which were due to arrive the following day.  Our loyal volunteers arrived expecting an easy day of planting and instead we surprised them with spades, shovels and a huge pile of soil! We needed to create a gentler slope on the bank and to do that involved some serious work. But with visions of tea and cake we soon got stuck in and the bank started to take shape.

Luke working hard

Meanwhile, we also had a team putting up bird boxes in the area. These bird boxes have been designed with grey wagtails in mind, a bird which you can often see skipping along the back channel.

The Bird Boxes

The day ended with a pilot test of our bat boxes. We have brought five bat boxes to put up in the area. They are odd looking things with flat wood and small crevices between for the bats to roost in – almost like a bat multistory car park! With wire and a ladder, Luke and the volunteers tried to install the first one to perfect the technique ready for the next day.

A Bat Multi-Storey Car Park

Day 2

Day 2 soon came round with slightly improved weather and all 2000 plants had arrived! We ordered a variety of species – some were to be planted in the water, and others would be added to the banks such as lesser pond sedge and reed canary grass. All together these would make a great marginal community of native plants.

2000 Plants

We had 2 sites to plant up so we divided the trays into piles of different species – one pile for each site. Our 9 volunteers then headed off to site number 1 armed with dibbers, waders and gloves.

First site all planted up

By lunchtime, the site was finished and everyone was ready for tea, coffee and cake.

A planted plant

After lunch we moved onto site 2 and decided to focus on the plants that needed water so they were in before we had to leave for the day. So it was wader time again…

Day 3

On our third and final day we were joined by 5 volunteers to do the last bits of the project. First we all focused on the final 1000 plants – and even I had the chance to get involved!

Planters at work

Louise from the Living Wandle Landscape Partnership team couldn’t resist coming for a visit and doing some planting as well.

Louise planting away

The pile slowly got smaller and after a quick lunch break we had all 2000 plants happily installed in their new homes.

Yet more planting

The next job was raking and seeding the bare ground with wildflower and grass mix. It was a great 3 days out in the field and a big thank you to all the volunteers who came to help!

The finished work

A big thanks to Lawrence who helped run the event with Luke and myself.

Thank you to all our volunteers for coming: Barbara, Charles, Dave, Jason, John, Lawrence, Maureen, Mike, Neil, Nick, Rob, Tim and Wally.

Next week – Wimbledon Common and the Beverley Brook!

 

A little light goes a long way…

Our restoration projects along the Wandle are all progressing well, and it is time to introduce the next site on our list: the Ravensbury Park Back Channel.

The Ravensbury Park Back Channel is a remnant of the industrial milling era along the Wandle. Back channels, or “by-pass channels” were used as a mechanism to control the water passing through a mill allowing us to increase or decrease the flow depending on how much power was required. Although no longer used for this purpose, the back channel at Ravensbury Park has become part of the park’s landscape and could offer a valuable refuge for wildlife in the Wandle; in particular fish which could use the channel to by-pass the weir.

So what’s the problem?

  1. Channelisation

Like so many urban and rural rivers, the Ravensbury Park back channel has been engineered and modified to contain the river within a predetermined channel. This removes habitat and creates a stream with little variation.

Wooden banks and channelised nature of the stream

Wooden banks and channelised nature of the stream

  1. Un-natural banks

To protect the surrounding landscape from flooding, the natural sloping banks of this stream have been replaced with concrete and wood. This creates a ‘hard-edged’ bank and prevents important natural communities of marginal and aquatic plants from establishing here. A more gradually sloping vegetated bank provides habitat for many different species of riverine wildlife. Without this habitat there is a significant loss of biodiversity.

Concrete banks

A high concrete bank removes all interaction with the stream ecosystem.

  1. Little light

The Ravensbury Park back channel suffers from low light levels due to a dense tree canopy. This canopy limits the growth of aquatic plants both around the stream as well as within the stream.

A dense vegetative canopy prevents aquatic plant growth

A dense vegetative canopy prevents aquatic plant growth

Each of these issues on their own have negative consequences, but combined they significantly impact on the ecological structure and function of this little stream.

What can we do?

Over the next few months, the Wandle Trust will be taking steps to restore the Ravensbury Park back channel. This work is being funded by Defra’s Catchment Restoration Fund, and is also part of the Heritage Lottery Funded Living Wandle Landscape Partnership.

The main aim of the restoration works will be to create new habitats both in the stream and along the margins that will support fish, invertebrates and birds. More importantly, our works will provide a favourable environment for both aquatic and marginal plants which are a fundamental source of food and shelter for some organisms; vital for a thriving ecosystem.

We will be working further on our plans for this stream so keep your eyes peeled for new updates.