2021 didn’t bring the ‘return to normal’ that we had hoped for, but instead remained full of full of uncertainties around the ongoing pandemic, global events and extreme weather. Despite the challenges faced, Unlocking the Severn have had a lot of achievements to celebrate this year. Join us as we look back at our Top 10 highlights for 2021!

1. The Completion of Diglis Fish Pass and Underwater Viewing Gallery

In April 2021, our second fish pass was completed! At 100m long, 8m wide and 5m deep, Diglis is the biggest deep vertical slot fish pass in England and Wales. The fish pass also features a unique underwater viewing gallery, where a window into the River Severn offers people the chance to see wild fish swimming past. The completion of Diglis Fish Pass this year meant that the twaite shad can finally swim past Diglis Weir in Worcester on their spring migration for the first time in nearly 180 years!

After a successful run of pilot tours this Autumn, Diglis Fish Pass and viewing gallery will be open for an extended tour programme in the Spring and Summer of 2022. To keep up to date with announcements beginning early next year, keep an eye on our website and social media @SevernUnlocked. You can also subscribe to our newsletter. Information found at the bottom of any webpage.

Watch our short film celebrating the completion of Diglis Fish Pass below.

2. Shad are seen swimming through Diglis Fish Pass

After all the planning, construction, and hard work, it was a historic moment (and a rather big relief!) when twaite shad were seen using the fish pass. Thanks to the scientific monitoring cameras in the viewing gallery, we were able to spot the first shad passing through. The first recorded shad swam through Diglis Fish Pass on 9th May. Since then we have seen hundreds of shad use the pass, and hope to see many more in 2022 when the Severn Shad Run begins again in the Spring.

Watch shad swim past the viewing window in the clip below:

3. Her Royal Highness The Princess Royal visits Diglis

Photography: Aaron Scott Richards

On Friday 8th October, Unlocking the Severn were very pleased to welcome HRH The Princess Royal to Diglis Fish Pass. Her Royal Highness officially opened the fish pass and underwater viewing gallery, celebrating the completion of Diglis fish pass in the spring and the viewing gallery in September.

Her Royal Highness was hosted by Richard Parry, Chief Executive of the Canal & River Trust, and met a number of Unlocking the Severn team members, project partners, funders and volunteers on the day.

Read more about the royal visit HERE.

4. The project wins an ICE Award

Members of the Unlocking the Severn team and main contractor, Kier, pose for a photo with the ICE Award, alongside Chris Binnie

In October, Unlocking the Severn received an award at the Institute of Civil Engineers (ICE) annual awards ceremony. The team picked up the first ever Highly Commended Chris Binnie Award for Sustainable Water Management.

ICE wrote about Unlocking the Severn: “this project was highly commended for its success, benefits, and sustainability principles. As one of the earliest deep slot fish passes it is highly innovative and applicable for other locations where similar systems could be installed.”

5. Lincomb Fish Pass is completed

Photography: Skynique

In June 2021, following hot on the heels of Diglis, our third fish pass at Lincomb was completed. A lot of the lessons learned from Diglis were used in the construction of Lincomb, as the two were built almost at the same time and were the same design: a deep vertical slot fish pass.

In the short film below, Stacey Corcoran, project manager at lead contractor, Kier, shares her experiences of the project. Stacey reflects upon the challenges of building a fish pass in a pandemic, the excitement and pride from her team when the pass was completed, and tells a delightful anecdote about an eager shoal of fish!

6. We welcome our first school groups to Diglis Island and the Fish Pass

This Autumn, 5 school groups visited Diglis Island and Fish Pass during our pilot tour programme. 132 children from a range of school years, from Year 4 to Year 13, have learned about the River Severn and its fish, the problem that weirs pose for fish and what we are doing about it.

They have been introduced to our project through a hands-on STEM-based activity on Diglis Island, a tour of Diglis Fish Pass, and a view of the underwater world in our viewing gallery.

Highlights have included helping children understand fish pass engineering through a fun marble-run activity, being able to offer the same exciting experience to students with special educational needs, and of course Barry the Barbel – a fish who was named by one school group and caused a lot of excitement from the children when he took up temporary residence in the pass!

7. Our volunteers did amazing work with us in 2021

We welcomed 159 new volunteers to the Unlocking the Severn project, who joined us for a range of river conservation activities. Our list of volunteering projects this year included:

  • The Green Team
  • The Severn Conservation Taskforce
  • River Conservation Placement Volunteers
  • Shad Migration Volunteers
  • Acoustic Monitoring Volunteers
  • Explorer Volunteers
  • Diglis Island Guides
  • Work experience students
  • University student volunteers
  • Corporate volunteer groups
  • Administration Volunteers


Our Green Team volunteers did an impressive job on Diglis Island this year. Not only transforming the overgrown and messy areas into a space to welcome visitors, but also completing various projects to benefit the ecology of the island. Some of these include building and installing bird boxes, laying hedges to act as nest site for birds, and creating a wildflower meadow to benefit insects and strengthen the base of the foodweb on the island.

We are very pleased to have the brilliant Explorer Volunteers helping to run our school visits, and our wonderful new Diglis Island Guides leading our visitor tours. Both these volunteering groups will be particularly important to us as we begin our Diglis Island and Fish Pass tour programme in Spring 2022.

Citizen science is a huge part of our project, especially during the Severn Shad Run (the migration of the  twaite shad) in May. Volunteers have helped us count shad online and at Upper Lode Weir, listened for spawning activity, and assisted with acoustic tagging of shad as we track their migration through the River Severn.


8. We introduced more people to our project with a big splash on TV and radio

This year the project has made a big splash in the media. We’ve introduced people to Unlocking the Severn on TV, radio, newspapers and online. Some of our favourite appearances this year were;

The One Show

Unlocking the Severn were very excited to be featured on The One Show in August! Did you catch it?

BBC Midlands Today

Coinciding with the twaite shad migration on the River Severn, Unlocking the Severn featured on BBC Midlands Today to show how scientific monitoring and volunteering is combined to help us monitor shad populations.

BBC Earth

We also featured in a mini documentary for BBC Earth, as part of their Rewilding series on Facebook. Watch below:

You can also read our feature in the BBC News Online.

9. We released our new animated film ‘Up River!’

The short animated film was produced in collaboration with the children of Cherry Orchard Primary School, Worcester, Unlocking the Severn staff, and professional film makers and animations from biggerhouse films.

The film tells the story of two young twaite shad who migrate into the River Severn from the sea, and face challenges on their journey to reach their historic spawning grounds.

Over the course of 4 days, over 180 year 5 and 6 children took part in the workshops for Unlocking the Severn. Whilst the whole school of more than 600 children were involved in colouring pictures of the shad fish and contributing sound effects.

Watch the video below:

Find out more about how Up River! was produced


10. 23 species of fish recorded through Diglis Fish Pass

If you have been following along with our #FestiveFishes advent calendar this December, you will have been introduced to some of the 23 species of fish recorded using Diglis Fish Pass so far. This is an exciting achievement for the project. The fish pass was designed with the twaite shad in mind, but also to accommodate the wide range of fish species we have in the River Severn throughout the year.

Scientific research, part-funded by our project, has shown how multiple weirs on the River Severn create a cumulative effect on other endangered fish like sea lamprey. We have therefore been overjoyed to see such species cruising upstream through the fish pass.

Take a peak through Diglis Fish Window at some of the species that we have seen using the fish pass, including twaite shad, lamprey and salmon!


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