About this project

Project Aims

Our cutting-edge heritage and science programmes brought people together in learning, skills development and creative endeavours, for the largest and most ambitious river restoration of its kind in Europe.  Our project had 4 main aims:

1. Bring back the shad

This important rare fish will reach its former freshwater habitats and all fish will have improved access to the upper reaches of the River Severn.

In 2022, the first year the river was fully unlocked for shad, we achieved this goal. Read all about it here.

2. Our Severn

More people and a wider range of people will care about, visit and enjoy the River Severn making it a vibrant and exciting place to be.

Our extensive community engagement programme provided lots of opportunities for people to connect with their local river. Tours of Diglis Island & Fish Pass, as well as activities and events at many other locations along the river, brought people together as we told the story of the shad.

3. Deepen Connections

The River Severn will become an engaging route to learning that enriches people’s lives.

A range of formal learning activities formed a huge part of Unlocking the Severn. These included schools workshops, online activities, and in person visits to the riverside in Worcester and Tewkesbury.

Learning resources for teachers and parents became vital during the COVID-19 pandemic, as learning had to take place at home. Then, as we emerged from lockdown, face-to-face engagement provided a way for children and adults to reconnect with the river. Through visits to the underwater viewing gallery Diglis Fish Pass and citizen science counts at Upper Lode Weir, school children learned new facts and skills related to rivers, fish, wildlife, and the Unlocking the Severn project.

During the project, STEM careers tasters, work experience placements and apprenticeships opened doors and provided routes into different careers.

4. Volunteers at the heart of heritage and science

Together we will discover, share and celebrate the stories of the River Severn, and create an amazing legacy for the future.

Unlocking the Severn would not have achieved all its aims without the hard work, passion and enthusiasm of all the volunteers who gave their time to the project.

From educators and tour guides to corporate away days and habitat creation, to citizen scientists and fish pass window cleaners – there were a large number of volunteering roles offered as part of the project. Special mention to the Green Team, Fish Pass Volunteers, Explorer Education Volunteers, and Diglis Island Guides – four key volunteering groups continuing to help maintain Diglis Island and the fish passes, or providing an unforgettable visitor experience at Diglis.

A huge thank you to every one of our volunteers.

Project timeline

In 2017, long-term scientific monitoring was established to effectively assess twaite shad populations and connectivity in the Rivers Severn and Teme associated with the Severn Estuary SAC. Data from monitoring points around and upstream of the fish passes, provided information on the presence of adults, and spawning success in the middle reaches of the Severn and lower reaches of the Teme. Scientific monitoring between 2017-2023 would enable us to measure the success of the project.

In 2018, The Environment Agency began work modifying two weirs on the River Teme to provide fish passage.

In 2019, work began to build a deep vertical slot fish pass at Diglis, and a nature-like bypass channel fish pass at Bevere in Worcestershire.

By 2019, best practice fish access was provided for twaite shad at two man-made structures on the River Teme opening 63km of currently unreachable historic spawning habitat associated with the Severn Estuary SAC.

In autumn/winter 2019-20, exceptional flooding affected work at our construction sites. Work on the fish passes was halted for many weeks.

In September 2020, Bevere Fish Pass was the first of the four River Severn fish passes to be completed.

In May 2021, our largest fish pass, the 100m-long Diglis Fish Pass was completed. On 9th May, the first shad swam through Diglis Fish Pass. This was the first recorded time a shad had accessed habitat upstream of Worcester since the weir was built!

In October 2021, HRH Princess Royal officially opened Diglis Island & Fish Pass for public tours and events. The first public tours of Diglis Island & Fish Pass commenced.

In February 2022, our documentary film, produced by award-winning photographer Nina Constable and narrated by broadcaster Monty Halls, premiered on the Unlocking the Severn YouTube channel.


By spring 2022, all four fish passes on the River Severn were complete. Best practice fish access was provided for twaite shad on the Severn. The building of the River Severn fish passes opened 190km of previously inaccessible historic spawning and nursery habitat associated with the Severn Estuary Special Area of Conservation (SAC).

In May 2022, we celebrated the first Shad Run (shad migration season) in a fully-unlocked River Severn! In addition, the Shad Symposium brought together over 100 delegates from 9 different European countries to share knowledge and best practice for shad conservation.

In 2022, twaite shad DNA was recorded above our most northerly fish pass at Lincomb, near Stourport. This evidence proved that shad were able to reclaim key spawning habitats for the first time in nearly 180 years.

31st May 2023, the 10,000th visitor was welcomed to Diglis Island & Fish Pass.  local communities understand the biological and potential social and economic value of twaite shad, the river and the SAC, in terms of its historic and present-day importance, through a series of events and dissemination actions.

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