THE Diglis fish pass has proved popular since it was unveiled as part of the Unlocking the Severn project.

The project was set up to save the endangered twait shad. We went to visit for a behind the scenes tour.

What can you see at the Diglis Fish Pass?

The Diglis Fish Pass contains a room below the River Severn, with a large viewing window where fish can be seen making their way upstream.

Two cameras are stationed in the viewing room, which both monitor every fish which passes through.

The viewing window is illuminated with a backlight so that the cameras can detect fish at all times of the day.

Fish that can be seen at the window include twait shad, dace, lampreys (or vampire fish), pike and even salmon.

READ MORE: Moment biggest shoal of fish yet swim by Diglis fish pass

On our visit, we saw a large pike and a shoal of small fish swimming together.

What is a Fish Pass?

The purpose of a fish pass is to allow fish to move past manmade blockages in water. In Diglis, the weir means that many fish looking to travel upstream struggle due to the two-metre separation.

The weir was installed in the 1840s to create a deeper, more reliable pool of water upstream for boats.

Stronger fish like salmon are occasionally able to get past the weir by jumping, but many species do not possess the required strength.

The pass consists of 11 small pools, each just 20 cm higher than the last, making it more manageable for the fish to swim through.

The fish detect the stream of water in the river and can travel upwards, with walls in each pool relieving some of the force created by the water. 

Can you visit the Diglis Fish Pass?

Worcester News: Underwater viewing room at Diglis Fish Pass,Underwater viewing room at Diglis Fish Pass,

The Diglis Fish Pass relies on volunteer staff who provide tours that can be booked via the Unlocking the Severn website.

The tickets are free, but are very popular, with dates throughout April disappearing quickly.

There will be some drop-in sessions throughout May on the following dates:

  • Wed 4th May 
  • Wed 11th May 
  • Sat 14th May 
  • Sat 21st May 
  • Tue 31st May 

These sessions operate via a queuing system, with times being published on the website nearer to the dates.