Friday 17th August, 2018

After a desperate summer for the rivers, there is some good news to report from our Gravelling the Elan System (GES) project. This week, electrofishing surveys confirmed that for the first time since monitoring started in 1972 (and possibly well before), salmon and trout have successfully spawned in the upper section of the river below the dams.

The Foundation, along with partners Dwr Cymru Welsh Water and Natural Resources Wales have been replenishing the lost gravels in this part of the Elan over the past two years. The project was designed to restore the river's ecology and to enable salmon and trout to once again use the full potential of this important upper Wye tributary for spawning and juvenile habitat.

Following gravel introductions in 2016 & 2017, initial monitoring results showed improvements in the invertebrate populations in the previously depleted areas. Last year, adult trout numbers were also found to have risen, probably taking advantage of this improved food supply.

Last winter an adult salmon was seen leaping below the weir at the Visitor Centre, just upstream of the gravel introduction point. Then, in December, at least one probable salmon redd was observed in the new gravel but confirmation of whether this was evidence of successful spawning would have to wait until this summer.

At a site near the Elan Valley Village, where some of the new gravel had accumulated, the monitoring team found 6 salmon fry. Trout fry were also recorded at 6 of the 8 upper Elan monitoring sites. The result shows that the newly introduced gravel has been used by both salmon and trout to spawn.

The monitoring team also found that numbers of bullhead (Cottus gobio), an SAC designated species that lives in gravel, were also up in the previously denuded areas. Additionally, densities of  salmon fry in the lower sections of the Elan had increased fivefold.

Looking ahead, the Elan could become an increasingly important spawning area for salmon and trout. The extreme hot and dry conditions of this summer are probably a sign of things to come. Provided the habitat is right, the controlled flows of the Elan dams provide them with some refuge to the extremes of temperature and flow.

This project has been several years in development, requiring lengthy and, at times, painstaking negotiations. We would very much like to thank Dwr Cymru Welsh Water and Natural Resources Wales for their support and determination in making it possible. This result is proof that the gravel initiative was worthwhile.

There will be a further introduction this year and some work to loosen compacted old gravels. We hope then to be able to secure the funding required to continue with yearly top-ups so that the newly restored areas do not fall back into their pre-project state.