A restoration project with ambitions to make a Pembrokeshire river more resilient to the challenges of the climate and nature emergencies is making great strides.

The Natural Resources Wales Four Rivers for LIFE project team began work to restore the Western Cleddau River in Pembrokeshire in October 2023, with the goal of creating valuable habitat for important fish and wildlife.

The first project saw the introduction of several pieces of large wood into the river to mimic the natural processes that happen when trees fall into rivers. 

Introducing wood narrows the river channel and forces the water around the wood causing localised erosion and creating new meanders.

As material from the erosion deposits in the flow shadow of the wood over time, new gravel, sand and silt bars will be created which will, in turn, create vital habitat and areas for important fish such as lamprey and trout to spawn and raise their young.

The wood also provides shelter for fish from fast flows, shade and cooler water, and cover from predators.

The second project saw the re-introduction of large boulders into a stretch of the Western Cleddau River, near Letterston village.

The boulders are believed to have been removed from the river as part of historic dredging in the late 1960s. This was confirmed by the presence of similar types and sizes of boulders found nearby. These boulders showed clear signs of weathering and erosion as opposed to bank protection boulders, which are quarried and angular in shape.

Introducing the boulders will create more natural flow diversity, as water speeds up on either side of the boulder and slows down upstream and downstream.

These different flow types create perfect conditions for different insects which are part of the food chain that supports species like salmon and otters.

The calm water flows also offer rest areas for fish, as they move up and downstream and swim from boulder to boulder to save energy.

Both projects were funded by the Four Rivers for LIFE Project, an EU LIFE funded programme looking to restore freshwater habitats for rare and important species.