New bridge will help Carmarthenshire stream flow freely

Afon Glir – also known locally as Clearbrook Stream in Carmarthenshire is flowing more naturally once again following the installation of a new bridge at the National Botanic Garden of Wales (NBGW).

Working in partnership, Natural Resources Wales’ Four Rivers for LIFE project and the team at NBGW have replaced an existing culvert crossing with a clear-span bridge, helping to improve the natural function and ecological connectivity of the stream.

Afon Gir flows through the Restored Landscapes at the Botanic Gardens and onwards into the River Tywi Special Area of Conservation (SAC).

The previous culvert had become perched above the level of the stream bed over time, affecting the continuity of the river channel and creating conditions that required ongoing management of the surrounding banks and crossing.

The new clear-span bridge removes this restriction and allows the stream channel  and bed to function more naturally beneath the crossing.  It also provides a stronger and safer access route for livestock and visitors using the site.

Importantly, removing the culvert improves connectivity along the stream, allowing small fish and invertebrates easier access to habitat further upstream. Improving connectivity in this way can provide species with a greater area of suitable habitat in which to feed, shelter and reproduce.

Ieu Davies, National Nature Reserve and Farm Manager from the National Botanic Garden of Wales said:

“The previous crossing required ongoing management and restricted the natural continuity of the stream. Replacing the crossing with a clear-span bridge gives the channel more space to function naturally, improving connectivity for aquatic wildlife and providing us with a robust and practical crossing for the future.”

Chris Thomas from the Four Rivers for LIFE said:

“Restoring river habitat is at the absolute heart of what we do. Replacing the culvert with a clear-span bridge improves the natural function and connectivity of this important tributary of the River Tywi SAC, and should help reduce pressure on the stream banks and movement of sediment downstream.”

Engineered for minimal disruption, the bridge was pre-fabricated off-site and installed in its position in just five days by contractor Spencer Quantum.

The Four Rivers for LIFE Project is funded by the EU LIFE Programme with support from Welsh Government.