River Clydach – Log Jam at Tunnel Ynysybwl

Clearance of a multi tree log-jam on the River Clydach, downstream of the Tunnel at Ynysybwl  to allow unrestricted access  migratory fish, to access approx. 4 Km upstream of Ynysybwl to enable them to utilize the spawning gravels and nursery areas in the headwaters and tributaries of the river Clydach. 

This multi tree log-jam was identified while SEWRT and NRW  were reviewing previously identified barriers to fish migration on the river Clydach.The natural falling of trees into a water course can result in a dam that can in some cases inhibit fish passage but also cause over time flooding.

This blockage was located  downstream of the tunnel at Ynysybwl and consisted of approx 12 medium sized trees, that blocked the full width of the river and extended downstream for approx  10 meters.

Establishing the many land owner ships, for permission to access the site of the log- jam proved very difficult, but eventually with the assistance of NRW they were all identified and we obtained the necessary written permissions to access the site.

Access to the site was good allowing the use of winches and chainsaws.  The project was completed within a day to our satisfaction. The woody materials and other debris, were removed from site by the contractor after completion of  the clearance.