Natural Resources Wales is returning boulders to sections of a seven-kilometre stretch of the upper River Wye near Llangurig.
The work aims to restore natural river conditions and improve habitat for Atlantic salmon and other wildlife.
Monitoring has identified substantial numbers of young salmon but relatively poor survival as they mature.
The project will create more varied river depths and flows, providing shelter and feeding opportunities.
It forms part of a wider restoration programme involving farmers and landowners.
Why it matters: The River Wye faces significant ecological pressures, and restoring habitats is one component of improving its environmental condition.
NRW will continue monitoring to establish whether the interventions improve salmon survival.
The original NRW update was published on 8 October and received further coverage today; this is not a newly announced project.
