Weirs and impacts on river life

A lot of attention is paid to the "barrier to migration" effect of weirs - but this misses the vital point that the transportation of riverbed material is also interrupted. Not only that, but holding back large areas of slower water also damages the habitat of a wide range of flora and fauna. Whilst fish passes can be a vital "last resort" that (when they work and are well maintained) may at least allow some wildlife to pass through this degraded habitat; they cannot do anything to improve the habitat itself. The combination of the facts that there is no fish pass as good as "no weir" and that weir removal restores nature's ability to heal itself means that much more needs to be done to explore the potential to modify and remove weirs in part or in their entirety.

https://www.youtube.com/watch?v=ILofBcLiDts