In some parts of Europe, weirs are being removed at a rapid rate. They were useful when a good head of water was needed to feed a watermill. The water held behind them was a regular haunt of aquatic life when water levels were low.
Yet weirs are being removed at a rapid rate in some countries.
In some countries, dams are being built to retain a lot more fresh water than any one weir ever did, but in a long river weirs did the job of retaining a lot of fresh clean water which would seep into the surrounding land, through it and top up the aquifers.
Still, weirs are regularly being removed as part of some big plan which will speed up the loss of fresh water from the rivers and their surrounding land mass. If aquifers were not being emptied so fast for farming and domestic water supply, their reserve would keep the water tables up and the soils alive for root growth.
But you’ll find that there’s a plan to take away a weir or too within a few km / miles of where you live.
Close to the WoW Field Centre there was a river that flowed year round up to a few years ago. Not today. Today it’s a dry river bed. No sign of life or even a damp stone. The reasons are many and a lack of rainfall is top of the list. But when rainfall is low, it’s useful to have weirs – weirs that retain safe ponds of water where river life can survive.
Generations before ours watched beavers at work building dams that would create bodies of water upstream – places where fish would gather in times of low rainfall making a good larder.
So are we removing weirs so that reintroduced beavers have a blanker canvas? Are we removing weirs because we have too much fresh water or too many flood plains where we can’t develop housing estates?
Or are we removing weirs because we think it’s too expensive to maintain them or add fish ladders to them?
Perhaps we’ll learn from the beavers again and re-invent the ‘wheel’ in the future.