Weirs and the Backwards Ways that Rivers Work
One of my favourite sayings on river restoration is a mangled quote from a movie
"...boxing is an unnatural act. Everything in boxing is backwards: sometimes the best way to deliver a punch is to step backwards...but step back too far and you ain't fighting at all".
So my mangled version starts out "Everything in rivers is backwards...". Basically, I never seem to run out of new examples of "what SEEMS to happen in a river is actually the complete opposite of what really happens".
The rest of this article looks at many of the "backwards" things about weirs and rivers - and finishes off with a real-world case-study that is playing out right now on the River Dove.
One spoiler alert is that, from an ecological point of view, it is almost always safe to assume that:
The best biological outcome for a river is the removal of some or all of an artificial weir.
Now, I don't expect you to believe that…
It was my great pleasure to travel up to the west coast of Scotland on Sunday (24th June)to meet up with Alan Kettle-White and Daniel Brazier of Argyll Fisheries Trust . Staying over until Tuesday enabled me to get in a habitat survey of the Black Lynn Burn in Oban on the Monday as well as meeting local stakeholders such as businessman Graham MacQueen of MacQueen Brothers who are keen to have local community members discover, re-engage and value their local urban river. Hopping into the river to walk along the riverbed was the best way to get to know the burn.
It didn't take long to find signs of life:
In fact, away from prying eyes, there was some very good habitat- particularly for juvenile trout (although also a lot of Himalayan balsam and Japanese knotweed also in evidence!)
As long as this small structure does not conceal services (such as sewage/gas pipes or electrical cables) and appropriate permission can be gained, the variety in depth and flow upstream…
Here is a great short piece that captures what the work of the Wild Trout Trust is all about. It was made for (and broadcast on) the very first "World Fishing Day" - a 24hr live fishing programme created by FishingTV.com. It features TV personalities (and WTT President & Vice President respectively!) Jon Beer and Matthew Wright as well as Director of the Trust, Shaun Leonard.