Dynamics...

A river is a dynamic thing if it is allowed to be so.  Where does the gravel come from?  It comes from erosion of the banks.  Uninhibited erosion, such as that which happens in winter on rivers with no perennial plant roots to protect their banks. is a very bad thing for the health of the river.  That alien annual, Himalayan Balsam, out competes native perennials and takes over the banks of many British rivers.  The balsam plant, when it has finished shooting its seeds all around it to a distance of as much as thirty feet, dies and because it is very shallow rooted is washed away at the very first winter flood, leaving the soil bare and unprotected.  Every instance of high water from them on washes the bank away.  The farmer loses land, the gravels get blinded with soil, the eggs are suffocated and the angler ends up with no wild trout and no native marginal plants to enjoy.

But there is another, beneficial, type of erosion.  This happens where root protected banks are slowly undercut by the river, so the gravel, deposited by the glaciers thousands of years ago, is gradually released into the river bed and is then graded by the currents to make clean, productive beds for fish to spawn in, fly larvae to live in and Ranunculus fluitans to set root in...

Ranunculus fluitans

This beneficial erosion can spontaneously start anywhere where the current may be newly directed to the bank.  Such new direction often comes from something new ending up in the river and, in Duck Holds Wood that something new is usually a tree, or part of a tree.  Here's a newcomer.

The Song Room Willow

This willow fell years ago but, until this winter, it had for the most part stayed out of the water.  This winter something caused it to complete its fall.  I have no doubt that it will change the dynamic of the Derbyshire Wye for a few yards at least and it will be interesting to see if new gravel is scoured out and deposited in the downstream pool, which, as an acknowledgement to the constant symphony of birds singing away round here on most days, is known as "the Song Room".  This finally-fallen willow has already changed the dynamic of your faithfull blogger's fly box.  It took at least half a dozen casts and one forced fly replacement before one of the brown trout living right in the middle of this picture made that essential mistake we all pray for...



Regular Rod