View Full Version : Rivers at flood

Matty B
04-01-2010, 03:21 PM
Does anyone know what effect the massive amounts of water and flooding of the rivers will have on our river fishing when the levels subside?

I know from experience many trout will hunker down behind cover and stay out of the flow. But there must be hundreds (thousands?) of fish that end up miles down river in lakes and reservoirs. How long does it take them to migrate back to their old haunts?

Matty B

04-02-2010, 01:01 PM
You'd be surprised what a fish can withstand. I doubt there will be much in the way of redistribution of fish due to the flooding. We get heavily flooded rivers up here every year and the same places seem to hold fish. The big changes will be on how sediment and scouring will impact the river. There is a whole science called fluvial geomorphology that studies the sediment movements in streams. One fallen bank or a new gravel bar up river can impact areas miles down stream. Every time a bar or bank moves, the river changes unless there is enough riparian buffer to prevent substantial erosion, but that is the natural moevment of any river. That is why it is so important to retain proper riparian buffers and access to a rivers historical flood plains. Without thos things rivers will move much more than they would in their natural state and can impact fish habitat. Sedimentation also fills the little cracks and crevices insects use to live and grow. There are often a couple of year of bad hatches after extreme floods and with increased sedimentation the insect biota can change over time, usually from mayflies to caddis flies as the water quality decreases though that is in general only.

Matty B
04-03-2010, 11:51 AM
Thanks for the info. Great post.