No Crawdads

Prior to fabricating and installing the new Coanda-style cover for my hydroelectric capturing box, every couple weeks I would notice a drop-off in the water flow to the turbine.  Sometimes it stopped altogether.  So, I had to turn off the water at the bottom, flip up the turbine housing and remove the nozzles.  Invariably the orifice was crammed solid with a crawdad body, sometimes compressed to the point where I needed to drive it back out with a metal rod.  It happened so much I kept a tool right there for the task.

With the former configuration the intake was covered with 1/4″ inch hardware cloth, even then the little crustaceans figured out how to get into the capturing box and were sucked into the pipeline.  A minute or two and 1200-feet later they wound up crushed at the bottom when their carcasses were too large to fit through the turbine nozzles.  Hence the need for regular clean-out.

Since I installed the new cover there have been zero crawdads in the nozzles.  .

A big step forward.