The long summers have almost done for our crayfish. The last two dry years have reduced the flow to a trickle but a real problem developed during the seemingly never ending summer holidays of youth. The local children lived in the river last summer, day after day and moved and removed all the crayfish stones. Any crayfish that were captured were collected up in buckets and moved around. We need a few permanent refuges that couldn’t be prised up and they have been provided with a few lengths of half log, with hollowed out centres and access notches.
The 16mm rebar needs to be long enough to resist little hands and fingers. I think it is.
The log sits flush to the bed leaving only the access gaps. It will be nice and dark in there, and they will be safe from fish and children.