I am a newby to this game but not to life ( 70 in April) but my thoughts on the definition of dredging, for what they are worth? are as follows.
1. if you are sucking sand from the bottom of a designated water course into a sluice which runs back into the watercourse, are you in fact removing material, eg dredging, or just disturbing the material.
1. if you are sucking sand from the bottom of a designated water course into a sluice which runs back into the watercourse, are you in fact removing material, eg dredging, or just disturbing the material.