From the NSW Fossicking Guide under the How do I protect waterways when I fossick? topic
The Fisheries Management Act 1994
regulates a range of activities including those that harm the habitat of native fish (including threatened species of fish) and recreational fishing.
Following the guidelines and avoiding the activities listed below will assist you in complying with this Act:
removing or disturbing any material that is important habitat for fish (including threatened
species of fish) from the bed or banks of a waterway including woody debris (snags) greater
than 3m in length, large cobbles, rocks or boulders (greater than 500mm in diameter) or
aquatic vegetation; or
placing or reshaping any material across a waterway that may obstruct the free passage of
fish.