Human Intervention at Tumbi Wetlands Bushcare 
Does it matter what goes down the drain?
Garden waste can contain some hidden seeds or excess fertiliser.

Once in the storm water drain it is all swept away;
the seeds germinate and cause trouble for the native plants and animals. The fertiliser will nourish weeds, giving them an advantage over native plants, thus causing further damage.
Don't clog drains
Drains are for carrying away storm water, so allowing garden or other waste to get into storm water can clog drains, and may cause flooding.