What are sediment and silt? Sediment is matter which settles at the bottom of liquid.  Silt is earthy matter, fine sand or the like,carried by moving water and deposited as sediment.	Click here for sound
	What might happen to silt in a fast moving stream? The silt would be moved along by the flow of the stream and so very little sediment would drop to the bottom of the stream. Many creatures need the sediment as it provides a home for them. The stream would become turbid. Tubidity is a waterway which is muddy.
What's a bit of muddy water going to hurt? A bit of muddy water is going to hurt a lot of plants and animals. It would kill many animals by destroying spawning beds and fish habitats.   Sediment can also hold chemicals and heavy metals which can poison the water ways.	Click here for sound
	How did all that soil get into the water in the first place? Grass and trees keep the soil in place and in this picture the paddock on the hill has been overgrazed. This means that animals have eaten the grass to the roots. As a result the soil underneath the grass has been caught by the run off.
By Kayleigh, Carmen and Jessica.