Sedimentation


Definition:

Sedimentation occurs when mineral and organic materials block the flow of a waterbody.

 

Why does it cause pollution?

When sedimentation occurs in a waterbody, can block water flow. When the water is slowed down, the oxygen levels are lowered. There are two ways that oxygen enters water: photosynthesis and physical mixing. Instream sedimentation usually results in the opposite of physical mixing, stagnation.

 

How does it get into water?

Sediment can get into the water any time vegetation is cleared from the land of a stream is straightened. Without vegetation in place, the soil easily erodes away. Any time there is a narrow place in the channel of a waterbody or some sort of blockage, the flow will slow down. This will lower the flow causing some of the sediment to fall to the channel bottom. Of course, the more sediment falls to the channel bottom, the more blocked the channel becomes. This cycles continues until the permanent blockage is removed by fast-moving stream flow or people.

 

What land uses are the source of this type of pollution in the B-T Basin?

Causes in the Barataria and Terrebonne Basins are unknown. In some other places they might be caused by forestry, flow alteration, construction, or urban or agricultural runoff.

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