Today’s Erosion and Sediment Control Tip: #16

 Today’s Erosion and Sediment Control Tip



Sediment Basins require a device to dewater from the surface of the basin to remove the cleanest (less turbid) water.  This is often accomplished with a skimming device that is designed to remove the stored construction runoff over a period of 2 to 5 days.  It is important that the skimmer be installed and maintained properly. Skimmers must have a flexible connection to the rigid pipe or riser system that goes through the dam.  It should easily operate at all design elevations.  When placed on a principal spillway riser, the pipe from the skimmer to the flexible connection should be about 1.5 x the height of the riser structure. The flexible pipe outlet at the rigid pipe or riser system through the dam should be at the standing pool elevation to ensure the skimmer does not function below the required elevation. A rock pad should be constructed for the skimming device to rest on when discharge is complete.  The skimmer may need checking occasionally to remove blockages that could occur in the orifice in the skimmer.  The skimmer must be easily accessible even if the basin is full of water.  A rope tied to the skimmer could be used to pull the skimmer to the shoreline to do this. 

Skimmers are the preferred mechanism for dewatering a sediment basin.  They must be designed, installed, and maintained to function as planned so the runoff water from the basin is as clean as it can be.

 

Perry L. Oakes, PE
Erosion & Sediment Control Program Coordinator


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Anonymous said…
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10/26/2021
Anonymous said…
Hi Perry
10/26/2021
Perry said…
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10/26/2021
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