How is a sediment basin dewatered?

The water contained in the sediment volume space (dry volume between the principal spillway riser crest and the permanent pool level) should be slowly dewatered to allow most of the finer suspended sediment particles (primarily clay and fine silts) contained in the water column to settle out before releasing to a receiving stream. This is best achieved by “skimming” off the upper, cleaner part of the pond water over a relatively long period of time. Proper design, correct installation, and regular inspection and maintenance are vital to effective operation of any dewatering device.  more