Weirs are structures which allow surface liquids and floating debris to flow by gravity downstream. They can, therefore, be classified as gravity skimmers. Fixed, movable and floating skimmer weirs have been designed and used in oil cleanup operations and various water, wastewater, mine tailing, and stormwater applications. Surface skimmer outlets from small and large drainage impoundments have been shown to improve performance of Best Management Practices (BMPs) by increasing the trapping efficiencies of sediments and other pollutants.

The skimming properties of basic rectangular, triangular and trapezoidal weirs are summarized in this paper according to a newly developed hydraulic theory for skimmer weirs. The weir skimming properties are compared in terms of a skimming function, which defines the distribution of outflow per unit height above the crest of the weir. A key parameter, which characterizes the weir skimming performance, is the elevation at which the skimming function reaches a maximum value. Higher skimming performances compared to basic weirs have been achieved in this study with polynomial weir geometries. The method of designing such high-performing polynomial skimmer weirs is discussed.

Hydraulic Design of Polynomial Skimmer Weirs

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[Paper Proceedings](https://doi.org/10.1061/9780784483466)