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Tony L. Wahl, Dale J. Lentz. 2011. "Physical Hydraulic Modeling of Canal Breaches". Bureau of Reclamation, Report Number HL-2011-09.

Abstract: Canals have the potential to be a source of serious flooding when embankments erode and breach. To assess and address risks associated with canal embankments, the erosion and breach processes must be understood so that potential flooding can be modeled. Breaching processes for canal embankments are potentially different from those of traditional embankment dams impounding large reservoirs due to several factors, including the effect of water flowing in a canal past the developing breach and limitations on the ability of a canal to convey water to a breach site as the breach develops. This may significantly affect the mechanics of the erosion process and the resulting breach outflow hydrograph. This study used laboratory physical models to study the breaching processes of typical canal embankments. The effects of varying material properties and different failure initiation conditions were considered. Material erodibility was quantified by in situ and laboratory submerged jet erosion testing. Relations for predicting canal breach outflow rates as a function of canal and embankment geometry and geotechnical/erodibility characteristics are proposed. These relations could support appraisal-level evaluation of flooding risks posed by existing canals. For detailed analyses of specific cases, the data collected in this study can support the development of canal-specific breach simulation computer models.


Web Link: http://www.usbr.gov/pmts/hydraulics_lab/pubs/HL/HL-2011-09.pdf

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