Morganza Spillway to add height to the permanent levee by building a supplemental sandbag levee on top of it. However, additional rainfall raised the flood crest higher than even the supplemental sandbags, sending floodwaters over these levees into of cropland located within the floodway. The 2011 Mississippi River floods began to become serious in April. In response, the Corps first analyzed the flooding, and then opened the spillway in a controlled manner. The Corps studied four flooding scenarios, all of which assumed the Bonnet Carré Spillway would be concurrently operating at full capacity (100%). Following this analysis, which showed that extensive flooding
Flow control structure dam across a shallow stream, forcing all of the water to one side to allow it to be easily collected in a canal. This can keep a canal full even with very low flows in a stream. Another simple device is a series of concrete piers installed in a spillway to slow down the descending water so that it does not cause damage at the bottom of the spillway. Flow control structure A flow control structure is a device that alters the flow of water in a stream, drainage channel or pipe. As a group these are passive structures since