Copyright © 2019 Association of State Dam Safety Officials, Inc. All Rights Reserved.Extreme flooding has become more prevalent due to climate change and has been causing extensive damage, loss of property, and fatalities around the world. Levees are often constructed to prevent inundation in floodplains and urban areas. Flood mitigation efforts during extreme floods include forcing a breach in the levee at a strategic location to avoid flooding at target locations. A well-known example of engineered levee breaches along the Mississippi River is the New Madrid Floodway at Birds Point, controlled by the US Army Corps of Engineers, where a fuse plug design is utilized to detonate a portion of the levee and divert floodwater from the Mississippi River. In our study, laboratory experiments are conducted to investigate the effects of a levee breach opening on the attenuation of the flood hydrograph at upstream and downstream target locations of the engineered breach. The inflow hydrograph is initiated by a computer-controlled valve allowing for various peak discharges and flood durations in the channel. The backwater effect due to the floodplain storage is assessed by adjusting the basin storage volume and the tailwater depth. Flood stage at target locations is recorded using ultrasonic probes. Data obtained from the measurement is analyzed to find the effect of tailwater depth in the floodplain basin on reduction of water depth at target locations.