The study investigated the discharge coefficient of a modified rubber weir with a crest gate at fully closed conditions. By conducting experiments on a hydraulic model resembling a real weir, researchers found that this type of weir has a higher discharge coefficient compared to traditional weirs like Ogee Weir and Sluice Gate. This is because the unique shape of the Crest Gate Rubber Weir reduces flow resistance, allowing more water to pass through even when fully closed.