Fusegates are commonly considered for increasing reservoir capacity by maintaining higher water levels upstream of spillways. The purpose of present study is to extend the application range by installing a set of fusegates alongside on the river base so that they fulfil a sole barrier for the incident flow without the need for an extra flood mitigating structure. A scale model of standard WHH-type fusegate is conducted in the laboratory flume. The complex flow field observed in the experimental setup is decomposed into three basic scenarios, each of which are analyzed independently with theoretical results supported by the head and discharge measurements. The scenarios describe the hydraulics of fusegate system interacting with a sharp-crested weir. The results from suggested scenarios compare favorably well with the available empirical as well as theoretical results, with the maximum relative errors not exceeding 2.85%, 4.37% and 8.8%. In a real world practice, a combination of basic scenarios is examined and an operational pattern is proposed with the relative merit of reducing the number of fusegates to control a certain design discharge.
