Ballum floodgate is a Protection gate at the outlet of Brede Å in Southern Jutland. The nearby Ballum floodgate-inn is part of settlement. 3 km south of the Romo dam, on the coast road between the dam and Ballum. 

History: The builder's designer was Hinrich's dough engineer, while the plant itself was handled by Philip Holzmann & Co. Construction began in 1914, but was delayed by World War I, which was declared the same year. Much of the construction work was imposed on French and Russian prisoners of war. In 1915 the actual sluice mill was completed.

In 1920 the area became Danish again at the Reunion. From 1786 the ferry crossing took place from Bådsbøl-Ballum to Rømø. Around 1900, a motor ferry sailed from Skærbæk Brohoved north of the current dam; but later the ferry route moved back to Bådsbøl-Ballum, until after the Reunion it was transferred to the newly built Ballum Sluse, where a jetty was constructed. From there, the ferry continued to Rømø from 1923 until the dam was inaugurated in 1948.