The Ochtumsperrwerk near Lemwerder is located at the mouth of the Ochtum in the Weser. It serves the flood protection behind the barrage lying low and thus in particular the protection of parts of Bremen, where there was the only fatalities in the Unterweserraum during the storm surge in February 1962, Delmenhorst and Stuhr. The barrage was built on the basis of a treaty of the states of Lower Saxony and Bremen.
Together with the barrages at the Lesum and the Hunte the Ochtumsperrwerk is part of an overall concept for flood protection on the Lower Weser, which was able to go on 1 October 1979 with the completion of the Huntsperrwerks in operation. The Ochtumsperrwerk is operated by the Lower Saxony State Agency for Water, Coastal and Nature Conservation (NLWKN), Brake.
The barrage was built in the 1970s. Construction began in 1971/1972 and in July 1976 the barrage was operational. For the choice of location 300 meters above the Ochtummündung the entry lane of an airfield and two gas lines that cross the Weser, prevail. The construction was carried out in a 1.5 kilometer long average, which moved the river bed of the Ochtum and its mouth a little to the southeast. The barrage has two 10-meter-wide openings, which can be closed at high tide by lifting gates. For the strong sport boat traffic on the Ochtum a 20 meters long and 8 meters wide lock was built.
On average, the Ochtumsperrwerk is closed 82 times a year.