Hamme was straightened and the numerous meanders were cut at a total of seven places, so that the length of the river was reduced from 9 to 4.3 km. Behind the locks in Ritterhude, built in 1876, which keep the Hamme tide-free, the Hamme joins the tidal river of the Wümme near the city limits of Bremen and together they form the salt-waters of the Lesum, which enters the Weser 10 km downstream. The old branches of the river were mainly preserved as one-sided confluences with the Hamme. A remaining part of the so-called Altarm 3 ("Old Arm no. 3") southeast of Scharmbeckstotel was de-sludged in 2007 as part of the Hamme Depression Nature Conservation Project and in 2008 a sill was added to prevent it from running empty at low water. At the end of January 2020, after three months of construction, the 230-metre-long stretch of this waterbody that had been filled in was dug up again over its length and connected to the Hamme. The total length of the river is 48 km and it descends through about 45 m. See also List of rivers of Lower Saxony References Hamme Rivers of Germany