the city and also the numerous tanneries of the city and to fill the protecting ditches located outside the medieval town wall. During the annual floodings cities along the Isar were flooded again and again, causing severe damage and even killing people. In 1813 a bridge in Munich collapsed during a flood, killing more than 100 people who were watching the flooding from the bridge. From 1806 on, the banks of the river were fixed and the river was canalized. This led to its deeper digging into the river bed due to its flowing faster. Further extensive measures have been taken since the 1920s to install hydroelectric power plants. From 1954 to 1959 the then much-disputed Sylvensteinspeicher was built for the generation of electricity and for protection against floodings. The village of Fall was drowned in the reservoir. When the water level in the reservoir is very low the church tower can still be seen sticking out of the water. Only over the last few years the Isar was partly turned back from a canal into a more natural river. At the lower Isar between Moosburg and Plattling gold was washed from the river’s sediments during the 16th and 17th century. However, there was no big economic revenue in this due to the minor amounts of the metal found in the river. Following their executions on October 16, 1946, the ashes of the convicted Nazi war criminals Joachim von Ribbentrop, Hans Frank, Wilhelm Keitel, Alfred Jodl, Alfred Rosenberg, Ernst Kaltenbrunner, Wilhelm Frick, Arthur Seyss-Inquart, Fritz Sauckel and Julius Streicher were scattered in the Isar, as were those of Hermann Göring who had committed suicide the previous night in defiance of his scheduled execution. Environmental issues Since the 1920s the water of the Isar has been used for the generation of electricity. This has had far-reaching consequences not only for the local fauna and flora but also for people. To provide the 28 hydroelectric power plants with enough water power the river’s water is diverted several times and almost the whole river was canalized. For example, just north of Mittenwald all the river’s water was diverted to the lake Walchensee in 1923 for the Walchensee hydroelectric plant. Since 1990 a small portion of the water, 4 cubic meters per second (1100 U.S. gallons per second) is allowed to remain in the river to keep the area from being dry. The construction