Here you can see the result of the July drought in the southern and eastern parts of Germany. The Elbe river is blocked for larger boats. This is a picture of Dresden from July 21.
The Elbe river (originating in the Riesengebirge on the Czech-Polish border) always has to struggle with low water levels much more than the Rhine, which has three times as much water discharge and doesn't dry out that much as water supply from the Alps is much steadier throughout summer, too.
http://www.focus.de/fotos/fast-ausgetrocknet-blick-auf-dresden-und-die-elbe_id_4829538.html