| Pinnau | |
| Mouth Coordinates: | 53.6762°N 9.5455°W |
| Subdivision Type1: | Country |
| Subdivision Type2: | State |
The Pinnau is a 41adj=midNaNadj=mid river, which flows right or northeast of the main river, Elbe. The Pinnau is therefore a tributary in the southern part of Schleswig-Holstein, Germany.
The Pinnau is categorized by German (Federal/state association water) by "flow type" as a "marshland water body". The lower part between the Elbe and Uetersen is navigable for Class II ships, the middle part between Uetersen and Pinneberg is navigable but not classified.[1]
The Pinnau has its source in the town of Henstedt-Ulzburg, then flows southwest, in Pinneberg to the west and ends in the municipality of Haselau in the Elbe, which streams in northwestern direction.
The Pinnau is very much tide dependent and strongly influenced by tidal range.
The Pinnau was called in earlier times Ütristina or in later times Aue to Ueterst.
The Pinnau is a federal waterway within the remit of the (Waterways and Shipping Office Hamburg) from the south-western edge of the railway bridge in Pinneberg to the mouth of the Pagensander Nebenelbe with, at Elbe-km 658.99. It is one of the inland waterways, on which the German (Maritime Traffic Regulations) applies.