Pinnau (river)

The Pinnau is a river in Schleswig-Holstein, Germany. It is a right tributary of the Elbe. The Pinnau's source is near Henstedt-Ulzburg, and it flows generally south, passing through or near Quickborn, Pinneberg, and Uetersen. It joins the Elbe near the town of Haseldorf. The river is approximately 41 kilometers (25 miles) long.

The Pinnau is navigable for smaller vessels in its lower reaches and is used for recreational boating. The surrounding area is characterized by marshes and agricultural land. The river's name is believed to be of Slavic origin. The Pinnau plays a role in the drainage of the surrounding region and has been subject to various flood control and water management measures over the centuries.