Abwasser- und Sielmuseum, Sewage and sewer system museum in St. Pauli, Hamburg, Germany.

The Abwasser- und Sielmuseum was a museum run by Hamburger Stadtentwässerung at the Pumpwerk Hafenstraße, near the St. Pauli Landungsbrücken. It explained the history of Hamburg wastewater disposal and the layout of the sewer system, and displayed historical cleaning equipment and a collection of curiosities recovered from the wastewater by employees.

The sewage system began operations in 1842 as the first of its kind in continental Europe and set a new standard for urban wastewater management. This pioneering infrastructure influenced how other cities approached public health and sanitation.

The collection displays items recovered from the sewers by maintenance workers over many decades, revealing what people discarded and how they lived. These objects tell stories about everyday life beneath the streets of the city.

The museum has been closed since March 2009, so there is no visiting access; the site is the Pumpwerk Hafenstraße by the St. Pauli Landungsbrücken. The pump station still lifts the collected wastewater of the Stammsiel under the Elbe to the Klärwerk Köhlbrandhöft. The historic vault of the Bootskammer, where two sewers meet, is not open to the public.

The museum closed in March 2009, so the pumping station at Hafenstraße can no longer be visited as an exhibition. Its former displays included cleaning equipment and a collection of odd objects that workers had fished out of the wastewater.