A Wasser- und Schifffahrtsamt is a federal German agency, responsible for the administration of federal navigable waters and for the regulation of vessel traffic.
The thirty-nine offices are supervised by the national Wasser- und Schifffahrtsverwaltung des Bundes and accountable to the Federal Ministry of Transport and Digital Infrastructure. In total the offices cover 23,000 km² of maritime waters and 7,350 km of inland waterways.
Wikipedia https://en.wikipedia.org/wiki/Wasser-_und_Schifffahrtsamt
Official Website https://www.wsa-weser.wsv.de/Webs/WSA/Weser/DE/03_WSA_Weser/02_Unser_Revier/07_Nienburg/Nienburg.html
Phone +49 5021 887770-0
Coordinates 52°38'39.593" N 9°12'18.582" E