DAHLEM Beratende Ingenieure GmbH & Co. Wasserwirtschaft KG
Bonsiepen 7
45136 Essen, Germany

Represented by

Director Dr.-Ing. Jan-Gregor Dahlem
Director Dipl.-Ing. Mathias Kleffmann
Director Dipl.-Betriebsw. Jörg Müller


Fon: +49 (0) 201.8967-0
Fax: +49 (0) 201.8967-123


Legal Form

GmbH & Co. KG
Trade Register Essen: HRA 67 15

Professional registration

Dr.-Ing. Jan-Gregor Dahlem
Consulting Engineer, NRW Chamber of Civil Engineers
Authorized to sign building documents, NRW Chamber of Engineers

Dipl.-Ing. Mathias Kleffmann
Voluntary Member, NRW Chamber of Civil Engineers


NRW Chamber of Civil Engineers
Hessen Chamber of Civil Engineers
Berlin Chamber of Civil Engineers
OAI Luxembourg Chamber of Civil Engineers

Value added tax identification number

UST-ID-Nr.: DE203134982

Professional indemnity insurance

VHV-Platz 1, 30177 Hannover
Phone: 0511/907-8989
Geographical scope of the insurance: worldwide with the exception of USA and Canada

Legal professional regulations

Chamber of Civil Engineers Act of the Federal State of NRW (BauKaG NRW) in the version released 09.12.2008

Regulation on the Implementation of the Chamber of Civil Engineers Act (DVO BauKaG NRW)

"Engineer (m/f)" (Engineering Act - IngG)

Regulation on the fees for architectural and engineering services (Fee schedule for architects and engineers (Honorarordnung für Architekten und Ingenieure) – HOAI)

Concept and maintenance of the website

Project management:
Dipl.-Ing. Angelika Allroggen
Dr.-Ing. Jan-Gregor Dahlem

Graphic design and layout:

A-Quadrat Werbeagentur


Konzeptmonster GmbH

Image sources:

IWW (2019): 49. Internationales Wasserbau-Symposium Aachen (IWASA) am 10./11. Januar 2019, Technologiezentrum Aachen (TZA). Institut für Wasserbau und Wasserwirtschaft (IWW) der RWTH Aachen University

Architekten Auer+Weber+Assoziierte GmbH:
Facade construction digester Würzburg

City of Bocholt FB property management:
Aerial view of Mussum industrial area

Aerial view of Pumping Station Oberhausen

mach:idee, Ingenieurbüro R. Mach:
3-D Animation Water Supply Treatment Plant Mörscher Wald

Links to our website

All links set by us should be taken as a recommendation. Despite the content control of external links when the site is started for the first ime, we assume no liability for their content. We will not remove this link until we have ascertained or pointed out that an external link triggers a civil or criminal liability.


The content of our website is protected by copyright. The duplication of information or data, in particular the use of texts or images, requires the prior consent of Dahlem Beratende Ingenieure GmbH & Co. Wasserwirtschaft KG.