He played a leading role in many of the Third Reich's biggest engineering projects, including the construction of the Siegfried Line (Westwall), the Atlantic Wall and numerous other fortifications in Germany and occupied Europe.

Dorsch joined the embryonic Nazi Party and its paramilitary wing, the Sturmabteilung (SA), in 1922 and he participated in the unsuccessful Beer Hall Putsch of 8–9 November 1923.

[5] Todt recruited Dorsch to serve as his deputy and Leiter (head) of the OT Zentrale office in Berlin, working on the autobahn project.

[6] From December 1941 he directed the construction of the Atlantic Wall along the western coastline of occupied Europe, though his work was criticised by the military for ignoring input from the Army and Navy.

Hermann Göring, the Reich Minister of Aviation, also ordered Dorsch to undertake the construction of underground aircraft hangars for the Luftwaffe.

[15] Dorsch was put in charge of the armaments ministry's building office and served as the minister's deputy as general commissioner for construction industry matters, as well as retaining his existing post as the head of the OT.

[9] Dorsch avoided prosecution following the war[16] and was commissioned by the United States Army to write a 1,000-page study of the Organisation Todt, which was published in 1947.