Bettina Hoffmann
Catalogue of Solo and Chamber Music for Viola da Gamba
Bach, Johann Christoph
Cantata (Lamento) «Ach, daß ich Wassers genug hätt» for Alto solo con Violine, 3 Violdigamb et Basso Cont: J. C. Bach
manuscript
D B SA 5160, Faszikel 1 (score) and 2 (parts)
http://www.bach-digital.de/receive/BachDigitalWork_work_00009088
The composer's name was added by Johann Ambrosius Bach and could be questioned.
The cantata is probably identical with an anonymous work of the same text, scoring and tonality registered in the catalogue of the Michaeliskirche di Lüneburg (Seiffert-1908, p. 594).
https://opac.rism.info/search?id=469516000&View=rism
http://www.bach-digital.de/receive/BachDigitalWork_work_00009088
Max Seiffert, Die Chorbibliothek der St. Michaelisschule in Lüneburg zu Seb. Bach's Zeit, Sammelbände der Internationalen Musikgesellschaft, 9. Jahrgang, Heft 4. (Juli-September 1908), pp. 593-621
, p. 594