Related Rule
Germany
Practice Relating to Rule 54. Attacks against Objects Indispensable to the Survival of the Civilian Population
Germany’s Soldiers’ Manual (1991) provides: “The objects indispensable to the survival of the civilian population (e.g. drinking water installations) may not be destroyed.” 
Germany, Taschenkarte, Humanitäres Völkerrecht in bewaffneten Konflikten – Grundsätze, Bearbeitet nach ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, Zentrum Innere Führung, June 1991, p. 4.
Germany’s Military Manual (1992) provides:
It is … prohibited to attack … objects indispensable to the civilian population, e.g. production of foodstuffs, clothing, drinking water installations, with the aim to prevent the civilian population from being supplied. 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten KonfliktenHandbuch, August 1992, § 463.
The manual further states:
Grave breaches of international humanitarian law are in particular: … starvation of civilians by destroying, removing or rendering useless objects indispensable to the survival of the civilian population (e.g. foodstuffs, means for the production of foodstuffs, drinking water installations and supplies, irrigation works). 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten KonfliktenHandbuch, August 1992, § 1209.
Germany’s Soldiers’ Manual (2006) states: “The objects indispensable to the survival of the civilian population (e.g. drinking water installations) may not be destroyed.” 
Germany, Druckschrift Einsatz Nr. 03, Humanitäres Völkerrecht in bewaffneten Konflikten – Grundsätze, Erarbeitet nach ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, DSK SF009320187, Bundesministerium der Verteidigung, R II 3, August 2006, p. 4.
Germany’s Law Introducing the International Crimes Code (2002) punishes anyone who, in connection with an international or a non-international armed conflict, “uses starvation of civilians as a method of warfare by depriving them of objects indispensable to their survival”. 
Germany, Law Introducing the International Crimes Code, 2002, Article 1, § 11(1)(5).
At the 26th International Conference of the Red Cross and Red Crescent in 1995, Germany stated: “The deprivation of resources necessary for survival, such as water, [has] been used repeatedly and [has] to be condemned.” 
Germany, Statement at the 26th International Conference of the Red Cross and Red Crescent, Geneva, 3–7 December 1995.
Germany’s Military Manual (1992) provides: “Any deviations from this prohibition [attacking objects indispensable for the survival of the civilian population] shall be permissible only on friendly territory if required by imperative military necessity.” 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten KonfliktenHandbuch, August 1992, § 463.