Соответствующая норма
Practice Relating to Rule 54. Attacks against Objects Indispensable to the Survival of the Civilian Population
Section A. Attacks against objects
Switzerland’s Basic Military Manual (1987) states: “Objects vital to the civilian population, such as drinking water, foodstuffs, crops and livestock as well as agricultural areas, must not be rendered useless.” 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 35.
Switzerland’s Regulation on Legal Bases for Conduct during an Engagement (2005) states:
201 Pillage and wilful damage to civilian property, as well as to facilities and objects indispensable to the survival of the civilian population (e.g. water supply), are prohibited at any time and in any place.
14 Protected objects
14.4 Objects indispensable to the survival of the civilian population
215 It is prohibited to attack or destroy objects essential for the civilian population, such as foodstuffs or water supply installations as well as stocks of these goods and irrigation works.
15.2 Prohibited methods of warfare
225 Indiscriminate attacks, i.e. attacks which cannot distinguish between protected persons/objects and military objectives, as well as attacks directed against protected persons/objects or acts of revenge are prohibited in any place and at any time.
226 Starvation of and threats against the civilian population, destroying essential objects such as water sources, stocks of foodstuffs and seeds, as well as deliberately damaging the environment, are prohibited in any place and at any time.
17 Sanctions for violations of the international law of armed conflict
237 The following in particular are criminal offences: … harmful acts against internationally protected persons and objects[.] 
Switzerland, Bases légales du comportement à l’engagement (BCE), Règlement 51.007/IVf, Swiss Army, issued based on Article 10 of the Ordinance on the Organization of the Federal Department for Defence, Civil Protection and Sports of 7 March 2003, entry into force on 1 July 2005, §§ 201, 215, 225–226 and 237.
Switzerland’s ABC of International Humanitarian Law (2009) states:
Civilian objects
International humanitarian law distinguishes between Civilian objects and Military objectives, prohibiting acts of violence against the former. Other provisions provide special protection for certain specific civilian objects, some of which are expected to bear distinctive signs: … goods indispensable for the survival of the population … Civilian objects are all objects which are not military objectives. 
Switzerland, Federal Department of Foreign Affairs, ABC of International Humanitarian Law, 2009, p. 12.