In case of an emergency, the drinking water supply of the population should be provided at the expense of underground water bodies protected from pollution and clogging with proven groundwater reserves, the suitability of which is determined on the basis of sanitary and epidemiological conclusions. Reserving sources of drinking water supply is of national importance, as it is the main element of the country's security system. During the search, assessment and exploration of groundwater for the organization of a backup water supply source, a number of difficulties periodically arise. During the round table, problems during the search and evaluation work, the organization of backup water supply in water-deficient regions, and the protection of underground sources will be discussed.