A collection of systematised information on the country's rivers, lakes, swamps, seas, glaciers and groundwater. It is necessary for the assessment of water resources with a view to their rational and integrated use at the level of the whole country or of individual regions. It includes the hydrological study of the main hydrological characteristics and surface water resources. The water cadastre includes accounting data and water use, which consists of three sections: surface water, groundwater, water use.

The State Water Cadastre is a compilation of information on water bodies, representing the unified state fund of water resources with constantly updated information on the regime, water quality and their use by consumers. 

It is a document for the development of water management balances, current and future planning of water consumption in industrial and civil construction, development of schemes for the integrated use of the natural environment, water protection and implementation of water protection measures, forecasting changes in hydrological conditions, hydrogeological parameters and the quality of the surface and underground hydrosphere.

It is important for rationing water consumption and monitoring the implementation of measures for the use and protection of water as the most important natural resource for life. Includes data on all natural and artificial water bodies (rivers, lakes, reservoirs, canals, glaciers, inland seas, territorial waters of the outer seas), groundwater (aquifers, complexes, basins, deposits), hydroelectric power plants, reservoirs, channels of territorial distribution of runoff, water bodies of mine water use, complex structures cleaning and preparation of stocks for use in drinking and technical water supply.