Regular echosounding bottom topography allows to monitoring changes in elevation of the reservoirs bottom and the position of coastline, allows to track the migration of the longshore underwater bars, allows to find many morphometric parameters for hand-made and naturals lakes. In this connection, there is a question of creating a correct and accurate digital elevation models bottom of the reservoirs according to the echosounding data. The article discusses the complex method includes, field and office works. Field works include – bottom topography surveying; shoreline position survey; if necessary, coastal profiles survey, etc. Cameral works include – reduction of all field data into a single system, echosounding data processing, building digital elevation models of bottom, comparing multi-temporal digital elevation models, preparation of various reservoirs parameters using DEM, etc. The article gives examples of different scale digital elevation models of the bottom. The article deals with the problem of comparing multi-temporal data, the problem of using the minimum amount of echosounding data for the optimal DEM and other.