In 2010 – 2012, the hydrogeological model (HM) of Latvia (LAMO) has been established by scientists of Riga Technical University (RTU). LAMO is run by the commercial program Groundwater Vistas (GV). LAMO has generalized geological and hydrogeological data that were provided for the active groundwater zone by the Latvian Environment, Geology and Meteorology Centre (LEGMC). In 2013 – 2014, LAMO has been notably upgraded and large amount of real hydrogeological data were added. In 2015, the new improvements of LAMO were accomplished. The size of HM plane approximation step was reduced twofold (from 500 metres to 250 metres), the base flows of rivers were calibrated by using hydrological data of measured river streams, the permeability maps of HM aquifers were refined. Essence of the new updates are described.