Presented at the 2015 Aquarius/SAC-D Science Team MeetingThe National Water Institute, in response to the Aquarius / SAC-D Announcement of Opportunity, carried out a project called Assimilation of Soil Moisture Estimates into Flow-Forecasting Hydrologic Models, with the purpose of implementing a conceptual lumped hydrologic model with assimilation of mission soil moisture retrievals, to be used in basin-outlet flow simulation and forecast at two lowland catchments in Argentina, i.e. Gualeguay River (14,900 sq. km) and Pergamino Brook (1,200 sq. km). The main quantitative project outcomes are summarized, including human resources training, publications, procurement of instruments and equipment, and field campaigns.