The ecological status of surface water bodies from Siret River Basin is monitored systematically and spatial in accordance with the requirements of European Directives in the water area. Analysis temporary and spatial of qualitative and quantitative status of surface waters (rivers, lakes) is achieved according to the specificities of each body of water resulting from physical and geographical conditions, climatic and hydromorphological regimes of river basin and from human activities.In order to know of those features, there are needed specific monitoring systems of water bodies. The parameters underlying the assessment of ecological status of rivers and lakes are monitored systematically and temporary: daily, monthly, quarterly, annually, according to these characteristics. In this context, the daily variations in environmental condition, expresses the current status of surface waters. Monthly changes are correlated with climate change and characterize the seasonal variations. On annual basis are identified the mean, minimum and maximum for each parameter and the trends (increase, decrease, regularity, periodicity, changes, etc.). Based on this information, extensive to multiannual level, it can achieve medium and long term forecasts and it might be issued the concepts and strategies for maintaining a balance and sustainable development of water resources. In this paper we have presented some issues related to the synthesis of spatial-temporal ecological status of water bodies managed by Administration of Siret Water Basin (ABAS). Results of studies on the ecological status of water bodies have been presented for the year 2009. Also, in this paper it was presented an evolution of the quantities of pollutants from wastewater discharged in surface receptors and their purification by water users from of activity of ABAS area in 1999-2009 periods.