The misuse of water, problems of water governance, population growth, the effects of climate change such as decreased precipitation, increased temperature and the disappearance of glaciers, make water availability increasingly scarce, and as a result increased pressure on surface water resources. The Yanacocha lagoon is the main source of water supply for the population of Carhuamayo. Therefore, this research determined scenarios of water sustainability of the lagoon by 2030 for the supply of this population. To estimate the parameters of precipitation and temperature in the Yanacocha micro-basin, the method of regionalization of the period 1970 to 2019 was carried out. In addition, water sustainability scenarios were estimated based on water supply and demand related to sustainability indicators (water-soil quality and plant coverage) and the level of water culture of the inhabitants. The results showed 18 scenarios of water sustainability for 2030 between optimists, stabilization and pessimists; all of them favorable and positive, with a medium-high level of water culture in the community. Finally, the study allowed regional and local authorities to establish environmental management strategies in the mitigation of environmental, social and economic impact.