The following thesis is the study of the flooding area of a section of the Chicama River located in the progressives 26+500 to 39+000, based on the history of flows from the year 1971 to the first half of 2017, with the support of a two-dimensional river modeling software called Hec-Ras, which uses algorithms based on hydraulic, hydrological, topographic calculations and other factors such as Manning's n. Firstly, a study of the normal behaviour of the Chicama River is done, in order to determine which areas are the ones that normally flood and what their flows are under normal conditions, secondly the analysis focuses on the phenomenon of El Niño Costero, occurred in In 2017, for which an analysis was made through the use of Yevjevich frequency tables, which gives us an idea of how the river behaved in that period of time, we also rely on the development of a hydrograph for the calcula...